Microalgal Biotechnology for Bioproducts and Food Applications

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Applied Sciences applsci	2.5	5.3	2011	18.4 Days	CHF 2400
Foods foods	4.7	7.4	2012	14.5 Days	CHF 2900
Bioengineering bioengineering	3.8	4.0	2014	16.4 Days	CHF 2700
Molecules molecules	4.2	7.4	1996	15.1 Days	CHF 2700
Phycology phycology	-	-	2021	21 Days	CHF 1000

19 pages, 6324 KiB

Open AccessArticle

Enhancement of Metabolite Production in High-Altitude Microalgal Strains by Optimized C/N/P Ratio

by William H. Suárez Quintana, Ramón O. García-Rico, Janet B. García-Martínez, Néstor A. Urbina-Suarez, Germán L. López-Barrera, Andrés F. Barajas-Solano and Antonio Zuorro

Appl. Sci. 2022, 12(13), 6779; https://doi.org/10.3390/app12136779 - 4 Jul 2022

Cited by 8 | Viewed by 3257

Abstract

This study evaluated the role of C/N/P in the increase in the synthesis of carbohydrates, proteins, and lipids in two high-mountain strains of algae (Chlorella sp. UFPS019 and Desmodesmus sp. UFPS021). Three carbon sources (sodium acetate, sodium carbonate, and sodium bicarbonate), and [...] Read more.

This study evaluated the role of C/N/P in the increase in the synthesis of carbohydrates, proteins, and lipids in two high-mountain strains of algae (Chlorella sp. UFPS019 and Desmodesmus sp. UFPS021). Three carbon sources (sodium acetate, sodium carbonate, and sodium bicarbonate), and the sources of nitrogen (NaNO₃) and phosphate (KH₂PO₄ and K₂HPO₄) were analyzed using a surface response (3 factors, 2 levels). In Chlorella sp. UFPS019, the optimal conditions to enhance the synthesis of carbohydrates were high sodium carbonate content (3.53 g/L), high KH₂PO₄ and K₂HPO₄ content (0.06 and 0.14 g/L, respectively), and medium-high NaNO₃ (0.1875 g/L). In the case of lipids, a high concentration of sodium acetate (1.19 g/L) coupled with high KH₂PO₄ and K₂HPO₄ content (0.056 and 0.131 g/L, respectively) and a low concentration of NaNO₃ (0.075 g/L) drastically induced the synthesis of lipids. In the case of Desmodesmus sp. UFPS021, the protein content was increased using high sodium acetate (2 g/L), high KH₂PO₄ and K₂HPO₄ content (0.056 and 0.131 g/L, respectively), and high NaNO₃ concentration (0.25 g/L). These results demonstrate that the correct adjustment of the C/N/P ratio can enhance the capacity of high-mountain strains of algae to produce high concentrations of carbohydrates, proteins, and lipids. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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10 pages, 2500 KiB

Open AccessArticle

Media Supplementation with Mannitol and Biotin Enhances Squalene Production of Thraustochytrium ATCC 26185 through Increased Glucose Uptake and Antioxidative Mechanisms

by M. Kashif Ali, Biswarup Sen, Yaodong He, Mohan Bai and Guangyi Wang

Molecules 2022, 27(8), 2449; https://doi.org/10.3390/molecules27082449 - 11 Apr 2022

Cited by 8 | Viewed by 2338

Abstract

Media supplementation with exogenous chemicals is known to stimulate the accumulation of important lipids produced by microalgae and thraustochytrids. However, the roles of exogenous chemicals in promoting and preserving the terpenoids pool of thraustochytrids have been rarely investigated. Here, we realized the effects [...] Read more.

Media supplementation with exogenous chemicals is known to stimulate the accumulation of important lipids produced by microalgae and thraustochytrids. However, the roles of exogenous chemicals in promoting and preserving the terpenoids pool of thraustochytrids have been rarely investigated. Here, we realized the effects of two media supplements—mannitol and biotin—on the biomass and squalene production by a thraustochytrid strain (Thraustochytrium sp. ATCC 26185) and elucidated their mechanism of action. A significant change in the biomass was not evident with the exogenous addition of these supplements. However, with mannitol (1 g/L) supplementation, the ATCC 26185 culture achieved the best concentration (642 ± 13.6 mg/L) and yield (72.9 ± 9.6 mg/g) of squalene, which were 1.5-fold that of the control culture (non-supplemented). Similarly, with biotin supplementation (0.15 mg/L), the culture showed 459 ± 2.9 g/L and 55.7 ± 3.2 mg/g of squalene concentration and yield, respectively. The glucose uptake rate at 24 h of fermentation increased markedly with mannitol (0.31 g/Lh⁻¹) or biotin (0.26 g/Lh⁻¹) supplemented culture compared with non-supplemented culture (0.09 g/Lh⁻¹). In addition, the reactive oxygen species (ROS) level of culture supplemented with mannitol remained alleviated during the entire period of fermentation while it alleviated after 24 h with biotin supplementation. The ∆ROS with mannitol was better compared with biotin supplementation. The total antioxidant capacity (T-AOC) of the supplemented culture was more than 50% during the late stage (72–96 h) of fermentation. Our study provides the potential of mannitol and biotin to enhance squalene yield and the first lines of experimental evidence for their protective role against oxidative stress during the culture of thraustochytrids. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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14 pages, 1976 KiB

Open AccessArticle

Influence of Irradiance and Wavelength on the Antioxidant Activity and Carotenoids Accumulation in Muriellopsis sp. Isolated from the Antofagasta Coastal Desert

by Daniela Diaz-MacAdoo, Maria Teresa Mata and Carlos Riquelme

Molecules 2022, 27(8), 2412; https://doi.org/10.3390/molecules27082412 - 8 Apr 2022

Cited by 13 | Viewed by 3025

Abstract

Microalgae are a valuable natural resource for a variety of biocompounds such as carotenoids. The use of different light spectra and irradiance has been considered as a promising option to improve the production of these compounds. The objective of this study was to [...] Read more.

Microalgae are a valuable natural resource for a variety of biocompounds such as carotenoids. The use of different light spectra and irradiance has been considered as a promising option to improve the production of these compounds. The objective of this study was to evaluate the influence of different wavelengths (white, red, and blue) and irradiances (80 and 350 µmol photons/m²/s) on the photosynthetic state, total carotenoids and lutein productivity (HPLC), lipids (Nile red method) and antioxidant activity (DPPH) of the microalgae Muriellopsis sp. (MCH-35). This microalga, which is a potential source of lutein, was isolated from the coastal desert of Antofagasta, Chile, and adapted to grow in seawater. The results indicate that the culture exposed to high-intensity red light showed the highest biomass yield (2.5 g/L) and lutein productivity (>2.0 mg L⁻¹day⁻¹). However, blue light was found to have a stimulating effect on the synthesis of lutein and other carotenoids (>0.8% dry wt). Furthermore, a direct relationship between lipid accumulation and high light intensity was evidenced. Finally, the highest antioxidant activity was observed with high-intensity white light, these values have no direct relationship with lutein productivity. Therefore, the findings of this study could be utilized to obtain biocompounds of interest by altering certain culture conditions during the large-scale cultivation of MCH-35. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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15 pages, 3157 KiB

Open AccessArticle

Optimization and Rheological Study of an Exopolysaccharide Obtained from Fermented Mature Coconut Water with Lipomyces starkeyi

by Yilin Guo, Wentian Li, Haiming Chen, Weijun Chen, Ming Zhang, Qiuping Zhong and Wenxue Chen

Foods 2022, 11(7), 999; https://doi.org/10.3390/foods11070999 - 29 Mar 2022

Cited by 2 | Viewed by 2744

Abstract

The current research aimed to solve the environmental pollution of mature coconut water by Lipomyces starkeyi and provide a study of its high value utilization. The innovation firstly investigated the rheological properties and interface behavior of a crude exopolysaccharide and provided a technical [...] Read more.

The current research aimed to solve the environmental pollution of mature coconut water by Lipomyces starkeyi and provide a study of its high value utilization. The innovation firstly investigated the rheological properties and interface behavior of a crude exopolysaccharide and provided a technical support for its application in food. A response surface methodology was performed to ameliorate the fermentation factors of the new exopolysaccharide with mature coconut water as a substrate, and the consequences suggested that the maximum yield was 7.76 g/L under optimal conditions. Rotary shear measurements were used to study the influence of four variables on the viscosity of the exopolysaccharide solution. The results illustrated that the exopolysaccharide solution demonstrated a shear-thinning behavior and satisfactory thermal stability within the test range. The viscosity of the exopolysaccharide solution was significantly affected by ionic strength and pH; it reached the peak viscosity when the concentration of NaCl was 0.1 mol/L and the pH was neutral. The adsorption behavior of the exopolysaccharide at the medium chain triglyceride–water interface was investigated by a quartz crystal microbalance with a dissipation detector. The results demonstrated that the exopolysaccharide might form a multilayer adsorption layer, and the thickness of the adsorption layer was at its maximum at a concentration of 1.0%, while the interfacial film was the most rigid at a concentration of 0.4%. Overall, these results suggest that the exopolysaccharide produced by Lipomyces starkeyi is an excellent biomaterial for usage in drink, makeup and drug fabrications as a thickening and stabilizing agent. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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12 pages, 1606 KiB

Open AccessArticle

Obtaining Fat-Soluble Pigments—Carotenoids from the Biomass of Chlorella Microalgae

by Julia Bazarnova, Yulia Smyatskaya, Antonina Shlykova, Aleksei Balabaev and Saša Đurović

Appl. Sci. 2022, 12(7), 3246; https://doi.org/10.3390/app12073246 - 23 Mar 2022

Cited by 11 | Viewed by 4899

Abstract

The aim of this study was to use a directed mode of cultivation of the microalgae Chlorella for biomass production, followed by the subsequent extraction of carotenoids. The effect of a stress inducer of carotenogenesis (hydrogen peroxide) and a growth stimulator (pyridoxine, vitamin [...] Read more.

The aim of this study was to use a directed mode of cultivation of the microalgae Chlorella for biomass production, followed by the subsequent extraction of carotenoids. The effect of a stress inducer of carotenogenesis (hydrogen peroxide) and a growth stimulator (pyridoxine, vitamin B6) on the accumulation of photosynthetic pigments by the biomass of the microalga C. vulgarisBIN in the process of directed cultivation was studied. It was revealed that the combination of these additives in the culture medium increases the content of chlorophylls and carotenoids in the biomass twofold compared to the control sample. The preliminary activation of the biomass by high-speed ultra-homogenization (a rotor rotation range from 6000 to 12,000 rpm) was also investigated. Using ultrasound extraction, the pigment complex was isolated from the activated biomass. The saponification and subsequent neutralization of carotenoids were carried out in an inert medium. The resulting sample contained carotenoids in the amount of 52 ± 3 mg/mL. The chemical profile of the carotenoids in the biomass of the microalga Chlorella vulgaris BIN was also established. The major carotenoid was lutein (45%), followed by fucoxanthin (12%) and β-carotene (4.3%). The oil extract of the carotenoids may be used for the further production of a microencapsulated product with the aim of targeted delivery to the lower parts of the gastrointestinal tract. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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17 pages, 1371 KiB

Open AccessArticle

Assessment of Antioxidant and Anticancer Activities of Microgreen Alga Chlorella vulgaris and Its Blend with Different Vitamins

by Ragaa A. Hamouda, Amera Abd El Latif, Ebtihal M. Elkaw, Amenah S. Alotaibi, Asma Massad Alenzi and Hanafy A. Hamza

Molecules 2022, 27(5), 1602; https://doi.org/10.3390/molecules27051602 - 28 Feb 2022

Cited by 17 | Viewed by 3939

Abstract

There is a very vital antioxidant extracted from microgreen alga. Chlorella vulgaris has major advantages and requires high yield worldwide. Some microalgae require vitamins for their growth promotion. This study was held to determine the impact of different vitamins including Thiamine (B1), Riboflavin [...] Read more.

There is a very vital antioxidant extracted from microgreen alga. Chlorella vulgaris has major advantages and requires high yield worldwide. Some microalgae require vitamins for their growth promotion. This study was held to determine the impact of different vitamins including Thiamine (B1), Riboflavin (B2), Pyridoxine (B6), and Ascorbic acid (c) at concentrations of 0.02, 0.04, 0.06, and 0.08 mg/L of each. Each vitamin was added to the BG11 growth medium to determine the effect on growth, total carbohydrate, total protein, pigments content, antioxidant activities of Chlorella vulgaris. Moreover, antitumor effects of methanol extract of C. vulgaris without and with the supplement of thiamine against Human prostate cancer (PC-3), Hepatocellular carcinoma (HEPG-2), Colorectal carcinoma (HCT-116) and Epitheliod Carcinoma (Hela) was estimated in vitro. C. vulgaris supplemented with various vitamins showed a significant increase in biomass, pigment content, total protein, and total carbohydrates in comparison to the control. Thiamine was the best vitamin influencing as an antioxidant. C. vulgaris supplemented with thiamine had high antitumor effects in vitro. So, it’s necessary to add vitamins to BG11 media for enhancement of the growth and metabolites. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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11 pages, 1119 KiB

Open AccessBrief Report

Optimization of Extraction Conditions of Carotenoids from Dunaliella parva by Response Surface Methodology

by Yujia Li, Xiaojuan Huang, Lirong Luo and Changhua Shang

Molecules 2022, 27(4), 1444; https://doi.org/10.3390/molecules27041444 - 21 Feb 2022

Cited by 5 | Viewed by 2715

Abstract

Extraction conditions can exert a remarkable influence on extraction efficiency. The aim of this study was to improve the extraction efficiency of carotenoids from Dunaliella parva (D. parva). Dimethyl sulfoxide (DMSO) and 95% ethanol were used as the extraction solvents. The [...] Read more.

Extraction conditions can exert a remarkable influence on extraction efficiency. The aim of this study was to improve the extraction efficiency of carotenoids from Dunaliella parva (D. parva). Dimethyl sulfoxide (DMSO) and 95% ethanol were used as the extraction solvents. The extraction time, extraction temperature and the proportions of mixed solvent were taken as influencing factors, and the experimental scheme was determined by Central Composite Design (CCD) of Design Expert 10.0.4.0 to optimize the extraction process of carotenoids from D. parva. The absorbance values of the extract at 665 nm, 649 nm and 480 nm were determined by a microplate spectrophotometer, and the extraction efficiency of carotenoids was calculated. Analyses of the model fitting degree, variance and interaction term 3D surface were performed by response surface analysis. The optimal extraction conditions were as follows: extraction time of 20 min, extraction temperature of 40 °C, and a mixed solvent ratio (DMSO: 95% ethanol) of 3.64:1. Under the optimal conditions, the actual extraction efficiency of carotenoids was 0.0464%, which was increased by 18.19% (the initial extraction efficiency of 0.03926%) with a lower extraction temperature (i.e., lower energy consumption) compared to the standard protocol. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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15 pages, 4972 KiB

Open AccessArticle

Effectively Converting Cane Molasses into 2,3-Butanediol Using Clostridiumljungdahlii by an Integrated Fermentation and Membrane Separation Process

by Yuling Yang, Tingting Deng, Weifeng Cao, Fei Shen, Sijia Liu, Jing Zhang, Xinquan Liang and Yinhua Wan

Molecules 2022, 27(3), 954; https://doi.org/10.3390/molecules27030954 - 30 Jan 2022

Cited by 9 | Viewed by 3245

Abstract

Firstly, 2,3-butanediol (2,3-BDO) is a chemical platform used in several applications. However, the pathogenic nature of its producers and the expensive feedstocks used limit its scale production. In this study, cane molasses was used for 2,3-BDO production by a nonpathogenic Clostridium ljungdahlii. [...] Read more.

Firstly, 2,3-butanediol (2,3-BDO) is a chemical platform used in several applications. However, the pathogenic nature of its producers and the expensive feedstocks used limit its scale production. In this study, cane molasses was used for 2,3-BDO production by a nonpathogenic Clostridium ljungdahlii. It was found that cane molasses alone, without the addition of other ingredients, was favorable for use as the culture medium for 2,3-BDO production. Compared with the control (i.e., the modified DSMZ 879 medium), the differential genes are mainly involved in the pathways of carbohydrate metabolism, membrane transport, and amino acid metabolism in the case of the cane molasses alone. However, when cane molasses alone was used, cell growth was significantly inhibited by KCl in cane molasses. Similarly, a high concentration of sugars (i.e., above 35 g/L) can inhibit cell growth and 2,3-BDO production. More seriously, 2,3-BDO production was inhibited by itself. As a result, cane molasses alone with an initial 35 g/L total sugars was suitable for 2,3-BDO production in batch culture. Finally, an integrated fermentation and membrane separation process was developed to maintain high 2,3-BDO productivity of 0.46 g·L⁻¹·h⁻¹. Meanwhile, the varied fouling mechanism indicated that the fermentation properties changed significantly, especially for the cell properties. Therefore, the integrated fermentation and membrane separation process was favorable for 2,3-BDO production by C. ljungdahlii using cane molasses. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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15 pages, 679 KiB

Open AccessArticle

Microalgae as a Potential Functional Ingredient: Evaluation of the Phytochemical Profile, Antioxidant Activity and In-Vitro Enzymatic Inhibitory Effect of Different Species

by Marta Vinha Vieira, Igor Piotr Turkiewicz, Karolina Tkacz, Claudio Fuentes-Grünewald, Lorenzo M. Pastrana, Pablo Fuciños, Aneta Wojdyło and Paulina Nowicka

Molecules 2021, 26(24), 7593; https://doi.org/10.3390/molecules26247593 - 15 Dec 2021

Cited by 24 | Viewed by 4458

Abstract

The functional food market has been in a state of constant expansion due to the increasing awareness of the impact of the diet on human health. In the search for new natural resources that could act as a functional ingredient for the food [...] Read more.

The functional food market has been in a state of constant expansion due to the increasing awareness of the impact of the diet on human health. In the search for new natural resources that could act as a functional ingredient for the food industry, microalgae represent a promising alternative, considering their high nutritional value and biosynthesis of numerous bioactive compounds with reported biological properties. In the present work, the phytochemical profile, antioxidant activity, and enzymatic inhibitory effect aiming at different metabolic disorders (Alzheimer’s disease, Type 2 diabetes, and obesity) were evaluated for the species Porphyridium purpureum, Chlorella vulgaris, Arthorspira platensis, and Nannochloropsis oculata. All the species presented bioactive diversity and important antioxidant activity, demonstrating the potential to be used as functional ingredients. Particularly, P. purpureum and N. oculata exhibited higher carotenoid and polyphenol content, which was reflected in their superior biological effects. Moreover, the species P. purpureum exhibited remarkable enzymatic inhibition for all the analyses. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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17 pages, 9023 KiB

Open AccessArticle

Protein Enrichment of Wheat Bread with Microalgae: Microchloropsis gaditana, Tetraselmis chui and Chlorella vulgaris

by Waqas Muhammad Qazi, Simon Ballance, Katerina Kousoulaki, Anne Kjersti Uhlen, Dorinde M. M. Kleinegris, Kari Skjånes and Anne Rieder

Foods 2021, 10(12), 3078; https://doi.org/10.3390/foods10123078 - 10 Dec 2021

Cited by 38 | Viewed by 5571

Abstract

Cell wall disrupted and dried Microchloropsis gaditana (Mg), Tetraselmis chui (Tc) and Chlorella vulgaris (Cv) microalgae biomasses, with or without ethanol pre-treatment, were added to wheat bread at a wheat flour substitution level of 12%, to enrich bread protein by 30%. Baking performance, [...] Read more.

Cell wall disrupted and dried Microchloropsis gaditana (Mg), Tetraselmis chui (Tc) and Chlorella vulgaris (Cv) microalgae biomasses, with or without ethanol pre-treatment, were added to wheat bread at a wheat flour substitution level of 12%, to enrich bread protein by 30%. Baking performance, protein quality and basic sensory properties were assessed. Compared to wheat, Mg, Tc and Cv contain higher amounts of essential amino acids and their incorporation markedly improved protein quality in the bread (DIAAS 57–66 vs. 46%). The incorporation of microalgae reduced dough strength and bread volume and increased crumb firmness. This was most pronounced for Cv and Tc but could be improved by ethanol treatment. Mg gave adequate dough strength, bread volume and crumb structure without ethanol treatment. To obtain bread of acceptable smell, appearance, and colour, ethanol treatment was necessary also for Mg as it markedly reduced the unpleasant smell and intense colour of all algae breads. Ethanol treatment reduced the relative content of lysine, but no other essential amino acids. However, it also had a negative impact on in vitro protein digestibility. Our results show that Mg had the largest potential for protein fortification of bread, but further work is needed to optimize pre-processing and assess consumer acceptance. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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12 pages, 1547 KiB

Open AccessArticle

Transamination-Like Reaction Catalyzed by Leucine Dehydrogenase for Efficient Co-Synthesis of α-Amino Acids and α-Keto Acids

by Xiaoqing Mu, Xian Feng, Tao Wu, Feng Zhou, Yao Nie and Yan Xu

Molecules 2021, 26(23), 7287; https://doi.org/10.3390/molecules26237287 - 30 Nov 2021

Cited by 4 | Viewed by 5619

Abstract

α-Amino acids and α-keto acids are versatile building blocks for the synthesis of several commercially valuable products in the food, agricultural, and pharmaceutical industries. In this study, a novel transamination-like reaction catalyzed by leucine dehydrogenase was successfully constructed for the efficient enzymatic co-synthesis [...] Read more.

α-Amino acids and α-keto acids are versatile building blocks for the synthesis of several commercially valuable products in the food, agricultural, and pharmaceutical industries. In this study, a novel transamination-like reaction catalyzed by leucine dehydrogenase was successfully constructed for the efficient enzymatic co-synthesis of α-amino acids and α-keto acids. In this reaction mode, the α-keto acid substrate was reduced and the α-amino acid substrate was oxidized simultaneously by the enzyme, without the need for an additional coenzyme regeneration system. The thermodynamically unfavorable oxidation reaction was driven by the reduction reaction. The efficiency of the biocatalytic reaction was evaluated using 12 different substrate combinations, and a significant variation was observed in substrate conversion, which was subsequently explained by the differences in enzyme kinetics parameters. The reaction with the selected model substrates 2-oxobutanoic acid and L-leucine reached 90.3% conversion with a high total turnover number of 9.0 × 10⁶ under the optimal reaction conditions. Furthermore, complete conversion was achieved by adjusting the ratio of addition of the two substrates. The constructed reaction mode can be applied to other amino acid dehydrogenases in future studies to synthesize a wider range of valuable products. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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13 pages, 20316 KiB

Open AccessArticle

The Bactericidal Efficacy and the Mechanism of Action of Slightly Acidic Electrolyzed Water on Listeria monocytogenes’ Survival

by Huiying Li, Duo Liang, Jin Huang, Chaojing Cui, Huan Rao, Dandan Zhao and Jianxiong Hao

Foods 2021, 10(11), 2671; https://doi.org/10.3390/foods10112671 - 3 Nov 2021

Cited by 20 | Viewed by 3029

Abstract

In the present work, the bactericidal efficacy and mechanism of slightly acidic electrolyzed water (SAEW) on L. monocytogenes were evaluated. The results showed that the strains of L. monocytogenes were killed completely within 30 s by SAEW whose available chlorine concentration (ACC) was [...] Read more.

In the present work, the bactericidal efficacy and mechanism of slightly acidic electrolyzed water (SAEW) on L. monocytogenes were evaluated. The results showed that the strains of L. monocytogenes were killed completely within 30 s by SAEW whose available chlorine concentration (ACC) was higher than 12 mg/L, and it was confirmed that ACC is the main factor affecting the disinfection efficacy of SAEW. Moreover, our results demonstrated that SAEW could destroy the cell membrane of L. monocytogenes, which was observed by SEM and FT-IR, thus resulting in the leakage of intracellular substances including electrolyte, protein and nucleic acid, and DNA damage. On the other hand, the results found that SAEW could disrupt the intracellular ROS balance of L. monocytogenes by inhibiting the antioxidant enzyme activity, thus promoting the death of L. monocytogenes. In conclusion, the bactericidal mechanism of SAEW on L. monocytogenes was explained from two aspects including the damage of the cell membrane and the breaking of ROS balance. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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19 pages, 2067 KiB

Open AccessArticle

Effectiveness of the Influence of Selected Essential Oils on the Growth of Parasitic Fusarium Isolated from Wheat Kernels from Central Europe

by Teresa Krzyśko-Łupicka, Sławomir Sokół, Monika Sporek, Anna Piekarska-Stachowiak, Weronika Walkowiak-Lubczyk and Adam Sudoł

Molecules 2021, 26(21), 6488; https://doi.org/10.3390/molecules26216488 - 27 Oct 2021

Cited by 5 | Viewed by 2430

Abstract

The aim of the study was to determine the effectiveness of selected seven commercial essential oils (EsO) (grapefruit, lemongrass, tea tree (TTO), thyme, verbena, cajeput, and Litsea cubeba) on isolates of common Central European parasitic fungal species of Fusarium obtained from infected [...] Read more.

The aim of the study was to determine the effectiveness of selected seven commercial essential oils (EsO) (grapefruit, lemongrass, tea tree (TTO), thyme, verbena, cajeput, and Litsea cubeba) on isolates of common Central European parasitic fungal species of Fusarium obtained from infected wheat kernels, and to evaluate the oils as potential natural fungicides. The study was conducted in 2 stages. At each stage, the fungicidal activity of EsO (with concentrations of 0.025; 0.05; 0.125; 0.25; 0.50; 1.0, and 2.0%) against Fusarium spp. was evaluated using the disc plate method and zones of growth inhibition were measured. At the first stage, the fungistatic activity of EsO was evaluated against four species of Fusarium from the Polish population (F. avenaceum FAPL, F. culmorum FCPL, F. graminearum FGPL and F. oxysporum FOPL). The correlation coefficient between the mycelial growth rate index (T) and the fungistatic activity (FA) was calculated. At the second stage, on the basis of the mycelium growth rate index, the effectiveness of the EsO in limiting the development of Fusarium isolates from the German population (F. culmorum FC1D, F. culmorum FC2D, F. graminearum FG1D, F. graminearum FG2D and F. poae FP0D) was assessed. The first and second stage results presented as a growth rate index were then used to indicate essential oils (as potential natural fungicides) effectively limiting the development of various common Central European parasitic species Fusarium spp. Finally, the sensitivity of four Fusarium isolates from the Polish population and five Fusarium isolates from the German population was compared. The data were compiled in STATISTICA 13.0 (StatSoft, Inc, CA, USA) at the significance level of 0.05. Fusarium isolates from the German population were generally more sensitive than those from the Polish population. The sensitivity of individual Fusarium species varied. Their vulnerability, regardless of the isolate origin, in order from the most to the least sensitive, is as follows: F. culmorum, F. graminearum, F. poae, F. avenaceum and F. oxysporum. The strongest fungicidal activity, similar to Funaben T, showed thyme oil (regardless of the concentration). Performance of citral oils (lemongrass and Litsea cubeba) was similar but at a concentration above 0.025%. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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13 pages, 1084 KiB

Open AccessArticle

Bioprocess Optimization for the Production of Arthrospira (Spirulina) platensis Biomass Enriched in the Enzyme Alkaline Phosphatase

by Giorgos Markou

Bioengineering 2021, 8(10), 142; https://doi.org/10.3390/bioengineering8100142 - 15 Oct 2021

Cited by 2 | Viewed by 2997

Abstract

The enzyme alkaline phosphatase (ALP) is gaining interest because it exerts bioactive properties and may be a potentially important therapeutic agent for many disorders and diseases. Microalgae are considered an important novel source for the production of diverse bio-compounds and are gaining momentum [...] Read more.

The enzyme alkaline phosphatase (ALP) is gaining interest because it exerts bioactive properties and may be a potentially important therapeutic agent for many disorders and diseases. Microalgae are considered an important novel source for the production of diverse bio-compounds and are gaining momentum as functional foods/feeds supplements. So far, studies for the production of ALP are limited to mammalian and partly to some heterotrophic microbial sources after its extraction and/or purification. Methods: Arthrospira was cultivated under P-limitation bioprocess and the effect of the P-limitation degree on the ALP enrichment was studied. The aim of this work was to optimize the cultivation of the edible and generally-recognized-as-safe (GRAS) cyanobacterium Arthrospira platensis for the production of single-cell (SC) biomass enriched in ALP as a potential novel functional diet supplement. Results: The results revealed that the relationship between intracellular-P and single-cell alkaline phosphatase (SC-ALP) activity was inverse; SC-ALP activity was the highest (around 50 U g^?1) when intracellular-P was the lowest possible (around 1.7 mg-P g^?1) and decreased gradually as P availability increased reaching around 0.5 U g^?1 in the control cultures. Under the strongest P-limited conditions, a more than 100-fold increase in SC-ALP activity was obtained; however, protein content of A. platensis decreased significantly (around 22–23% from 58%). Under a moderate P-limitation degree (at intracellular-P of 3.6 mg-P g^?1), there was a relatively high SC-ALP activity (>28 U g^?1) while simultaneously, a relative high protein content (46%) was attained, which reflects the possibility to produce A. platensis enriched in ALP retaining though its nutritional value as a protein rich biomass source. The paper presents also results on how several parameters of the ALP activity assay, such as pH, temperature etc., and post-harvest treatment (hydrothermal treatment and biomass drying), influence the SC-ALP activity. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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13 pages, 2150 KiB

Open AccessArticle

Voltammetric Determination of Isopropylmethylphenols in Herbal Spices

by Magdalena Jakubczyk, Slawomir Michalkiewicz, Agata Skorupa and Daria Slefarska

Molecules 2021, 26(20), 6095; https://doi.org/10.3390/molecules26206095 - 9 Oct 2021

Cited by 3 | Viewed by 1888

Abstract

Thymol and carvacrol—the components of herbal spices—are known for their broad biological activity as antimicrobials and antioxidants. For this reason, it is important to develop new methods for their determination in plant material. A simple, rapid, and sensitive method for determination of total [...] Read more.

Thymol and carvacrol—the components of herbal spices—are known for their broad biological activity as antimicrobials and antioxidants. For this reason, it is important to develop new methods for their determination in plant material. A simple, rapid, and sensitive method for determination of total content of these analytes in herbal spices using differential pulse voltammetry (DPV) has been developed. The basis of the research is the oxidation process of isopropylmethylphenols on a platinum microelectrode in glacial acetic acid containing acetonitrile (20%, v/v) and 0.1 mol L^?1 sodium perchlorate as the supporting electrolyte. Linear voltammetric responses for thymol and carvacrol were obtained in a wide concentration range from 0.39–1105 and 0.47–640 µg mL^?1, with a low detection limit of 0.04 and 0.05 µg mL^?1, respectively. The analysis was performed using the multiple standard addition method. The results of the voltammetric determination are in good agreement with the data of the standard chromatographic method. To the best of our knowledge, this is the first presentation of an electrochemical procedure to determine these compounds in these environmental and electrode materials. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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22 pages, 2455 KiB

Open AccessArticle

Characterization of Macro- and Microalgae Extracts Bioactive Compounds and Micro- and Macroelements Transition from Algae to Extract

by Ernesta Tolpeznikaite, Vadims Bartkevics, Modestas Ruzauskas, Renata Pilkaityte, Pranas Viskelis, Dalia Urbonaviciene, Paulina Zavistanaviciute, Egle Zokaityte, Romas Ruibys and Elena Bartkiene

Foods 2021, 10(9), 2226; https://doi.org/10.3390/foods10092226 - 19 Sep 2021

Cited by 25 | Viewed by 6104

Abstract

The aim of this study was to evaluate the characteristics of macroalgae (Cladophora rupestris, Furcellaria lumbricalis, Ulva intestinalis) and microalgae (Arthrospira platensis (Sp1, Sp2), Chlorella vulgaris) extracts, including micro- and macroelement transition to extract, antioxidant, antimicrobial properties, [...] Read more.

The aim of this study was to evaluate the characteristics of macroalgae (Cladophora rupestris, Furcellaria lumbricalis, Ulva intestinalis) and microalgae (Arthrospira platensis (Sp1, Sp2), Chlorella vulgaris) extracts, including micro- and macroelement transition to extract, antioxidant, antimicrobial properties, the concentrations of chlorophyll (-a, -b), and the total carotenoid concentration (TCC). In macroalgae, the highest TCC and chlorophyll content were found in C. rupestris. In microalgae, the TCC was 10.1-times higher in C. vulgaris than in Sp1, Sp2; however, the chlorophyll contents in C. vulgaris samples were lower. A moderate negative correlation was found between the chlorophyll-a and TCC contents (r = ?0.4644). In macroalgae extract samples, C. rupestris and F. lumbricalis showed the highest total phenolic compound content (TPCC). DPPH antioxidant activity and TPCC in microalgae was related to the TCC (r = 0.6191, r = 0.6439, respectively). Sp2 extracts inhibited Staphylococcus haemolyticus; C. rupestris, F. lumbricalis, U. intestinalis, and Sp2 extracts inhibited Bacillus subtilis; and U. intestinalis extracts inhibited Streptococcus mutans strains. This study showed that extraction is a suitable technology for toxic metal decontamination in algae; however, some of the desirable microelements are reduced during the extraction, and only the final products, could be applied in food, feed, and others. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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25 pages, 828 KiB

Open AccessReview

Effects of Insecticides and Microbiological Contaminants on Apis mellifera Health

by Aleksandra Leska, Adriana Nowak, Ireneusz Nowak and Anna Górczyńska

Molecules 2021, 26(16), 5080; https://doi.org/10.3390/molecules26165080 - 22 Aug 2021

Cited by 42 | Viewed by 10208

Abstract

Over the past two decades, there has been an alarming decline in the number of honey bee colonies. This phenomenon is called Colony Collapse Disorder (CCD). Bee products play a significant role in human life and have a huge impact on agriculture, therefore [...] Read more.

Over the past two decades, there has been an alarming decline in the number of honey bee colonies. This phenomenon is called Colony Collapse Disorder (CCD). Bee products play a significant role in human life and have a huge impact on agriculture, therefore bees are an economically important species. Honey has found its healing application in various sectors of human life, as well as other bee products such as royal jelly, propolis, and bee pollen. There are many putative factors of CCD, such as air pollution, GMO, viruses, or predators (such as wasps and hornets). It is, however, believed that pesticides and microorganisms play a huge role in the mass extinction of bee colonies. Insecticides are chemicals that are dangerous to both humans and the environment. They can cause enormous damage to bees’ nervous system and permanently weaken their immune system, making them vulnerable to other factors. Some of the insecticides that negatively affect bees are, for example, neonicotinoids, coumaphos, and chlorpyrifos. Microorganisms can cause various diseases in bees, weakening the health of the colony and often resulting in its extinction. Infection with microorganisms may result in the need to dispose of the entire hive to prevent the spread of pathogens to other hives. Many aspects of the impact of pesticides and microorganisms on bees are still unclear. The need to deepen knowledge in this matter is crucial, bearing in mind how important these animals are for human life. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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14 pages, 1525 KiB

Open AccessArticle

Characteristics of Bacterial Strains with Desirable Flavor Compounds from Korean Traditional Fermented Soybean Paste (Doenjang)

by Sung-Hun Yi and Sang-Pil Hong

Molecules 2021, 26(16), 5067; https://doi.org/10.3390/molecules26165067 - 21 Aug 2021

Cited by 24 | Viewed by 3209

Abstract

To identify and analyze the characteristics of the microorganisms involved in the formation of the desirable flavor of Doenjang, a total of 179 strains were isolated from ninety-four Doenjang collected from six regions in South Korea, and fourteen strains were selected through [...] Read more.

To identify and analyze the characteristics of the microorganisms involved in the formation of the desirable flavor of Doenjang, a total of 179 strains were isolated from ninety-four Doenjang collected from six regions in South Korea, and fourteen strains were selected through a sensory evaluation of the aroma of each culture. The enzyme activities of amylase, protease and lipase was shown in the various strains. Bacillus sp.-K3, Bacillus sp.-K4 and Bacillus amyloliquefaciens-J2 showed relatively high protease activity, at 317.1 U, 317.3 U and 319.5 U, respectively. The Bacillus sp.-K1 showed the highest lipase activity at 2453.6 U. In the case of amylase, Bacillus subtilis-H6 showed the highest activity at 4105.5 U. The results of the PCA showed that Bacillus subtilis-H2, Bacillus subtilis-H3, and Bacillus sp.-K2 were closely related to the production of 3-hydroxy-2-butanone (23.51%~43.37%), and that Bacillus subtilis-H5 and Bacillus amyloliquefaciens-J2 were significantly associated with the production of phenethyl alcohol (0.39% and 0.37%). The production of peptides was observed to vary among the Bacillus cultures such as Val-Val-Pro-Pro-Phe-Leu and Pro-Ala-Glu-Val-Leu-Asp-Ile. These peptides are precursors of related volatile flavor compounds created in Doenjang via the enzymatic or non-enzymatic route; it is expected that these strains could be used to enhance the flavor of Doenjang. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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14 pages, 28548 KiB

Open AccessArticle

Characterization of Bacillus cereus AFA01 Capable of Degrading Gluten and Celiac-Immunotoxic Peptides

by Jun Lu, Yong Wu, Juanli Yuan, Jin Yuan, Zhongliang Wang, Jinyan Gao and Hongbing Chen

Foods 2021, 10(8), 1725; https://doi.org/10.3390/foods10081725 - 26 Jul 2021

Cited by 10 | Viewed by 3052

Abstract

Wheat gluten elicits a pro-inflammatory immune response in patients with celiac disease. The only effective therapy for this disease is a life-long gluten-free diet. Gluten detoxification using glutenases is an alternative approach. A key step is to identify useful glutenases or glutenase-producing organisms. [...] Read more.

Wheat gluten elicits a pro-inflammatory immune response in patients with celiac disease. The only effective therapy for this disease is a life-long gluten-free diet. Gluten detoxification using glutenases is an alternative approach. A key step is to identify useful glutenases or glutenase-producing organisms. This study investigated the gluten-degrading activity of three Bacillus cereus strains using gluten, gliadin, and highly immunotoxic 33- and 13-mer gliadin peptides. The strain AFA01 was grown on four culture media for obtaining the optimum gluten degradation. Complete genome sequencing was performed to predict genes of enzymes with potential glutenase activity. The results showed that the three B. cereus strains can hydrolyze gluten, immunotoxic peptides, and gliadin even at pH 2.0. AFA01 was the most effective strain in degrading the 33-mer peptide into fractions containing less than nine amino acid residues, the minimum peptide to induce celiac responses. Moreover, growth on starch casein broth promoted AFA01 to degrade immunotoxic peptides. PepP, PepX, and PepI may be responsible for the hydrolysis of immunotoxic peptides. On the basis of the potential of gluten degradation, AFA01 or its derived enzymes may be the best option for further research regarding the elimination of gluten toxicity. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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10 pages, 441 KiB

Open AccessFeature PaperArticle

Stability of Fucoxanthin in Pasteurized Skim and Whole Goat Milk

by Maryuri T. Nuñez de González, Rahmat Attaie, Adela Mora-Gutierrez, Selamawit Woldesenbet and Yoonsung Jung

Foods 2021, 10(7), 1647; https://doi.org/10.3390/foods10071647 - 16 Jul 2021

Cited by 9 | Viewed by 3658

Abstract

Obesity has become a worldwide problem giving rise to several health issues. Fucoxanthin, a marine carotenoid with anti-obesity activity, has potential application as a biofunctional ingredient in human food. The objective of this study was to evaluate the thermal stability of fucoxanthin at [...] Read more.

Obesity has become a worldwide problem giving rise to several health issues. Fucoxanthin, a marine carotenoid with anti-obesity activity, has potential application as a biofunctional ingredient in human food. The objective of this study was to evaluate the thermal stability of fucoxanthin at pasteurization temperature and, subsequently, its storage stability in goat whole milk (WM) and skim milk (SM) at refrigeration temperature for four weeks. Additionally, the effect of supplementation of fucoxanthin on the composition of milk, pH, acidity, color, and lipid oxidation of WM and SM was evaluated during the four week storage period. Fresh goat WM and SM were supplemented with fucoxanthin at a concentration of 10.67 µg/mL (2.56 mg/240 mL of milk, one serving), pasteurized at 64 °C for 30 min and stored at 4 °C for four weeks. The quantification of fucoxanthin in WM and SM was performed every week using a HPLC method. Moreover, the effect of supplementation of fucoxanthin on the composition of WM and SM was evaluated by a LactiCheck milk analyzer, and the color was evaluated by reflectance using a HunterLab colorimeter. Lipid oxidation, as the 2-thiobarbituric acid-reactive substances (TBARS) at A₅₃₂, was determined using a Spectramax Plus spectrophotometer during storage. Data were analyzed by a split-plot design using PROC MIXED of SAS. The recovery yields of fucoxanthin from the pasteurized WM and SM were 96.17 ± 1.5 % and 96.89 ± 1.5 %, respectively. Both milks exhibited high recovery yields of fucoxanthin. Fucoxanthin was stable in goat WM and SM during storage at 4 °C for four weeks. The addition of fucoxanthin, at the concentration reported to have an anti-obesity effect in humans, to pasteurized WM and SM did not affect the composition or the physicochemical properties of milks but influenced the color, especially increasing the yellowness in the samples. These results revealed that goat milk can be used as a suitable matrix for the supplementation of fucoxanthin as a biofunctional ingredient in human foods. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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17 pages, 3790 KiB

Open AccessArticle

Nutritional Profiling and Preliminary Bioactivity Screening of Five Micro-Algae Strains Cultivated in Northwest Europe

by Joran Verspreet, Lise Soetemans, Caoimhe Gargan, Maria Hayes and Leen Bastiaens

Foods 2021, 10(7), 1516; https://doi.org/10.3390/foods10071516 - 1 Jul 2021

Cited by 24 | Viewed by 4852

Abstract

This study aimed to map the nutritional profile and bioactivities of five microalgae that can be grown in Northwest Europe or areas with similar cultivation conditions. Next to the biochemical composition, the in vitro digestibility of carbohydrates, proteins, and lipids was studied for [...] Read more.

This study aimed to map the nutritional profile and bioactivities of five microalgae that can be grown in Northwest Europe or areas with similar cultivation conditions. Next to the biochemical composition, the in vitro digestibility of carbohydrates, proteins, and lipids was studied for Chlamydomonas nivalis, Porphyridium purpureum, Chlorella vulgaris, Nannochloropsis gaditana, and Scenedesmus species biomass. These microalgae were also assessed for their ability to inhibit the angiotensin-1-converting enzyme (ACE-1, EC 3.4.15.1), which is known to play a role in the control of blood pressure in mammals. Large differences in organic matter solubility after digestion suggested that a cell disruption step is needed to unlock the majority of the nutrients from N. gaditana and Scenedesmus species biomass. Significant amounts of free glucose (16.4–25.5 g glucose/100 g dry algae) were detected after the digestion of C. nivalis, P. purpureum, and disrupted Scenedesmus. The fatty acid profiles showed major variations, with particularly high ?-3 fatty acid levels found in N. gaditana (5.5 ± 0.5 g/100 g dry algae), while lipid digestibility ranged from 33.3 ± 6.5% (disrupted N. gaditana) to 67.1 ± 11.2% (P. purpureum). C. vulgaris and disrupted N. gaditana had the highest protein content (45–46% of dry matter), a nitrogen solubility after digestion of 65–71%, and the degree of protein hydrolysis was determined as 31% and 26%, respectively. Microalgae inhibited ACE-1 by 73.4–87.1% at physiologically relevant concentrations compared to a commercial control. These data can assist algae growers and processors in selecting the most suitable algae species for food or feed applications. Full article

(This article belongs to the Topic Microalgal Biotechnology for Bioproducts and Food Applications)

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