Search Results (196)

The traditional fermentation of table olives is a complex and dynamic, process, carried out by a consortium of microorganisms that interact with each other and contribute to the uniqueness and attractiveness of the final product. Fermentation is conducted by yeasts and lactic acid bacteria (LAB) that coexist in olive fruits. The succession of one microbial population to the detriment of others depends on internal and external factors that affect the process, e.g., the maturation degree of fruits, cultivar, endophytic, or epiphytic state of microorganisms, pH, water activity, temperature, and salt concentration. Thus, studying microbiota evolution and their identification in natural table olive fermentations is paramount. This review aims to provide an overview of the knowledge on the natural fermentation of table olives, namely regarding microbial dynamics, as to report the main species involved in the fermentation process, highlight the influence of the olive oil ecosystem on the origin of the microbiota and consequently on the obtaining of the final product. The results report a total of 97 yeast species and 45 LAB species described in olives and brine over the last few decades. Full article

Grapevines (Vitis vinifera L.) face significant challenges from abiotic stresses caused by climate change, including drought, salinity, and temperature extremes. This comprehensive review examined the role of beneficial microorganisms in enhancing grapevine tolerance to these stresses, focusing on arbuscular mycorrhizal fungi (AMF), plant growth-promoting rhizobacteria (PGPR), and endophytes. The study analyzes species-specific effects and their molecular mechanisms, highlighting how single and consortium inoculations improve plant resilience. AMF species, particularly Funneliformis mosseae and Rhizophagus irregularis, demonstrated significant enhancement in drought and salinity tolerance through improved nutrient uptake and stress response modulation. The PGPRs, Bacillus and Pseudomonas species, show remarkable abilities to mitigate various abiotic stresses through mechanisms including phytohormone production and antioxidant defense enhancement. Endophytic microorganisms such as Pseudomonas fluorescens RG11 and Serendipita indica play crucial roles in stress mitigation through melatonin production and improved water retention, respectively. The synergistic effects of combined AMF, PGPR, and PGPF applications led to a significant increase in grapevine drought and salinity tolerance, improving nutrient uptake, photosynthesis rates, and antioxidant defense mechanisms. Molecular analysis revealed that these microbial consortia regulate the expression of stress-responsive genes, particularly VvNCED and VvP5CS, enhancing grapevine resilience through improved osmotic adjustment, ROS scavenging, and hormonal regulation. These findings provide valuable insights into the molecular pathways underlying stress tolerance, offering promising strategies for sustainable viticulture under climate change. Full article

Background: Nowadays, the microbial degradation of cellulose represents a new perspective for reducing cellulose waste from industry and households and at the same time obtaining energy sources. Methods: We isolated and enriched two aerobic (at 37 °C and 50 °C) and one anaerobic microbial consortium from an anaerobic bioreactor for biogas production by continuous subculturing on peptone cellulose solution (PCS) medium supplemented with 0.3% treated or untreated Whatman filter paper under static conditions. Samples were taken every 7 days until day 21 to determine the percentage of cellulose biodegradation. We determined the antimicrobial resistance of aerobic and anaerobic consortia and some single colonies by disc diffusion method, against 42 clinically applied antibiotics. PCR analyses were performed to search for the presence of eight genes for cellulolytic activity and nine genes for antibiotic resistance. By metagenomics analysis, the bacterial and fungal genus distributions in the studied populations were determined. Results: Aerobes cultured at 50 °C degraded cellulose to the greatest extent (47%), followed by anaerobes (24–38%) and aerobes (8%) cultured at 37 °C. The bacterial sequence analysis showed that the dominant phyla are Bacillota and Bacteroidetes and genera—Paraclostridium, Defluvitalea, Anaerobacillus, Acetivibrio, Lysinibacillus, Paenibacillus, Romboutsia, Terrisporobacter, Clostridium, Sporanaerobacter, Lentimicrobium, etc. in a different ratio depending on the cultivation conditions and the stage of the process. Some of these representatives are cellulolytic and hemicellulolytic microorganisms. We performed lyophilization and proved that it is suitable for long-term storage of the most active consortium, which degrades even after the 10th re-inoculation for a period of one year. We proved the presence of ssrA, ssrA BS and blaTEM genes. Conclusions: Our findings demonstrated the potential utility of the microbial consortium of anaerobes in the degradation of waste lignocellulose biomass. Full article

The cashew apple constitutes approximately 90% of the total fruit mass produced by the cashew tree, with the remaining 10% being the cashew nut. Despite its high nutritional value, it is regarded as an agricultural byproduct. Numerous scientific studies have explored the technological and nutritional potential of the cashew apple by leveraging microorganisms in its fermentation process for beverage applications. This paper provides an overview of existing fermented cashew apple beverages and discusses perspectives for new fermented cashew apple products. Five fermented cashew apple beverages were recorded. These include wine, edible alcohol, probiotic and prebiotic beverages, and cashew apple-based vinegar. New fermented cashew apple beverages with organoleptic, nutritional, and functional properties can be considered. Among these are fermented cashew apple beverages such as kefir or kombucha-type drinks. A promising avenue for future research is the exploration of the indigenous microbiota of the cashew apple and their interactions within a consortium. This could lead to innovative developments in food technology and improvements in the organoleptic and nutritional characteristics of fermented cashew apple beverages. Full article

Commercial tomato hybrids exhibit robust performance in modern high-input agricultural systems. However, their suitability for low-input farming remains uncertain. With the goal that by 2030, 25% of European agricultural production must be organic as part of the European Green Deal, this study aims to assess whether existing commercial tomato hybrids can offer a viable solution for low-input farming. Additionally, the impact of beneficial microorganisms such as plant growth-promoting rhizobacteria (PGPR), in relation to the growth and productivity of tomato hybrids under low-input cultivation is assessed. For this purpose, a well-defined microbial consortium, including Azotobacter chroococcum, Clostridium pasteurianum, Lactobacillus plantarum, Bacillus subtilis, and Acetobacter diazotrophicus, was applied as a liquid suspension to enhance root colonization and promote plant growth. Seven commercial tomatoes (Solanum lycopersicum L.) hybrids—the most popular in the Greek market—were evaluated for their performance under high-input (hydroponic) and low-input cultivation systems (with and without the use of PGPR). Several parameters related to yield, fruit quality, nutritional value, descriptive traits, and leaf elemental concentration were evaluated. In addition, a techno-economic analysis was conducted to assess whether hybrids developed under high-input conditions and intended for such cultivation environments suit low-input farming systems. The results indicated that such hybrids are not a viable, efficient, or profitable strategy for low-input cultivation. These findings underscore the importance of breeding tomato varieties, specifically adapted to low-input farming, highlighting the need for targeted breeding strategies to enhance sustainability and resilience in future agricultural systems. Notably, this study is among the first to comprehensively assess the response of commercial tomato hybrids under low-input conditions, addressing a critical gap in the current literature. Full article

This publication presents an analysis of the possibilities for home biogas production using an original method. The assumptions for a biogas-generating system and key principles for the methane fermentation process are outlined. Research on the methane fermentation of both kitchen waste and green waste was conducted using a methanogenic consortium. The studies allowed for the characterization of the microorganisms comprising the consortium, and tests confirmed the feasibility of conducting methane fermentation of both types of waste at both laboratory and technical scales, as well as estimating the biogas productivity of the substrates. Based on the research conducted at both scales, the range of conditions under which the biogas production process is possible was determined, with particular reference to temperature conditions and the pH of the leachate. The tests, primarily conducted at a technical scale, allowed for the definition and implementation of optimization measures that resulted in increased process efficiency at the technical scale. Among the main optimization measures were the use of sand as a phase to maintain an anaerobic zone at the start of the process, the use of wood ash to stabilize pH, and the use of substrates and water at room temperature. Full article

This research aimed to characterise hydrocarbonoclastic bacteria isolated from naturally hydrocarbon-contaminated springs and the surrounding soils in the Agri Valley (Southern Italy) and to assess the effectiveness of bioaugmentation using a four-strain microbial consortium for removing hydrocarbons from artificially diesel-contaminated lake waters in mesocosm experiments. Four novel bacterial strains were selected for the experimentation: Gordonia amicalis S2S5, Rhodococcus erythropolis S2W2, Acinetobacter tibetensis S2S8, and Acinetobacter puyangensis S1W1. The four isolates can use diesel oil as their sole carbon source, and some exhibited a relatively high emulsifying capacity and ability to adhere to hydrocarbons. Furthermore, genome analyses revealed the presence of genes associated with the degradation, detoxification, and transport of various contaminants. Mesocosm experiments demonstrated that the bioaugmentation enhanced the capacities of the native lake microbial communities to remove hydrocarbons, although drastic changes in their composition (analysed through Next-Generation Sequencing—NGS) were observed. Taken together, these results suggest that naturally contaminated environments can serve as a valuable reservoir of microorganisms with significant biotechnological potential, particularly in the field of bioremediation. However, a complete understanding of the ability of the isolated bacterial strains to efficiently degrade contaminants requires further research to fully assess their capabilities and limitations across different settings. Full article

The development of microbial-based biostimulants to enhance the growth of crops and support a healthy and sustainable soil requires the isolation and large-scale industrial culture of effective microorganisms. In this study, work was undertaken to isolate and characterize free-living nitrogen-fixing bacteria capable of acting as biostimulants alone or by incorporation into and/or supplementation with a current commercial crop biostimulant for farmers. Free-living bacteria were isolated from soil, sugar cane mulch, and plant roots following preliminary culture in a nitrogen-free media that targeted specific groups of known diazotrophs. Following the identification of each isolate by 16S rDNA sequence analysis, isolates selected for further study were identified as most closely related to Priestia megaterium, Sphingobium yanoikuyae, and Burkholderia paludis. Each isolate was investigated for its capacity to promote plant growth in nitrogen-free media. Wheat seedlings were inoculated with the isolates separately, together as a consortium, or in combination with the commercial biostimulant, Great Land Plus^®. Compared to no-treatment control plants, the fresh weights were higher in both the shoots (183.2 mg vs. 330.6 mg; p < 0.05) and roots (320.4 mg vs. 731.3 mg; p < 0.05) of wheat seedlings inoculated with P. megaterium. The fresh weights were also higher in the shoots (267.8 mg; p < 0.05) and roots (610.3 mg; p = 0.05) of wheat seedlings inoculated with S. yanoikuyae. In contrast, the fresh weight of the shoot and root systems of plants inoculated with B. paludis were significantly lower (p < 0.05) than that of the no-treatment control plants. Moreover, when Great Land Plus^® was supplemented with a consortium of P. megaterium and S. yanoikuyae, or a consortium of P. megaterium, S. yanoikuyae, and B. paludis no promotion of plant growth was observed. Full article

The adoption of “consortium” of potential microorganisms can optimize the forest seedling production process. The objective of this study was to evaluate in greenhouse conditions the effect of co-inoculation between Trichoderma harzianum, Bradyrhizobium diazoefficiens, and B. elkanni on the growth of Schizolobium parahyba var. parahyba (Vell.) Blake seedlings. The treatments consisted of fungi strains (T. harzianum ESALQ 1306); bacteria strains (B. elkanni (SEMIA 5080) + B. diazoefficiens (SEMIA 587)); consortium (Trichoderma +Bradyrhizobium), and a control treatment. The seeds were sown, and evaluations were carried out 120 days after sowing. The variables analyzed were shoot height (SH), stem diameter (SD), root length (RL), shoot fresh mass (SFM), root fresh mass (RFM), total fresh biomass (TFM), shoot dry mass (SDM), root dry mass (RFM), total dry biomass (BIO), and Dickson quality index (DQI). The evaluated microorganisms proved to be effective in the production of S. parahyba var. parahyba, with emphasis on co-inoculation for growth parameters, promoting an increase in SH (23%), SD (36%), and RL (84%). For mass, non-inoculated seedlings (control) obtained a decrease of 67% (TFM) and 83% (BIO) compared to co-inoculation. The results indicate a promising method in seedling production; the biostimulators allowed the increase in plant development, which led to success in the morphometric indices. The mechanisms involved in the co-inoculation of microorganisms’ consortium in promoting the growth of native wood species to allow their production on a large scale in the silvicultural sector are still scarce, and new research is needed to elucidate the physiological and biochemical mechanisms involved. Full article

Plastic and plasticizer pollution has been a concern worldwide over the past decade. Bis(2-ethylhexyl) phthalate (DEHP) is the most produced plasticizer and has been detected in coastal and marine ecosystems. This study aimed to assess the toxicity of acute exposure (24, 48, 72, and 96 h) to DEHP concentrations (0.045–6.00 mg·L⁻¹) on marine and estuarine tropical species from distinct trophic levels. The lethality and sublethal responses were assessed on two microorganisms and three invertebrates, independently. The microorganisms—the microalga Tetraselmis sp. and the microbial consortium MP001—showed high tolerance and a density-rising tendency during exposure to DEHP. Among the invertebrates, the mortality of the brine shrimp Artemia sp. and the amphipod Apohyale media rose with increasing DEHP concentrations. However, A. media was more sensitive across time since its lethality reached 100% in almost all DEHP concentrations from 72 h. The dark false mussel Mytilopsis leucophaeata was the most tolerant invertebrate: no significant lethality (≤20%) was observed exclusively from 72 h of exposure to DEHP at intermediate–high concentrations. Artemia sp. and M. leucophaeata presented sublethal responses that seem to be good endpoints for ecotoxicological assays. These results reinforce evidence of DEHP contamination risks for tropical coastal ecosystems, as well as suggest candidate species for its biodegradation. Full article

Aquaculture reliance on fishmeal protein has become a bottleneck due to long-term sustainability concerns and increasing costs. Given its abundance and nutrient-rich profile, the green macroalga Ulva rigida is a promising alternative protein source. However, the bioaccessibility of its proteins is hindered by an embedding matrix of ulvan, a gel-forming polysaccharide. Saccharification of the alga crude fiber followed by microbial fermentation improves protein bioaccessibility and leads to products of higher protein content and quality. Also, upon fermentation, the nutritional and bioactive properties of these feed ingredients are enhanced, since microorganisms synthesize vitamins, new proteins, and essential amino acids. The carbohydrate fraction of Ulva rigida was hydrolyzed into a sugar-rich syrup and subsequently used as a substrate in microbial fermentations. Three types of fermentation were tested, namely, with a consortium of four lactic acid bacteria (LAB), with Saccharomyces cerevisiae, and with a co-culture of lactobacilli and yeast. A functional analysis of lyophilized whole-fermentation broths revealed that the yeast-fermented products had stronger antioxidant properties when compared to the LAB-fermented products. The protein bioaccessibility in the fermented products was 11- to 12-fold higher than that of the raw alga. These findings highlight the potential of utilizing S. cerevisiae and lactobacilli starter cultures in seaweed fermentation to produce Ulva-based feed ingredients. Full article

The hypothesis that cultivating açaí in agroforestry systems (AFS) can recruit beneficial microorganisms to its rhizosphere was tested in this study. For this purpose, rhizospheric soil samples were collected from an AFS area. The colony-forming unit (CFU) counts of the soil samples were 3.5 × 10⁶ CFU/g, with no statistically significant differences between the plants (p < 0.05). Regarding PGPR characteristics, of the 44 isolated strains, 18% produced siderophores, 9% mineralized organic phosphate, 15% solubilized inorganic phosphate, and 7% produced indole-3-acetic acid (IAA) and antimicrobial substances. Strains AP4-03, AP1-33, and AP2-36 were affiliated with the genus Bacillus sp. and produced IAA at 1.45, 1.35, and 2.02 µg/mL, respectively. Furthermore, these strains were able to inhibit the growth of the fungus Pestalotiopsis by 69%, 67%, and 71%, respectively. Regarding the antifungal activity of bacterial extracts, inhibition zones of 23 mm (AP-03), 20 mm (AP-33), and 18 mm (AP-36), with 96% and 92% inhibition at 50 mg/mL (AP4-03 and AP1-33) and 100% inhibition at 41 mg/mL (AP2-36), were observed. Considering seedling germination, açaí palms inoculated with the strain AP1-33 statistically differed from the controls in terms of root length and hypocotyl length. Furthermore, treatments inoculated with the strain AP2-36 or all strains in the consortium differed when only the hypocotyl length was compared to the control. Thus, the analyzed strains showed potential to improve the initial development of açaí plants. Full article

Experiments were conducted to evaluate domestic low-grade laterites and serpentinite waste as potential secondary sources of nickel and magnesium and to assess leaching residues for carbon dioxide adsorption. Solids were leached chemically using sulfuric acid, while bioreductive dissolution under anoxic conditions employed a consortium of microorganisms dominated by Sulfobacillus. The efficiency of laterite bioreduction was 26.81% for Ni and 63.92% for Mg. In the case of serpentinite, 20.54% Ni and 92.88% Mg were extracted. The chemical dissolution yielded 26.73% Ni and 61.37% Mg in the case of laterites and 16.20% Ni and 77.49% Mg for serpentinite waste. Specific surface area was analyzed during the processes, showing a systematic increase over time. Based on the changes in this parameter, a mathematical description of the process was proposed using a shrinking particle model (SPM). Except for laterite bioreduction, leaching was shown to be a two-stage process controlled by a chemical reaction. The serpentinite solid processed in the presence of microorganisms exhibited the highest surface area (267 m²/g) and a CO₂ adsorption capacity of 19.9 cm³/g. Full article

This study investigated the ability of bacterial strains to neutralize odorous substances from cattle slurry (CS). The research was performed to develop a microbial preparation for the deodorization of CS. Among the strains of bacteria (Bacillus and Pseudomonas) isolated from natural environments, those with the highest ammonia and hydrogen sulfide reduction were selected, and the bacterial consortium was prepared. The biopreparation reduced ammonia by 98% in the unshaken culture and 100% in the aeration culture, after 10 days of incubation (compared to the initial sample). Complete elimination of hydrogen sulfide was noted on day 6 of the deodorization process for both cultures. The microbiological supplementation also had a positive effect on the chemical composition of the slurry, increasing its fertilizer value. The addition of biopreparation to the slurry resulted in a reduced loss of ammonium ions and increased nitrogen concentration by 29%. It was found that the use of the microbial consortium also increased the availability of potassium and phosphorus, which can be used in agricultural production. Nitrogen retention by microorganisms in the slurry increases its organic value and leads to a reduction in the use of mineral fertilizers. Full article

Due to its persistence, glyphosate contamination in soil poses environmental and health risks. Plant growth-promoting bacteria (PGPB) offer a potential solution for mitigating glyphosate pollution. This study assessed the glyphosate degradation capacity of three airborne PGPB isolates (Exiguobacterium indicum AS03, Kocuria sediminis AS04, and Rhodococcus rhodochrous AS33) individually and in a consortium (CS) compared to natural attenuation in microcosms as the control (CTL), where soil autochthonous microorganisms (MS) were present. AS03 exhibited the highest glyphosate degradation (86.3%), followed by AS04 and AS33 at 14 days (61.6% and 64.7%). The consortium accelerated glyphosate removal, reaching 99.7%, while the control treatment removal was 94% at 60 days. Aminomethylphosphonic acid (AMPA) is the main metabolite in glyphosate degradation, and it had a maximum peak in concentration at 28 days in the CS + MS (1072 mg kg⁻¹) and CTL (990 mg kg⁻¹) treatments. Subsequently, a decrease in AMPA concentration was observed at 60 days up to 349 mg kg⁻¹ and 390 mg kg⁻¹, respectively. These results suggested that soil autochthonous microorganisms and their interactions with a consortium have similar biotransformation of glyphosate, but the AMPA conversion to other intermedium metabolites through degradation was slow. A minimum AMPA concentration of 15–45 mg kg⁻¹ over time was detected with the consortium. The microbiome analysis revealed shifts in microbial composition, with an increase in glyphosate-degrading genera like Psychrobacter and Lyzobacter. These changes enhance soil resilience and fertility, demonstrating the potential of airborne PGPB for bioremediation and environmental sustainability. Full article