Search Results (1,139)

N-Acetylneuraminic acid (Neu5Ac), the predominant form of sialic acids (Sias), is extensively utilized in the food, pharmaceutical, and cosmetic industries. Microbial fermentation serves as a critical production method for its economical, eco-friendly, and scalable production. Escherichia coli and Bacillus subtilis, as primary industrial workhorses for Neu5Ac production, have been extensively investigated owing to their well-characterized genetic frameworks and mature molecular toolkits. Nevertheless, the intricate regulatory networks inherent to microbial systems present formidable obstacles to the high-efficiency biosynthesis of Neu5Ac. This review delineates the genetic and molecular mechanisms underlying Neu5Ac biosynthesis in both E. coli and B. subtilis. Furthermore, the rational and irrational strategies for constructing Neu5Ac microbial cell factories are systematically summarized, including the application of rational metabolic engineering to relieve feedback regulation, reconfigure metabolic networks, implement dynamic regulation, and optimize carbon sources; as well as the use of irrational strategies including directed evolution of key enzymes and high-throughput screening based on biosensors. Finally, this review addresses current challenges in Neu5Ac bioproduction and proposes integrative solutions combining machine learning with systems metabolic engineering to advance the construction of high-titer Neu5Ac microbial cell factory and the refinement of advanced fermentation technologies. Full article

Infectious diseases caused by pathogenic microorganisms have caused serious economic losses to animal husbandry, and the use of appropriate disinfectants is crucial for eliminating these pathogens. Plant essential oils (PEOs), as natural bioproducts, have the characteristics of safety, non-toxicity, and broad spectrum. In this study, the inhibition efficacies against bacteria, viruses, and mycoplasmas of a compound PEO disinfectant (designated as Lei-Huo-Fu) were evaluated through determination of minimum inhibitory concentration (MIC) and bactericidal rate against Escherichia coli, Staphylococcus aureus, and Salmonella spp.; inactivation rate of avian infectious bronchitis virus (IBV); as well as determination of MIC of Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS). The results showed that the MIC values of the PEO disinfectant against Escherichia coli, Staphylococcus, and Salmonella spp. were as low as 0.00375 µg/mL to 0.03 µg/mL. The bactericidal rates against Escherichia coli, Staphylococcus aureus, and Salmonella spp. reached over 95% within 30 min at a concentration of 0.03 µg/mL. For three dominant prevalent genotype strains of LX4-type, Mass-type, and Taiwan-type of IBV, the inactivation rates achieved by the PEO disinfectant at a concentration of 0.015 µg/mL and a disinfection time of 30 min were all above 99.9%. The MIC of the PEO disinfectant against MG and MS was 0.001875 µg/mL and 0.00375 µg/mL, respectively. In conclusion, the compound PEO disinfectant (Lei-Huo-Fu) has significant inhibitory effects on bacteria, viruses, and mycoplasmas, and possesses broad-spectrum antimicrobial activity. However, it is important to note that these findings are based on laboratory assays, and the efficacy in practical settings, along with the exact mechanisms of action, require further investigation. In this study, the compound PEO disinfectant demonstrates promising in vitro efficacy, suggesting its potential as a candidate for development into a safe, efficient, and natural disinfectant, pending further validation. Full article

Peripheral nerve injuries remain a major clinical problem, and cell-free therapies using stem cell-derived bioproducts have emerged as promising alternatives. This study evaluated the influence of neurogenic differentiation and passage number on the secretomic and exosomal profile of human dental pulp stem cells (hDPCSs). Conditioned media from undifferentiated and neurodifferentiated hDPSCs, and exosomes derived from undifferentiated hDPSCs at passages 4 and 7, were analyzed using multiplex immunoassays, RT-PCR, and scanning electron microscopy (SEM). Neurodifferentiated hDPSCs at early passages secreted higher levels of neurotrophic, angiogenic and immunomodulatory factors, including FGF-2, IL-6, IL-8, and PDGF-AA. Exosomes from early-passage undifferentiated cells showed a more abundant and relevant neuroregenerative mRNA cargo in comparison to the later passages. Both cell types and exosomes adhered to the Reaxon^® nerve guidance conduit, confirming the permissive nature of the materials regarding cells and cellular products, allowing adhesion and survival. Neurite outgrowth assays performed on neurodifferentiated hDPSCs confirmed functional neural behavior. In later passages, a decline in secretory and exosomal activity was noted. These results highlight the relevance of early-passage hDPSCs as a source of bioactive factors and support their application in cell-free approaches for peripheral nerve regeneration. Full article

This review consolidates recent advancements in microbial biotechnology for sustainable food systems. It focuses on the fermentation processes used in this sector, emphasizing precision fermentation as a source of innovation for alternative proteins, fermented foods, and applications of microorganisms and microbial bioproducts in the food industry. Additionally, it explores food preservation strategies and methods for controlling microbial contamination. These biotechnological approaches are increasingly replacing synthetic additives, contributing to enhanced food safety, nutritional functionality, and product shelf stability. Examples include bacteriocins from lactic acid bacteria, biodegradable microbial pigments, and exopolysaccharide-based biopolymers, such as pullulan and xanthan gum, which are used in edible coatings and films. A comprehensive literature search was conducted across Scopus, PubMed, ScienceDirect, and Google Scholar, covering publications from 2014 to 2025. A structured Boolean search strategy was applied, targeting core concepts in microbial fermentation, bio-based food additives, and contamination control. The initial search retrieved 5677 articles, from which 370 studies were ultimately selected after applying criteria such as duplication removal, relevance to food systems, full-text accessibility, and scientific quality. This review highlights microbial biotransformation as a route to minimize reliance on synthetic inputs, valorize agri-food byproducts, and support circular bioeconomy principles. It also discusses emerging antimicrobial delivery systems and regulatory challenges. Overall, microbial innovations offer viable and scalable pathways for enhancing food system resilience, functionality, and environmental stewardship. Full article

Pollution and freshwater scarcity, coupled with the energy sector’s continued dependence on fossil fuels, constitute a dual challenge to sustainable development. A promising response is biosystems that jointly address wastewater treatment and the production of renewable products. This review centers on a managed consortium of aquatic macrophytes and microalgae, in which the spatial architecture of plant communities, rhizosphere processes, and the photosynthetic activity of microalgae act in concert. This configuration simultaneously expands the spectrum of removable pollutants and yields biomass suitable for biorefinery, thereby linking remediation to the production of energy carriers and bioproducts within a circular bioeconomy. The scientific novelty lies in treating the integrated platform as a coherent technological unit, and in using the biomass “metabolic passport” to align cultivation conditions with optimal valorization trajectories. The work offers a practical framework for designing and scaling such consortia that can reduce the toxicological load on aquatic ecosystems, return macronutrients to circulation, and produce low-carbon energy carriers. Full article

Lignin, as one of the three primary components of renewable lignocellulosic biomass, can be converted into aromatic platform chemicals and holds significant potential for high-value applications. p-Hydroxybenzaldehyde is a compound derived from lignin. In this study, the mutant Δ60 of the glycosyltransferase UGT_BL1 derived from Bacillus licheniformis was adopted to catalyze the glycosylation reaction of p-hydroxybenzaldehyde, producing a bioactive compound Helicid analogue (p-hydroxybenzaldehyde β-glucoside). Truncation mutations targeting loop regions may reduce local flexibility, thereby facilitating enhanced access of p-hydroxybenzaldehyde to the active site pocket and promoting relative activity. Under optimal conditions (35 °C, pH 7.5, and glucose 200 mM), a high yield of 97.8% for p-hydroxybenzaldehyde β-glucoside was achieved from 2 mM p-hydroxybenzaldehyde within 10 h. The conversion of 3 mM p-hydroxybenzaldehyde (366.4 mg/L) yielded up to 2.7 mM (767.5 mg/L) of p-hydroxybenzaldehyde β-glucoside within 48 h. According to the molecular docking results, the CDOCKER energy value of mutant Δ60 was lower than that of the wild-type, at −16.0 kcal/mol. To our knowledge, this is the first example of an efficient and environmentally sustainable approach for the synthesis of p-hydroxybenzaldehyde β-glucoside, providing a new insight for the valorization of lignin into valuable biobased chemicals. Full article

Food waste (FW) presents a critical issue, representing an environmental liability and a largely untapped resource. Its heterogeneity and low valorization rate among main-stream alternative treatments challenge its integration into economically and environmentally sustainable bioprocesses. We explore biorefineries as a solution that can address the complexity of urban food waste through biological strategies capable of converting food waste into valuable products. Exploring the current landscape of FW biorefineries, this study focused on the interplay between feedstock heterogeneity, pretreatment strategies, microbial dynamics, and integration potential. We propose a framework distinguishing between robust fermentations that can use minimally treated FW and tailored fermentations, which require refined media pretreatment and/or supplementation to yield higher-value compounds. Drawing on recent techno-economic and life cycle assessments, this article evaluates process viability and environmental impacts across multiple scales, reinforcing the need for robust analysis to support decision-making. Real-world initiatives and policy frameworks are analyzed to contextualize technological advances within regulatory and infrastructural realities. By linking practical constraints to biochemical and operational strategies, this work outlines how food waste biorefineries can contribute meaningfully to circular economy goals. Instead of treating FW as an intractable problem, it is seen as a versatile feedstock that demands integration, investment, and adaptive process design. Full article

Processing economically and socio-culturally significant Amazonian fruits—andiroba (Carapa guianensis Aubl.), açai (Euterpe oleracea Mart.), and babassu (Attalea speciosa Mart. ex Spreng.)—generates substantial biomass waste, posing critical environmental and waste management challenges. This study explored the valorization of these abundant residual biomasses as sustainable feedstocks for biosurfactant production by bacterium Pseudomonas aeruginosa P23G-02, while simultaneously profiling their nutritional value and broader implications for a circular bioeconomy. Through liquid fermentation, biosurfactants were produced at an approximate yield of 6 mg/mL. The isolated biosurfactants exhibited favorable properties, including emulsification indices of around 60% and surface tension reduction to below 30 mN/m, with the andiroba-derived biosurfactant identified as a rhamnolipid type. Nutritional profiling of the residues revealed significant energy values, reaching up to 656 kcal/100 g, with açai and babassu residues being carbohydrate-rich (exceeding 80%), and andiroba residues exhibiting a high lipid profile (up to 57%). These distinct compositions critically influenced biosurfactant yield. These findings underscore the viability of Amazonian fruit biomass as valuable resources for developing eco-friendly bioproducts and innovative waste management solutions. While highlighting a promising pathway for circular bioeconomy development, future research should address biosafety and explore alternative microbial hosts for applications in sensitive sectors such as food and nutrition. Full article

Graesiella emersonii, an aeroterrestrial green microalga, exhibits high adaptability to extreme environmental conditions, making it of interest for biotechnological applications. Investigating photosynthetic performance is essential to select high-yield strains and optimize the sustainable production of biomass and bio-products. In this study, two strains (053 and 054) were cultured under atmospheric (0.04%) and elevated (2%) CO₂ conditions to analyze growth, pigment content, and photosynthesis. Strain 053 showed superior photosynthetic performance and productivity under atmospheric conditions, whereas 2% CO₂ enhanced growth in both strains, with a significant increase in photosynthetic efficiency in strain 054. The observed differences highlight strain-specific adaptations to CO₂ availability and suggest the potential of each strain depending on the cultivation environment. Full article

This study details a biorefinery approach to valorize Dosidicus gigas squid pen waste. The process starts with the enzymatic deproteinization of squid pens, which prove effective with both Alcalase and Novozym, with the latter exhibiting a slightly higher efficiency to yield a material with 73% chitin content. Subsequent alkaline hydrolysis produces highly deacetylated chitosan (>90% degree of deacetylation), followed by controlled depolymerization to obtain polymers with molecular weights ranging from 50 to 251 kDa. Both native and depolymerized chitosan exhibit antimicrobial activity against Escherichia coli and Bacillus cereus, with B. cereus demonstrating greater resistance to chitosan compared to E. coli. The research also explores the bioconversion of deproteinization and deacetylation effluents. Deproteinization effluents prove superior in sustaining microbial growth, supporting comparable growth and lactic acid production for human probiotic strains (Lactobacillus plantarum and Leuconostoc mesenteroides) when substituting commercial peptones. Marine bacteria (Pseudomonas fluorescens and Phaeobacter sp.) show lower productivity. Integrating these processes into a biorefinery framework enables the conversion of 1 kg of dry squid pens into 350 g of chitosan, and facilitates the production of 937–949 g of lactic acid using human lactic acid bacteria cultures in media formulated with squid pen-derived effluents, glucose, yeast extract, and mineral salts. This integrated approach highlights the potential for maximizing resource utilization from squid pen waste, reducing environmental impact and generating high-value bioproducts. Full article

The growing need for environmentally friendly separation processes has motivated the search for alternative solvents to petroleum-derived chemicals for the recovery of biosynthesized products. Although effective, conventional petroleum-based solvents pose major environmental and sustainability concerns, including pollution, ecotoxicity, human health risks, and high costs and energy demands for recycling. Consequently, current research and industrial practice increasingly focus on their replacement with safer and more sustainable alternatives. This study investigates the use of natural oils (i.e., grapeseed, sweet almond, and flaxseed oils) as renewable, biodegradable, and non-toxic diluents in reactive extraction systems for the separation of 7-aminocephalosporanic acid (7-ACA). The combination of these oils with tri-n-octylamine (TOA) as extractant enabled high extraction efficiencies, exceeding 50%. The system comprising 120 g/L tri-n-octylamine in grapeseed oil, an aqueous phase pH of 4.5, a contact time of 1 min, and a temperature of 25 °C resulted in a 7-ACA extraction efficiency of 63.4%. Slope analysis suggests that complex formation likely involves approximately one molecule each of tri-n-octylamine and 7-ACA, although the apparent order of the amine is reduced in systems using natural oils. This study highlights the potential of natural oil-based reactive extraction as a scalable and environmentally friendly method for 7-ACA separation, aligning with the principles of green chemistry and environmental biotechnology. Full article

This study aims to evaluate the use of sugarcane industry byproducts (bagasse and molasses), as well as glycerol from the liquor of the organosolv pretreatment of bagasse, to bioproduce 1,3-propanediol (1,3-PDO). For this purpose, Lentilactobacillus diolivorans was used, which can produce 1,3-PDO from a mixture of glycerol and sugars. First, experiments were conducted using the MRS medium to investigate the effect of various carbohydrate sources and their mixtures on the growth profile and 1,3-PDO production by L. diolivorans. Subsequently, the carbohydrates in the MRS medium were replaced with sugarcane byproducts. The results showed that the type of carbohydrate plays a crucial role in growth kinetics and 1,3-PDO production. Xylose and glucose showed the best results; however, sucrose was not enough to support biomass formation. The presence of xylose increased sucrose assimilation, resulting in a 4.5-fold increase in the concentration of 1,3-PDO from 1.3 to 6.18 g/L. An auspicious outcome was observed when the liquor of the acid pretreatment of sugarcane bagasse, molasses, and organosolv liquor were used as substrates, resulting in a production of 5.47 g/L 1,3-PDO with an efficiency of 82.77%. Therefore, producing a high-value chemical such as 1,3-PDO from the sugarcane byproducts seems to be a very promising strategy. Full article

Algal biorefineries constitute an emerging platform for the sustainable production of renewable bioproducts; however, their economic viability remains constrained by the high costs associated with microalgal cultivation and biomass harvesting. This study investigated an integrated strategy combining macronutrient optimization with electrocoagulation–flocculation (ECF) harvesting for Chlorella vulgaris. A Central Composite Design (CCD) was employed to optimize concentrations of NaNO₃, KH₂PO₄, and MgSO₄ with the dual objective of maximizing biomass yield and enhancing biocompound content. Subsequently, the ECF process parameters—current density, electrolysis duration, pH, and electrolyte concentration—were optimized to improve harvesting efficiency. Under the optimal macronutrient conditions (NaNO₃: 100.00 mg/L; KH₂PO₄: 222.12 mg/L; MgSO₄: 100.84 mg/L), the model predicted a maximum biomass concentration of 0.475 g/L, along with 32.79% w/w carbohydrates and 6.79 mg/L chlorophyll-a. Optimal ECF harvesting conditions (current: 0.57 A; pH: 4.00; electrolysis time: 12.70 min; electrolyte: 1.74 g/L) achieved a biomass recovery efficiency of 89.51% w/v. These results demonstrate that coupling nutrient optimization with ECF-based harvesting offers a synergistic, scalable, and cost-effective pathway to improve the sustainability of algal biorefineries. Full article

The prevalence of infectious diseases is steadily increasing. If left untreated, they can lead to more serious health problems. Antibiotics currently available on the market are facing growing resistance, prompting the development of increasingly powerful antibacterial molecules. One alternative currently under investigation is the use of antibacterial peptides, whose mechanisms of action differ from those of conventional drugs. These peptides are produced naturally by all living organisms and can also be synthesized. However, as peptide chains become longer, synthesis and purification become increasingly complex and laborious. For decades, antimicrobial peptides have been synthesized on polymer supports using automated systems. Unfortunately, longer chains tend to fold more, preventing access of reagents within the cross-linked polymer network. Recombinant production of antimicrobial peptides has been achieved in various organisms called “cell factories,” allowing for more sustainable synthesis. Recently, microalgae have emerged as a promising and sustainable alternative for the production of antimicrobial peptides. They are inexpensive, easy to cultivate, and capable of producing biologically valuable molecules, offering a potential solution to antibiotic resistance. This work reviews the current state of these “cell factories” and examines the advantages and limitations of microalgae for the future of biopharmaceutical production. Full article

Microalgae are photosynthetic microorganisms that could be used as potential microbial cell factories by directly converting CO₂ into valuable bioproducts and biofuels. This study aims to improve the production of biofuel from the isolated green alga Chlorella sp., in terms of an increase in its lipid content and its conversion to fatty acid methyl esters (FAMEs) when the cells are grown under the influence of phosphorus (P) limitation and heavy metal addition. The results show that the highest content of lipids, at 68.9%, was achieved within one day under 0% P with a 17 µM cobalt addition. Moreover, supplementation with a low Pb concentration increased cell growth even under P limitation, but under this condition, its lipid content was decreased after seven days of growth. The lipids of Chlorella sp. were transesterified to produce FAMEs. The overall biodiesel properties of the obtained FAMEs were of acceptable quality according to the standards (ASTM and EN). Additionally, the energy conversion from light energy to lipids was shown to be in the range of 10–16% conversion efficiency within seven days. Hence, the physiological modification of Chlorella sp. culture by phosphorus limitation coupled with the addition of a low concentration of heavy metals enabled the improvement of lipid content, with the subsequent transesterification resulting in the production of biodiesel with acceptable quality. Full article