ABSTRACT: Enhanced Fermentation for Lactic Acid Production from Food Waste via Hydrothermal Pretreatment: Performance Evaluation and Metagenomic Analysis
Project description:Highland barley liquor is a distilled spirit made from highland barley on the Tibetan Plateau, but its alcohol yield is limited by the high fiber content of the raw material. In the field of biomass resources, functional microorganisms are commonly used in pretreatment to degrade cellulose and other substances, improving fermentation output. In this study, we isolated the cellulose-degrading probiotic Lactobacillus delbrueckii GR-8 (CMCase 6.21 U/mL) from the traditional vegetable-based fermented food "Jiangshui" and applied biological pretreatment to the fermentation of highland barley liquor. During pretreatment, probiotics enhanced cellulase and amylase activities in the fermented grains, resulting in a 25% reduction in cellulose content and a 112% increase in free reducing sugar content. The pretreatment significantly altered the microbial community structure, enhancing microbial diversity. After distillation, alcohol yield increased by 3.5%, and total acid and ester contents rose by 25% and 23%, respectively. Pyrazine compounds increased by 1290%, while higher alcohols like nonanol, phenylethanol, and hexanol decreased. The treated liquor caused less harm to mice, who showed improved memory, motor skills, and lower oxidative liver damage. This study demonstrates that biological pretreatment enhances both fermentation and the quality of Chinese spirits.
2025-03-04 | GSE290678 | GEO
Project description:Enhanced VFAs production through anaerobic co-fermentation of dewatered sludge and food waste: Insights into performance, microbial dynamics and metabolic pathways
Project description:Background. Transforming waste and non-food materials into bulk biofuels and chemicals represents a major stride in creating a sustainable bioindustry, optimizing the use of resources while reducing environmental footprints. Yet, despite these advancements, the production of high-value natural products often continues to rely on first-generation substrates, underscoring the intricate processes and specific requirements of their biosynthesis. This is also true for Streptomyces lividans, a renowned host organism celebrated for its capacity to produce and uncover a wide array of natural products, attributed to its genetic versatility and potent secondary metabolism. Given this context, it becomes imperative to assess and optimize this microorganism for the synthesis of natural products specifically from waste and non-food substrates. Results. We metabolically engineered S. lividans TK24 to heterologously produce the ribosomally synthesized and post-translationally modified peptide, bottromycin, as well as the polyketide, pamamycin. The modified strains successfully produced these compounds using waste and non-food model substrates like protocatechuate (derived from lignin), 4-hydroxybenzoate (sourced from plastic waste), and mannitol (from seaweed). Comprehensive transcriptomic and metabolomic analyses offered insights into how these substrates influenced the cellular metabolism of S. lividans. When evaluating production efficiency, S. lividans showcased remarkable tolerance, especially in a fed-batch process using a mineral medium containing the toxic aromatic 4-hydroxybenzoate, leading to enhanced and highly selective bottromycin production. Additionally, it generated a unique spectrum of pamamycins when cultured in mannitol-rich seaweed extract without the need for added nutrients. Conclusion. Our study showcases the successful production of high-value natural products using varied waste and non-food raw materials, thereby circumventing the reliance on costly, food-competing resources. S. lividans exhibited remarkable adaptability and resilience across these diverse substrates. When cultured on aromatic compounds, it displayed a distinct array of intracellular CoA esters, presenting promising avenues for polyketide production. Future research could focus on enhancing S. lividans' substrate utilization pathways to more efficiently process the intricate mixtures commonly found in waste and non-food sources.
2023-11-05 | GSE246798 | GEO
Project description:Enhanced pretreatment methodologies and ingredient optimization for the vermicomposting of food waste
Project description:Many food fermentations are carried out by mixed cultures of lactic acid bacteria. Interactions between strains are of key importance for the performance of these fermentations. Yoghurt fermentation by Streptoccus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus (L.bulgaricus) is one of the best-described mixed culture fermentations. These species stimulate each other’s growth by the exchange of metabolites such as folic acid and carbon dioxide. Recently, post-genomic studies have been applied to reveal the global physiological response to mixed culture growth in S. thermophilus, but an in-depth molecular analysis of mixed culture growth of both strains remains to be established. Here we report the application of mixed culture transcriptome profiling and a systematic analysis of candidate interaction compounds on growth, which allowed the unraveling of the molecular responses associated with co-culture growth in batch of S. thermophilus CNRZ1066 and L. bulgaricus ATCC BAA-365 in milk. Comparisons of mono cultures versus mixed cultures, at four time-points in batch fermentation, and comparisons between the four time-points within each fermentation, all in duplicate
Project description:Mining waste streams of food production for bioactive plant polysaccharides that affect the fitness and expressed activities of targeted human gut microbes