Microbial Fermentation Research Articles

HMOs Impact the Gut Microbiome of Children and Adults Starting from Low Predicted Daily Doses.

Recent studies suggest that the dietary intake of human milk oligosaccharides (HMOs) provides health benefits from infancy up to adulthood. Thus far, beneficial changes in the adult gut microbiome have been observed at oral doses of 5-20 g/day of HMOs. Efficacy of lower doses has rarely been tested. We assessed four HMO molecular species-2'Fucosyllactose (2'FL), Lacto-N-neotetraose (LNnT), 3'Sialyllactose (3'SL), and 6'Sialyllactose (6'SL)-at predicted doses from 0.3 to 5 g/day for 6-year-old children and adults (n = 6 each), using ex vivo SIFR® technology (Cryptobiotix, Ghent, Belgium). This technology employing bioreactor fermentation on fecal samples enables us to investigate microbial fermentation products that are intractable in vivo given their rapid absorption/consumption in the human gut. We found that HMOs significantly increased short-chain fatty acids (SCFAs), acetate, propionate (in children/adults), and butyrate (in adults) from predicted doses of 0.3-0.5 g/day onwards, with stronger effects as dosing increased. The fermentation of 6'SL had the greatest effect on propionate, LNnT most strongly increased butyrate, and 2'FL and 3'SL most strongly increased acetate. An untargeted metabolomic analysis revealed that HMOs enhanced immune-related metabolites beyond SCFAs, such as aromatic lactic acids (indole-3-lactic acid/3-phenyllactic acid) and 2-hydroxyisocaproic acid, as well as gut-brain-axis-related metabolites (γ-aminobutyric acid/3-hydroxybutyric acid/acetylcholine) and vitamins. The effects of low doses of HMOs potentially originate from the highly specific stimulation of keystone species belonging to, for example, the Bifidobacteriaceae family, which had already significantly increased at doses of only 0.5 g/day LNnT (adults) and 1 g/day 2'FL (children/adults).

Comparative studies on enzymatic efficacy and microbiological properties of Garbage Enzyme produced from various fruits and vegetables peels in biodegradation of cow dung

The present work was conducted to study the enzymatic potentials and microbiological properties of Garbage Enzyme produced from various fruits and vegetables peels. Completely randomized designed experiment was framed with seven treatments each with fruits and vegetable peels separately. All the treatments exhibited positive result for Amylase Test, Lipase Test, Cellulase Test, Urease Test, Protease Test, MR Test and Alcohol and low pH, indicating that Garbage enzyme produced from fruit and vegetable wastes contained mixture of enzymes, alcohol and acid brought about by microbial fermentation. Highest enzymatic efficacy was shown by T3- Pomegranate followed by T6- Banana. GE produced by vegetable wastes was less effective than fruit peels and maximum enzymatic activity exhibited by T1-Radish. A total of 27 amylase producing bacteria, 27 protease producing bacteria, 26 lipase producing bacteria, 26 cellulase producing bacteria 24 urease producing bacteria, 21 pectinase producing bacteria and 01 Amylase producing fungus was screened isolated from all the treatments. Garbage enzyme treatments in tray assay neutralized the alkaline pH of cow dung as garbage enzyme is acidic in nature. Highest Nitrogen (172 Kg/Hec) content was found when treated with garbage enzyme produced with banana peel. It is concluded that Garbage enzyme contains various enzymes, acid, and alcohol, can be utilized as a low cost alternative to biodegrade wastes to reduce pollution load of our environment. Keywords: Garbage Enzyme, vegetable and fruit wastes, enzyme activity, biodegradation

Engineering of the Lrp/AsnC-type transcriptional regulator DecR as a genetically encoded biosensor for multilevel optimization of L-cysteine biosynthesis pathway in Escherichia coli.

L-cysteine is an important sulfur-containing amino acid being difficult to produce by microbial fermentation. Due to the lack of high-throughput screening methods, existing genetically engineered bacteria have been developed by simply optimizing the expression of L-cysteine-related genes one by one. To overcome this limitation, in this study, a biosensor-based approach for multilevel biosynthetic pathway optimization of L-cysteine from the DecR regulator variant of Escherichia coli was applied. Through protein engineering, we obtained the DecRN29Y/C81E/M90Q/M99E variant-based biosensor with improved specificity and an 8.71-fold increase in dynamic range. Using the developed biosensor, we performed high-throughput screening of the constructed promoter and RBS combination library, and successfully obtained the optimized strain, which resulted in a 6.29-fold increase in L-cysteine production. Molecular dynamics (MD)simulations and electrophoretic mobility shift analysis (EMSA)showed that the N29Y/C81E/M90Q/M99E variant had enhanced induction activity. This enhancement may be due to the increased binding of the variant to DNA in the presence of L-cysteine, which enhances transcriptional activation. Overall, our biosensor-based strategy provides a promising approach for optimizing biosynthetic pathways at multiple levels. The successful implementation of this strategy demonstrates its potential for screening improved recombinant strains.

Postnatal Growth and Development of the Rumen: Integrating Physiological and Molecular Insights.

The rumen plays an essential role in the physiology and production of agriculturally important ruminants such as cattle. Functions of the rumen include fermentation, absorption, metabolism, and protection. Cattle are, however, not born with a functional rumen, and the rumen undergoes considerable changes in size, histology, physiology, and transcriptome from birth to adulthood. In this review, we discuss these changes in detail, the factors that affect these changes, and the potential molecular and cellular mechanisms that mediate these changes. The introduction of solid feed to the rumen is essential for rumen growth and functional development in post-weaning calves. Increasing evidence suggests that solid feed stimulates rumen growth and functional development through butyric acid and other volatile fatty acids (VFAs) produced by microbial fermentation of feed in the rumen and that VFAs stimulate rumen growth and functional development through hormones such as insulin and insulin-like growth factor I (IGF-I) or through direct actions on energy production, chromatin modification, and gene expression. Given the role of the rumen in ruminant physiology and performance, it is important to further study the cellular, molecular, genomic, and epigenomic mechanisms that control rumen growth and development in postnatal ruminants. A better understanding of these mechanisms could lead to the development of novel strategies to enhance the growth and development of the rumen and thereby the productivity and health of cattle and other agriculturally important ruminants.

Sustainable production of heavy metal-binding levan by a subarctic permafrost thaw lake Pseudomonas strain 2ASCA

Pseudomonas strain 2ASCA isolated in subarctic Québec, Canada, produced a cell membrane bound levan-type exopolymer (yield 1.17 g/L), after incubation in growth media containing 6 % sucrose (w/v) at temperature of 15 °C for 96 h. The objective of this study was to optimize levan production by varying the growth parameters. Moreover, the polymer's chemical characterization has been studied with the aim of increasing knowledge and leading to future applications in many fields, including heavy metal remediation. Higher levan yields (7.37 g/L) were reached by setting up microbial fermentation conditions based on the re-use of the molasses obtained from sugar beet processing. Spectroscopy analyses confirmed the levan-type nature of the exopolymer released by strain 2ASCA, consisting of a β-(2,6)-linked fructose repeating unit. Gel permeation chromatography revealed that the polymer has a molecular weight of 13 MDa. Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) showed that the levan sequestered with a strong affinity Cr(III), which has never been previously reported, highlighting an interesting biosorption potential. In addition, SEM analysis revealed the formation of nanoparticles in acidified water solution.

Influence of Fermented Mulberry Leaves as an Alternative Animal Feed Source on Product Performance and Gut Microbiome in Pigs

Mulberry leaves are rich in nutrients but contain anti-nutrient factors that hinder their digestion and absorption. Feeding animals with mulberry leaves directly could harm their health. The microbial fermentation of mulberry leaves could reduce their anti-nutritional factors’ content and improve their nutritional value. Sequencing and analyzing mulberry leaves before and after fermentation showed that fermentation increased the relative abundance of Pediococcus, Bradyrhizobium, Hydrotalea, and Rhodanobacteria, and decreased that of Enterobacter. Fermentation improved the quality of mulberry leaves by rebuilding the bacterial community. Finishing pigs were raised on fermented mulberry leaves (FML), and their carcass performance, meat quality, economic benefits, and gut microbiome were evaluated. FML had no negative impact on pig carcass performance, meat quality, and antioxidant capacity, and could somewhat improve the economic benefits. FML decreased the relative abundance of Proteobacteria in the colon and Streptococcus in the feces, and increased that of Actinobacteria (cecum, colon, feces) and Prevotella (colon). The gut core microorganisms in the FML group were mainly enriched with Actinobacteria, Bifidobacterium, Bifidobacteriaceae, Bifidobacteriales, and other beneficial microorganisms. Dietary FML reduced ammonia, indole, and skatole contents in the feces. In conclusion, FML reshaped the gut microbiota without negatively affecting pig product performance, produced cleaner waste, and improved environmental protection and sustainability, making it an attractive prospective feed for pigs.

Strategies for the efficient biosynthesis of β-carotene through microbial fermentation.

β-Carotene is an orange fat-soluble compound, which has been widely used in fields such as food, medicine and cosmetics owing to its anticancer, antioxidant and cardiovascular disease prevention properties. Currently, natural β-carotene is mainly extracted from plants and algae, which cannot meet the growing market demand, while chemical synthesis of β-carotene cannot satisfy the pursuit for natural products of consumers. The β-carotene production through microbial fermentation has become a promising alternative owing to its high efficiency and environmental friendliness. With the rapid development of synthetic biology and in-depth study on the synthesis pathway of β-carotene, microbial fermentation has shown promising applications in the β-carotene synthesis. Accordingly, this review aims to summarize the research progress and strategies of natural carotenoid producing strain and metabolic engineering strategies in the heterologous synthesis of β-carotene by engineered microorganisms. Moreover, it also summarizes the adoption of inexpensive carbon sources to synthesize β-carotene as well as proposes new strategies that can further improve the β-carotene production.

Desert legumes as sustainable sources of proteins and bioactive peptides: Technological insights into functional food development from underutilized plants

This review explores the trends in consumption of dietary protein from (animal-based sources) and plant-based alternatives, particularly focusing on conventional as well as underutilized desert legumes. Acknowledging the essential role of proteins in cellular homeostasis, this report also underscores the risks associated with prolonged animal protein consumption. The rising popularity of plant-based proteins from legumes and their potential to address the global issue of malnutrition, along with the nutritional significance of legume-based proteins and bioactive peptides, is discussed in detail. Underutilized desert legumes, as sustainable protein sources, have the potential to offer promising health benefits and industrial applications like plant-based cheese and meat production. We have highlighted a few desert legumes- Prosopis cineraria, Cyamopsis tetragonoloba, Acacia senegal, Vigna aconitifolia and their potential to ensure global food security in the face of climate change. The underexplored legumes, often neglected due to limited knowledge about their benefits, hold resilient solutions to the growing demand for high quality protein. The review compares the protein quality of representative legumes, both conventional and overlooked, and highlights the need for the integration of desert legumes into mainstream agriculture and the technological challenges for functional food production. Several advantages of desert legumes are compromised by the presence of anti-nutritional factors (ANFs) in them causing sensory limitations and consumer unacceptability. These problems can be addressed by exploring physical processing techniques, microbial fermentation, and extrusion to eradicate ANFs. Application of novel technologies like 3-D printing and their potential for protein and peptide product development from underutilized desert legumes have also been emphasized.

Metabolic Engineering of Corynebacterium glutamicum for Highly Efficient Production of Ectoine.

Ectoine is a compatible solute that functions as a cell protector from various stresses, protecting cells and stabilizing biomolecules, and is widely used in medicine, cosmetics, and biotechnology. Microbial fermentation has been widely used for the large-scale production of ectoine, and a number of fermentation strategies have been developed to increase the ectoine yield, reduce production costs, and simplify the production process. Here, Corynebacterium glutamicum was engineered for ectoine production by heterologous expression of the ectoine biosynthesis operon ectBAC gene from Halomonas elongata, and a series of genetic modifications were implemented. This included introducing the de3 gene from Escherichia coli BL21 (DE3) to express the T7 promoter, eliminating the lysine transporter protein lysE to limit lysine production, and performing a targeted mutation lysCS301Y on aspartate kinase to alleviate feedback inhibition of lysine. The new engineered strain Ect10 obtained an ectoine titer of 115.87 g/L in an optimized fed-batch fermentation, representing the highest ectoine production level in C. glutamicum and achieving the efficient production of ectoine in a low-salt environment.

Exploring the Intestinal Microbial Community of Lantang Pigs through Metagenome-Assembled Genomes and Carbohydrate Degradation Genes

High-fiber, low-cost agricultural byproducts offer a sustainable alternative for mitigating the competition for crops between humans and livestock. Pigs predominantly utilize dietary fibers through the process of microbial fermentation within the gut. This study explored the gut microbiota and the capacity for carbohydrate degradation in 30 individual Lantang pigs, a breed indigenous to China. Through metagenomic analysis, a total of 671 metagenome-assembled genomes (MAGs) were assembled and assigned into 14 bacterial and 1 archaeal phylum, including 97 species from uncultured microbes. The phylum with the highest abundance were identified as Bacillota_A, Bacteroidota, and Bacillota. Remarkably, the investigation revealed nearly 10,000 genes implicated in the degradation of carbohydrates, with a pronounced prevalence within five principal bacterial genera: Prevotella, Cryptobacteroides, Gemmiger, Vescimonas, and Faecousia. Additionally, 87 distinct types of carbohydrate-degrading enzymes were exclusively identified within the gut microbiota of the Lantang pig. These insights not only enhance our understanding of the microbial diversity specific to native Chinese pig breeds but also augment the body of research regarding porcine fiber degradation capabilities. The implications of this study are twofold: it provides strategic directions for optimizing feed efficiency and reducing breeding costs, and it furnishes an expanded gene pool for the microbial synthesis of industrial enzymes in the future.

Design-build-test of recombinant Bacillus subtilis chassis cell by lifespan engineering for robust bioprocesses

Microbial cell factories utilize renewable raw materials for industrial chemical production, providing a promising path for sustainable development. Bacillus subtilis is widely used in industry for its food safety properties, but challenges remain in the limitations of microbial fermentation. This study proposes a novel strategy based on lifespan engineering to design robust B. subtilis chassis cells to supplement traditional metabolic modification strategies that can alleviate cell autolysis, tolerate toxic substrates, and get a higher mass transfer efficiency. The modified chassis cells could produce high levels of l-glutaminase, and tolerate hydroquinone to produce α-arbutin efficiently. In a 5 L bioreactor, the l-glutaminase enzyme activity of the final strain CRE15TG was increased to 2817.4 ± 21.7 U mL−1, about 1.98-fold compared with that of the wild type. The α-arbutin yield of strain CRE15A was increased to 134.7 g L−1, about 1.34-fold compared with that of the WT. To our knowledge, both of the products in this study performed the highest yields reported so far. The chassis modification strategy described in this study can Improve the utilization efficiency of chassis cells, mitigate the possible adverse effects caused by excessive metabolic modification of engineered strains, and provide a new idea for the future design of microbial cell factories.

Membrane technologies for the separation and purification of functional oligosaccharides: A review

Functional oligosaccharides have numerous health benefits. They hold considerable promise in the food processing and healthcare sectors. However, oligosaccharides derived from microbial fermentation, chemical decomposition, and enzymatic hydrolysis often contain impurities, necessitating further purification to enhance the quality and economic value of the final product. Among various purification techniques, membrane separation stands out owing to its operational simplicity, low energy requirements, and scalability, making it ideal for industrial applications. Recently, this method has increasingly been used to separate and purify functional oligosaccharides. Microfiltration and ultrafiltration membranes are typically used in the early stages of filtration to remove proteins, bacterial contaminants, and particulates. In contrast, nanofiltration membranes offer higher separation precision, making them preferable for the detailed purification, concentration, and classification of functional oligosaccharides. This review article mainly focuses on the applications of nanofiltration membrane technologies in the processing of typical functional oligosaccharides, such as fructooligosaccharides, galactooligosaccharides, and xylooligosaccharides. Recent advancements in nanofiltration are discussed, and the properties of the feed liquid, operational parameters, and challenges related to membrane fouling are analyzed. This review aims to serve as a comprehensive guide for the efficient separation and purification of functional oligosaccharide membranes, and advocates for the broader implementation of membrane technologies in the food and medical industries.

Epiberberine: a potential rumen microbial urease inhibitor to reduce ammonia release screened by targeting UreG

Rumen microbial urease inhibitors have been proposed for regulating nitrogen emission and improving nitrogen utilization efficiency in ruminant livestock industry. However, studies on plant-derived natural inhibitors of rumen microbial urease are limited. Urease accessory protein UreG, plays a crucial role in facilitating urease maturation, is a new target for design of urease inhibitor. The objective of this study was to select the potential effective inhibitor of rumen microbial urease from major protoberberine alkaloids in Rhizoma Coptidis by targeting UreG. Our results showed that berberine chloride and epiberberine exerted superior inhibition potential than other alkaloids based on GTPase activity study of UreG. Berberine chloride inhibition of UreG was mixed type, while inhibition kinetics type of epiberberine was uncompetitive. Furthermore, epiberberine was found to be more effective than berberine chloride in inhibiting the combination of nickel towards UreG and inducing changes in the second structure of UreG. Molecular modeling provided the rational structural basis for the higher inhibition potential of epiberberine, amino acid residues in G1 motif and G3 motif of UreG formed interactions with D ring of berberine chloride, while interacted with A ring and D ring of epiberberine. We further demonstrated the efficacy of epiberberine in the ruminal microbial fermentation with low ammonia release and urea degradation. In conclusion, our study clearly indicates that epiberberine is a promising candidate as a safe and effective inhibitor of rumen microbial urease and provides an optimal strategy and suitable feed additive for regulating nitrogen excretion in ruminants in the future.Key points• Epiberberine is the most effective inhibitor of rumen urease from Rhizoma Coptidis.• Urease accessory protein UreG is an effective target for design of urease inhibitor.• Epiberberine may be used as natural feed additive to reducing NH3 release in ruminants.

Production of Vanillin from Pineapple Peels Using Alkaline Hydrolysis and Microbial Fermentation

Vanillin is one of the most commonly utilized aromatic flavoring chemicals in the food and cosmetics industries. It is derived from natural sources, making it more expensive than synthetic vanillin, and it constitutes less than one percent of the annual market demand. Pineapple peel stands out as a valuable source for extracting ferulic acid, which in turn is utilized in the synthesis of vanillin. As a result, researchers are exploring alternative methods for producing vanillin, such as biotechnological production from ferulic acid. In this study, the capability of pineapple peels as a substrate for the microbial fermentation of ferulic acid by Aspergillus niger to produce vanillin in a single step was investigated. The biotransformation of ferulic acid from pineapple peel by alkaline hydrolysis was optimized using different concentrations of NaOH. Further, the detection and quantification of vanillin and ferulic acid were carried out using High-Performance Liquid Chromatography and thiobarbituric acid (TBA) method. Through HPLC analysis, the amount of vanillin concentration produced from the supernatant culture was 1.47±0.24 µg/ml from 1.0 M NaOH concentration and 2.83±0.44 µg/ml from 2.0 M NaOH concentration. From this study, 57.09±1.84 µg/ml and 83.84±4.01 µg/ml of ferulic acid were produced from the 1.0 M NaOH and 2.0M NaOH, respectively. In addition, using the TBA technique, vanillin concentrations were calculated, resulting in 12.92 ± 0.54 µg/ml and 15.38 ± 0.77 µg/ml from 1.0 M and 2.0 M NaOH concentrations, respectively. Briefly, the pineapple peel has been discovered as a good source for vanillin production using Aspergillus niger in the fermentation method.

Microbiota dynamics preceding bariatric surgery as obesity treatment: a comprehensive review.

The review present data on the intricate relationship between bariatric surgery, gut microbiota, and metabolic health in obesity treatment. Bariatric surgery, is recognized as an effective intervention for managing morbid obesity, including various techniques with distinct mechanisms of action, efficacy, and safety profiles including Roux-en-Y Gastric Bypass (RYGB), Sleeve Gastrectomy (SG), Laparoscopic Adjustable Gastric Banding (LAGB), and Biliopancreatic Diversion (BPD). RYGB and SG are the most prevalent procedures globally, inducing gut microbiota changes that influence microbial diversity and abundance. Post-surgery, alterations in bacterial communities occur, such as the increased of Escherichia coli inversely correlated with fat mass and leptin levels. During digestion, microbiota produce physiologically active compounds like bile acids (Bas) and short-chain fatty acids (SCFAs). SCFAs, derived by microbial fermentation, influence appetite, energy metabolism, and obesity-related pathways. Bas, altered by surgery, modulate glucose metabolism and insulin sensitivity. Furthermore, SG and RYGB enhance incretin secretion, particularly glucagon-like peptide 1 (GLP-1). Therefore, understanding microbiota changes after bariatric surgery could be crucial for predicting metabolic outcomes and developing targeted interventions for obesity management.

Structural characterization of a novel polysaccharide from Tremella fuciformis and its interaction with gut microbiota.

Because of their diverse biological activities, polysaccharides derived from Tremella fuciformis have received growing attention. This study aimed to investigate the structural characterization of a purified polysaccharide (designated as PTP-3a) derived from T. fuciformis and explore its interaction with gut microbiota in vitro. The findings revealed that PTP-3a had a molecular weight of 1.22 × 103 kDa and consisted of fucose, glucose, xylose, mannose and glucuronic acid in a molar ratio of 0.271:0.016:0.275:0.400:0.038. The primary linkage types identified in PTP-3a were 1,3-linked-manp, 1,4-linked-xylp and 1,2,3-linked-fucp, with corresponding ratios of 0.215:0.161:0.15. In addition, PTP-3a demonstrated notable thermal stability and exhibited a triple-helical structure. Moreover, following in vitro fermentation for 48 h, PTP-3a was efficiently utilized, resulting in a reduction in carbohydrate levels, the production of short-chain fatty acids (SCFAs) and pH adjustment. Furthermore, during in vitro fecal microbial fermentation, PTP-3a decreased the relative abundance of Firmicutes while increasing the proportions of Bacteroidetes and Proteobacteria, resulting in a significantly reduced Firmicutes/Bacteroidetes ratio. Additionally, PTP-3a stimulated the growth of beneficial bacteria such as Parabacteroides merdae, Gordonibacter pamelaeae, Bifidobacterium pseudolongum and Parabacteroides distasonis. Importantly, a strong correlation was observed between the production of SCFAs and specific microorganisms. These findings suggested that PTP-3a has potential as a prebiotic for modulating the gut microbiota. © 2024 Society of Chemical Industry.

Biomanufacturing for a Sustainable Future: Unleashing the Potential of Biotechnology in Pharmaceutical Raw Material Production

The pharmaceutical industry relies heavily on raw materials for drug development, with Active Pharmaceutical Ingredients (APIs) and excipients forming the fundamental components of pharmaceutical formulations. Traditional methods of pharmaceutical raw material production are plagued by inefficiencies, environmental concerns, and limitations in producing complex molecules. In contrast, biotechnology offers a promising alternative with its capacity for efficient, sustainable, and precise synthesis of pharmaceutical raw materials. This article explores the potential of biotechnology in pharmaceutical raw material production, focusing on techniques such as recombinant DNA technology, microbial fermentation, biocatalysis, and cell culture technology. These methods enable the production of complex molecules with high specificity, purity, and scalability, addressing the shortcomings of traditional approaches. Furthermore, biotechnology facilitates the development of novel drugs, personalized medicine strategies, and innovative treatments, offering hope for previously untreatable conditions. Despite the transformative potential of biotechnology, challenges such as high initial investment, regulatory considerations, and safety concerns need to be addressed for its widespread adoption. In conclusion, embracing biotechnology represents a paradigm shift in pharmaceutical production, promising a more sustainable, personalized, and effective healthcare future. Collaboration between stakeholders is essential to navigate challenges and ensure the responsible advancement of biotechnological applications in healthcare, ultimately improving the quality of life for millions worldwide

Production of vitamin B12 via microbial strains isolated from marine and food sources in Egypt

Background Vitamin B12 is a very important water-soluble vitamin, which was first isolated from the liver as an anti-pernicious anemia factor. The sole source of vitamin B12 is the animal-based food. It has a complicated structure and requires expensive multi-steps to be synthesized chemically. Intriguingly, vitamin B12 can be produced through microbial fermentation by microorganisms in a cheap and more effective manner. Objective This study aims to isolate and characterize microorganisms that have the capability to produce vitamin B12. In addition, the current work aims to optimize the vitamin B12 production conditions by isolating strains using suitable waste materials to obtain a high vitamin B12 yield. Materials and methods Different bacterial and yeast isolates were isolated from marine and food samples using the pour-plate technique. These isolates were screened for vitamin B12 production using a specific growth medium that lacked vitamin B12 and a test indicator bacterium. The content of vitamin B12 was estimated using spectrophotometer measurement and high-performance liquid chromatography (HPLC). The isolates that showed high vitamin B12 productivity were identified using MALDI-TOF technique. The identified strains were implemented for the optimization of vitamin B12 production to reveal the most proper and optimum conditions for the production. Response surface methodology (RSM) was employed to enhance the production of vitamin B12 in a flask scale. Agro-industrial wastes such as molasses were used for vitamin B12 production using the most optimum conditions as determined by RSM. Results and conclusion Eighty-seven actinomycetes, bacterial, and yeast isolates were screened for vitamin B12 production. Out of these isolates, 15 showed high vitamin B12 productivity. We found that bacilli and yeast isolates were the most productive among the tested cocci and actinomycetes isolates. The highly productive Bacillus and yeast isolates were identified using the MALDI-TOF analysis. The isolates were identified as Candida pelliculosa, Geotrichum candidum, Bacillus subtilis and Bacillus sp. One strain of Candida pelliculosa (coded BYI), three strains of Geotrichum candidum (coded as MZYC, MZYD, and MZYG) were selected for studying the effect of sugar type and inoculum size on the yield of vitamin B12 production. Strain MZYD was selected for the statistical modelling using RSM to optimize seven factors for the vitamin B12 production. These factors included temperature, fermentation time, salt concentration, pH, sugar concentration, inoculum size, and aeration. Five factors i.e., temperature, pH, sugar concentration, and inoculum size were shown to significantly improve the vitamin B12 production. A maximum yield of 64.21 μg/100 ml was obtained using the optimized RSM conditions. These optimized conditions were used to produce vitamin B12 using molasses as a raw material for the microbial growth.

Liquid Organic Fertilizer Produced from Innards Waste of Catfish (Pangasius djambal) by Using Fermentative Microbes (EM4) and Molasses

Liquid organic fertilizer is a liquid fertilizer yielded from the decomposition of organic materials derived from varied wastes which contain more than one nutrient element. The study was aimed to determine the quality of liquid organic fertilizer made from catfish innards waste by adding fermentative microbes (EM4) and molasses. The research method used was experimental with different formulation consisting of 0% EM4 + 30% molasses (K1), 30% EM4 + 0% molasses (K2), 20% EM4 + 20% molasses (P1), 30% EM4 + 30% molasses (P2), and 40% EM4 + 40% molasses (P3). The percentage is calculated from the total weight of all raw materials used. Parameters measured include yield, pH, total lactic acid bacteria (LAB), Nitrogen, Phosphorus, and Potassium. The results showed that the best value for yield was shown in K2 at 34.73%, the pH value in P3 at 5.10, total amount of LAB in P3 at 2.104 cfu/g, the value of Nitrogen (N) in P3 at 4.30%, the value of Phosphorus (P2O5) in P3 at 0.41%, and the value of Potassium (K2O) in P3 at 3.11 ppm. It is possible to increase the content of phosphorus and potassium by adding with EM4 and molasses more than 40% each.

Diet and well-being of 1st year Medical Interns during hospital placement

Hospital placement is essential training for medical interns, involving shift work and high-pressure environments. This can increase physiological and psychological stress, which may be mediated by metabolites of microbial digestion(1). Nutrients of interest include those accessible to microbial digestion and associated with altered signalling within the microbiota-gut-brain axis (MGBA)(1). Fibre is fermented by gut microbes to produce short-chain fatty acids(2) and is associated with improved psychological outcomes(3). Tryptophan, a precursor to gut-derived serotonin(2), has been negatively associated with anxiety(4). Processed foods contain food additives, excess sugars, and saturated fats that may disrupt gut homeostasis(1) and impact psychological well-being(4). Lastly, total energy intake may determine the level of substrate available for microbial fermentation(2). Therefore, this research explores how microbiota-accessible food components interact with physical and psychological well-being in a cohort of medical interns undertaking their first-year of hospital placement. Participants were healthy medical interns, during first-year hospital placement (n = 21) from the Hunter New England Local Health District, NSW, Australia. Participants completed diet and wellbeing surveys at baseline and every 2 months over a 10-month period. 24-hour diet diaries were self-recorded from participants using a mobile application (Easy Diet Diary) and analysed using AusNut and the NOVA classification system of ultra-processed foods (ULP). Wellbeing surveys include depression, anxiety, stress scale (DASS), and PROMIS survey for mental (M), physical (P), and sleep well-being. Current data represents an ‘in-progress’ of the longitudinal data collection. This study utilised Spearman correlation and Tukey’s post hoc test for mixed methods analysis. From baseline to timepoint 3 (T3, 4 months) daily energy intake was consistent with cohort estimated energy requirements (EER). However, consumption ranged from 37% to 167% of EER, indicating a large variation of intakes. Energy consumed from ULP ranged from 30% to 34% (p = 0.6875). Baseline tryptophan intake (x¯ = 1139mg) was within the suggested target, whilst fibre intake (x¯ = 23g) was below the recommended intake. Neither saw significant changes from baseline to T3. Fibre intake was positively correlated with mental and physical well-being at baseline (x¯ = 23.1g, M: r = 0.474, p = 0.04, P: r = 0.608, p = 0.007), and timepoint 2 (x¯ = 31.5g, M: r = 0.647,p = 0.026, P: r = 0.780, p = 0.004) but not at T3. In addition, baseline consumption of sugar (x¯ = 18g) and poly-unsaturated fats (x¯ = 15g) were both negatively correlated with mental and physical well-being. Overall, no significant dietary changes were evident from baseline to mid-year collection in a first-year medical intern cohort during hospital placements. Fibre was significantly associated with mental and physical well-being, building on current understanding of fibre’s role in the MGBA. Planned metabolite analysis will explore the mechanisms of proposed microbiome-accessible nutrients alongside diet, well-being, and microbiota data. Findings from this study will identify how diet-microbiome interactions change under stress, with wider positive implications on intense workplace environments with the aim to preserve individual wellbeing.