Microbial Source Research Articles

Discovery and Molecular Characterization of a Novel 9S-Lipoxygenase from Enhygromyxa salina for Fatty Acid Biotransformations.

Iron-dependent lipoxygenases (LOXs) are involved in the synthesis of oxylipins from polyunsaturated fatty acids. However, they are usually difficult to overexpress in functional form in microbial cell factories. Moreover, 9-LOXs, generating 9-hydroperoxy fatty acids from C18 polyunsaturated fatty acids, have rarely been found from microbial sources. Here, we discovered a novel 9S-LOX in the marine myxobacterium Enhygromyxa salina (Es-9S-LOX). The recombinant enzyme produced in Escherichia coli exhibited remarkable activity in the dioxygenation of linoleic acid (LA, 1), α-linolenic acid, γ-linolenic acid, and arachidonic acid specifically at the C9 position to yield the product with (S)-configuration at catalytic efficiency of 3.94, 1.42, 1.38, and 0.69 μM-1·s-1, respectively. The elucidated X-ray crystal structure of Es-9S-LOX reveals a long and narrow hydrophobic pocket that allows the substrate to be near the metal ion and the oxygen tunnel. The enzyme was successfully used in a chemoenzymatic reaction to generate a hydroxy fatty acid from LA. Our study thus contributes to the valorization of renewable polyunsaturated fatty acids into a variety of fatty acid derivatives, including hydroxy fatty acids.

Biocontrol potential of Botrytis fabiopsis against the weeds of agricultural fields in the Qing-Tibetan Plateau.

In screening biocontrol strains with broad-spectrum and high-efficiency herbicidal activities, a strain with strong pathogenicity, HY-021, was isolated from the leaves of Rumex acetosa, which was identified as Botrytis fabiopsis based on morphology and molecular biology. The herbicidal activities of the fermentation filtrate of strain HY-021 against nine weeds, including Chenopodium album L., Elsholtzia densa Benth., Malva verticillata L. var. Crispa, Polygonum lapathifolium L., Amaranthus retroflexus L., Avena fatua L., Thlaspi arvense L., Polygonum aviculare L., and Galium spurium L., were determined in vitro and in vivo. The results showed that the pathogenicity of strain HY-021 to the different weeds in vitro was as follows: E. densa > A. retroflexus > P. aviculare > P. lapathifolium > M. verticillata > T. arvense > G. spurium > A. fatua > C. album. Seven days after inoculation with the HY-021 strain, the incidences in nine weeds were in the range of 32.9-87.23%, and the disease index values of the nine weeds were 41.73-94.57%. The pathogenic effects from high to low were A. retroflexus > E. densa > A. fatua > G. spurium > C. album > M. verticillata > T. arvense > P. aviculare > P. lapathifolium. The crop safety test showed that the biocontrol strain HY-021 was safe to V. faba, P. sativum, H. vulgare, and T. aestivum, but had a slight effect on B. napus. Scanning electron microscopy showed that the mycelium of strain HY-021 invaded the tissue through the stomata of C. album leaves, parasitized and reproduced in the tissue, and gradually destroyed the tissue. The results of this study provide a basis for the development and utilization of new and efficient microbial source herbicides.

Identifying potential introduced and natural sources of pollution in Delaware watersheds.

Managing water quality with microbial impairment caused by Enterococcus poses unique challenges regarding the determination of fecal host origin. Most water monitoring is performed based on Enterococcus counts that neither detect the location of the introduction of pollution nor identify the type of contaminating Enterococcus. The use of sequenced-based microbial source tracking could allow for identification of fecal origin and potential remediation of pollution. The state of Delaware has numerous waterways with high microbial impairment from unknown sources, so we used sequence-based microbial source tracking to investigate potential microbial pollution in three watersheds with significant variation in land use and population density. In this study, we use a 16S rRNA sequence reference library of microbial communities from relevant fecal sources (wild animal, domestic animal, sediment, and septic/wastewater) to determine the most likely sources of microbial impairment in three Delaware watersheds. This study assigned sources of microbial contamination to mostly human-related sources (septic and wastewater) or unknown sources indicating that waste infrastructure may have a larger influence on microbial community structure in Delaware watersheds than previously considered. Our results suggest that long-term source tracking is valuable for ruling out native or domesticated animals as contributors to water pollution.IMPORTANCETraditional microbial pollution monitoring utilizes specific fecal indicator bacteria that need to grow in the laboratory for detection. Here, we show the use of sequence information from whole microbial communities and an expanded reference library in microbial source tracking. Expanding the host detection range by including the whole microbial community may allow for a wider range of potential fecal origin identification even when specific fecal indicators are absent or in low concentration. We show that many Delaware waterways bear the signature of human influence compared to natural sources. In addition, the robust reference library built in this study can be used to conduct source tracking studies in the mid-Atlantic USA.

Exploring newly isolated thermotolerant, halotolerant and antimicrobial resistant Bacillus subtilis ProNTL1 from tannery waste and its alkaline protease production.

A hydrolytic enzyme called protease from microbial sources has expansive applications in leather as well as tannery industries and thus leaves no choice but to discover a potential candidate for efficient yield of protease with eccentric characteristics. In the current study, using skim milk agar medium, three bacterial strains (Pro SS14, Pro NTL1, Pro SM) were identified for protease production out of thirty tannery waste samples. The bacterial isolates were identified through morphological, biochemical and molecular basis and the highest protease producer (134U/mL) having the paramount protein content (8.75%) with the greatest biomass (absorbance 1.7 at 600nm) was further bioinformatically identified as Bacillus subtilis Pro NTL1. Moreover, the cultural conditions-pH, temperature, incubation period and salinity were tested to get the optimized condition for the three isolates where Bacillus subtilis Pro NTL1 gave best growth at pH 9 demonstrating alkaline protease producing capability, at 45°C for 72h proving its thermotolerance characteristics and at 3% NaCl concentration declaring its halotolerance property. Furthermore, following Kirby-Bauer agar disc diffusion technique, the antimicrobialsusceptibility pattern was investigated showing Bacillus subtilis Pro NTL1 was resistant to ampicillin, penicillin, sulfafurazole and sensitive to amoxicillin, gentamycin, cefotaxime, kanamycin, imipenem, tetracycline. Additionally, Bacillus subtilis Pro NTL1 showed antagonistic activity against three pathogens named Bacillus cereus, Bacillus megaterium and Escherichia coli. Thus, these findings suggest that Bacillus subtilis Pro NTL1 is a newly isolated strain with unique features which might help to contribute in several biotechnological purposes with significant industrial benefits.

Nourishing Aquatic Life: A Comprehensive Reviewing of Fish Feed Strategies and Disease Combat in Aquaculture

With an increasing focus on creating sustainable methods that satisfy the nutritional requirements of aquatic life while successfully containing disease outbreaks, aquaculture has emerged as a crucial element of global food security. Nourishing Aquatic Life: A Comprehensive Review of Fish Feed Strategies and Disease Combat in Aquaculture explores the delicate balance between disease management and feed optimization, two crucial factors influencing the ecological sustainability and productivity of aquaculture systems. Innovative substitutes, including plant-based proteins, insect meal, and microbial sources, are being assessed alongside conventional fish feed formulations, which rely on fishmeal and fish oil to lessen environmental stresses while preserving high nutritional value. This article also covers how probiotics, prebiotics, and immunostimulants can improve fish immunity and resilience against common diseases, lowering the need for antibiotics and the likelihood of resistance. Additionally, we look at the most recent developments in fish feed formulation using biofloc, genetic engineering, and nanotechnology, emphasizing their implications for better fish health and disease resistance. These innovative strategies offer a hopeful vision for the future of aquaculture, inspiring us to continue our efforts in this field.

Nanobiopolymers in cancer therapeutics: advancing targeted drug delivery through sustainable and controlled release mechanisms.

Nanobiopolymers have emerged as a transformative frontier in cancer treatment, leveraging nanotechnology to transform drug delivery. This review provides a comprehensive exploration of the multifaceted landscape of nano-based biopolymers, emphasizing their diverse sources, synthesis methods, and classifications. Natural, synthetic, and microbial nanobiopolymers are scrutinized, along with elucidation of their underlying mechanisms and impact on cancer drug delivery; the latest findings on their deployment as targeted drug delivery agents for cancer treatment are discussed. A detailed analysis of nanobiopolymer sources, including polysaccharides, peptides, and nucleic acids, highlights critical attributes like biodegradability, renewability, and sustainability essential for therapeutic applications. The classification of nanobiopolymers based on their origin and differentiation among natural, synthetic, and microbial sources are thoroughly examined for inherent advantages, challenges, and suitability for cancer therapeutics. The importance of targeted drug release at tumour sites, crucial for minimizing adverse effects on normal tissues, is discussed, encompassing various mechanisms. The role of polymer membrane coatings as a pivotal barrier for facilitating controlled drug release through diffusion is elucidated, providing further insight into efficient methods for cancer treatment and thus consolidating the current knowledge base for researchers and practitioners in the field of nanobiopolymers and cancer therapeutics.

Recent advances in microbially derived chlorinated antiparasitic compounds.

Parasitic diseases remain a significant global health challenge, especially in developing countries, contributing to approximately one million deaths annually. Notably, among the 143 FDA-approved antiparasitic drugs, thirty-four possess chlorine in their chemical structure, highlighting the importance of chlorine substitution. This underscores the significance of chlorine atoms in elucidating structure-activity relationships crucial for drug discovery, aiming to develop safer, more selective, and environmentally friendly molecules with enhanced efficacy. Of particular interest some are naturally occurring chlorinated metabolites derived from PKS, NRPS, and PKS-NRPS biosynthetic pathways, which offer the potential for further manipulation. However, there is limited literature on antiparasitic chlorinated compounds from microbial sources. To address this, we conducted a comprehensive literature survey from 1963 to the present, identifying 28 chlorinated compounds with confirmed antiparasitic properties. This review underscores the potential of enzymatic machinery for selective chlorine substitution, offering insights for biochemists and synthetic chemists to develop versatile chlorinated compounds through synthetic biology, combinatorial chemistry, and organic synthesis.

Fusarium verticillioides pigment: production, response surface optimization, gamma irradiation and encapsulation studies

BackgroundNatural pigments are becoming more significant because of the rising cost of raw materials, pollution, and the complexity of synthetic pigments. Compared to synthetic pigments, natural pigments exhibit antimicrobial properties and is less allergic. Pigments from microbial sources could easily be obtained in an inexpensive culture media, produced in high yields, and microbes are capable of producing different colored pigments. Searching for new sources for natural pigments to replace synthetic ones in food applications has become an urgent necessity, but the instability of these compounds is sometimes considered one of the obstacles that reduce their application. Encapsulation provides an ideal solution for natural dye protection through a controlled release strategy. Thus, this study aims at isolation of several soil fungi and subsequent screening their pigment production ability. The chosen pigment-producing fungal strain underwent full identification. The produced pigment was extracted with ethyl acetate and estimated spectrophotometrically. As there is a necessity to obtain a high pigment yield for efficient industrial application, the best production medium was tested, optimum conditions for maximum dye production were also investigated through the response surface methodology, and gamma irradiation was also employed to enhance the fungal productivity. Encapsulation of the produced pigment into chitosan microsphere was tested. The pigment release under different pH conditions was also investigated.ResultsA new strain, Fusarium verticillioides AUMC 15934 was chosen and identified for a violet pigment production process. Out of four different media studied, the tested strain grew well on potato dextrose broth medium. Optimum conditions are initial medium pH 8, 25 °C-incubation temperature, and for 15-day incubation period under shaking state. Moreover, a 400 Gy irradiation dose enhanced the pigment production. Chitosan microsphere loaded by the pigment was successfully prepared and characterized by infrared spectroscopy and scanning electron microscopy.ConclusionThis irradiated Fusarium strain provides a more economically favorable source for production of a natural violet dye with an optimum productivity, enhanced yield, and improved properties (such as, enhanced stability, controlled release, and bioaccessibility) by encapsulation with chitosan for efficient application in food industry.

Unprecedented N2O production by nitrate-ammonifying Geobacteraceae with distinctive N2O isotopocule signatures.

Dissimilatory nitrate reduction to ammonium (DNRA), driven by nitrate-ammonifying bacteria, is an increasingly appreciated nitrogen-cycling pathway in terrestrial ecosystems. This process reportedly generates nitrous oxide (N2O), a strong greenhouse gas with ozone-depleting effects. However, it remains poorly understood how N2O is produced by environmental nitrate-ammonifiers and how to identify DNRA-derived N2O. In this study, we characterize two novel enzymatic pathways responsible for N2O production in Geobacteraceae strains, which are predominant nitrate-ammonifying bacteria in paddy soils. The first pathway involves a membrane-bound nitrate reductase (Nar) and a hybrid cluster protein complex (Hcp-Hcr) that catalyzes the conversion of NO2- to NO and subsequently to N2O. The second pathway is observed in Nar-deficient bacteria, where the nitrite reductase (NrfA) generates NO, which is then reduced to N2O by Hcp-Hcr. These enzyme combinations are prevalent across the domain Bacteria. Moreover, we observe distinctive isotopocule signatures of DNRA-derived N2O from other established N2O production pathways, especially through the highest 15N-site preference (SP) values (43.0‰-49.9‰) reported so far, indicating a robust means for N2O source partitioning. Our findings demonstrate two novel N2O production pathways in DNRA that can be isotopically distinguished from other pathways.IMPORTANCEStimulation of DNRA is a promising strategy to improve fertilizer efficiency and reduce N2O emission in agriculture soils. This process converts water-leachable NO3- and NO2- into soil-adsorbable NH4+, thereby alleviating nitrogen loss and N2O emission resulting from denitrification. However, several studies have noted that DNRA can also be a source of N2O, contributing to global warming. This contribution is often masked by other N2O generation processes, leading to a limited understanding of DNRA as an N2O source. Our study reveals two widespread yet overlooked N2O production pathways in Geobacteraceae, the predominant DNRA bacteria in paddy soils, along with their distinctive isotopocule signatures. These findings offer novel insights into the role of the DNRA bacteria in N2O production and underscore the significance of N2O isotopocule signatures in microbial N2O source tracking.

Effects of plastic film mulching on soil microbial carbon metabolic activity and functional diversity at different maize growth stages in cool, semi-arid regions.

Plastic film mulching has been widely used to enhance soil hydrothermal conditions and increase crop yields in cool, semi-arid areas. However, its impact on soil microbial carbon metabolic activity and functional diversity during plant growth remains unclear despite their important roles in nutrient cycling and soil quality evaluation. This study used the Biolog EcoPlate technique to investigate the dynamics and driving factors of soil microbial carbon metabolic activity and functional diversity at different maize growth stages following plastic film mulching. The results revealed that film mulching significantly increased microbial carbon metabolic activities [represented by average well color development (AWCD)] by 300% at the seedling stage and by 26.8% at maturity but decreased it by 47.4% at the flowering stage compared to the control (without mulching). A similar trend was observed for the microbial functional diversity index. Redundancy analysis identified soil moisture (SM), soil temperature (ST), dissolved organic carbon (DOC), microbial biomass carbon (MBC), and bacteria amounts as the primary factors influencing changes in soil microbial carbon source utilization. The mulch treatment significantly increased SM at all growth stages, while its warming effect disappeared at the flowering stage. Soil DOC, MBC, and bacterial populations were notably higher under mulching at the seedling and maturity stages but lower at the flowering stage. Pearson correlation analysis showed that changes in SM, ST, DOC, MBC, and bacterial populations positively correlated with the utilization of all carbon source classes, AWCD, and functional diversity indexes after film mulching. Furthermore, maize grain yield and water use efficiency increased by 142 and 129%, respectively, following film mulching. In conclusion, plastic film mulching enhanced soil microbial carbon metabolic activity and functional diversity at the seedling and maturity stages, improving crop yields in cool, semi-arid areas. Furthermore, the decrease in soil carbon metabolic capacity at flowering stage highlights that supplementing soil carbon sources should be considered after continuous film mulching to sustain or enhance farmland productivity and soil quality.

Regulation mechanisms of allergenic epitope sites in casein by microbial and plant-derived proteases

Casein (CN) is the primary factor leading to allergic reactions in infants to bovine milk, severely limiting the intake of bovine milk formula by allergic infants. This study investigates the conformational changes and regulation of linear epitopes during the hydrolysis of CN by five proteases derived from microbial and plant sources using multiple spectroscopic techniques combined with LC/MS-MS. The results showed that the IgE inhibition rates for SD (subtilisin hydrolysate), PD (papain hydrolysate), BD (bromelain hydrolysate), KD (proteinase K hydrolysate), and FD (ficin hydrolysate) were 43.19%, 41.99%, 35.45%, 48.15%, and 14.80%, respectively. The differences in antigenic residues remaining after hydrolysis by different proteases mainly result from the varying degrees of structural alteration of CN and the hydrolysis allergic epitope regions. This study provides theoretical basis for understanding the mechanism by which proteases reduce the allergenicity of CN. It also offers new insights into the development of multienzyme combinatorial hydrolysis strategies.

Microbial source tracking to address of bacterial contamination in recreational waters

Abstract Background Beach closures in the USA are determined by fecal indicator bacteria thresholds, which are insufficient to identify causes of contamination. We use microbial source tracking (MST) to identify the species source of bacteria entering chronically impaired waters. We find canine bacteria is the primary source of high E.coli levels and demonstrate the power of MST for direction of remediation efforts. Methods This environmental sampling study was performed in Short Beach, Branford, Connecticut, USA. Water samples were collected from outfalls under wet and dry precipitation conditions by 10 Citizen Scientist volunteers. The highest E.coli samples were analyzed for avian, human, and canine markers using MST. Results E.coli from 103 samples was tested from April-October 2023. Pearson’s r between average site E.coli and same day precipitation was 0.71 (p-value = 0.006). Among the high E.coli samples, 19 (76%) were low/non detectable, 5 (20%) were moderate, and 1 (4%) were high for human tracers; 10 (50%) were low/non detectable and 10 (50%) were moderate for avian tracers, and 3 (15%) were low/non detectable, 11 (55%) were moderate, and 6 (30%) were high for canine tracers. Conclusions Precipitation is a driver of elevated bacteria levels. Canine bacteria is likely the primary source of elevated bacterial levels in beach waters, while avian contributors are of moderate concern and human contributors are of low concern. As a result, an education campaign and watertight waste receptacles, rather than costly sewer line replacements, are being deployed to improve beach quality. Key messages • Use of microbial source tracking found canine bacteria is the likely driver of elevated E.coli levels in local beaches, initiating a community education campaign rather than costly sewer replacements. • Microbial source tracking technology offers a powerful public health tool for identifying causes of bacterial contamination in chronically impaired recreational waters.

Polyphenol rewiring of the microbiome reduces methane emissions.

Methane mitigation is regarded as a critical strategy to combat the scale of global warming. Currently, about 40% of methane emissions originate from microbial sources, which is causing strategies to suppress methanogens, either through direct toxic effects or by diverting their substrates and energy, to gain traction. Problematically, current microbial methane mitigation knowledge derives from rumen studies and lacks detailed microbiome-centered insights, limiting translation across ecosystems. Here we utilize genome-resolved metatranscriptomes and metabolomes to assess the impact of a proposed methane inhibitor, catechin, on greenhouse gas emissions for high-methane-emitting peatlands. In microcosms, catechin drastically reduced methane emissions by 72-84% compared to controls. Longitudinal sampling allowed for reconstruction of a novel catechin degradation pathway involving Actinomycetota and Clostridium, which break down catechin into smaller phenolic compounds within the first 21 days, followed by degradation of phenolic compounds by Pseudomonas_E from days 21 to 35. These genomes also co-expressed hydrogen-uptake genes, suggesting that hydrogenases may act as a hydrogen sink during catechin degradation, depriving methanogens of substrates. This was supported by decreased gene expression in hydrogenotrophic and hydrogen-dependent methylotrophic methanogens under catechin treatment. We also saw reduced gene expression from genomes inferred to be functioning syntrophically with hydrogen-utilizing methanogens. We propose that catechin metabolic redirection effectively starves hydrogen-utilizing methanogens, offering a potent avenue for curbing methane emissions across diverse environments including ruminants, landfills, and constructed or managed wetlands.

Maternal gastrointestinal microbiome shapes gut microbial function and resistome of newborns in a cow-to-calf model

BackgroundThe maternal gut microbiome is the direct and important source of early colonization and development of the neonatal gut microbiome. However, differences in unique and shared features between mothers with different physiological phenotypes and their newborns still lack exhaustive investigation. Here, using a cow-to-calf model, a comprehensive investigation was conducted to elucidate the pattern and characterization of microbial transfer from the maternal source to the offspring.ResultsThe microbiota in the rumen and feces of dairy cows were divided into two clusters via enterotype analysis. The cows from the enterotype distinguished by Prevotella in the rumen had better production performance, whereas no difference was observed in the cows classified by feces enterotype. Furthermore, through a pairwise combination of fecal and ruminal enterotypes, we screened a group of dairy cows with excellent phenotypes. The gastrointestinal microbiomes of cows with different phenotypes and their offspring differed significantly. The rumen was a more important microbial source for meconium than feces. Transmission of beneficial bacteria from mother to offspring was observed. Additionally, the meconium inherits advantageous metabolic functions of the rumen. The resistome features of the rumen, feces, and meconium were consistent, and resistome abundance from cows to calves showed an expanding trend. The interaction between antibiotic-resistance genes and mobile genetic elements from the rumen to meconium was the most remarkable. The diversity of core metabolites from cows to calves was stable and not affected by differences in phenotypes. However, the abundance of specific metabolites varied greatly.ConclusionsOur study demonstrates the microbial taxa, metabolic function, and resistome characteristics of maternal and neonatal microbiomes, and reveals the potential vertical transmission of the microbiome from a cow-to-calf model. These findings provide new insights into the transgenerational transmission pattern of the microbiome.2cueHjjtpyRzwmAWUdZ5oAVideo

The Microbial Sources of Bioactive Compounds: Potential Anticancer Therapeutic Options

Chemotherapy and other traditional anticancer treatments are losing their efficacy in the battle against cancer. As a result, cancer treatment strategies must be continually adjusted to meet the rising demand for alternative medicines. Several viral and non-viral vectors have been used previously. However, it has been shown that microorganisms are a strong contender for successfully combating cancer. They are a remarkable source of toxins, polysaccharides, tumor-specific anticancer genes, nanodrugs and gene-delivery vectors. One of the emerging key players in cancer therapy is bacteria. It has been demonstrated that traditional methods of altering the microbiome, such as antibiotics, probiotics and microbiota transplants, can sometimes increase the effectiveness of cancer therapies. However, problems with these methods, such as consistency and collateral damage to the commensal microbiota, spur the development of new technologies specifically aimed at the microbiome-cancer interface. In light of nanotechnology’s success in transforming cancer diagnostics and treatment, nanotechnologies with the capacity to control interactions that occur across microscopic and molecular length scales in the microbiome and the tumor microenvironment have the potential to provide innovative methods for cancer treatment. The relationship between nanotechnology, the microbiome and cancer offers tremendous potential. This paper highlights the contributions of significant bacterial groups to several anticancer research fields.

Fulvic Acid Enhances Nitrogen Fixation and Retention in Paddy Soils through Microbial-Coupled Carbon and Nitrogen Cycling.

Fulvic acid, the most soluble and active humic substance, is widely used as an agent to remediate contaminated soils and improve soil fertility. However, the influence of fulvic acid (FA), as a microbial carbon source, on carbon and nitrogen cycles in paddy soils remains elusive. Therefore, to investigate it, an incubation experiment was conducted. Gas analyses indicated that the carbon dioxide and methane emissions were enhanced in FA treatment, which increased up to 94.08-fold and 5.06-fold, respectively. 15N-labeling experiments revealed that nitrogen fixation capability was promoted (1.2-fold) to reduce the carbon and nitrogen imbalance due to fulvic acid amendment. Metagenomic analysis further revealed that gene abundances of degradation of lignin-like compounds, gallate degradation, methanogenesis, nitrogen fixation, and urea hydrolysis increased, while the bacterial ammonia oxidation and anaerobic ammonium oxidation decreased, caused by FA application. Metabolic reconstruction of metagenome-assembled genomes revealed that Azospirillaceae, Methanosarcinaceae, and Bathyarchaeota, with higher abundance in FA treatment, were the key microorganisms to maintain the carbon and nitrogen balance. The metabolic pathways of fulvic acid degradation and coupled nitrogen fixation and retention were constructed. Collectively, our results provided novel insights into the theoretical basis of the use of humic substances for reducing nitrogen fertilization and climate change.

Upgrading Isoquercitrin Concentration via Submerge Fermentation of Mulberry Fruit Extract with Edible Probiotics to Suppress Gene Targets for Controlling Kidney Cancer and Inflammation.

In recent years, kidney cancer has become one of the most serious medical issues. Kidney cancer is treated with a variety of active compounds that trigger genes that cause cancer. We identified in our earlier research that isoquercitrin (IQ) can activate PIK3CA, IGF1R, and PTGS2. However, it has a very low bioavailability because of its lower solubility in water. So, we utilized sub-merge fermentation technology with two well-known probiotics, Lactobacillus acidophilus and Bacillus subtilis, as a microbial source and mulberry fruit extract as a substrate, which has a high IQ level to improve IQ yield. Furthermore, we compared the total phenolic, flavonoid, and antioxidant contents of fermented and non-fermented samples, and we found that the fermented samples had greater levels than non-fermented sample. In addition, the high-performance liquid chromatography (HPLC) results showed that the fermented mulberry fruit extract from B. subtilis and L. acidophilus showed higher IQ values (190.73 ± 0.004μg/ml and 220.54 ± 0.007μg/ml, respectively), compared to the non-fermented samples, which had IQ values (80.12 ± 0.002μg/ml). Additionally, at 62.5µg/ml doses of each sample, a normal kidney cell line (HEK 293) showed higher cell viability for fermented and non-fermented samples. Conversely, at the same doses, the fermented samples of L. acidophilus and B. subtilis in a kidney cancer cell line (A498) showed an inhibition of cell growth around 36% and 31%, respectively. Finally, we performed RT and qRT PCR assay, and we found a significant reduction in the expression of the PTGS2, PIK3CA, and IGF1R genes. We therefore can conclude that the fermented samples have a higher concentration of isoquercitrin, and also can inhibit the expression of the genes PTGS2, PIK3CA, and IGF1R, which in turn regulates kidney cancer and inflammation.

Relationship between infant gastrointestinal microorganisms and maternal microbiome within 6 months of delivery.

To investigate the association between the microbiota in mothers and gut microbiota in infants from 0 to 6 months, the microbiotas in infant feces, maternal feces, and breast milk were determined by 16S rRNA gene sequencing. The contribution of each maternal microbiome to the infant was assessed using fast expectation-maximization for microbial source tracking calculations. The levels of short-chain fatty acids (SCFAs) and secretory immunoglobulin A (sIgA) in the feces of infants were also determined using gas chromatography and IDK-sIgA ELISA to gain a more comprehensive understanding of the infant gut microbiome. The results of this study showed that in addition to Firmicutes (E1) and Bifidobacterium (E2), the dominant microorganisms of the intestinal microbiota of infants aged 0-6 months include Proteobacteria, which is different from previous findings. Acetic acid, the most abundant SCFA in the infant gut, was positively correlated with Megasphaera (P < 0.01), whereas sIgA was positively correlated with Bacteroides (P < 0.05) and negatively correlated with Klebsiella and Clostridium_XVIII (P < 0.05). The maternal gut microbiota contributed more to the infant gut microbiota (43.58% ± 11.13%) than the breast milk microbiota, and significant differences were observed in the contribution of the maternal microbiota to the infant gut microbiota based on the delivery mode and feeding practices. In summary, we emphasize the key role of maternal gut health in the establishment and succession of infant gut microbiota.IMPORTANCEThis study aims to delineate the microbial connections between mothers and infants, leveraging the fast expectation-maximization for microbial source tracking methodology to quantify the contribution of maternal microbiota to the constitution of the infant's gut microbiome. Concurrently, it examines the correlations between the infant gut microbiota and two distinctive biomolecules, namely short-chain fatty acids (SCFAs) and secretory immunoglobulin A (sIgA). The findings indicate that the maternal gut microbiota exerts a greater influence on the infant's gut microbial composition than does the microbiota present in breast milk. Infants born via vaginal delivery and receiving mixed feeding display gut microbiota profiles more similar to their mothers'. Notably, the SCFA acetate displays positive associations with beneficial bacteria and inverse relationships with potentially harmful ones within the infant's gut. Meanwhile, sIgA positively correlates with Bacteroides species and negatively with potentially pathogenic bacteria. By delving into the transmission dynamics of maternal-infant microbiota, exploring the impacts of metabolic byproducts within the infant's gut, and scrutinizing how contextual factors such as birthing method and feeding practices affect the correlation between maternal and infant microbiota, this research endeavors to establish practical strategies for optimizing early-life gut health management in infants. Such insights promise to inform targeted interventions that foster healthier microbial development during the critical first 6 months of life.

Microbial source tracking and identification of fecal contamination patterns in saltwater estuaries between base- and storm-flow events using dual genome-based approaches

Fecal contamination from natural and anthropogenic sources poses significant threats to saltwater estuaries, particularly after storms or heavy rainfall. Monitoring fecal contamination is essential for protecting these vulnerable ecosystems having important ecological and economic values. In this study, we investigated the abundance, sources, and potential causes of fecal contamination at three marine and seven freshwater stations across Vaughn Bay (WA, USA), a shellfish growing district, during base- and storm-flow events. Additionally, we evaluated the performance of fecal indicator bacteria (FIB) quantification, optical brightener assessment, and qPCR analysis for fecal contamination quantification. We compared the effectiveness of qPCR-based microbial source tracking (MST), which targeted a broad range of hosts including, such as humans, birds, cows, horses, ruminants, dogs, and pigs, with sequencing-based MST in identifying fecal contamination sources. Both MST analysis approaches identified birds and humans as the primary sources of fecal contamination. For marine water stations, freshwater creeks VBU001, VBU002, and VB047, along with drain VB007, were identified as the main sources of human-derived fecal contamination in Vaughn Bay, based on Kendall's tau analysis (τ: 0.58–0.97). This information indicates that the septic systems in the catchment areas of these creeks and drains require further investigation to achieve effective fecal contamination control. Optical brightener, FIB enumeration and qPCR quantification results were generally higher during storm-flow events, although they showed poor correlation with each other (Pearson r < 0.40), likely due to physiological and phylogenetic differences among the target organisms of these methods. However, the sequencing-based method faces challenges in precise quantitative identification of differences in fecal contamination between base- and storm-flow events. Due to its high-throughput and cost-effectiveness, we recommend using sequencing-based analysis for large-scale identification of the primary sources of fecal contamination in water environments, followed by targeted qPCR quantification of MST markers for more precise assessments.

Campylobacteriosis Outbreak Linked to Municipal Water, Nebraska, USA, 20211.

In September 2021, eight campylobacteriosis cases were identified in a town in Nebraska, USA. We assessed potential exposures for a case-control analysis. We conducted whole-genome sequencing on Campylobacter isolates from patients' stool specimens. We collected large-volume dead-end ultrafiltration water samples for Campylobacter and microbial source tracking testing at the Centers for Disease Control and Prevention. We identified 64 cases in 2 waves of illnesses. Untreated municipal tap water consumption was strongly associated with illness (wave 1 odds ratio 15.36; wave 2 odds ratio 16.11). Whole-genome sequencing of 12 isolates identified 2 distinct Campylobacter jejuni subtypes (1 subtype/wave). The town began water chlorination, after which water testing detected coliforms. One dead-end ultrafiltration sample yielded nonculturable Campylobacter and avian-specific fecal rRNA genomic material. Our investigation implicated contaminated, untreated, municipal water as the source. Results of microbial source tracking supported mitigation with continued water chlorination. No further campylobacteriosis cases attributable to water were reported.