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Applied and Environmental Microbiology Aug 2018The aim of this work was to better understand the roles of extracellular polymeric substances (EPS) in membrane biofouling at the single-strain level. In the present...
The aim of this work was to better understand the roles of extracellular polymeric substances (EPS) in membrane biofouling at the single-strain level. In the present study, a total of 23 bacterial strains were isolated from a sludge sample. The EPS extracted from pure-cultured bacteria were assessed for their fouling potentials and were simultaneously analyzed using Fourier transform infrared spectroscopy (FTIR). Further, the impact of calcium on the chemical composition of EPS and membrane fouling behavior was investigated in a strain-dependent manner. The EPS of the 23 bacterial strains exhibited different IR features for protein and polysaccharide regions. In addition, an α-1,4-glycosidic linkage (920 cm) and amide II (1,550 cm) correlated very well with the fouling potentials of all pure-cultured bacteria. In contrast to low-fouling strains, medium- and high-fouling strains exhibited two distinct peaks at 1,020 cm (uronic acids) and 1,250 cm (-acetyl), which accelerate membrane fouling given their gelling capacities. In the presence of calcium, the fouling potential of a high-fouling strain ( sp. strain JSB10) was profoundly reduced ( < 0.0005) due to the binding activity of an α-1,4-glycosidic linkage and amide II with calcium. However, the impact of calcium on a low-fouling strain ( sp. strain JSB21) was insignificant. Two-dimensional FTIR correlation spectroscopic (2D-FTIR-COS) analysis further revealed that the susceptibilities of functional groups to calcium largely relied on the composition and abundance of the above-described functional groups in EPS. These findings suggest that bacterial strains with different fouling potentials exhibit varied responses to calcium. Membrane biofouling is one of the main challenges for the operation of membrane-based processes used for water and wastewater treatment. This study revealed the functional determinants of EPS in membrane biofouling of 23 bacterial strains isolated from a full-scale membrane bioreactor (MBR) plant. We found that an α-1,4-glycosidic bond, amide II, and uronic acids of EPS significantly correlated with the fouling potentials of bacteria. The roles of these EPS groups in membrane fouling were impacted by calcium resulting from EPS-calcium interactions. In addition, our results also demonstrated that any perturbations in the sludge bacterial community in MBRs can lead to varied filtration potentials of the bulk liquor.
Topics: Bacteria; Bacterial Physiological Phenomena; Biofilms; Biofouling; Calcium; Extracellular Polymeric Substance Matrix; Sewage; Spectroscopy, Fourier Transform Infrared; Wastewater
PubMed: 29858205
DOI: 10.1128/AEM.00756-18 -
PeerJ 2023Sodium hypochlorite is generally used as a disinfectant in washing of freshwater fishes where the safety aspect of health is of concern. Although plant-based essential...
Sodium hypochlorite is generally used as a disinfectant in washing of freshwater fishes where the safety aspect of health is of concern. Although plant-based essential oils and synthetic chemical agents have been applied, they might contain toxic substances, are expensive and can cause undesirable quality. This research aims to fill the knowledge gap necessary to validate juice as a disinfecting agent for preserving striped catfish steaks at -20 °C for 28 days. Fifty (50) ppm sodium hypochlorite was used as a commercial disinfectant (control). The results showed that a negative color characteristic (higher a* and increased b*) was found in the control but not in striped catfish steaks immersed in juice (TM) on days 14 and 28. No significant differences were found in the peroxide value among the treatments on days 14 and 28 ( > 0.05). A lower accumulation of trichloroacetic acid soluble peptides was detected in TM but not in control, while total volatile basic nitrogen of all treatments was up to standard of fish quality during storage. Contrastingly, the total viable count of both treatments increased to >7.0 log CFU/g on day 28 which did not meet the edible limit of standard for freshwater fishes. The spoilage microbial community was observed on days 0 and 28 of storage which showed a decrease in relative abundance of , and as found in TM on day 28, when compared to the control. Thus, these results implied that juice could replace sodium hypochlorite as an alternative disinfecting agent to control the microbiological spoilage and physico-chemical quality of striped catfish steaks.
Topics: Animals; Sodium Hypochlorite; Catfishes; Disinfectants; Plant Oils; Citrus
PubMed: 37065691
DOI: 10.7717/peerj.15168 -
Saudi Journal of Biological Sciences Apr 2023Diseases are quite common in fish farms because of changes in physico-chemical characteristics in the aquatic environment, and operational concerns, i.e., overstocking...
Diseases are quite common in fish farms because of changes in physico-chemical characteristics in the aquatic environment, and operational concerns, i.e., overstocking and feeding issues. In the present study, potential factors (water physico-chemical characteristics and heavy metal load) on the disease-causing state of the pathogenic bacteria and sp. were examined with machine learning techniques in a trout farm. Recording of physico-chemical characteristics of the water, fish sampling and bacteria identification were carried out at bimonthly intervals. A dataset was generated from the physico-chemical characteristics of the water and the occurrence of bacteria in the trout samples. The eXtreme Gradient Boosting (XGBoost) algorithm was used to determine the most important independent variables within the generated dataset. The most important seven features affecting bacteria occurrence were determined. The model creation process continued with these seven features. Three well-known machine learning techniques (Support Vector Machine, Logistic Regression and Naïve Bayes) were used to model the dataset. Consequently, all the three models have produced comparable results, and Support Vector Machine (93.3% accuracy) had the highest accuracy. Monitoring changes in the aquaculture environment and detecting situations causing significant losses through machine learning techniques have a great potential to support sustainable production.
PubMed: 37008282
DOI: 10.1016/j.sjbs.2023.103625 -
Microbial Biotechnology May 2019Vermicomposting using black soldier fly (BSF) larvae (Hermetia illucens) has gradually become a promising biotechnology for waste management, but knowledge about the...
Vermicomposting using black soldier fly (BSF) larvae (Hermetia illucens) has gradually become a promising biotechnology for waste management, but knowledge about the larvae gut microbiome is sparse. In this study, 16S rRNA sequencing, SourceTracker, and network analysis were leveraged to decipher the influence of larvae gut microbiome on food waste (FW) biodegradation. The microbial community structure of BSF vermicompost (BC) changed greatly after larvae inoculation, with a peak colonization traceable to gut bacteria of 66.0%. The relative abundance of 11 out of 21 metabolic function groups in BC were significantly higher than that in natural composting (NC), such as carbohydrate-active enzymes. In addition, 36.5% of the functional genes in BC were significantly higher than those in NC. The changes of metabolic functions and functional genes were significantly correlated with the microbial succession. Moreover, the bacteria that proliferated in vermicompost, including Corynebacterium, Vagococcus, and Providencia, had strong metabolic abilities. Systematic and complex interactions between the BSF gut and BC bacteria occurred over time through invasion, altered the microbial community structure, and thus evolved into a new intermediate niche favourable for FW biodegradation. The study highlights BSF gut microbiome as an engine for FW bioconversion, which is conducive to bioproducts regeneration from wastes.
Topics: Animals; Biotransformation; Cluster Analysis; Composting; DNA, Bacterial; DNA, Ribosomal; Diptera; Food; Gastrointestinal Microbiome; Larva; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Waste Management
PubMed: 30884189
DOI: 10.1111/1751-7915.13393 -
Microbiology Spectrum Apr 2024Given the burgeoning Nyctereutes procyonoides breeding industry and its growing scale, it is imperative to investigate the impact of high-fat diets on the health of...
Given the burgeoning Nyctereutes procyonoides breeding industry and its growing scale, it is imperative to investigate the impact of high-fat diets on the health of these animals. This study involved 30 male Nyctereutes procyonoides of comparable weights (3 kg ±0.5), randomly assigned to either a control group or a high-fat diet group ( = 15 each). The latter group was fed a mixture of lard and basal diet in a 2:5 ratio, establishing a high-fat diet model in Nyctereutes procyonoides. This diet induced diarrhea and histopathological changes in the Nyctereutes procyonoides. Analysis of the small intestine contents using 16S rRNA sequencing revealed a high-fat diet-induced disruption in the gut microbiota. Specifically, emerged as the biomarker in the high-fat diet group ( = 0.049), while was prevalent in the control group ( = 0.049), indicating a significant increase in harmful bacteria in the high-fat diet group. Furthermore, this disrupted gut flora correlated with inflammation and oxidative stress, as evidenced by marked increases in TNF-α ( < 0.01), IL-1β ( < 0.05), and IL-6 ( < 0.05) levels, measured q-PCR, Western blot, and oxidative stress assays. In addition, q-PCR analysis revealed significant upregulation of apoptosis and necrosis markers, including Bax, Caspase3, Caspase9, Caspase12, RIPK3, and RIPK1 ( < 0.01 to < 0.001), and a concurrent downregulation of the anti-apoptotic gene Bcl-2 ( < 0.01) in the high-fat diet group, consistent with protein expression trends. These findings suggest that a high-fat diet alters the gut microbiome toward a more harmful bacterial composition, escalating inflammatory responses and intestinal tissue permeability, culminating in intestinal cell apoptosis and necrosis.IMPORTANCEThis study examines the impact of high-fat diets on Nyctereutes procyonoides. Our research established a Nyctereutes procyonoides model on a high-fat diet, revealing significant health impacts, such as diarrhea, histological anomalies, and alterations in the gut microbiota. These findings emphasize the importance of preventing health issues and promoting sustainable industry growth. They highlight the significant impact of diet on gut microbiota and overall animal health.
Topics: Animals; Male; Apoptosis; Bacteria; Diarrhea; Diet, High-Fat; Gastrointestinal Microbiome; Inflammation; Intestines; Necrosis; Raccoon Dogs; RNA, Ribosomal, 16S; Tight Junctions
PubMed: 38376358
DOI: 10.1128/spectrum.04182-23 -
BMC Infectious Diseases Mar 2024Vagococcal infections are extremely rare in humans. There are limited studies on the optimal methods for identification, antimicrobial susceptibility testing, and...
BACKGROUND
Vagococcal infections are extremely rare in humans. There are limited studies on the optimal methods for identification, antimicrobial susceptibility testing, and clinical manifestations of vagococcal infections. Herein, we report a patient with a urinary tract infection who had Vagococcus fluvialis in the urine.
CASE PRESENTATION
An 84-year-old man presented to our urology department with a fever that had persisted for several days. He previously worked as a zoo clerk. The patient underwent a left nephroureterectomy for ureteral cancer 5 years ago, and total cystectomy and right cutaneous ureterostomy for muscle-invasive bladder cancer 1 year prior. He was empirically treated with 500 mg of levofloxacin intravenously every 24 h for the urinary tract infection. V. fluvialis was detected in his urine samples and Pseudomonas aeruginosa was detected in his urine and blood samples. Two bacterial species were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. He was administered intravenous levofloxacin for approximately 1 week, followed by oral levofloxacin for another week, after which the infections were eradicated.
CONCLUSIONS
To the best of our knowledge, this is the first report of V. fluvialis detected in human urine in Japan. Vagococcus spp. is commonly isolated from fish or animals, and based on the patient's work history, it is possible that the patient was a carrier because of transmission from animals.
Topics: Aged, 80 and over; Humans; Male; Enterococcaceae; Gram-Positive Cocci; Japan; Levofloxacin; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Urinary Tract Infections
PubMed: 38515029
DOI: 10.1186/s12879-024-09193-4 -
Frontiers in Microbiology 2019Seafood and fishery products are very perishable commodities with short shelf-lives owing to rapid deterioration of their organoleptic and microbiological quality....
Salmon Gravlax Biopreservation With Lactic Acid Bacteria: A Polyphasic Approach to Assessing the Impact on Organoleptic Properties, Microbial Ecosystem and Volatilome Composition.
Seafood and fishery products are very perishable commodities with short shelf-lives owing to rapid deterioration of their organoleptic and microbiological quality. Microbial growth and activity are responsible for up to 25% of food losses in the fishery industry. In this context and to meet consumer demand for minimally processed food, developing mild preservation technologies such as biopreservation represents a major challenge. In this work, we studied the use of six lactic acid bacteria (LAB), previously selected for their properties as bioprotective agents, for salmon dill gravlax biopreservation. Naturally contaminated salmon dill gravlax slices, with a commercial shelf-life of 21 days, were purchased from a French industrial company and inoculated by spraying with the protective cultures (PCs) to reach an initial concentration of 10 log CFU/g. PC impact on gravlax microbial ecosystem (cultural and acultural methods), sensory properties (sensory profiling test), biochemical parameters (pH, TMA, TVBN, biogenic amines) and volatilome was followed for 25 days of storage at 8°C in vacuum packaging. PC antimicrobial activity was also assessed against . This polyphasic approach underlined two scenarios depending on the protective strain. SF1944, EU2229 and EU2249, were very competitive in the product, dominated the microbial ecosystem, and displayed antimicrobial activity against the spoilage microbiota and The strains also expressed their own sensory and volatilome signatures. However, of these three strains, SF1944 did not induce strong spoilage and was the most efficient for growth control. By contrast, CD264, MIP2551 and SF1044 were not competitive, did not express strong antimicrobial activity and produced only few organic volatile compounds (VOCs). However, CD264 was the only strain to extend the sensory quality, even beyond 25 days. This study shows that SF1944 and CD264 both have a promising potential as bioprotective cultures to ensure salmon gravlax microbial safety and sensorial quality, respectively.
PubMed: 32038547
DOI: 10.3389/fmicb.2019.03103 -
3 Biotech Feb 2021An innovative investigation was undertaken into the abundance and diversity of high antibiotic-resistant bacteria in aquaculture waters in Shandong Province, China,...
UNLABELLED
An innovative investigation was undertaken into the abundance and diversity of high antibiotic-resistant bacteria in aquaculture waters in Shandong Province, China, through cumulation incubation, PCR amplification of 16S rDNA, and high-throughput sequencing. The results showed that and were abundant in the aquaculture waters, whereas other phylum including , , and had relatively lower abundance. Our studies revealed the presence of different bacteria in different locations in the aquaculture waters, most of which were resistant to multiple antibiotics. That is, the same microbial species from the same aquaculture wastewater can resist different antibiotics. Altogether, a considerable portion of the microbial community were found to be multi-drug resistant. It is essential that the spread of the antibiotic-resistant bacteria is controlled so that the distribution of antibiotic resistance genes to other environments is avoided.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s13205-021-02656-4.
PubMed: 33552832
DOI: 10.1007/s13205-021-02656-4 -
Bioscience of Microbiota, Food and... 2020The objective of this study was to identify the relevant fecal microbes from mice with food allergy and investigate the impact of these microbes on intestinal epithelial...
The objective of this study was to identify the relevant fecal microbes from mice with food allergy and investigate the impact of these microbes on intestinal epithelial cells and allergen-specific T-cell responses. A murine model of ovalbumin (OVA)-induced food allergy was employed. The profile of fecal microbiota was evaluated by the traditional plating method and next-generation sequencing (NGS) of the 16S ribosomal RNA gene. The density of fecal bacteria growth on RCM, TSA and LB plates was elevated in mice with food allergy, whereas the diversity of fecal bacteria was decreased. Additionally, the relative abundances of Prevotellaceae and were increased. The isolated fecal strains, mostly belonging to and significantly reduced the viability of intestinal Caco-2 cells but increased the production of interleukin (IL)-8, C-C motif chemokine ligand (CCL)-2, CCL-5, CCL-20 and C-X-C motif chemokine ligand (CXCL)-1. Moreover, cell expansion and secretion of IL-2, interferon (IFN)-γ, IL-4 and IL-17 by mesenteric lymph node (MLN) cells were augmented, whereas the production of IL-10 and transforming growth factor (TGF)-β was diminished. Although individual fecal strains had varying degrees of impact on Caco-2 cells and MLN cells, these results precisely indicate a different profile of fecal microbiota between normal mice and allergic mice. Most important, the relevant fecal microbes involved in allergen-induced dysbiosis have the potential to induce intestinal cytokine/chemokine network and T-cell immune responses.
PubMed: 33117622
DOI: 10.12938/bmfh.2020-014 -
New Microbes and New Infections Jan 2016Vagococcus lutrae is a Gram-positive coccus initially isolated from the common otter (Lutra lutra) but that has never been reported as a human pathogen. We describe the...
Vagococcus lutrae is a Gram-positive coccus initially isolated from the common otter (Lutra lutra) but that has never been reported as a human pathogen. We describe the first case of human infection due to Vagococcus lutrae in Marseille, France.
PubMed: 26862437
DOI: 10.1016/j.nmni.2015.11.008