-
International Journal of Biological... Aug 2023Polysaccharides derived from microorganisms exhibit diverse structures and bioactivities, making them promising candidates for the treatment of various diseases....
The structure, characterization and immunomodulatory potential of exopolysaccharide produced by Planococcus rifietoensis AP-5 from deep-sea sediments of the Northwest Pacific.
Polysaccharides derived from microorganisms exhibit diverse structures and bioactivities, making them promising candidates for the treatment of various diseases. However, marine-derived polysaccharides and their activities are relatively little known. In this work, fifteen marine strains were isolated from surface sediments in the Northwest Pacific Ocean for screening of EPS production. Planococcus rifietoensis AP-5 produced a maximum yield of EPS at 4.80 g/L. The purified EPS (referred to as PPS) had a molecular weight of 51,062 Da and contained amino, hydroxyl, and carbonyl groups as its major functional groups. PPS primarily consisted of →3)-α-D-Galp-(1 → 4)-α-D-Manp-(1 → 2)-α-D-Manp-(1 → 4)-α-D-Manp-(1 → 4,6)-α-D-Glcp-(1 → 6)-β-D-Galp-(1→, with a branch consisting of T-β-D-Glcp-(1→. Additionally, surface morphology of PPS was hollow, porous, and sphere-like stack. PPS primarily contained C, N, and O elements, with a surface area of 33.76 m/g, a pore volume of 0.13 cc/g, and a pore diameter of 1.69 nm, respectively. Based on the TG curve, the degradation temperature of PPS was measured to be 247 °C. Furthermore, PPS demonstrated immunomodulatory activity through dose-dependently upregulating the expression level of cytokines. It significantly enhanced the cytokine secretion at a concentration of 5 μg/mL. To sum up, this study offers valuable insights for screening marine polysaccharide-based immunomodulators.
Topics: Polysaccharides; Immunologic Factors; Cytokines; Molecular Weight
PubMed: 37331538
DOI: 10.1016/j.ijbiomac.2023.125452 -
Archives of Microbiology Feb 2024Aphids shelter several bacteria that benefit them in various ways. The associates having an obligatory relationship are non-culturable, while a few of facultative...
Aphids shelter several bacteria that benefit them in various ways. The associates having an obligatory relationship are non-culturable, while a few of facultative associates are culturable in insect cell lines, axenic media or standard microbiology media. In the present investigation, isolation, and characterization of the culturable bacterial associates of various aphid species, viz., Rhopalosiphum maidis, Rhopalosiphum padi, Sitobion avenae, Schizaphis graminum, and Lipaphis erysimi pseudobrassicae were carried out. A total of 42 isolates were isolated using different growth media, followed by their morphological, biochemical, and molecular characterization. The isolated culturable bacterial associates were found to belong to the genera Acinetobacter, Bacillus, Brevundimonas, Cytobacillus, Fictibacillus, Planococcus, Priestia, Pseudomonas, Staphylococcus, Sutcliffiella, and Tumebacillus which were grouped under seven families of four different orders of phyla Bacillota (Firmicutes) and Pseudomonata (Proteobacteria). Symbiont-entomopathogen interaction study was also conducted, in which the quantification of colony forming units of culturable bacterial associates of entomopathogenic fungal-treated aphids led us to the assumption that the bacterial load in aphid body can be altered by the application of entomopathogens. Whereas, the mycelial growth of entomopathogens Akanthomyces lecanii and Metarhizium anisopliae was found uninhibited by the bacterial associates obtained from Sitobion avenae and Rhopalosiphum padi. Analyzing persistent aphid microflora and their interactions with entomopathogens enhances our understanding of aphid resistance. It also fosters the development of innovative solutions for agricultural pest management, highlighting the intricate dynamics of symbiotic relationships in pest management strategies.
Topics: Animals; Aphids; Bacteria; Bacillaceae; Firmicutes; Bacillus
PubMed: 38349547
DOI: 10.1007/s00203-024-03830-x -
Bioresource Technology May 2024Understanding large-scale composting under natural conditions is essential for improving waste management and promoting sustainable agriculture. In this study, corn...
Understanding large-scale composting under natural conditions is essential for improving waste management and promoting sustainable agriculture. In this study, corn straw (400 tons) and pig manure (200 tons) were composted with microbial inoculants. The thermophilic phase of composting lasted for fourteen weeks, resulting in an alkaline final product. Microbial systems with low-temperature initiation and high-temperature fermentation played a crucial role in enhancing lignocellulose degradation and humic substances (HS) formation. Adding microbes, including Rhodanobacter, Pseudomonas, and Planococcus, showed a positive correlation with degradation rates of cellulose, hemicellulose, and lignin. Bacillus, Planococcus, and Acinetobacter were positively correlated with HS formation. Microorganisms facilitated efficient hydrolysis of lignocelluloses, providing humic precursors to accelerate composting humification through phenolic protein and Maillard pathways. This study provides significant insights into large-scale composting under natural conditions, contributing to the advancement of waste management strategies and the promotion of sustainable agriculture.
Topics: Manure; Composting; Animals; Zea mays; Lignin; Humic Substances; Bacteria; Cold Temperature; Temperature; Hydrolysis; Swine; Waste Products
PubMed: 38614144
DOI: 10.1016/j.biortech.2024.130696 -
Microbial Ecology Nov 2019A resumption of climate warming in maritime Antarctica, arising from continued greenhouse gas emissions to the atmosphere, is predicted to lead to further expansions of...
A resumption of climate warming in maritime Antarctica, arising from continued greenhouse gas emissions to the atmosphere, is predicted to lead to further expansions of plant populations across the region, with consequent increases in nutrient inputs to soils. Here, we test the main and interactive effects of warming, applied with open top chambers (OTCs), and nutrient amendment with tryptic soy broth (TSB), an artificial growth substrate, on bacterial community composition and diversity using Illumina sequencing of 16S rRNA genes in soil from a field experiment in the southern maritime Antarctic. Substantial effects of TSB application on bacterial communities were identified after 49 months, including reduced diversity, altered phylogenetic community assembly processes, increased Proteobacteria-to-Acidobacteria ratios and significant divergence in community composition, notably increases in the relative abundances of the gram-positive genera Arthrobacter, Paeniglutamicibacter and Planococcus. Contrary to previous observations from other maritime Antarctic field warming experiments, we recorded no effects of warming with OTCs, or interactive effects of OTCs and TSB application, on bacterial community composition or diversity. Based on these findings, we conclude that further warming of the maritime Antarctic is unlikely to influence soil bacterial community composition or diversity directly, but that increased nutrient inputs arising from enhanced plant growth across the region may affect the composition of soil bacterial communities, with possible effects on ecosystem productivity.
Topics: Antarctic Regions; Bacteria; Bacterial Physiological Phenomena; Fertilizers; Global Warming; Hot Temperature; Microbiota; RNA, Bacterial; RNA, Ribosomal, 16S; Soil Microbiology
PubMed: 30989354
DOI: 10.1007/s00248-019-01373-z -
The Science of the Total Environment Sep 2021The anaerobic oxidation of methane (AOM) mediated by microorganisms is a key process in the reduction of methane emissions, and AOM-coupled electron acceptors have been...
The anaerobic oxidation of methane (AOM) mediated by microorganisms is a key process in the reduction of methane emissions, and AOM-coupled electron acceptors have been shown to regulate methane emissions into the atmosphere in marine systems. Paddy fields are a significant source of methane and account for 20% of global methane emissions, but the effect of electron acceptors on the methane emission process in flooded paddy fields has been poorly characterized. This study aimed to determine whether the electron acceptors ferric iron and nitrate, and biochar, acting as an electron shuttle, can regulate the AOM process in paddy soil, with or without interaction between biochar and these two electron acceptors. We also aimed to characterize which microorganisms are actively involved. Here, we added C-labeled CH (CH) into anaerobic microcosms to evaluate the role of electron acceptors by measuring the methane oxidation rate and the enrichment of C-labeled CO (CO). We then combined DNA-stable isotope probing with amplicon sequencing to study the active microorganisms. We found for the first time that, in addition to nitrate, ferric iron can also effectively promote AOM in paddy soil. However, there was no significant effect of biochar. Ferric iron-dependent AOM was mainly carried out by iron-reducing bacteria (Geobacter, Ammoniphilus and Clostridium), and nitrate-dependent AOM was mainly by nitrate-reducing bacteria (Rhodanobacter, Paenibacillus and Planococcus). Our results demonstrate that the AOM process, regulated by the electron acceptors ferric iron and nitrate, can alleviate methane emission from paddy soil. The potentially active microorganisms related to electron acceptor reduction may be crucial for this methane sink and deserve further research.
Topics: Anaerobiosis; Archaea; Iron; Methane; Microbiota; Nitrates; Oxidation-Reduction; Soil
PubMed: 34029806
DOI: 10.1016/j.scitotenv.2021.147773 -
Journal of Hazardous Materials Jul 2021Long-term exposure of anammox process to 1,4-dioxane was investigated using periodic anammox baffled reactor (PABR) under different 1,4-dioxane concentrations. The...
Long-term exposure of anammox process to 1,4-dioxane was investigated using periodic anammox baffled reactor (PABR) under different 1,4-dioxane concentrations. The results generally indicated that PABR (composed of 4 compartments) has robust resistance to 10 mg-dioxane/L. The 1 compartment acted as a shield to protect subsequent compartments from 1,4-dioxane toxicity through secretion of high extracellular polymeric substance (EPS) of 152.9 mg/gVSS at 10 mg-dioxane/L. However, increasing 1,4-dioxane to 50 mg/L significantly inhibited anammox bacteria; e.g., ~ 93% of total nitrogen removal was lost within 14 days. The inhibition of anammox process at this dosage was most likely due to bacterial cell lysis, resulting in the decrease of EPS secretion and specific anammox activity (SAA) to 105.9 mg/gVSS and 0.04 mg N/gVSS/h, respectively, in the 1 compartment. However, anammox bacteria were successfully self-recovered within 41 days after the cease of 1,4-dioxane exposure. The identification of microbial compositions further emphasized the negative impacts of 1,4-dioxane on abundance of C. Brocadia among samples. Furthermore, the development of genus Planococcus in the 1 compartment, where removal of 1,4-dioxane was consistently observed, highlights its potential role as anoxic 1,4-dioxane degrader. Overall, long-term exposure to 1,4-dioxane should be controlled not exceeding 10 mg/L for a successful application.
Topics: Anaerobiosis; Bioreactors; Dioxanes; Extracellular Polymeric Substance Matrix; Fatigue; Humans; Kinetics; Microbial Consortia; Nitrogen; Oxidation-Reduction
PubMed: 34030408
DOI: 10.1016/j.jhazmat.2021.125533 -
Microbiome Feb 2024Microbial functioning on marine plastic surfaces has been poorly documented, especially within cold climates where temperature likely impacts microbial activity and the...
Novel functional insights into the microbiome inhabiting marine plastic debris: critical considerations to counteract the challenges of thin biofilms using multi-omics and comparative metaproteomics.
BACKGROUND
Microbial functioning on marine plastic surfaces has been poorly documented, especially within cold climates where temperature likely impacts microbial activity and the presence of hydrocarbonoclastic microorganisms. To date, only two studies have used metaproteomics to unravel microbial genotype-phenotype linkages in the marine 'plastisphere', and these have revealed the dominance of photosynthetic microorganisms within warm climates. Advancing the functional representation of the marine plastisphere is vital for the development of specific databases cataloging the functional diversity of the associated microorganisms and their peptide and protein sequences, to fuel biotechnological discoveries. Here, we provide a comprehensive assessment for plastisphere metaproteomics, using multi-omics and data mining on thin plastic biofilms to provide unique insights into plastisphere metabolism. Our robust experimental design assessed DNA/protein co-extraction and cell lysis strategies, proteomics workflows, and diverse protein search databases, to resolve the active plastisphere taxa and their expressed functions from an understudied cold environment.
RESULTS
For the first time, we demonstrate the predominance and activity of hydrocarbonoclastic genera (Psychrobacter, Flavobacterium, Pseudomonas) within a primarily heterotrophic plastisphere. Correspondingly, oxidative phosphorylation, the citrate cycle, and carbohydrate metabolism were the dominant pathways expressed. Quorum sensing and toxin-associated proteins of Streptomyces were indicative of inter-community interactions. Stress response proteins expressed by Psychrobacter, Planococcus, and Pseudoalteromonas and proteins mediating xenobiotics degradation in Psychrobacter and Pseudoalteromonas suggested phenotypic adaptations to the toxic chemical microenvironment of the plastisphere. Interestingly, a targeted search strategy identified plastic biodegradation enzymes, including polyamidase, hydrolase, and depolymerase, expressed by rare taxa. The expression of virulence factors and mechanisms of antimicrobial resistance suggested pathogenic genera were active, despite representing a minor component of the plastisphere community.
CONCLUSION
Our study addresses a critical gap in understanding the functioning of the marine plastisphere, contributing new insights into the function and ecology of an emerging and important microbial niche. Our comprehensive multi-omics and comparative metaproteomics experimental design enhances biological interpretations to provide new perspectives on microorganisms of potential biotechnological significance beyond biodegradation and to improve the assessment of the risks associated with microorganisms colonizing marine plastic pollution. Video Abstract.
Topics: Plastics; Bacteria; Multiomics; Biofilms; Biodegradation, Environmental; Microbiota
PubMed: 38389111
DOI: 10.1186/s40168-024-01751-x -
The Onderstepoort Journal of Veterinary... Jul 2019Several types of odours are involved in the location of host animals by tsetse (Diptera: Glossinidae), a vector of animal African trypanosomiasis. Host animals' ageing...
Several types of odours are involved in the location of host animals by tsetse (Diptera: Glossinidae), a vector of animal African trypanosomiasis. Host animals' ageing urine has been shown to be the source of a phenolic blend attractive to the tsetse. Nevertheless, limited research has been performed on the microbial communities' role in the production of phenols. This study aimed at profiling bacterial communities mediating the production of tsetse attractive phenols in mammalian urine. Urine samples were collected from African buffalo (Syncerus caffer), cattle (Bos taurus) and eland (Taurotragus oryx) at Kongoni Game Valley Ranch and Kenyatta University in Kenya. Urine samples, of each animal species, were pooled and left open to age in ambient conditions. Bacteriological and phenols analyses were then carried out, at 4 days ageing intervals, for 24 days. Phenols analysis revealed nine volatile phenols: 4-cresol, ortho-cresol, 3-cresol, phenol, 3-ethylphenol, 3-propylphenol, 2-methyloxyphenol, 4-ethylphenol and 4-propylphenol. Eight out of 19 bacterial isolates from the ageing urine revealed the potential to mediate production of phenols. 16S rRNA gene characterisation of the isolates closely resembled Enterococcus faecalis KUB3006, Psychrobacter alimentarius PAMC 27887, Streptococcus agalactiae 2603V, Morganella morganii sub.sp. morganii KT, Micrococcus luteus NCTC2665, Planococcus massiliensis strain ES2, Ochrobactrum pituitosum AA2 and Enterococcus faecalis OGIRF. This study established that some of the phenols emitted from mammalian urine, which influence the tsetse's host-seeking behaviour, are well characterised by certain bacteria. These results may allow the development of biotechnological models in vector control that combines the use of these bacteria in the controlled release of semiochemicals.
Topics: Animals; Antelopes; Bacteria; Buffaloes; Cattle; Chemotaxis; Kenya; Microbiota; Odorants; Phenols; RNA, Bacterial; RNA, Ribosomal, 16S; Tsetse Flies
PubMed: 31368325
DOI: 10.4102/ojvr.v86i1.1724 -
Life (Basel, Switzerland) Jan 2021(1) Background: Future missions to potentially habitable places in the Solar System require biochemistry-independent methods for detecting potential alien life forms....
(1) Background: Future missions to potentially habitable places in the Solar System require biochemistry-independent methods for detecting potential alien life forms. The technology was not advanced enough for onboard machine analysis of microscopic observations to be performed in past missions, but recent increases in computational power make the use of automated in-situ analyses feasible. (2) Methods: Here, we present a semi-automated experimental setup, capable of distinguishing the movement of abiotic particles due to Brownian motion from the motility behavior of the bacteria . Supervised machine learning algorithms were also used to specifically identify these species based on their characteristic motility behavior. (3) Results: While we were able to distinguish microbial motility from the abiotic movements due to Brownian motion with an accuracy exceeding 99%, the accuracy of the automated identification rates for the selected species does not exceed 82%. (4) Conclusions: Motility is an excellent biosignature, which can be used as a tool for upcoming life-detection missions. This study serves as the basis for the further development of a microscopic life recognition system for upcoming missions to Mars or the ocean worlds of the outer Solar System.
PubMed: 33445805
DOI: 10.3390/life11010044 -
The Science of the Total Environment Apr 2020The response mechanism of wastewater treatment biofilms to salt stress has not yet been fully established. The aim of this study was to reveal the comprehensive...
The response mechanism of wastewater treatment biofilms to salt stress has not yet been fully established. The aim of this study was to reveal the comprehensive biological effects of salinity on biofilm microbial community and metabonomic characteristics. The study assessed performance at a range of sodium chloride (NaCl) concentrations of 0.6, 14 and 20 g/L. Biofilm coverage rate decreased significantly with increasing NaCl concentrations. High NaCl concentrations resulted in more compact and smoother biofilm morphologies. NaCl concentrations affected bacterial community variation at the class and genus level, with Gammaproteobacteria being the most dominant Proteobacteria, exhibiting NaCl tolerance at concentrations ranging from 0 to 20 g/L. Also, NaCl sensitive or tolerant species were identified, such as Pseudomonas and Planococcus, respectively. Dominant metabolites in wastewater treatment biofilms belonging to nucleotide, lipid, vitamin, amino acid and carbohydrate metabolism pathways decreased with increasing NaCl concentrations. High concentrations of NaCl regulated cell motility, transcription and membrane transport functions. In particular, the activity of ABC transporters were up-regulated at NaCl concentrations of 0.6 g/L and down-regulated at higher salinity concentrations. In addition, transcription machinery were inhibited under the stress of 14 g/L NaCl. These findings further our understanding of the short-term adaption mechanisms of wastewater treatment biofilms to high NaCl concentration environments.
Topics: Bacteria; Biofilms; Microbiota; Salinity; Wastewater
PubMed: 31812393
DOI: 10.1016/j.scitotenv.2019.134437