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Current Microbiology Dec 2022Polyethylene terephthalate (PET) as one of the main crude oil-based derivatives, produces a significant amount of waste that is difficult to degrade. Currently,...
Polyethylene terephthalate (PET) as one of the main crude oil-based derivatives, produces a significant amount of waste that is difficult to degrade. Currently, microbial degradation of PET is an eco-friendly, efficient, and economical method. This study was conducted to propose a novel screening strategy for PET-degrading bacteria, and evaluate their degradation efficiency of PET. Two strains, Pseudomonas nitroreducens S8 and Pseudomonas monteilii S17, were isolated and could utilize PET as a carbon source by co-culture. The combined use of both bacteria gave a synergistic effect on the disruption of the PET surface through colonization behavior, which could enhance the subsequent degradation of PET. Its time of reaching a peak value of PET degradation rate (94.5% at 6 d) was 2 days earlier than these of single bacteria. A similar synergistic effect was also observed in the metabolization of PET monomers, and the metabolic rate was expressed as 82.4% of bis (2-hydroxyethyl) terephthalate (BHET), 64.0% of mono (2-hydroxyethyl) terephthalate (MHET), and 20.0% of terephthalic acid (TPA), respectively. This study is novel in showing the degradation of PET waste by combinations of bacterial pretreatment and enzymatic treatment, which can be a promising method.
Topics: Petroleum; Pseudomonas
PubMed: 36474116
DOI: 10.1007/s00284-022-03139-2 -
International Journal of Molecular... Nov 2022The B12-producing strains DSM 1650 and sp. CCUG 2519 (both formerly ), with the most distributed pathway among bacteria for exogenous choline/betaine utilization, are...
The B12-producing strains DSM 1650 and sp. CCUG 2519 (both formerly ), with the most distributed pathway among bacteria for exogenous choline/betaine utilization, are promising recombinant hosts for the endogenous production of B12 precursor betaine by direct methylation of bioavailable glycine or non-proteinogenic -alanine. Two plasmid-based de novo betaine pathways, distinguished by their enzymes, have provided an expression of the genes encoding for -methyltransferases of the halotolerant cyanobacterium or plant to synthesize the internal glycine betaine or -alanine betaine, respectively. These betaines equally allowed the recombinant pseudomonads to grow effectively and to synthesize a high level of cobalamin, as well as to increase their protective properties against abiotic stresses to a degree comparable with the supplementation of an exogenous betaine. Both de novo betaine pathways significantly enforced the protection of bacterial cells against lowering temperature to 15 °C and increasing salinity to 400 mM of NaCl. However, the expression of the single plant-derived gene for the -alanine-specific -methyltransferase additionally increased the effectiveness of exogenous glycine betaine almost twofold on cobalamin biosynthesis, probably due to the ' ability to use two independent pathways, their own choline/betaine pathway and the plant -alanine betaine biosynthetic pathway.
Topics: Betaine; Choline; Pseudomonas; Stress, Physiological; Methyltransferases; beta-Alanine; Vitamin B 12
PubMed: 36430408
DOI: 10.3390/ijms232213934 -
Frontiers in Microbiology 2022Electrified biotrickling filters represent sustainable microbial electrochemical technology for treating organic carbon-deficient ammonium-contaminated waters. However,...
Electrified biotrickling filters represent sustainable microbial electrochemical technology for treating organic carbon-deficient ammonium-contaminated waters. However, information on the microbiome of the conductive granule bed cathode remains inexistent. For uncovering this black box and for identifying key process parameters, minimally invasive sampling units were introduced, allowing for the extraction of granules from different reactor layers during reactor operation. Sampled granules were analyzed using cyclic voltammetry and molecular biological tools. Two main redox sites [-288 ± 18 mV and -206 ± 21 mV vs. standard hydrogen electrode (SHE)] related to bioelectrochemical denitrification were identified, exhibiting high activity in a broad pH range (pH 6-10). A genome-centric analysis revealed a complex nitrogen food web and the presence of typical denitrifiers like and with none of these species being identified as electroactive microorganism so far. These are the first results to provide insights into microbial structure-function relationships within electrified biotrickling filters and underline the robustness and application potential of bioelectrochemical denitrification for environmental remediation.
PubMed: 35711746
DOI: 10.3389/fmicb.2022.869474 -
3 Biotech May 2022A novel glufosinate-tolerant sp. LA21, was isolated from soil samples of an oil palm plantation with a long history of glufosinate application. The genome of sp. LA21...
UNLABELLED
A novel glufosinate-tolerant sp. LA21, was isolated from soil samples of an oil palm plantation with a long history of glufosinate application. The genome of sp. LA21 was sequenced with 150 bp paired-end conducted using Illumina sequencing technology. De novo genome assembly was performed using SPAdes, ABySS, and Velvet assemblers. Phylogenetic analysis using 16S rRNA gene sequence showed that sp. LA21 was closely related to ATCC 33634. Multilocus sequence analysis (MLSA) based on four bacterial housekeeping genes (16S rRNA, , , and ) was conducted together with 138 reference genomes of species. The phylogenetic tree derived from MLSA analysis using concatenated 16S rRNA- sequences grouped sp. LA21 under group and subgroup. Detailed phylogenomic analysis using average nucleotide identity (ANI) and genome-to-genome distance calculator (GGDC) approaches showed that sp. LA21 could be classified as a novel species.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s13205-022-03185-4.
PubMed: 35547011
DOI: 10.1007/s13205-022-03185-4 -
Molecular Plant-microbe Interactions :... Apr 2022
Topics: Acyl-Butyrolactones; Pseudomonas; Quorum Sensing
PubMed: 35285671
DOI: 10.1094/MPMI-12-21-0310-A -
Current Microbiology Feb 2022Production of fuels from renewable resources is of utmost importance due to fast depletion of fossil resources and related environmental issues. The present study...
Production of fuels from renewable resources is of utmost importance due to fast depletion of fossil resources and related environmental issues. The present study explored the intrinsic capability of microbial strains to produce alka(e)nes, the next-generation biofuel, thus to reduce the dependence upon current petroleum fuels. Eight bacterial strains, namely, SDK-1, SDK-2, SDK-6, SDK-7, SDK-8, SDK-9, SDK-10, and SDK-11 were isolated from sludge and soil samples collected from different sources using lauric acid as a substrate with a potential to produce alka(e)nes. Production of different medium- and long-chain alka(e)nes by these isolates was confirmed via gas chromatography-mass spectrometer (GC-MS) analysis. SDK-1 (7.2%), SDK-2 (3.72%), and SDK-6 (3.52%) produced significant proportion of medium-chain hydrocarbons as compared to SDK-10 and control with no production. These isolates may be further investigated for production of these alternative sources of energy. In contrary, maximum fraction of long-chain hydrocarbons is produced in SDK-8 (75.28%) followed by SDK-9 (61.51%). Similarly more than 50% of the total hydrocarbons produced in SDK-8 constitute fossil mimic hydrocarbons while only 10.78% fractions were found in SDK-10. Since these fractions resemble different hydrocarbons obtained from crude oil, hence may be explored for their wide applications in different fields. Biochemical characterization and sequencing of the 16S rRNA gene revealed the homology of SDK-1, SDK-2 and SDK-6 with Pseudomonas aeruginosa, SDK-7 and SDK-9 with Enterobacter cloacae, SDK-8 with Klebsiella pnuemoniae, SDK-10 with Enterobacter hormaechei and SDK-11 with Pseudomonas nitroreducens, respectively.
Topics: Bacteria; Biodegradation, Environmental; Biofuels; Hydrocarbons; Petroleum; RNA, Ribosomal, 16S
PubMed: 35129690
DOI: 10.1007/s00284-022-02781-0 -
Chinese Medicine Nov 2021Codonopsis pilosula, an important medicinal plant, can accumulate certain metabolites under moderate drought stress. Endophytes are involved in the metabolite...
BACKGROUND
Codonopsis pilosula, an important medicinal plant, can accumulate certain metabolites under moderate drought stress. Endophytes are involved in the metabolite accumulations within medicinal plants. It is still unknown that the endophytes of C. pilosula are associated with the accumulations of metabolites. This study aims to investigate the promoting effect of endophytes on the accumulations of active substances in C. pilosula under drought stress.
METHODS
High-performance liquid chromatography and high-throughput sequencing technology were performed to investigate changes in the contents of secondary metabolite and endophyte abundances of C. pilosula under drought stress, respectively. Spearman's correlation analysis was further conducted to identify the endophytic biomarkers related to accumulations of pharmacodynamic compounds. Culture-dependent experiments were performed to confirm the functions of endophytes in metabolite accumulations.
RESULTS
The distribution of pharmacological components and diversity and composition of endophytes showed tissue specificity within C. pilosula. The contents of lobetyolin, syringin, and atractylolide III in C. pilosula under drought stress were increased by 8.47%‒86.47%, 28.78%‒230.98%, and 32.17%‒177.86%, respectively, in comparison with those in untreated groups. The Chao 1 and Shannon indices in different parts of drought-stressed C. pilosula increased compared with those in untreated parts. The composition of endophytic communities in drought treatment parts of C. pilosula was different from that in control parts. A total of 226 microbial taxa were identified as potential biomarkers, of which the abundances of 42 taxa were significantly and positively correlated to the pharmacodynamic contents. Culture-dependent experiments confirmed that the contents of lobetyolin and atractylolide III were increased by the application of Epicoccum thailandicum, Filobasidium magnum, and Paraphoma rhaphiolepidis at the rates of 11.12%‒46.02%, and that the content of syringin was increased by Pseudomonas nitroreducens at the rates of 118.61%‒119.36%.
CONCLUSIONS
Certain endophytes participated in the accumulations of bioactive metabolites, which provided a scientific evidence for the development and application of microorganisms to improve the quality of traditional Chinese medicine.
PubMed: 34809641
DOI: 10.1186/s13020-021-00533-z -
Biotechnology Reports (Amsterdam,... Dec 2021The mechanisms of tolerance to heavy metals used by some microorganisms identified by bioprospection processes are useful for the development and implementation of...
The mechanisms of tolerance to heavy metals used by some microorganisms identified by bioprospection processes are useful for the development and implementation of bioremediation strategies for contaminated environments with high toxic load caused by heavy metals. A total of seven native microbial isolates were obtained from wastewater bodies from an industrial zone in the municipality of Girardota, Antioquia, Colombia. Subsequently, they were selected to evaluate their lead tolerance capacity at different concentrations. In addition, some parameters were determined, such as the capacity to produce exopolysaccharides and their biosorption to understand potential mechanisms associated to lead tolerance. According to the biocehemical test (Vitek) and the molecular analysis of sequences of 16S rDNA, bacterial were identified as , and . We determined that the seven isolates had the capacity to tolerate concentrations higher than 50 mg/ml of lead, and that the concentration and exposure time (40 h) to this metal significantly affect the spp. isolates. Statistically significant differences were detected ( < 0.05) in the production of the exopolysaccharide (EPS) among the isolates. (P16) was the strain with the maximum absorbance exopolysaccharide measured. We evidenced that (P14) and (P20) have 80% capacity to biosorber lead using live mass (minimum range from 80.9% to 87%). It is suggested that the tolerance to lead exhibited by the environmental isolates of spp. can be attributed to the production of exopolysaccharides and biosorption, which are protection factors for its survival in contaminated places. Finally, it was determined that the adsorption measured from dead biomass was significant ( < 0.05) from 40 h of exposure to metal (Average 182.2 ± 7). We generated new knowledge about the potential use of the spp. genus to bioremediate affluent contaminated with heavy metals.
PubMed: 34765463
DOI: 10.1016/j.btre.2021.e00685 -
Frontiers in Microbiology 2021Quorum quenching (QQ) is a novel, promising strategy that opens up a new perspective for controlling quorum-sensing (QS)-mediated bacterial pathogens. QQ is performed by...
Quorum quenching (QQ) is a novel, promising strategy that opens up a new perspective for controlling quorum-sensing (QS)-mediated bacterial pathogens. QQ is performed by interfering with population-sensing systems, such as by the inhibition of signal synthesis, catalysis of degrading enzymes, and modification of signals. In many Gram-negative pathogenic bacteria, a class of chemically conserved signaling molecules named -acyl homoserine lactones (AHLs) have been widely studied. AHLs are involved in the modulation of virulence factors in various bacterial pathogens including . is the causal agent of plant-rot disease of bananas, rice, maize, potatoes, etc., causing enormous economic losses of crops. In this study, a highly efficient AHL-degrading bacterial strain W-7 was isolated from activated-sludge samples and identified as . Strain W-7 revealed a superior ability to degrade -(3-oxododecanoyl)-l-homoserine lactone (OdDHL) and completely degraded 0.2 mmol/L of OdDHL within 48 h. Gas chromatography-mass spectrometry (GC-MS) identified -cyclohexyl-propanamide as the main intermediate metabolite during AHL biodegradation. A metabolic pathway for AHL in strain W-7 was proposed based on the chemical structure of AHL and intermediate products. In addition to the degradation of OdDHL, this strain was also found to be capable of degrading a wide range of AHLs including -(3-oxohexanoyl)-l-homoserine lactone (OHHL), -(3-oxooctanoyl)-l-homoserine lactone (OOHL), and -hexanoyl-l-homoserine lactone (HHL). Moreover, the application of strain W-7 as a biocontrol agent could substantially attenuate the soft rot caused by EC1 to suppress tissue maceration in various host plants. Similarly, the application of crude enzymes of strain W-7 significantly reduced the disease incidence and severity in host plants. These original findings unveil the biochemical aspects of a highly efficient AHL-degrading bacterial isolate and provide useful agents that exhibit great potential for the control of infectious diseases caused by AHL-dependent bacterial pathogens.
PubMed: 34413838
DOI: 10.3389/fmicb.2021.694161 -
BMJ Case Reports May 2021A man in his 50s with neutropenic fever and multifocal lung opacities was diagnosed with a viral pneumonia. A small number of bacteria grown from bronchoalveolar lavage...
A man in his 50s with neutropenic fever and multifocal lung opacities was diagnosed with a viral pneumonia. A small number of bacteria grown from bronchoalveolar lavage fluid collected during a repeat bronchoscopy were initially identified as by VITEK-2 and mass spectrometry platforms. Whole-genome sequencing, however, subsequently demonstrated that the bacteria were , representing the first known case of cultured from human lungs.
Topics: Bronchoalveolar Lavage Fluid; Humans; Lung; Male; Pneumonia; Pseudomonas; Pseudomonas Infections; Pseudomonas aeruginosa
PubMed: 34031078
DOI: 10.1136/bcr-2020-241327