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Journal of Infection and Public Health Dec 2021Marine organisms are the potential contributors of novel bioactive molecules. Nevertheless, their biodiversity and the versatility of bioactive metabolites have not been...
BACKGROUND
Marine organisms are the potential contributors of novel bioactive molecules. Nevertheless, their biodiversity and the versatility of bioactive metabolites have not been fully explored. Hence, the aim of the present study was to investigate the potentials of gut associated bacteria from a marine crab for the production of novel antibacterial compound.
METHODS
Aerobic gut autochthonous bacteria isolated from marine crab (Lissocarinus orbicularis) collected from Pazhayar coastal area in Nagapattinam district of Tamil Nadu, India were screened for antibacterial activity. Optimization for bacterial growth and antimicrobial compound production, extraction, purification and characterization were studied.
RESULTS
In the present study, eight morphologically distinct colonies of L. orbicularis gut associated aerobic bacterial isolates (Iso1-Iso8) on Zobell marine agar plate were selected. Isolates were screened for antimicrobial activity against human bacterial pathogens such as Salmonella paratyphi, Vibrio cholera, Vibrio parahaemolyticus, Aeromonas hydrophila and Listeria monocytogenes. On the basis of screening results, isolate 5 (Iso5) was selected as the most potential strain and identified as Paenibacillus polymyxa using biochemical and 16S rRNA sequencing methods. The sequence data was submitted to NCBI (Gene bank Accession No: MK583465). Optimization of P. polymyxa for growth and antimicrobial compound production revealed incubation period (36 h), agitation (150 rpm), pH 8.0, 35 °C, 2.5% salinity, 2% glucose and 1% yeast extract as carbon and nitrogen sources respectively were the ideal conditions and mass culture was done with these parameters. Antimicrobial compound from the cell free supernatant of mass culture medium was extracted using ethanol. The lowest minimum inhibitory concentration (MIC) of 16 μg/ml was observed against of both V. parahaemolyticus and V. cholerae. GC-MS analysis of the active ethanol fraction showed the presence of different components such as dodecane (96.72%), Tridecane (1.69%), Undecane, 2,6-dimethyl- (1.69%), Tetradecane (1.12%) and Dodecane, 2,6,11-trimethyl- (1.12%).
CONCLUSION
The present study showed that the gut associated autochthonous bacteria of marine crabs are one of the potential sources of antibacterial compound. However, further studies are needed for the identification of the antimicrobial compound.
Topics: Anti-Bacterial Agents; Anti-Infective Agents; Drug Resistance, Bacterial; Humans; India; Microbial Sensitivity Tests; Phylogeny; RNA, Ribosomal, 16S
PubMed: 34750087
DOI: 10.1016/j.jiph.2021.10.003 -
Biotechnology Reports (Amsterdam,... Jun 2022We report the phenotypic variation in E681 (E681), a plant growth-promoting rhizobacterium (PGPR) isolated from a winter barley root in Korea. Phenotypic variation...
We report the phenotypic variation in E681 (E681), a plant growth-promoting rhizobacterium (PGPR) isolated from a winter barley root in Korea. Phenotypic variation (F-type) occurred when E681 (B-type) was grown in the media, and F-type was generated from B-type. B- and F-types were characterized by their morphological, Biolog, and GC-MIDI analyses. F-type cells altered the original biological capacity of B-type cells on endospore and flagella formation, changes in pH in culture, and carbon utilization. In growth curve analysis, B-type variants recovered bacterial growth as the variation occurred after the decline phase, but F-type variants did not. To determine this cause, we conducted comparative proteome analysis between B- and F-types using two-dimensional gel electrophoresis (2-DE). Of the identified proteins, 47% were involved in glycolysis and other metabolic pathways associated with carbohydrate metabolism. Therefore, our findings provide new knowledge on the mechanism of phenotypic variation and insights into agricultural biotechnology.
PubMed: 35686012
DOI: 10.1016/j.btre.2022.e00719 -
Frontiers in Chemistry 2022Microbial bactericides have been a research hotspot in recent years. In order to find new microbial fungicides for preventing and treating rice bacterial diseases, Y-1...
Microbial bactericides have been a research hotspot in recent years. In order to find new microbial fungicides for preventing and treating rice bacterial diseases, Y-1 ( Y-1) was isolated from in this study, and the optimal medium was selected by a single-factor experiment, and then eight metabolites were isolated from Y-1 fermentation broth by bioactivity tracking separation. The bioassay results showed that 2,4-di-tert-butylphenol, N-acetyl-5-methoxytryptamine, and P-hydroxybenzoic acid have good antibacterial activity against pv. () and pv. (), with 50% effective concentration values of 49.45 μg/ml, 64.22 μg/ml, and 16.32 μg/ml to , and 34.33 μg/ml, 71.17 μg/ml, and 15.58 μg/ml to , respectively, compared with zhongshengmycin (0.42 and 0.82 μg/ml, respectively) and bismerthiazol (85.64 and 92.49 μg/ml, respectively). experiments found that 2,4-di-tert-butylphenol (35.9 and 35.4%, respectively), N-acetyl-5-methoxytryptamine (42.9 and 36.7%, respectively), and P-hydroxybenzoic acid (40.6 and 36.8%, respectively) demonstrated excellent protective and curative activity against rice bacterial leaf blight, which were better than that of zhongshengmycin (38.4 and 34.4%, respectively). In addition, after 2,4-di-tert-butylphenol, N-acetyl-5-methoxytryptamine, and P-hydroxybenzoic acid acted on rice, SOD, POD, and CAD defense enzymes increased under the same condition. In conclusion, these results indicated that the activity and mechanism research of new microbial pesticides were helpful for the prevention and control of rice bacterial diseases.
PubMed: 35425761
DOI: 10.3389/fchem.2022.879724 -
Frontiers in Microbiology 2024In recent years, bacterial-based biocontrol agents (BCA) have become a new trend for the control of fungal diseases such as fusarium wilt that seriously threaten the...
In recent years, bacterial-based biocontrol agents (BCA) have become a new trend for the control of fungal diseases such as fusarium wilt that seriously threaten the yield and quality of cucumber, which are transmitted through infested soil and water. This study was set out with the aim of figuring the mechanism of the isolated rhizobacterial strain PJH16 in preventing f. sp. (). Biocontrol and growth-promoting experiments revealed that bacterial strain causes effective inhibition of the fungal disease through a significant growth-promoting ability of plants, and had activities of β-1,3-glucanase, cellulase, amylase and protease. It could produce siderophore and indole-3-acetic acid, too. Using the high-throughput sequencing tool PacBio Sequel II system and the database annotation, the bacterial strain was identified as PJH16 and contained genes encoding for presence of biofilm formation, antimicrobial peptides, siderophores and hydrolyases. From comparing data between the whole genome of PJH16 with four closely related strains, findings revealed markedly the subtle differences in their genome sequences and proposed new antifungal substances present in PJH16. Therefore, PJH16 could be utilized in bioengineering a microbial formulation for application as biocontrol agent and bio-stimulant, in the future.
PubMed: 38591040
DOI: 10.3389/fmicb.2024.1359263 -
Heliyon Mar 2023The rhizosphere microbes play a key role in plant nutrition and health. However, the interaction of beneficial microbes and (lobia) production remains poorly...
The rhizosphere microbes play a key role in plant nutrition and health. However, the interaction of beneficial microbes and (lobia) production remains poorly understood. Thus, we aimed to isolate and characterize the soil microbes from the rhizosphere and develop novel microbial consortia for enhancing lobia production. Fifty bacterial strains were isolated from the rhizosphere soil samples of lobia. Finally, five effective strains (e.g., sp. IESDJP-V1 and sp. IESDJP-V2, IESDJP-V3, IESDJP-V4, sp. IESDJP-V5) were identified and molecularly characterized by 16 S rDNA gene amplification. All selected strains showed positive plant growth promoting (PGP) properties in broth culture. Based on morphological, biochemical, and plant growth promoting activities, five effective isolated strains and two collected strains ( MTCC-4037 and BHUPSB17) were selected. The pot trials were conducted with seed inoculations of lobia var. Kashi Kanchan with thirty treatments and three replications. The treatment combination T3 ( sp. IESDJP-V2), T14 ( sp. IESDJP-V2 + ), T26 ( sp. IESDJP-V1+ IESDJP-V4 + ) and T27 (IESDJP-V1+ IESDJP-V5+ ) were recorded for enhancing plant growth attributes, yield, nutritional content like protein, total sugar, flavonoid and soil properties as compared to control and others. The effective treatments T3 ( sp.), T14 ( sp. IESDJP-V2 + ), T26 ( sp. IESDJP-V1+ IESDJP-V4 + ) and T27 (IESDJP-V1+ IESDJP-V5+ ) recorded as potential PGPR consortium for lobia production. The treatment of single ( sp.), duel (IESDJP-V2 + ) and triple combination (IESDJP-V1+ IESDJP-V4 + ) and (IESDJP-V1+ IESDJP-V5+ ) can be further used for developing effective indigenous consortium for lobia production under sustainable farming practices. These PGPR bio-inoculant will be cost-effective, environment-friendly and socially acceptable.
PubMed: 36895350
DOI: 10.1016/j.heliyon.2023.e13804 -
BMC Genomics Feb 2023Paenibacillus polymyxa WLY78 is a Gram-positive, endospore-forming and N-fixing bacterium. Our previous study has demonstrated that GlnR acts as both an activator and a...
BACKGROUND
Paenibacillus polymyxa WLY78 is a Gram-positive, endospore-forming and N-fixing bacterium. Our previous study has demonstrated that GlnR acts as both an activator and a repressor to regulate the transcription of the nif (nitrogen fixation) operon (nifBHDKENXhesAnifV) according to nitrogen availability, which is achieved by binding to the two GlnR-binding sites located in the nif promoter region. However, further study on the GlnR-mediated global regulation in this bacterium is still needed.
RESULTS
In this study, global identification of the genes directly under GlnR control is determined by using chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR) and electrophoretic mobility shift assays (EMSA). Our results reveal that GlnR directly regulates the transcription of 17 genes/operons, including a nif operon, 14 nitrogen metabolism genes/operons (glnRA, amtBglnK, glnA1, glnK1, glnQHMP, nasA, nasD1, nasD2EF, gcvH, ansZ, pucR, oppABC, appABCDF and dppABC) and 2 carbon metabolism genes (ldh3 and maeA1). Except for the glnRA and nif operon, the other 15 genes/operons are newly identified targets of GlnR. Furthermore, genome-wide transcription analyses reveal that GlnR not only directly regulates the expression of these 17 genes/operons, but also indirectly controls the expression of some other genes/operons involved in nitrogen fixation and the metabolisms of nitrogen and carbon.
CONCLUSION
This study provides a GlnR-mediated regulation network of nitrogen fixation and the metabolisms of nitrogen and carbon.
Topics: Paenibacillus polymyxa; Nitrogen; Promoter Regions, Genetic; Bacterial Proteins; Binding Sites; Gene Expression Regulation, Bacterial
PubMed: 36823556
DOI: 10.1186/s12864-023-09147-1 -
Journal of Food Science and Technology Jan 2022is a microorganism used for the production of carbohydrate biopolymer levan in this work. Film samples were prepared with different contents of levan/bentonite. Film...
is a microorganism used for the production of carbohydrate biopolymer levan in this work. Film samples were prepared with different contents of levan/bentonite. Film samples were evaluated for thickness, water vapor permeability, tensile strength and elongation properties. The most suitable film composite was chosen to evaluate antimicrobial activity. Antimicrobial properties were determined on different microorganisms by adding calendula oil, citronella oil, lemon oil, tamanu oil, peppermint (medical peppermint) oil in varying amounts to the film samples. The highest activity of levan/bentonite/oil composite film on microorganisms was measured with a diameter of 40 mm on in the composition of 0.5 mL of film content +1.5 mL of peppermint (medical peppermint) oil. This high antimicrobial activity film composite was characterized by TGA and SEM. It was made with levan/bentonite and peppermint oil, and the determination of antimicrobial effects of this film composite was reported for the first time. The bio-degradable film obtained has a high potential for use in different areas, especially in food packaging.
PubMed: 35068569
DOI: 10.1007/s13197-021-05009-4 -
ACS Infectious Diseases Apr 2024The polymyxins are nonribosomal lipopeptides produced by and are potent antibiotics with activity specifically directed against Gram-negative bacteria. While the... (Review)
Review
The polymyxins are nonribosomal lipopeptides produced by and are potent antibiotics with activity specifically directed against Gram-negative bacteria. While the clinical use of polymyxins has historically been limited due to their toxicity, their use is on the rise given the lack of alternative treatment options for infections due to multidrug resistant Gram-negative pathogens. The Gram-negative specificity of the polymyxins is due to their ability to target lipid A, the membrane embedded LPS anchor that decorates the cell surface of Gram-negative bacteria. Notably, the mechanisms responsible for polymyxin toxicity, and in particular their nephrotoxicity, are only partially understood with most insights coming from studies carried out in the past decade. In parallel, many synthetic and semisynthetic polymyxin analogues have been developed in recent years in an attempt to mitigate the nephrotoxicity of the natural products. Despite these efforts, to date, no polymyxin analogues have gained clinical approval. This may soon change, however, as at the moment there are three novel polymyxin analogues in clinical trials. In this context, this review provides an update of the most recent insights with regard to the structure-activity relationships and nephrotoxicity of new polymyxin variants reported since 2010. We also discuss advances in the synthetic methods used to generate new polymyxin analogues, both via total synthesis and semisynthesis.
Topics: Anti-Bacterial Agents; Polymyxins; Lipopeptides; Gram-Negative Bacteria; Structure-Activity Relationship
PubMed: 38470446
DOI: 10.1021/acsinfecdis.3c00630 -
Pathogens (Basel, Switzerland) Nov 2021are efficient producers of potent agents against bacterial and fungal pathogens, which are of great interest both for therapeutic applications in medicine as well as in...
are efficient producers of potent agents against bacterial and fungal pathogens, which are of great interest both for therapeutic applications in medicine as well as in agrobiotechnology. Lipopeptides produced by such organisms play a major role in their potential to inactivate pathogens. In this work we investigated two lipopeptide complexes, the fusaricidins and the polymyxins, produced by strains DSM 32871 and M1 by MALDI-TOF mass spectrometry. The fusaricidins show potent antifungal activities and are distinguished by an unusual variability. For strain DSM 32871 we identified numerous yet unknown variants mass spectrometrically. DSM 32871 produces polymyxins of type E (colistins), while M1 forms polymyxins P. For both strains, novel but not yet completely characterized polymyxin species were detected, which possibly are glycosylated. These compounds may be of interest therapeutically, because polymyxins have gained increasing attention as last-resort antibiotics against multiresistant pathogenic Gram-negative bacteria. In addition, the volatilomes of DSM 32781 and M1 were investigated with a GC-MS approach using different cultivation media. Production of volatile organic compounds (VOCs) was strain and medium dependent. In particular, strain M1 manifested as an efficient VOC-producer that exhibited formation of 25 volatiles in total. A characteristic feature of is the formation of volatile pyrazine derivatives.
PubMed: 34832640
DOI: 10.3390/pathogens10111485 -
Molecules (Basel, Switzerland) Jul 2022Incubation of , , and MPI764 with the microbial 2-benzoxazolinone (BOA)-degradation-product -acetamido-phenol, produced from 2-aminophenol, led to the recently...
Incubation of , , and MPI764 with the microbial 2-benzoxazolinone (BOA)-degradation-product -acetamido-phenol, produced from 2-aminophenol, led to the recently identified -(2-hydroxy-5-nitrophenyl) acetamide, to the hitherto unknown (2-hydroxy-5-nitrosophenyl)acetamide, and to (2-hydroxy-3-nitrophenyl)acetamide. As an alternative to the formation of phenoxazinone derived from aminophenol, dimers- and trimers-transformation products have been found. Identification of the compounds was carried out by LC/HRMS and MS/MS and, for the new structure (2-hydroxy-5-nitrosophenyl)acetamide, additionally by 1D- and 2D-NMR. Incubation of microorganisms, such as the soil bacteria , MPI763, the yeast and and the plants var. L. (kohlrabi) and Col-0, with -(2-hydroxy-5-nitrophenyl) acetamide, led to its glucoside derivative as a prominent detoxification product; in the case of , this was together with the corresponding glucoside succinic acid ester. In contrast, consortium synthesized 2-acetamido-4-nitrophenyl sulfate. 1 mM bioactive -(2-hydroxy-5-nitrophenyl) acetamide elicits alterations in the expression profile of several genes. The most responsive upregulated gene was pathogen-inducible terpene synthase The bioactivity of the compound is rapidly annihilated by glucosylation.
Topics: Acetamides; Acetanilides; Arabidopsis; Glucosides; Nitrates; Pantoea; Tandem Mass Spectrometry
PubMed: 35897961
DOI: 10.3390/molecules27154786