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Microbial Cell Factories Nov 2018N-acylhomoserine lactones (AHLs) are well-studied signalling molecules produced by some Gram-negative Proteobacteria for bacterial cell-to-cell communication or quorum...
BACKGROUND
N-acylhomoserine lactones (AHLs) are well-studied signalling molecules produced by some Gram-negative Proteobacteria for bacterial cell-to-cell communication or quorum sensing. We have previously demonstrated the degradation of AHLs by an Antarctic bacterium, Planococcus versutus L10.15, at low temperature through the production of an AHL lactonase. In this study, we cloned the AHL lactonase gene and characterized the purified novel enzyme.
RESULTS
Rapid resolution liquid chromatography analysis indicated that purified AidP possesses high AHL-degrading activity on unsubstituted, and 3-oxo substituted homoserine lactones. Liquid chromatography-mass spectrometry analysis confirmed that AidP functions as an AHL lactonase that hydrolyzes the ester bond of the homoserine lactone ring of AHLs. Multiple sequence alignment analysis and phylogenetic analysis suggested that the aidP gene encodes a novel AHL lactonase enzyme. The amino acid composition analysis of aidP and the homologous genes suggested that it might be a cold-adapted enzyme, however, the optimum temperature is 28 °C, even though the thermal stability is low (reduced drastically above 32 °C). Branch-site analysis of several aidP genes of Planococcus sp. branch on the phylogenetic trees also showed evidence of episodic positive selection of the gene in cold environments. Furthermore, we demonstrated the effects of covalent and ionic bonding, showing that Zn is important for activity of AidP in vivo. The pectinolytic inhibition assay confirmed that this enzyme attenuated the pathogenicity of the plant pathogen Pectobacterium carotovorum in Chinese cabbage.
CONCLUSION
We demonstrated that AidP is effective in attenuating the pathogenicity of P. carotovorum, a plant pathogen that causes soft-rot disease. This anti-quorum sensing agent is an enzyme with low thermal stability that degrades the bacterial signalling molecules (AHLs) that are produced by many pathogens. Since the enzyme is most active below human body temperature (below 28 °C), and lose its activity drastically above 32 °C, the results of a pectinolytic inhibition assay using Chinese cabbage indicated the potential of this anti-quorum sensing agent to be safely applied in the field trials.
Topics: 4-Butyrolactone; Amino Acid Sequence; Antarctic Regions; Bacterial Proteins; Carboxylic Ester Hydrolases; Models, Molecular; Pectins; Pectobacterium carotovorum; Planococcus Bacteria; Quorum Sensing; Sequence Analysis, Protein; Substrate Specificity
PubMed: 30445965
DOI: 10.1186/s12934-018-1024-6 -
International Journal of Systematic and... May 2022Three strains of members of the family , which can inhibit the growth of some Gram-stain-positive strains, designated M4U3P1, HD4P25 and RD4P76, were isolated from...
Three strains of members of the family , which can inhibit the growth of some Gram-stain-positive strains, designated M4U3P1, HD4P25 and RD4P76, were isolated from halophytes in Baotou, Inner Mongolia, PR China. A phylogenetic analysis based on the 16S rRNA gene and the whole genome sequences revealed that HD4P25 clustered with YIM 93174 with a similarity of 98.4 %, and RD4P76 shared the highest similarity of 16S rRNA gene with SA4 (97.5 %). M4U3P1 clustered with strains of genera and based on whole-genome sequence analyses, but its 16S rRNA gene had the highest similarity to '' EGI 80668 (96.1 %). The average nucleotide's identity by blast (ANIb) and digital DNA-DNA hybridization (dDDH) values of the three isolated strains to their close relatives were well below the threshold value for identifying a novel species.On the basis of the phylogenetic, physiological and phenotypic results, gen. nov., sp. nov. [type strain M4U3P1 (=CGMCC 1.17076=JCM 33851)] sp. nov. [type strain HD4P25 (=CGMCC 1.18651 =JCM 34524)] and sp. nov. [type strain RD4P76 (=CGMCC 1.18659=JCM 34525)] were proposed, respectively. All three species are ubiquitous in the bulk saline-alkaline soils, but only the species represented by strain RD4P76 was widely distributed in the rhizosphere soil, the above-ground part and the roots of . The species represented by M4U3P1 can be detected in the roots of , and rarely detected in the above-ground parts of . The species represented by HD4P25 was rarely detected in the interior of . The three strains could inhibit some of the Gram-stain-positive bacteria (i.e. members of the genera , and ) in the saline-alkali soil. A genomic analysis of these three strains revealed that they can synthesize different antagonistic compounds, such as aminobenzoate and bacitracin or subtilisin.
Topics: Bacillaceae; Bacillus; Bacterial Typing Techniques; Base Composition; Chenopodiaceae; DNA, Bacterial; Fatty Acids; Phospholipids; Phylogeny; RNA, Ribosomal, 16S; Salt-Tolerant Plants; Sequence Analysis, DNA; Soil
PubMed: 35550242
DOI: 10.1099/ijsem.0.005337 -
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 -
Proceedings of the National Academy of... Sep 2016Stable endosymbiosis of a bacterium into a host cell promotes cellular and genomic complexity. The mealybug Planococcus citri has two bacterial endosymbionts with an...
Stable endosymbiosis of a bacterium into a host cell promotes cellular and genomic complexity. The mealybug Planococcus citri has two bacterial endosymbionts with an unusual nested arrangement: the γ-proteobacterium Moranella endobia lives in the cytoplasm of the β-proteobacterium Tremblaya princeps These two bacteria, along with genes horizontally transferred from other bacteria to the P. citri genome, encode gene sets that form an interdependent metabolic patchwork. Here, we test the stability of this three-way symbiosis by sequencing host and symbiont genomes for five diverse mealybug species and find marked fluidity over evolutionary time. Although Tremblaya is the result of a single infection in the ancestor of mealybugs, the γ-proteobacterial symbionts result from multiple replacements of inferred different ages from related but distinct bacterial lineages. Our data show that symbiont replacement can happen even in the most intricate symbiotic arrangements and that preexisting horizontally transferred genes can remain stable on genomes in the face of extensive symbiont turnover.
Topics: Animals; Betaproteobacteria; Gammaproteobacteria; Gene Transfer, Horizontal; Genome, Bacterial; Phylogeny; Planococcus Insect; Sequence Analysis, DNA; Symbiosis
PubMed: 27573819
DOI: 10.1073/pnas.1603910113 -
Frontiers in Microbiology 2019Moderate halophilic bacteria thrive in saline conditions and produce biosurfactant (BS) which facilitates the oil scavenging activity in the oil polluted surroundings....
Moderate halophilic bacteria thrive in saline conditions and produce biosurfactant (BS) which facilitates the oil scavenging activity in the oil polluted surroundings. Production of such unusual bioactive molecules plays a vital role for their survival in an extreme and adverse environment. Current research deals with isolation of strain SAMP MCC 3013 from Indian Arabian coastline sea water for BS production. The bacterium tolerated up to 2.7 M NaCl demonstrating osmotic stress bearable physiological systems. We used integrated approach to explore the genomic insight of the strain SAMP and displayed the presence of gene for BS biosynthesis. The genome analysis revealed this potential to be intrinsic to the strain. Preliminary screening techniques viz., surface tension (SFT), drop collapse (DC) and oil displacement (OD) showed SAMP MCC 3013 as a potent BS producer. BS reduced SFT of phosphate buffer saline (PBS) pH: 7.0 from 72 to 30 mN/m with a critical micelle concentration (CMC) value of 1.3 mg/mL. Subsequent investigation on chemical characterization, using thin layer chromatography (TLC), Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (H NMR and C NMR) and liquid chromatography mass spectrometry (LC-MS) revealed terpene containing BS having sugar, lipid moieties. The genomic sequence analysis of SAMP showed complete genes in the pathway for the synthesis of terpenoid. Probably terpenoid is the accountable backbone molecule for the BS production, but the later stages of terpenoid conversion to the BS could not be found. Moreover, it is important to highlight that till today; no single report documents the in-detailed physico-chemical characterization of BS from sp. Based on genomic and functional properties, the term terpene containing BS is denoted for the surfactant produced by .
PubMed: 30863371
DOI: 10.3389/fmicb.2019.00235 -
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 -
Antonie Van Leeuwenhoek Apr 2015Strain NEAU-ST10-9(T) is a moderately halophilic, coccoid and non-motile bacterium isolated from saline and alkaline soils in the Dechang Township, Zhaodong City, China....
Strain NEAU-ST10-9(T) is a moderately halophilic, coccoid and non-motile bacterium isolated from saline and alkaline soils in the Dechang Township, Zhaodong City, China. The bacterium was found to be aerobic and Gram-stain positive. It forms orange colonies and grows at NaCl concentrations of 2-10 % (w/v) (optimum, 4 % w/v), at 4-50 °C (optimum, 30 °C) and at pH 6.0-10.0 (optimum, pH 7.0). Phylogenetic analyses based on 16S rRNA gene sequences indicated that it belongs to the genus Planococcus within the family Planococcaceae. The most closely related species was Planococcus maritimus, whose type strain (TF-9(T)) showed gene sequence similarities of 99.1 % for 16S rRNA, 83.7 % for gyrB and 87.0 % for rpoB with those of strain NEAU-ST10-9(T), respectively. DNA-DNA hybridization relatedness values between strain NEAU-ST10-9(T) and type strains P. maritimus DSM 17275(T) , P. rifietoensis DSM 15069(T) , P. plakortidis DSM 23997(T), P. citreus DSM 20549(T), P. maitriensis DSM 15305(T), P. salinarum KCTC 13584(T) and P. columbae DSM 17517(T) were from 55 ± 1 to 32 ± 2 %. The DNA G+C content was found to be 45.2 mol %. The major fatty acids (>5 %) were determined as C15:0 anteiso, C16:1 ω7c alcohol, C17:1 ω9c and C17:0 anteiso. The major menaquinones of strain NEAU-ST10-9(T) were identified as MK-7 and MK-8. The polar lipids were found to contain of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphocholine and two unknown lipids. The genotypic, chemotaxonomic and phenotypic analysis indicated that strain NEAU-ST10-9(T) represents a novel species of the genus Planococcus, for which we proposed the name Planococcus dechangensis sp. nov. The type strain is NEAU-ST10-9(T) (=CGMCC 1.12151(T)=DSM 25871(T)).
Topics: Aerobiosis; Bacterial Typing Techniques; Base Composition; China; Cities; Cluster Analysis; Cytosol; DNA Gyrase; DNA, Bacterial; DNA, Ribosomal; DNA-Directed RNA Polymerases; Fatty Acids; Hydrogen-Ion Concentration; Locomotion; Molecular Sequence Data; Nucleic Acid Hybridization; Phospholipids; Phylogeny; Planococcus Bacteria; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Sodium Chloride; Soil Microbiology; Temperature; Vitamin K 2
PubMed: 25652338
DOI: 10.1007/s10482-015-0399-1 -
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 -
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 -
Preparative Biochemistry & Biotechnology 2018The objective was to evaluate the anticancer and antioxidant activities of the methanolic extracts of halophilic bacteria, isolated from soil samples of Marakkanam...
Evaluation of the anti-oxidant property and cytotoxic potential of the metabolites extracted from the bacterial isolates from mangrove Forest and saltern regions of South India.
The objective was to evaluate the anticancer and antioxidant activities of the methanolic extracts of halophilic bacteria, isolated from soil samples of Marakkanam saltern and Pichavaram mangrove forest, India. Radical Scavenging activity, reducing power, and metal ion chelation ability was used to evaluate the antioxidant potential of the metabolic extracts, whereas cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The methanolic extract of Bacillus VITPS7 exhibited significant antioxidant property. Bacillus VITPS14 and Bacillus VITPS16 extracts were cytotoxic against HeLa cell lines but not to A549 cell lines. Colorimetric assays for the presence of specific metabolites including, total flavonoid and β carotene content were performed. The presence of these specific classes of metabolites was confirmed by UV-Visible spectrophotometry, Nuclear Magnetic Resonance (NMR) spectroscopy and Gas Chromatography-Mass Spectrometry (GC-MS). Specific NMR signals revealed the presence of aromatic and unsaturated metabolites whereas GC-MS analysis indicated the presence of metabolites such as squalene and methyl hexadeconate. The present study thus reports for the first time the presence of squalene in Bacillus VITPS12 and Planococcus maritimus VITP21, in addition to other metabolites that contribute to the observed antioxidant or/and cytotoxicity, thus revealing the therapeutic potential of these selected halophilic bacterial isolates.
Topics: Antineoplastic Agents; Antioxidants; Bacillus; Cytotoxins; HeLa Cells; Humans; India; Wetlands
PubMed: 30303456
DOI: 10.1080/10826068.2018.1508038