Planococcus Maritimus Research Articles

Synthesis of silver nanoparticles from marine bacteria and evaluation of antimicrobial, antifungal and cytotoxic effects

BackgroundMarine bacteria, a relatively untapped resource, have shown potential for synthesizing nanoparticles with distinct properties. MethodsThe AgNPs were synthesized by using the marine bacteria Planococcus maritimus MBP-2 as a reducing and capping agent. The nanoparticles produced were characterized by UV–Vis spectroscopy, TEM and FTIR. The Planococcus maritimus MBP-2 synthesized AgNPs adhered antibacterial activity against selected both gram-negative and gram-positive bacteria such as Staphylococcus aureus, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, and antifungal such Aspergillus niger, Aspergillus flavus, Penicillium commune and Penicillium digitatum. and the cytotoxic effect of Dalton’s Lymphoma Ascites (DLA) cell lines. ResultsThe formation of AgNPs by bacteria was confirmed visually by a shift in color of the solution and the presence of UV-absorption maxima at 440 nm. The TEM images revealed spherical and cubic structures, with an average size of 24.9 nm. FTIR analysis confirmed the presence of some functional groups by showing peaks at 3330 and 1636 cm−1. The AgNPs exhibited minimal antibacterial activity except P. aeruginosa. (11 mm). Whereas, inhibiting the growth of the fungi belonging to genus Aspergillus than to Penicillium. Also, in vitro cytotoxicity of AgNPs was evaluated using Dalton’s Lymphoma Ascites (DLA) cell lines. The percentage of cell death was maximum (95.4 ± 2.16) at 20 µg/mL, indicating an excellent cytotoxic efficiency of AgNPs against DLA cells from the peritoneal cavity of the tumor-bearing mouse. ConclusionThis study suggests that Planococcus maritimus MBP-2 bacteria-mediated AgNPs can effectively be used as a potential biomedical agent.

Isolation and characterization of novel carotenoid pigment from marine Planococcus maritimus MBP-2 and their biological applications

BackgroundNumerous types of carotenoids with other structures are produced by organisms like bacteria, fungi, algae, yeast, higher plants, etc. In the present study, carotenoid pigment-producing, orange or red-pigmented organisms were isolated from scraping from the ship hull. Material and MethodsAccording to Bergey's manual of systematic bacteriology, the isolated bright orange pigmented organism was identified based on morphology, biochemical and physiological characters, strain myelin basic protein MBP-2 and identified as Planococcus maritimus. ResultsOrange pigment was extracted by solvent extraction method and characterized by using UV–Vis spectroscopy, scanning electron microscope, Transmission electron microscope, and Fourier-transform infrared spectroscopy. The Maximum absorbance was obtained at 447 nm, justify the presence carotenoid pigment in MBP-2 and FTIR results reveals the same. The antibacterial activities were performed against gram positive bacteria, Staphylococcus aureus (ATCC 25923) was 6 ± 0.12 mm, Bacillus cereus (ATCC 14579) was 12.3 ± 1.02 mm and gram negative Escherichia coli was 5.8 ± 0.91 mm, Pseudomonas aeruginosa (ATCC 39315) was 5.6 ± 1.12 mm and Klebsiella pneumoniae (ATCC 13313) was 11.6 ± 1.01. Furthermore antifungal activities were tested against Aspergillus niger (5 ± 2.15 mm), Aspergillus flavus (25 ± 0.85 mm), Pencillium commune( 14.8 ± 1.15 mm), Pencillium digitatum (12.0 ± 1.8) mmand showed sensitive to some of the bacterial and fungal pathogens. The in-vitro cytotoxic activity of pigment showed 19.46 ± 1.46% of cell death against DLA cells at 20 μl/ml of the drug concentration. ConclusionThe isolated orange carotenoid is a good source to treat antimicrobial, antifungal and anticancer activates and further study to be implemented.

Prospective use of a cell‐free supernatant from the biosurfactant‐producing marine Planococcus maritimus SAMP MCC 3013 for oil removal and enhanced oil recovery

AbstractThe cell‐free supernatant (CFS) of the biosurfactant (BS) producing pure strain of Planococcus maritimus SAMP MCC 3013 was used for enhanced oil recovery (EOR). An indigenous marine culture of P. maritimus was grown in mineral salt medium (MSM) supplemented with glucose (1%) (w/v) (30°C, 120 rpm, 7 days). CFS was used to demonstrate its application for oil recovery through three assays: pumice stone, saturated gravel, and the glass beads‐packed column. The recovery of light paraffin oil was ∼40% in the pumice stone assay and ∼43% in the oil‐saturated gravel assay, respectively. The glass bead column demonstrated ∼42% of additional 2T engine oil recovery by CFS. Our study showed that BS containing CFS from P. maritimus SAMP MCC 3013 has the ability to recover oil in its crude form without using any sophisticated purification techniques. All three methods operated by us are harmonizing with each other with respect to the findings. Those methods can be employed in large scale operations for the bio‐recovery of oils using an environmentally friendly approach through the functional properties of BS. This is most likely the first report describing the use of a glass bead pack column for EOR applications particularly from Planococcus sp. These results are symbolic of prospective applications of BS containing CFS from indigenous P. maritimus SAMP MCC 3013 under ex‐situ conditions.

Systematic functional analysis and potential application of a serine protease from cold-adapted Planococcus bacterium

In this study, a gene encoding serine protease (PmSpr288) from cold-adapted bacterium, namely Planococcus maritimus XJ11, was cloned and overexpressed in Escherichia coli BL21 (DE3). Bioinformatics analysis revealed that PmSpr288 belongs to serine protease S8 superfamily with a classical catalytic triad comprised by the Asp49, His86 and Ser251. Moreover, PmSpr288 was found to be active over broad alkaline pH and low-moderate temperature, and exhibited wide range of protein substrate specificity. In addition, PmSpr288 was able to hydrolyze the meat proteins actin and myosin, and molecular docking results suggested that the crucial interaction between PmSpr288 and actin/myosin complexes was mainly occupied by hydrogen bonds. The muscle protein hydrolysates of silver carp prepared by PmSpr288 was shown to have antioxidant activity via DPPH radical scavenging assay, which presented an IC50 valve of 1.309 mg/mL. In conclusion, these characteristics imply that PmSpr288 has potential biotechnological application prospect for the production of bioactive peptides.

Production of Highly Modified C30-carotenoids with Singlet Oxygen-quenching Activities, 5-glucosyl-5,6-dihydro-4,4’-diapolycopen-4’-oic Acid, and Its Three Intermediates Using Genes from Planococcus maritimus Strain iso-3

Production of Highly Modified C30-carotenoids with Singlet Oxygen-quenching Activities, 5-glucosyl-5,6-dihydro-4,4’-diapolycopen-4’-oic Acid, and Its Three Intermediates Using Genes from Planococcus maritimus Strain iso-3

Heterologous production of novel and rare C30-carotenoids using Planococcus carotenoid biosynthesis genes

BackgroundMembers of the genus Planococcus have been revealed to utilize and degrade solvents such as aromatic hydrocarbons and alkanes, and likely to acquire tolerance to solvents. A yellow marine bacterium Planococcus maritimus strain iso-3 was isolated from an intertidal sediment that looked industrially polluted, from the Clyde estuary in the UK. This bacterium was found to produce a yellow acyclic carotenoid with a basic carbon 30 (C30) structure, which was determined to be methyl 5-glucosyl-5,6-dihydro-4,4′-diapolycopenoate. In the present study, we tried to isolate and identify genes involved in carotenoid biosynthesis from this marine bacterium, and to produce novel or rare C30-carotenoids with anti-oxidative activity in Escherichia coli by combinations of the isolated genes.ResultsA carotenoid biosynthesis gene cluster was found out through sequence analysis of the P. maritimus genomic DNA. This cluster consisted of seven carotenoid biosynthesis candidate genes (orf1–7). Then, we isolated the individual genes and analyzed the functions of these genes by expressing them in E. coli. The results indicated that orf2 and orf1 encoded 4,4′-diapophytoene synthase (CrtM) and 4,4′-diapophytoene desaturase (CrtNa), respectively. Furthermore, orf4 and orf5 were revealed to code for hydroxydiaponeurosporene desaturase (CrtNb) and glucosyltransferase (GT), respectively. By utilizing these carotenoid biosynthesis genes, we produced five intermediate C30-carotenoids. Their structural determination showed that two of them were novel compounds, 5-hydroxy-5,6-dihydro-4,4′-diaponeurosporene and 5-glucosyl-5,6-dihydro-4,4′-diapolycopene, and that one rare carotenoid 5-hydroxy-5,6-dihydro-4,4′-diapolycopene is included there. Moderate singlet oxygen-quenching activities were observed in the five C30-carotenoids including the two novel and one rare compounds.ConclusionsThe carotenoid biosynthesis genes from P. maritimus strain iso-3, were isolated and functionally identified. Furthermore, we were able to produce two novel and one rare C30-carotenoids in E. coli, followed by positive evaluations of their singlet oxygen-quenching activities.

Planococcus maritimus ML1206 Isolated from Wild Oysters Enhances the Survival of Caenorhabditis elegans against Vibrio anguillarum.

With the widespread occurrence of aquaculture diseases and the broad application of antibiotics, drug-resistant pathogens have increasingly affected aquatic animals’ health. Marine probiotics, which live under high pressure in a saltwater environment, show high potential as a substitute for antibiotics in the field of aquatic disease control. In this study, twenty strains of non-hemolytic bacteria were isolated from the intestine of wild oysters and perch, and a model of Caenorhabditis elegans infected by Vibrio anguillarum was established. Based on the model, ML1206, which showed a 99% similarity of 16S rRNA sequence to Planococcus maritimus, was selected as a potential marine probiotic, with strong antibacterial capabilities and great acid and bile salt tolerance, to protect Caenorhabditis elegans from being damaged by Vibrio anguillarum. Combined with plate counting and transmission electron microscopy, it was found that strain ML1206 could significantly inhibit Vibrio anguillarum colonization in the intestinal tract of Caenorhabditis elegans. Acute oral toxicity tests in mice showed that ML1206 was safe and non-toxic. The real-time qPCR results showed a higher expression level of genes related to the antibacterial peptide (ilys-3) and detoxification (ugt-22, cyp-35A3, and cyp-14A3) in the group of Caenorhabditis elegans protected by ML1206 compared to the control group. It is speculated that ML1206, as a potential probiotic, may inhibit the infection caused by Vibrio anguillarum through stimulating Caenorhabditis elegans to secrete antibacterial effectors and detoxification proteins. This paper provides a new direction for screening marine probiotics and an experimental basis to support the potential application of ML1206 as a marine probiotic in aquaculture.

Non-Target Effects of dsRNA Molecules in Hemipteran Insects.

Insect pest control by RNA interference (RNAi)-mediated gene expression knockdown can be undermined by many factors, including small sequence differences between double-stranded RNA (dsRNA) and the target gene. It can also be compromised by effects that are independent of the dsRNA sequence on non-target organisms (known as sequence-non-specific effects). This study investigated the species-specificity of RNAi in plant sap-feeding hemipteran pests. We first demonstrated sequence-non-specific suppression of aphid feeding by dsRNA at dietary concentrations ≥0.5 µg µL−1. Then we quantified the expression of NUC (nuclease) genes in insects administered homologous dsRNA (with perfect sequence identity to the target species) or heterologous dsRNA (generated against a related gene of non-identical sequence in a different insect species). For the aphids Acyrthosiphon pisum and Myzus persicae, significantly reduced NUC expression was obtained with the homologous but not heterologous dsRNA at 0.2 µg µL−1, despite high dsNUC sequence identity. Follow-up experiments demonstrated significantly reduced expression of NUC genes in the whitefly Bemisia tabaci and mealybug Planococcus maritimus administered homologous dsNUCs, but not heterologous aphid dsNUCs. Our demonstration of inefficient expression knockdown by heterologous dsRNA in these insects suggests that maximal dsRNA sequence identity is required for RNAi targeting of related pest species, and that heterologous dsRNAs at appropriate concentrations may not be a major risk to non-target sap-feeding hemipterans.

Genome sequencing of cold-adapted Planococcus bacterium isolated from traditional shrimp paste and protease identification.

Psychrophiles have evolved to adapt to freezing environments, and cold-adapted enzymes from these organisms can maintain high catalytic activity at low temperature. The use of cold-adapted enzymes has great potential for the revolution of food and molecular biology industries. In this study, four different strains producing protease were isolated from traditional fermented shrimp paste, one of which, named Planococcus maritimus XJ11 by 16S rRNA nucleotide sequence analysis, exhibited the largest protein hydrolysis clear zone surrounding the colonies. Meanwhile, the strain P. maritimus XJ11 was selected for further investigation because of its great adaptation to low temperature, low salinity and alkaline environment. The enzyme activity assay of P. maritimus XJ11 indicated that the optimum conditions for catalytic activity were pH 10.0 and 40 °C. Moreover, the enzyme also showed an increasing activity with temperatures from 10 to 40 °C and retained more than 67% activity of the maximum over a broad range of salinity (50-150 g L-1 ). Genome sequencing analysis revealed that strain XJ11 possessed one circular chromosome of 3 282 604 bp and one circular plasmid of 67 339 bp, with a total number of 3293 open reading frames (ORFs). Besides, 21 genes encoding protease, including three serine proteases, were identified through the NR database. Cold-adapted bacterium P. maritimus XJ11 was capable of producing alkaline proteases with high catalytic efficiency at low or moderate temperatures. Furthermore, the favorable psychrophilic and enzymatic characters of strain P. maritimus XJ11 seem to have a promising potential for industrial application. © 2020 Society of Chemical Industry.

Evaluation of bioremediation competence of indigenous bacterial strains isolated from fabric dyeing effluent

In this present assessment, fabric dyeing wastewater was subjected to the characterization of physical-chemical parameters in terms of colour, TDS, COD and chloride. The indigenous bacterial strains were isolated from the effluent and identified as Bacillus velezensis, Chryseomicrobium imtechense, Planococcus maritimus and Sphingobacterium daejeonense by 16S rRNA gene sequencing method. The bioremediation competency of the strains was evaluated by conducting treatment process with monoculture and bacterial consortium. The consortia removed about 98%, 71.5%, 79%, 69.65% of colour, TDS, COD and chloride, respectively. Among the four isolates, monoculture of B. velezensis showed effective diminution of pollutants from the effluent than other strains. The bacterial degradation of pollutants was determined by GC–MS based on the disappearance of certain peaks after bioremediation. The results suggested that the bioremediation efficiency of bacterial strains can be utilized as an eco-friendly and inexpensive method for dyeing effluent treatment.

Identification and characterization of psychrotrophic strain of Planococcus maritimus for glucosylated C30 carotenoid production

Cold-adapted bacteria produce various pigments as their adaptive strategy. Here, we studied an aerobic, gram-positive motile coccoid bacterial strain KK21, isolated from the Siachen, Himalayas and characterized the major pigments present in it. The KK21 strain is capable of growth in a broad range of temperature (-4 to 37°C), pH (6.0-13.0) and salinity (0.5-8%). Phylogenetic analysis based on 16S rRNA gene sequence showed that it belongs to the genus Planococcus and closely related to P. maritimus. Total pigment extraction was best found in polar methanol. Alanine among amino acids, NaCl among inorganic salts and evening primrose amongst oils best supported the pigment production at 10°C after 6 days in BHI at neutral pH of 7.0. Maximum pigment production was recorded at 3% of NaCl concentration. In photoprotection activity, radiation exposed plates showed increased colony forming units and more than 3.5 times of total carotenoid production after 15 min exposure compared to the control group. Detailed characterization of orange pigment was done systematically by TLC, HPLC and MALDI-TOF. Chromatographic and MALDI-TOF data have revealed the exclusive presence of glycosylated C30-carotenoid in P. maritimus KK21 with m/z of 655.871.

Exploring the Pharmacological Potentials of Biosurfactant Derived from Planococcus maritimus SAMP MCC 3013.

Therapeutic potential of biosurfactant (BS) has been improved in recent years. Our present study deals with production of BS from Planococcus maritimus SAMP MCC 3013 in a mineral salt medium (MSM) supplemented with glucose (1.5%w/v). Further, BS has been purified and partially characterized as glycolipid type through our previous publication. Current research article aimed to evaluate biological potential of BS against Mycobacterium tuberculosis, Plasmodium falciparum and cancerous cell lines. Planococcus derived glycolipid BS was found to be a promising inhibitor of M. tuberculosis (MTB) H37Ra at IC50 64.11 ± 1.64μg/mL and MIC at 160.8 ± 1.64μg/mL. BS also showed growth inhibition of P. falciparum at EC50 34.56 ± 0.26µM. Additionally, BS also displayed the cytotoxicity against HeLa (IC50 41.41 ± 4.21μg/mL), MCF-7 (IC50 42.79 ± 6.07μg/mL) and HCT (IC50 31.233 ± 5.08μg/mL) cell lines. Molecular docking analysis was carried for the most popular glycolipid type BS namely Rhamnolipid (RHL) aiming to interpret the possible binding interaction for anti-tubercular and anti-cancer activity. This analysis revealed the involvement of RHL binding with enoyl reductase (InhA) of M. tuberculosis. Docking studies of RHL with tubulin directed several hydrophobic and Vander Waal interactions to exhibit anti-cancer potential. The present study will be helpful for further development of marine bioactive molecules for therapeutic applications. Their anti-tubercular, anti-plasmodial and cytotoxic activities make BS molecules as a noteworthy candidate to combat several diseases. To the best of our knowledge, this is the first report on projecting the pharmacological potential of Planococcus derived BS.

Formulation of Effective Microbial Consortium and Its Application for Industrial Wastewater Treatment

The present study was conducted for auto mobile industry, food industry and pharmaceutical industries waste water treatment using effective microbial consortium. The effective microorganisms like Acinetobacter pittii, Escherichia coli, Fictibacillus nanhaiensis, Lysinibacillus xylanilyticus and Planococcus maritimus were isolated from respective sources. The microbial consortium was formulated using molasses as medium at pH 3.8 and incubated at 37°C for 3 days. The results showed that the formulated consortium was efficient for industrial waste water treatment and thereby it reduced the environmental impact.
 Keywords: Bio-remediation, Microbial consortium, Industrial waste water, Heavy metals

Differential Production of Pigments by Halophilic Bacteria Under the Effect of Salt and Evaluation of Their Antioxidant Activity.

Microorganisms that survive in the high salt environment have been shown to be a potential source for metabolites with pharmaceutical importance. In the present study, we have investigated the effect of 5 and 10% (w/v) NaCl on growth, biochemical changes, and metabolite production in seven moderately halophilic bacteria isolated from the salterns/mangrove area of South India. Metabolite production by Bacillus VITPS3 increased by 3.18-fold in the presence of 10% (w/v) NaCl concentration. Total phenolic and flavonoid content increased in Bacillus VITPS5 (11.3-fold) and Planococcus maritimus VITP21 (5.99-fold) whereas β-carotene content was less at higher NaCl concentrations. VITP21 and VITPS5, in response to NaCl, produced metabolites with higher (6.72- and 4.91-fold) DPPH and ABTS radical scavenging activity. UV/visible spectrophotometry of the extracts confirmed the presence of flavonoids, phenolics, and related compounds. 1H-NMR spectra indicated substantial changes in the metabolite production in response to salt concentration. Principal component analysis (PCA) revealed that VITP21 extracts exhibited the highest antioxidant activity compared with other extracts. The present study presents the first report on the comparative analysis of pigment production by moderate halophilic bacteria, in response to the effect of salt and their relation to radical scavenging property.

Indiicoccus explosivorum gen. nov., sp. nov., isolated from an explosives waste contaminated site.

A pink-pigmented, Gram-stain-positive, aerobic, coccoid-shaped bacterial strain, designated as S5-TSA-19T, was isolated from an explosives contaminated site in Panchkula, Haryana, India. The 16S rRNA gene sequencing blast analysis indicated that the strain is a member of the family Planococcaceae with the highest sequence similarity to Planomicrobium soli XN13T (96.1 %), followed by Planococcus maitriensis S1T (95.6 %), Planococcus plakortidis DSM 23997T (95.6 %), Planomicrobium flavidum ISL-41T (95.6 %), Planococcus rifietoensis M8T (95.5 %), Planococcus salinus LCB217T (95.5 %) and Planococcus maritimus DSM 17275T (95.5 %). Phylogenetic analysis based on 16S rRNA gene and whole-genome sequences (based on a conserved set of 400 proteins) retrieved the strain in a distinct branch indicating a separate lineage within the family Planococcaceae. Strain S5-TSA-19T had a distinctive chemotaxonomic pattern comprising A4α type peptidoglycan based on l-Lys-d-Asp, iso-C15 : 0 as the major fatty acid, absence of phosphatidylethanolamine as a major lipid and MK-7 and MK-6 as the major menaquinones, differentiating it from the genera Planococcus and Planomicrobium, thus supporting the findings of molecular phylogeny. Further, strain S5-TSA-19T was able to biotransform hexahydro-1,3,5,-trinitro-1,2,5-triazine (RDX) into nitrite derivatives under aerobic conditions in 2-4 days, whereas the closest reference strains did not possess this property. On the basis of polyphasic taxonomic characterization and a phylogenomics approach, strain S5-TSA-19T is proposed as the type strain of a novel species in a novel genus for which the name Indiicoccus explosivorum gen. nov., sp. nov. is proposed (=JCM 31737T=KCTC 33871T=MTCC 12608T).

Genomic Insights of Halophilic Planococcus maritimus SAMP MCC 3013 and Detail Investigation of Its Biosurfactant Production.

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 Planococcus maritimus 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 (1H NMR and 13C NMR) and liquid chromatography mass spectrometry (LC-MS) revealed terpene containing BS having sugar, lipid moieties. The genomic sequence analysis of P. maritimus 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 Planococcus sp. Based on genomic and functional properties, the term terpene containing BS is denoted for the surfactant produced by P. maritimus.

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.

An Uncharacterized Major Facilitator Superfamily Transporter From Planococcus maritimus Exhibits Dual Functions as a Na+(Li+, K+)/H+ Antiporter and a Multidrug Efflux Pump.

Within major facilitator superfamily (MFS), up to 27 unknown major facilitator families and many members of 60 well-characterized families have been functionally unknown as yet, due to their sharing no or significantly low sequence identity with characterized MFS members. Here we present the first report on the characterization of one functionally unknown MFS transporter designated MdrP with the accession version No. ANU18183.1 from the slight halophile Planococcus maritimus DS 17275T. During the screening of Na+/H+ antiporter genes, we found at first that MdrP exhibits Na+(Li+, K+)/H+ antiport activity, and propose that it should represent a novel class of Na+(Li+, K+)/H+ antiporters. However, we speculate that MdrP may possess an additional protein function. The existence of the signature Motif A of drug/H+antiporter (DHA) family members and phylogenetic analysis suggest that MdrP may also function as a drug efflux pump, which was established by minimum inhibitory concentration tests and drug efflux activity assays. Taken together, this novel MFS transporter exhibits dual functions as a Na+(Li+, K+)/H+ antiporter and a multidrug efflux pump, which will be very helpful to not only positively contribute to the function prediction of uncharacterized MFS members especially DHA1 family ones, but also broaden the knowledge of Na+/H+ antiporters.

Phylogenetic diversity and biotechnological potentials of marine bacteria from continental slope of eastern Arabian Sea.

Marine environments are substantially untapped source for the isolation of bacteria with the capacity to produce various extracellular hydrolytic enzymes, which have important ecological roles and promising biotechnological applications. Hydrolases constitute a class of enzymes widely distributed in nature from bacteria to higher eukaryotes. Marine microbial communities are highly diverse and have evolved during extended evolutionary processes of physiological adaptations under the influence of a variety of ecological conditions and selection pressures. A number of marine hydrolases have been described, including amylases, lipases and proteases, which are being used extensively for biotechnological applications. The present study was carried out to isolate marine bacteria from continental slope sediments of the eastern Arabian Sea and explore their biotechnological potential. Among the 119 isolates screened, producers of amylases (15%), caseinases (40%), cellulases (40%), gelatinases (60%), lipases (26%), ligninases (33%), phytase (11%) and Malachite Green dye degraders (16%) were detected. Phylogenetic analysis based on 16S rRNA gene sequencing showed that predominant marine sediment bacteria possessing more than four enzymatic activities belonged to the phyla Firmicutes and Proteobacteria, was assigned to the genera Bacillus, Planococcus, Staphylococcus, Chryseomicrobium, Exiguobacterium and Halomonas. Biodegradation of the dye Malachite Green using the liquid decolorization assay showed that both the individual cultures (Bacillus vietnamensis, Planococcus maritimus and Bacillus pumilus) and their consortium were able to decolorize more than 70% of dye within 24 h of incubation. This is the first report on diversity and extracellular hydrolytic enzymatic activities and bioremediation properties of bacteria from continental slope sediment of eastern Arabian Sea.

Planococcus versutus sp. nov., isolated from soil.

A taxonomic study was performed on a novel Gram-stain-positive, coccus-shaped, orange-pigmented motile bacterium, designated as strain L10.15T. The organism was isolated from a soil sample collected in Lagoon Island (close to Adelaide Island, western Antarctic Peninsula) using a quorum-quenching enrichment medium. Growth occurred at 4-30 °C, pH 6-11 and at moderately high salinity (0-15 %, w/v, NaCl), with optimal growth at 26 °C, at pH 7-8 and with 6 % (w/v) NaCl. 16S rRNA gene sequence analysis showed that strain L10.15T belonged to the genus Planococcus and was closely related to Planococcus halocryophilus Or1T (99.3 % similarity), Planococcus donghaensis JH1T (99.0 %), Planococcus antarcticus DSM 14505T (98.3 %), Planococcus plakortidis AS/ASP6 (II)T (97.6 %), Planococcus maritimus TF-9T (97.5 %), Planococcus salinarum ISL-6T (97.5 %) and Planococcus kocurii NCIMB 629T (97.5 %). However, the average nucleotide identity-MUMmer analysis showed low genomic relatedness values of 71.1-81.7 % to the type strains of these closely related species of the genus Planococcus. The principal fatty acids were anteiso-C15 : 0, C16 : 1ω7c and anteiso-C17 : 0, and the major menaquinones of strain L10.15T were MK-5 (48 %), MK-6 (6 %) and MK-7 (44 %). Polar lipid analysis revealed the presence of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and aminophospholipid. The DNA G+C content was 39.4 mol%. The phenotypic and genotypic data indicate that strain L10.15T represents a novel species of the genus Planococcus, for which the name Planococcus versutus sp. nov. is proposed. The type strain is L10.15T (=DSM 101994T=KACC 18918T).