Characterization of an exopolysaccharide produced by a marine <i>Enterobacter cloacae</i>

467-471An exopolysaccharide producing marine bacterium, Enterobacter cloacae, was isolated from marine sediment collected from Gujarat coast, India. Chemical investigation of exopolysaccharide (EPS 71 a) revealed that this exopolysaccharide was an acidic polysaccharide containing high amount of uronic acid, fucose and sulfate which is rare for bacterial exopolysaccharides. EPS 71a was found to have fucose, galactose, glucose and glucuronic acid in a molar ratio of 2:1:1:1

Antibacterial and Antioxidant Activities of Novel Actinobacteria Strain Isolated from Gulf of Khambhat, Gujarat

Bacterial secondary metabolites possess a wide range of biologically active compounds including antibacterial and antioxidants. In this study, a Gram-positive novel marine Actinobacteria was isolated from sea sediment which showed 84% 16S rRNA gene sequence (KT588655) similarity with Streptomyces variabilis (EU841661) and designated as Streptomyces variabilis RD-5. The genus Streptomyces is considered as a promising source of bioactive secondary metabolites. The isolated novel bacterial strain was characterized by antibacterial characteristics and antioxidant activities. The BIOLOG based analysis suggested that S. variabilis RD-5 utilized a wide range of substrates compared to the reference strain. The result is further supported by statistical analysis such as AWCD (average well color development), heat-map and PCA (principal component analysis). The whole cell fatty acid profiling showed the dominance of iso/anteiso branched C15–C17 long chain fatty acids. The identified strain S. variabilis RD-5 exhibited a broad spectrum of antibacterial activities for the Gram-negative bacteria (Escherichia coli NCIM 2065, Shigella boydii NCIM, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas sp. NCIM 2200 and Salmonella enteritidis NCIM), and Gram-positive bacteria (Bacillus subtilis NCIM 2920 and Staphylococcus aureus MTCC 96). Extract of S. variabilis strain RD-5 showed 82.86 and 89% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and metal chelating activity, respectively, at 5.0 mg/mL. While H2O2 scavenging activity was 74.5% at 0.05 mg/mL concentration. Furthermore, polyketide synthases (PKSs types I and II), an enzyme complex that produces polyketides, the encoding gene(s) detected in the strain RD-5 which may probably involve for the synthesis of antibacterial compound(s). In conclusion, a novel bacterial strain of Actinobacteria, isolated from the unexplored sea sediment of Alang, Gulf of Khambhat (Gujarat), India showed promising antibacterial activities. However, fractionation and further characterization of active compounds from S. variabilis RD-5 are needed for their optimum utilization toward antibacterial purposes

Influence of low salinity stress on virulence and biofilm formation potential in

The Gujarat government has proposed a project to convert a part of the Gulf of Khambhat (GoK), located in western India, into the world’s largest man-made freshwater reservoir in the near future (http://www.kalpasar.gujarat.gov.in/mainpage.ht

Assessment of heavy metal content in suspended particulate matter of coastal industrial town, Mithapur, Gujarat, India

Heavy metal concentrations in suspended particulate matter (SPM) were investigated for their distribution and source in the atmosphere of coastal industrial town, Mithapur, Gujarat, India. SPM, at 10 locations covering three seasons, were trapped on glass fibre filters using high volume samplers and quantification of metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) was done using Atomic Absorption Spectrometry employing HNO3 based wet digestion. Results show relatively low concentrations of SPM (211.3 to 375.2 μg/m3) compared to National Ambient Air Quality Standard (NAAQS), specified By Central Pollution Control Board (CPCB, India), however, they were 2–3 times higher as compared to reference site. Among the heavy metals Cr, Mn and Pb levels were low, while Ni and Cd found to be exceeding the USEPA standards. The metal levels were also compared with those reported for other rural, coastal, industrial and urban parts around the world. Enrichment Factor analysis indicated that Cd, Zn, Cu, Pb and Ni were highly enriched relative to their crustal ratios (to Fe) and correspond to substantial contribution of anthropogenic source of these metals. The source identification was carried out by principal component analysis by applying a Varimax Rotated Component Matrix

Occurrence and distribution of selected heavy metals and boron in groundwater of the Gulf of Khambhat region, Gujarat, India

The concentration of selected heavy metals, like As, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn as well as B, was measured by inductively coupled plasma–optical emission spectrometry (ICP–OES) in groundwater samples from various locations in the Gulf of Khambhat (GoK), an inlet of the Arabian Sea in the state of Gujarat, India, during postmonsoon, winter, and pre-monsoon seasons in a year. Most heavy elements are characterized by low mobility under slightly alkaline and reducing conditions; concentrations in confined aquifers are smaller than the maximum permissible values for drinking water. The temporal changes indicate that a majority of metals is entering the aquifer during monsoon. Principle component analysis of the heavy metal data suggests that Co, Cu, Cd, and Zn are interrelated with each other and derived significantly from anthropogenic route, while input of Pb and Cr may be due to atmospheric deposition in the study area. Both weathering of rocks and anthropogenic input were found to be main sources of elements in the groundwater. The heavy metal levels in groundwaters of the GoK region in comparison with some of the European and Asian sites were higher; however, these metal levels were found to be comparable with few urban sites in the world