Entity

Time filter

Source Type


Meena B.,Sathyabama University | Meena B.,Andaman and Nicobar Center for Ocean Science and Technology | Anburajan L.,SRM University | Ponni B.,Sathyabama University | And 2 more authors.
Gene Reports | Year: 2016

Glycine betaine (N, N, N-trimethylglycine) is an effective compatible solute, which maintains fluidity of membranes and protects the biological structure of the organisms under stress. In this study, glycine bataine biosynthesis genes; betaine aldehyde dehydrogenase (GbsA) and betaine alcohol dehydrogenase (GbsB) from halophilic Bacillus subtilis MA04 was heterologously expressed in Escherichia coli M15 (pREP4). The recombinant enzyme was purified by column chromatography using DEAE sepharose. The purified enzyme revealed a five-fold increase in the activity with choline as substrate and phenazine methosulfate as electron acceptor, compared to the control strain. The glycine betaine biosynthesis gene sequences reported in this study were diverse and appeared to be partially conserved with the GenBank reported sequences of many eubacteria, with subsequent amino acid changes in the translated proteins. © 2016 Elsevier Inc. All rights reserved. Source


Jha D.K.,National Institute of Ocean Technology ESSO NIOT | Jha D.K.,Andaman and Nicobar Center for Ocean Science and Technology | Devi M.P.,Bharathidasan University | Vidyalakshmi R.,Bharathidasan University | And 3 more authors.
Marine Pollution Bulletin | Year: 2015

Seawater samples at 54 stations in the year 2011-2012 from Chidiyatappu, Port Blair, Rangat and Aerial Bays of Andaman Sea, have been investigated in the present study. Datasets obtained have been converted into simple maps using coastal water quality index (CWQI) and Geographical Information System (GIS) based overlay mapping technique to demarcate healthy and polluted areas. Analysis of multiple parameters revealed poor water quality in Port Blair and Rangat Bays. The anthropogenic activities may be the likely cause for poor water quality. Whereas, good water quality was witnessed at Chidiyatappu Bay. Higher CWQI scores were perceived in the open sea. However, less exploitation of coastal resources owing to minimal anthropogenic activity indicated good water quality index at Chidiyatappu Bay. This study is an attempt to integrate CWQI and GIS based mapping technique to derive a reliable, simple and useful output for water quality monitoring in coastal environment. © 2015 Elsevier Ltd. Source


Jha D.K.,Earth System Science Organization ESSO National Institute of Ocean Technology ESSO NIOT | Jha D.K.,Andaman and Nicobar Center for Ocean Science and Technology | Devi M.P.,Bharathidasan University | Vidyalakshmi R.,Bharathidasan University | And 3 more authors.
Marine Pollution Bulletin | Year: 2015

Seawater samples at 54 stations in the year 2011-2012 from Chidiyatappu, Port Blair, Rangat and Aerial Bays of Andaman Sea, have been investigated in the present study. Datasets obtained have been converted into simple maps using coastal water quality index (CWQI) and Geographical Information System (GIS) based overlay mapping technique to demarcate healthy and polluted areas. Analysis of multiple parameters revealed poor water quality in Port Blair and Rangat Bays. The anthropogenic activities may be the likely cause for poor water quality. Whereas, good water quality was witnessed at Chidiyatappu Bay. Higher CWQI scores were perceived in the open sea. However, less exploitation of coastal resources owing to minimal anthropogenic activity indicated good water quality index at Chidiyatappu Bay. This study is an attempt to integrate CWQI and GIS based mapping technique to derive a reliable, simple and useful output for water quality monitoring in coastal environment. © 2015 Elsevier Ltd. Source


Dheenan P.S.,Andaman and Nicobar Center for Ocean Science and Technology | Jha D.K.,National Institute of Ocean Technology ESSO NIOT | Das A.K.,Andaman and Nicobar Center for Ocean Science and Technology | Vinithkumar N.V.,Andaman and Nicobar Center for Ocean Science and Technology | And 2 more authors.
Environmental Pollution | Year: 2016

Urbanization of coastal areas in recent years has driven us to consider a new approach for visually delineating sites that are contaminated with fecal bacteria (FB) in the coastal waters of the Andaman Islands in India. Geo-spatial analysis demarcated harbor, settlement, and freshwater/discharge influenced zones as hot spots for FB, while the open sea was demarcated as a cold spot. The land use types, such as developed and agriculture, with more anthropogenic activities increasing the FB counts while open sea showed the least FB. Box whisker plot indicated an increasing FB trend in the coastal waters during monsoon. Furthermore, principal component analysis revealed 67.35%, 78.62% and 70.43% of total variance at Port Blair, Rangat and Aerial bays, respectively. Strong factor loading was observed for depth (0.95), transparency (0.93), dissolved oxygen (0.93) and fecal streptococci (0.85). Distance proximity analysis revealed that fecal contaminations diluted significantly (P < 0.05) at the distance of 2.1 km toward the deeper or open sea water. This study demonstrates the effectiveness of an integrated approach in identifying the sources of fecal contamination and thus helping in better monitoring and management of coastal waters. © 2016 Elsevier Ltd. All rights reserved. Source


Meena B.,Andaman and Nicobar Center for Ocean Science and Technology | Rajan L.A.,Andaman and Nicobar Center for Ocean Science and Technology | Vinithkumar N.V.,Andaman and Nicobar Center for Ocean Science and Technology | Kirubagaran R.,ESSO National Institute of Ocean Technology NIOT
BMC Microbiology | Year: 2013

Background: Andaman and Nicobar Islands situated in the eastern part of Bay of Bengal are one of the distinguished biodiversity hotspot. Even though number of studies carried out on the marine flora and fauna, the studies on actinobacteria from Andaman and Nicobar Islands are meager. The aim of the present study was to screen the actinobacteria for their characterization and identify the potential sources for industrial and pharmaceutical byproducts. Results: A total of 26 actinobacterial strains were isolated from the marine sediments collected from various sites of Port Blair Bay where no collection has been characterized previously. Isolates were categorized under the genera: Saccharopolyspora, Streptomyces, Nocardiopsis, Streptoverticillium, Microtetraspora, Actinopolyspora, Actinokineospora and Dactylosporangium. Majority of the isolates were found to produce industrially important enzymes such as amylase, protease, gelatinase, lipase, DNase, cellulase, urease and phosphatase, and also exhibited substantial antibacterial activity against human pathogens. 77% of isolates exhibited significant hemolytic activity. Among 26 isolates, three strains (NIOT-VKKMA02, NIOT-VKKMA22 and NIOT-VKKMA26) were found to generate appreciable extent of surfactant, amylase, cellulase and protease enzyme. NIOT-VKKMA02 produced surfactant using kerosene as carbon source and emulsified upto E24-63.6%. Moreover, NIOT-VKKMA02, NIOT-VKKMA22 and NIOT-VKKMA26 synthesized 13.27 U/ml, 9.85 U/ml and 8.03 U/ml amylase; 7.75 U/ml, 5.01 U/ml and 2.08 U/ml of cellulase and 11.34 U/ml, 6.89 U/ml and 3.51 U/ml of protease enzyme, respectively. Conclusions: High diversity of marine actinobacteria was isolated and characterized in this work including undescribed species and species not previously reported from emerald Andaman and Nicobar Islands, including Streptomyces griseus, Streptomyces venezuelae and Saccharopolyspora salina. The enhanced salt, pH and temperature tolerance of the actinobacterial isolates along with their capacity to secrete commercially valuable primary and secondary metabolites emerges as an attractive feature of these organisms. These results are reported for the first time from these emerald Islands and expand the scope to functionally characterize novel marine actinobacteria and their metabolites for the potential novel molecules of commercial interest. © 2013 Meena et al.; licensee BioMed Central Ltd. Source

Discover hidden collaborations