Seawater quality conditions of the south Andaman Sea (Bay of Bengal, Indian Ocean) in lustrum during 2010s decade.

Andaman and Nicobar islands is one of the major tourism hubs of the World. Most travelers visit these islands for historical attractions, beaches, snorkeling, scuba diving, coral reefs, adventure and recreation. Port Blair is the capital and sole entry/exit point of these islands. The coasts of Port Blair Bay (PBB) and Wandoor Creek (WC) are largely populated due to its services offered to different public/private sectors and for the economic significance. Nevertheless, the global recognition of these islands relies on its healthy ecosystem. Effective management of beaches, bays and their environmental services requires knowledge of coastal water quality. This study assesses the datasets of twenty seawater quality parameters of PBB and WC generated during five years (2011-2015) at eight sites. Multivariate statistical techniques were used for (i) analysis and interpretation of water quality parameters (ii) identification of pollution factors/sources and (iii) understanding spatio-temporal variations valuable for coastal water quality management.

Spatial variability of heavy metals in estuarine, mangrove and coastal ecosystems along Parangipettai, Southeast coast of India.

An elaborate survey on the contamination of heavy metals was carried out in surface sediments of different ecosystems such as Vellar-Coleroon estuarine, Pichavaram mangrove and coastal region of Parangipettai, Southeast coast of India. The study was intended since, the coal based thermal power plant and oil refinery plant are proposed to set up along this coast and aquaculture industries and dredging activities are developing. The parameters such as soil texture, pH, total organic carbon (TOC) and heavy metal (Fe, Mn, Cu, Cd, Zn and Ni) concentrations were analyzed for the surface sediments during pre and postmonsoon seasons. Among the metals analyzed, Fe and Mn were found to have dominant as the levels were recorded as 11,804 µg g-1 and 845.2 µg g-1 respectively. A significant correlation was observed between total organic carbon (TOC) and heavy metals. In the mangrove ecosystem, the levels of heavy metals found to be maximum indicating that the rich organic matter acts as an efficient binding agent for metals. The overall finding of the present study indicated that the sediments from the entire Vellar-Coleroon estuarine and Pichavaram mangrove ecosystems were found moderately polluted with cadmium metal. The result of cluster analysis indicated disparity in accumulation of heavy metals in sediments of different ecosystems due to the variations in organic matter. The heavy metals were transported from land to coastal through flood during monsoon season reflecting the variations in their levels in different ecosystems at postmonsoon season.

Antioxidant and anticoagulant activity of sulfated polysaccharide from Gracilaria debilis (Forsskal).

Sulfated polysaccharide was isolated from Gracilaria debilis and purified through gel chromatography and their molecular weight was determined through AGE and PAGE. The total sugars in the crude, fractionated and purified polysaccharide were estimated as 52.65%, 59.70% and 67.60%, respectively. The ash and moisture content of crude and purified polysaccharide was found to be 14.2% and 23.5% and the polysaccharide was free from protein contamination. The sulfate and uronic acid contents in the crude, fractionated and purified were estimated as 14.08%, 15.33% and 16.01% and 10.12%, 13.56%, 16.70%. The elemental composition including carbon (crude - 23.12%, purified - 21.05%), hydrogen (crude - 3.4%, purified - 4.13%) and nitrogen (crude - 1.22%, purified - 0.56%) were also analyzed. The anticoagulant activity of the sulfated polysaccharide through APTT and PT was estimated at 14.11 and 8.23IU/mg. The purified polysaccharide with the molecular mass of 20kDa showed highest antioxidant activity (38.57%, 43.48% and 38.88%) in all the assays tested such as DPPH hydroxyl radical, superoxide radical, hydroxyl radical scavenging activities and the structural property was analyzed through FT-IR and (1)H NMR spectrum. The results together suggest that the isolated low molecular weight sulfated polysaccharide will demonstrate as a enormously available alternative natural source of antioxidant for industrial uses.

Sulfation of ß-chitosan and evaluation of biological activity from gladius of Sepioteuthis lessoniana.

ß-Chitosan extracted from the gladius of Sepioteuthis lessoniana was sulfated with chlorosufonic acid. The structural features of sulfated chitosan were analyzed by NMR spectroscopy. The elemental composition was analyzed using elemental analyzer. The molecular weight of sulfated chitosan estimated through viscometry was calculated as 12.47 × 10(4) Da. The water solubility of sulfated chitosan was found to be 81%. The sulfated chitosan was able to scavenge the DPPH, superoxide and hydroxyl radicals and the inhibitory concentration (IC50) of those free radicals was found to be 4, 0.428 and 0.473 mg/ml respectively. Sulfated chitosan also showed reducing and chelating property. The IC50 value of reducing and chelating ability was found to be 0.316 and 5.64 mg/ml respectively. The anticoagulant activity was determined for human plasma with respect to activated partial thromboplastin time and prothrombin time and it was 7.13 IU and 1.26 IU, respectively.

Physicochemical characterisation of ß-chitosan from Sepioteuthis lessoniana gladius.

ß-Chitin and its chitosan from the gladius of Sepioteuthis lessoniana have been isolated, purified, characterised and compared with the commercial chitosan. Ash, moisture, mineral, metal and elemental content were analyzed using standard techniques. The optical activity of chitin was found to be levorotatory. The degree of deacetylation was calculated by potentiometric titration and (1)H NMR. Viscosity average molecular weight of ß-chitosan was calculated by viscometry and size average molecular weight by GPC. The structure of ß-chitosan was elucidated with FT-IR and NMR. Thermal nature, crystalline structure and morphology of ß-chitosan were characterised through DSC, XRD and SEM, respectively. The water and fat binding capacity of ß-chitosan presently studied was significantly higher than that of the commercial chitosan. The result of the present study adds that S. lessoniana gladius is also an additional source of ß-chitin and chitosan of higher yield, lower molecular weight and higher degree of deacetylation.