In vivo appraisal of oxidative stress response, cell ultrastructural aberration and accumulation in Juvenile Scylla serrata exposed to uranium.

In vivo studies were performed to evaluate the organ specific tissue accumulation and cellular toxicity of uranium to mud crab Scylla serrata. The specimens were acclimated in natural seawater and the exposure to 50-250 µg/L uranium was investigated up to 60 days. The present study examined the effects of concentration and duration of uranium exposure in the tissue of S. serrata at cellular and subcellular level using scanning electron microscopy and bright field transmission electron microscopy in addition to histological analysis. The results indicated that accumulation of U in S. serrata was organ specific and followed the order gills > hepatopancreas > muscle. The response of key antioxidant enzyme activities such as SOD, GPx and CAT in different organs of crabs indicated oxidative stress due to U in the ambient medium and tissue. At 50 and 100 µg/L of U exposure, individuals were able to acclimate the oxidative stress and withstand the uranium exposure. This acclimation could not be sustained at higher concentrations (250 µg/L), affecting the production of CAT in the tissues. Cellular and subcellular changes were observed in the hemocytes with reduction in their number in consonance with the antioxidant enzymes. Histological aberrations like lamellar disruption of gill, necrosis of hepatopancreas, disruption and rupture of muscle bundles were observed at different concentrations and were severe at higher concentration (250 µg/L). Necrosis was observed in the electron micrographs of tissues shortly after 15 days of exposure. SEM micrograph clearly shows disrupted lamellae, folding of marginal canal and reduction of inter lamellar spaces in the gills of crab exposed to high concentration of uranium. Mitochondrial anomalies are reported for the first time in the present study in addition to the subcellular changes and vacuoles on exposure uranium in the cells of gill and hepatopancreas.

Malic acid production by chemically induced Aspergillus niger MTCC 281 mutant from crude glycerol.

In the present investigation, crude glycerol derived from transesterification process was utilized to produce the commercially-valuable malic acid. A combined resistant on methanol and malic acid strain of Aspergillus niger MTCC 281 mutant was generated in solid medium containing methanol (1-5%) and malic acid (40-80 g/L) by the adaptation process for 22 weeks. The ability of induced Aspergillus niger MTCC 281 mutant to utilize crude glycerol and pure glycerol to produce malic acid was studied. The yield of malic acid was increased with 4.45 folds compared with that of parent strain from crude glycerol. The highest concentration of malic acid from crude glycerol by using beneficial mutant was found to be 77.38 ±â€¯0.51 g/L after 192 h at 25 °C. This present study specified that crude glycerol by-product from biodiesel production could be used for producing high amount of malic acid without any pretreatment.

A new species of sand crab Jonas Hombron & Jacquinot, 1846 (Crustacea: Decapoda: Brachyura: Corystidae) from the southeastern coast of India.

A new species of sand crab of the genus Jonas Hombron & Jacquinot, 1846 (family Corystidae) is described from specimens collected from Kalpakkam, southeastern coast of India. Two other species, J. indicus (Chopra, 1935), and J. choprai Serène, 1971, have previously been recorded from this area. A detailed description of the new species is given and compared with the closely related J. formosae Balss, 1922, also from the Indo-West Pacific.