Bacillus subtilis, a Gram-positive, aerobic, endosporeforming bacterium, was evaluated for its probiotic potential in Indian major carp, Labeo rohita. Labeo rohita (15 AE 2 g) were fed a feed containing B. subtilis in three concentrations for 2 weeks, e.g., 0.5 (T 2 ), 1.0 (T 3 ) and 1.5 (T 4 ) Â 10 7 CFU g À1 feed. The control group (T 1 ) was fed feed without B. subtilis for the same period. Haematological and serum parameters were monitored at weekly intervals. The response variables were total erythrocyte count, total leucocyte count (TLC), haemoglobin, total protein, albumin, globulin, albumin^globulin ratio, alkaline phosphatase activity, alanine aminotransferase activity and aspartate aminotransferase activity. Fish were challenged intraperitoneally with a virulent strain of Aeromonas hydrophila after 2 weeks of feeding to the treatment groups and positive control group, while the negative control group was challenged with phosphate-bu¡ered saline only. Clinical signs and symptoms, and mortality/survival percentage were noted in each group. The haematological and serum parameters were monitored each week and during post challenge on the third and tenth day. The B. subtilis-treated ¢sh (T 4 ,1.5 Â 10 7 CFU g À1 feed) showed maximum per cent survival (87.50%), weight gain (35.5%), TLCs (3.23 Â 10 4 cells mm À 3 ), haemoglobin content (7.4 g%), total protein (2.37 g dL À1 ) and globulin content (1.28 g dL À1 ) during the pre-challenge. Enzymes showed higher activities during post challenge (Po0.05). The result suggests that B. subtilis can be used e¡ectively as a commercial product for use in aquaculture.

No abstract

No abstract

No abstract

CuO-loaded SnO2 element was earlier identified as a highly sensitive and selective H2S gas sensor. A number of techniques have been used by different authors for preparing thick and thin films of SnO2 doped with CuO, which among various metal oxides has outstanding promoter action for the sensitive detection of H2S by SnO2. Here we report the growth and characterization of CuO-doped SnO2 thin films by a thermal evaporation technique. These thin films show an extremely high sensitivity of ∼106 to few parts per million levels of H2S gas in air. The gas sensor is characterized at four operating temperatures and its long-term stability in response to H2S gas is tested over a period of 3 years.