During a short survey of soil and mosquito breeding sites in Lucknow, India for potential mycopathogen from a period of August-October 1996, 11 species of fungi in 5 genera were isolated using live mosquito larvae as host, Aspergillus flavus, A. fumigatus and Fusarium semitectum were the most frequently isolated species. Other fungi recorded were A. niger, A. ochraceus, A. terreus, A. versicolor, Geotrichum candidum, Penicillium verrucosum, Paecilomyces sp. and Fusarium sp. (Liseola/Elegans complex). Insect cell walls are known to contain chitin, so fungal isolates were tested for their chitinase activity on semi synthetic medium containing colloidal chitin. High chitinolytic activities were observed with A. flavus and A. ochraceus. Chitinase producers can be considered as potential pathogens. However, the higher incidence of F. semitectum could not be explained by inability to utilize chitin.

Animals↗

PubMedDate not supplied

Exposure estimates of chromeplaters in India: an exploratory study.

The literature has a paucity of knowledge on the exposure and effect estimates of chromeplaters in India. In an exploratory endeavour on chromium (Cr) exposure risk assessment, blood and urinary Cr levels plus the DNA-protein crosslink content were analysed in peripheral blood lymphocytes of chromeplaters (n=24). A cross-sectional study design was selected. Non-chromeplaters (n=35) were taken as the matching control. The results show that levels of blood and urinary Cr were greater in chromeplaters. A significant increase in DNA-protein crosslink coefficients of peripheral blood lymphocytes and urinary Cr levels was observed. The results demonstrate higher exposure estimates in chromeplaters and reveal exposure to a biologically effective dose of the toxic metal. The study also validated the employed biomarkers for Cr exposure risk assessment.

Adult↗

PubMedDate not supplied

A carbon-limited medium for growth and sporulation of Bacillus thuringiensis var. kurstaki.

A culture medium for batch production of d-endotoxin by Bacillus thuringiensis (B., t.) has been modified. Through batch and continuous cultivation studies, the original medium was diagnosed to be limited in organic nitrogen. Corn steep liquor was found to be an excellent source for the organic nitrogen and its addition resulted in a carbon limited medium and in a significant increase in the amount of spore-toxin complex formed in shake flasks. Results of bioassay, conducted on Trichoplusia ni, suggest enhancement of larvicidal efficacy under carbon-limited growth conditions.

Ammonium Sulfate↗