ABSTRACT
Esterase isozymic variations were documented in the haemolymph of developed multivoltine and bivoltine silkworm breeds during unfavorable seed crop seasons of May – September using α- and β- napthylacetate separately to identify specific and nonspecific esterase having thermotolerant potentiality. Variations existed in the isozyme pattern with three bands (Est-2, 3 and 4) in pure Nistari race and other developed multivoltine and bivoltine breeds. Est-2 and Est-3 were non-specific esterases as they were observed when both α- and β-napthylacetate was used as substrates separately. Est- 4 band was observed only with α-napthylacetate as substrate and was therefore confirmed to be specific α-esterase band in the haemolymph of silkworm, Bombyx mori L. Zymograms showed that the non-specific esterase band (Est-3) with Rf of 0.43 and specific α-esterase band (Est-4) with Rf of 0.32 predominately withstood a temperature of 70 ± 2oC for a duration of 10 min and were confirmed as thermostable esterases in haemolymph of silkworm, Bombyx mori L. This also categorized the presence of thermostable esterases in developed multivoltine and bivoltine breeds of silkworm, even though the qualitative activity was more in the former than the latter. The qualitative presence of thermostable esterases and their activity could be adopted as an indicative biochemical marker in relation to thermotolerance in silkworm.
ABSTRACT
A strain of Lactobacillus acidophilus (Strain HF) was isolated from human faeces. A chloramphenicol resistant strain (HFCm) and a strain (HFCmSm chloramphenicol and streptomycin were developed from the isolated strain (HF). All the ) restant to both Kyd Street, Calcutta 700 016 three strains showed similar in vitro susceptibility against host defence factors like gastric acid, bile salts and volatile as well as non-volatile fatty acids. In vivo tests were done by feeding these strains to mice. When the resistant strains were orally administered along with the antibiotic(s) they were stable up to 72 h.