NISCAIR Online Periodicals Repository Collection: IJEB Vol.50(01) [January 2012]

Staurosporine induced poly (ADP-ribose) polymerase independent cell death in Dictyostelium discoideum

Title: Staurosporine induced poly (ADP-ribose) polymerase independent cell death in Dictyostelium discoideum

Authors: Mir, Hina; Rajawat, Jyotika; Begum, Rasheedunnisa

Abstract: In the present study D. discoideum has been used as a model organism to understand the role of poly (ADP-ribose) polymerase (PARP) in caspase independent paraptotic cell death pathways. D. discoideum lacks caspases and Bcl-2 family proteins; nevertheless it has 9 potential genes for PARP. PARP has been known to get activated in various cell death associated diseases. In this study kinetics of cell death induced by staurosporine (STS), a bacterial alkaloid, was established to unravel the role of PARP. It was found that STS induced cell death in D. discoideum did not involve PARP activation, however it involved cathepsin D. Results indicated that an alternative mechanism may be existing in D. discoideum that lacks Bcl-2 family proteins for STS induced cell death that evades Bax involvement.

Page(s): 80-86

Secretion of cyclodextrin glucanotransferase in E. coli using Bacillus subtilis lipase signal peptide and optimization of culture medium

Title: Secretion of cyclodextrin glucanotransferase in E. coli using Bacillus subtilis lipase signal peptide and optimization of culture medium

Authors: Ayadi-Zouari, Dorra; Kammoun, Radhouane; Jemli, Sonia; Chouayekh, Hichem; Bejar, Samir

Abstract: The cyclodextrin glycosyltransferase (CGTase) of Paenibacillus pabuli US132 was fused to the secretive lipase signal peptide of B. subtilis. This leads to an efficient secretion of the recombinant enzyme into the culture medium of E. coli as an active and soluble form contrasting with the native construction leading to a periplasmic production. In order to enhance the yield of CGTase production, an experimental design methodology was applied for the optimization of the culture composition. Hence, the media components were submitted to preliminary screening using a Plakett-Burman design. The concentrations of the major operating ones were then optimized to enhance the secretion of CGTase using response surface methodology. The findings revealed that concentrations of 0.5% potato starch, 3% yeast extract, 3% tryptone, 1.5% casein hydrolysate, 0.5% NaCl, 0.2% KH₂PO_4,and 0.02% MgSO₄were the optimal conditions for CGTase production. The experimental value (9.43 U/ml) obtained for CGTase activity was very close to the predicted value (9.27 U/ml).

Page(s): 72-79

Optimization of medium composition for the production of mosquitocidal toxins from Bacillus thuringiensis subsp. israelensis

Title: Optimization of medium composition for the production of mosquitocidal toxins from Bacillus thuringiensis subsp. israelensis

Authors: Poopathi, Subbiah; Archana, B

Abstract: Optimization of chicken feather (CF) based culture medium for the production of Bacillus thuringiensis subsp. israelensis (Bti) biomass in combination with the agro industrial by-product (coconut cake, CC) and manganese chloride (MnCl₂) has been evaluated. The biomass yield of Bti spore/crystal toxin was highest (12.06 g/L) from the test medium (CF+CC+MnCl₂) compared to the reference medium (Luria Bertani, LB). Toxicity assay with Bti produced from the test medium against mosquito vectors (Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti) was also satisfactory and results were comparable with bacteria produced from LB. The results suggest that Bti can be produced to the maximum extent possible as a potential mosquitocidal activity as suggested by the test medium (CF+CC+MnCl₂).

Page(s): 65-71

Antinociceptive activity of Sesbania sesban (Linn) wood extracts, a preliminary study

Title: Antinociceptive activity of Sesbania sesban (Linn) wood extracts, a preliminary study

Authors: Nirmal, S A; Bairagi, J H; Patil, A N; Pal, S C; Upasani, C D; Mandal, S C

Abstract: The wood of the plant Sesbania sesban, is reported to have antinociceptive activity. To validate its folk use in the treatment of pain, wood was extracted successively with petroleum ether, chloroform, ethyl acetate, ethanol, and water to produce respective extracts. The extracts (50 and 100 mg/kg, ip) were screened for antinociceptive activity using hot plate test and acetic acid-induced writhing test in mice. Petroleum ether, chloroform, and ethyl acetate extracts showed significant and dose-dependent activity in both the tests. In order to find out the involvement of opioid receptors, effect of naloxone (1 mg/kg, sc) on the action of extracts was checked in hot plate test. Petroleum ether, chloroform, and ethyl acetate extracts showed significant and dose dependant antinociceptive activity. The antinociceptive action of the extracts was blocked by naloxone, suggesting involvement of opioid receptors in the action.

Page(s): 61-64