A STUDY ON QUANTITY OF Bt TOXIN IN Bt AND NBt COTTON RHIZOSPHERE

Genetically engineered plants and their residues may pose direct or indirect impacts on different ecosystem functions. The aim of this experiment was to determine the amount of Bt toxin (Cry 1 Ac δ endotoxin) present in the rhizosphere of Bt cotton during the crop period at regular intervals. Bt toxin was estimated from the rhizospheric soils of near isogenic Non Bt cotton crop for as a control. Cry 1 Ac δ endotoxin was estimated using Envirologix Quanti Kit plate (ELISA) method. The soil samples were collected in which Bt cotton was cultivating for more than ten years as monocrop, similarly Non Bt cotton fields where never cultivated transgenic crop were selected for this study. The quantity of the Cry 1Ac toxin levels in the rhizosphere of Bt cotton was estimated at different crop stages and it was 41.13 ppb at pre cultivation stage which is higher than that of Non Bt rhizosphere soil i.e.15.3 ppb. The toxin concentration increased gradually during different crop stages i.e 69.32 ppb, 95.24 ppb, 103.35 ppb at 30, 60,90 days crop stages respectively. It was decreased to 92.37 ppb at harvest stage and shown higher levels (173.24 ppb) at postharvest stage. But in case of Non Bt rhizosphere it is almost same at all the stages of crop. The results suggests that there is a significant difference between the Bt and Non Bt soils with respect to quantity of Cry toxin and there is also significant difference between different crop stages of Bt cotton with respect to Non Bt cotto

Enterocin from Enterococcus faecium isolated from mangrove environment

Enterococcus faecium isolated from mangrove environment produced enterocin and it showed broad inhibitory spectrum against gram positive and gram negative bacteria such as Lactobacillus plantarum, Enterococcus facealis, Listeria monocytogens and Salmonella paratyphii. The optimum production ofbacteriocin (2400 AU/ml) from E. faceium was obtained when the culture conditions were maintained at pH 6.0 and 35°C. Maximum yield was 40% in ion exchange chromatography. The molecular weight of the partially purified enterocin was estimated as 5 KDa by SDS PAGE electrophoresis

Thermostable &#945-amylase production by Bacillus firmus CAS 7 using potato peel as a substrate

Thermostable alkaline α-amylase producing bacterium Bacillus firmus CAS 7 strain isolated from marine sediment of Parangipettai coast grew maximally in both shake flasks. Potato peel was found to be a superior substrate for the production of α-amylase at 35°C, pH 7.5 and 1.0% of substrate concentrations. Under optimal conditions, B. firmus produced 676 U/ml of -amylase which was optimally active at 50°C and pH 9.0.Key words: α-Amylase, potato peel substrate, Bacillus firmus CAS 7, thermostable, marine

HPTLC fingerprinting of stem bark extract of Nyctanthes arbor-tristis (L.)

Fingerprint profile of   bark extract of Nyctanthes arbor-tristis using High Performance Thin Layer chromatography (HPTLC) has been established. HPTLC is a valuable tool for the investigation of medicinal plants with reference to the qualitative analysis of the phytoconstituents. Separation of the active constituents from the extracts has been developed using solvent system of Toluene: Ethyl acetate: Formic acid (5:4:1). The HPTLC analysis showed the presence of the flavonoid quercetin in the standard as well  as in the sample  and the  Rf value was  0.73. These images of fingerprinting help in the proper identification and quantification of the   marker compounds. On the basis of the marker compounds, new drugs could be formulated to treat various diseases Keywords: Nyctanthes arbor- tristis, HPTLC analysis, quercetin, bark extrac

Asymptomatic bacteriuria among antenatal women attending a tertiary care hospital in Kanchipuram: evaluation of screening tests and antibiotic susceptibility pattern

Background: Asymptomatic bacteriuria (ASB) occurring in pregnant women can lead onto complications like acute pyelonephritis, hypertensive disease of pregnancy, premature delivery and intrauterine growth retardation if untreated.Methods: The present study aims to estimate the occurrence of asymptomatic bacteriuria in antenatal women and to study the antibiotic susceptibility pattern of the isolates. The Gram staining, pus cell count and culture was performed for 120 urine samples. Antibiotic susceptibility testing was done by Kirby Baeur disk diffusion method. MRSA (Methicillin resistant Staphylococcus aureus) and ESBL (Extended spectrum Beta Lactamases) producers were identified by Standard guidelines. The   sensitivity, specificity, negative predictive values and positive predictive values of Gram staining and pus cell count was calculated.Results: Out of the 120 samples 14 (11.66%) were positive for asymptomatic bacteriuria. The Gram staining showed specificity and negative predictive value of 95.2% and 98.1% respectively. Pus cell count showed a specificity and negative predictive value of 96.29% and 98.11% respectively. Escherichia coli were the predominant species isolated 5 (35.7%). Among the gram negative bacteria, amikacin and nitrofurantoin showed a susceptibility of 90% and 80% each. All the staphylococcus aureus isolates showed 100% sensitivity for nitrofurantoin.  Two Klebsiella spp and one Escherichia coli isolate were identified as ESBL producers. Among the S. aureus isolates 3 were identified as Methicillin resistant (MRSA).Conclusions: Urine culture should be performed for all pregnant women irrespective of the symptoms and should be treated promptly to prevent the complications arising out of ASB.

Pulsed electric field and combination processing of mango nectar: effect on volatile compounds and HMF formation

Mango nectar is a commercially familiar and preferred product. The traditional processing of mango nectar has been by thermal processing which resulted in the alteration of the flavour of the product due to the effect of high temperature. The thermal processing of the nectar also resulted in the production of byproducts of non-enzymatic browning such as 5- hydroxy methyl furfural (HMF). These process induced effects, affect both the nutritive and sensory attributes of the fruit product, making it less preferable. With the growing interest and awareness about the benefits of alternative non-thermal technologies, such as pulsed electric field (PEF), the present work was proposed to use PEF to minimize the loss of volatiles and formation of HMF. The study involves thermal (96 ºC for 300 s and 600 s), PEF (24 µs, 120 Hz and 38 kV/cm) and combination processing (PEF + Thermal (96 ºC for 90 s)) of mango nectar. The effect of these treatments on the volatile composition of mango nectar has been analysed using GC-MS technique. The reduction in the volatile compounds was significant (p 0.05) different from unprocessed sample, proving the fresh-like character of the product