Radioactivity and radiation hazard assessment of Cauvery River, Tamilnadu, India

Natural radiation is constantly present in the environment and is emitted from a variety of natural and artificial sources. It affects human body and environment. The activity concentrations of [238]U, [232]Th and [40]K have been determined by Gamma ray spectrometer with an HPGe detector in sediments of Cauvery River, Tamilnadu, India. The absorbed dose rate, radium equivalent concentration, external [Hex] and internal [Hin] hazardous indices are calculated from criteria formula and compared with the international recommended limits. The radioactive heat production rate and activity concentration index are also calculated. The observed dose rate measurements from ERDM [Environmental Radiation Dosi Meter] at 1m above the ground level at each site of the both rivers are measured and correlated with calculated absorbed dose rate. From the various parameters and correlation between them, the Cauvery River does not pose a radiological hazard except the site no. 21, 22, 23, 30, 31 and 35

Studies on Agrobacterium rhizogenes isolated from the nodules of some leguminous plants

To compare the isolates of Agrobacterium of live different Leguminous plants viz., pisum sativum, Sesbania rostrata, vigna mungo, V. radiate and V. ungiculata. Bacteria were isolated from the nodules of host species as per the standard methods. The isolated bacteria were characterized and identified as Agrobacterium rhizogenes and confirmed by Pathogenicity test. Biochemical characteristics such as exopolysaccharide, glycogen, total protein, total free amino acids and total lipid were quantified from the agrobacterial isolates. Similarly protein profile was also carried out by SDS-PAGE. From the above results it is concluded that the agrobacteria of different leguminous plants showed lot of variants in their biochemical contents and hence be treated as separate strains of A. rhizogenes

Antimicrobial activity of Leaf extracts of Carissa carandas L.

Phytochemical investigations and antimicrobial activity studies for the leaf extracts of Carissa carandas Linn, were carried out. Four solvents i.e. Petroleum ether [60-80°C], Benzene [79-81°C], Chloroform [50.5-61.5°C], and Methanol were used for extraction of active principles from the dried powdered leaf material. The phytochemical tests of extracts revealed the presence of alkaloids, carbohydrates, glycosides, phenolic compounds, tannins and saponins. The antimicrobial screening was done with two Gram [-] ve [Escherichia coli NCIM 2065, Proteus vulgaris NCIM 2027] and two Gram [+] ve [Staphylococcus aureus NCIM 2079, Bacillus subtilis NCIM 2063] bacteria as test micro-organisms. Zones of inhibition produced by these extracts were measured as criteria to evaluate their antimicrobial activity. These zones of inhibition were compared with the standard antibiotic [Ciprofloxacin 30 mcg/ml] under similar conditions. The activity index of antimicrobial activity was calculated by comparing the effect of leaf extract with the effect induced by the standard antibiotic. Among the four micro-organisms tested, Staphylococcus aureus is the only organism found to be sensitive for all the leaf extracts. Benzene extract produced profound antibacterial activity and methanolic extract produced least antibacterial activity when compared with other leaf extracts