Functional Properties of Heavy Metal Tolerant Probiotic Strains Isolated from Curd

The two heavy metal tolerant bacterial isolates L. fermentum SN_4 and L. rhamnosus SN_6 were identified (isolated from curd samples) which were found to be potentially resistant to Cr6+, Pb2+ and Cd2+ under study. Both the isolates were resistant to simulated gastric juices at pH 2.0 and 3.0 at 0 hours and survived well more than 50% in 0.2%, 0.3%, 0.5% and 1.0% bile salt solution but the isolate L. rhamnosus SN_6 showed the best survival at all the concentrations of bile salt. These two isolates showed poor antagonistic agent activity against the four pathogenic bacteria viz. E. coli, B. cereus, S. typhimurium and V. cholera. L. fermentum SN_4 showed resistant to all antibiotic except clindamycin and azithromycin, on the other hand, L. rhamnosus SN_6 was found resistant to clindamycin and tetracycline only. Also, they were found to be haemolytic negative which proved them to be a potential probiotic.

Biosorption and elution of chromium from immobilized Bacillus coagulans biomass.

Bacillus coagulans, a tannery wastewater isolate, previously shown to bind dissolved Cr(VI), retained its ability to biosorb Cr(VI) in different matrices. Polymeric materials like agar, agarose, calcium alginate and polyacrylamide were screened. Agarose emerged as the suitable candidate for biomass immobilization mainly due to its higher stability and integrity in acidic pH. Aptness of agarose as the matrix for B. coagulans biomass was revealed during Cr(VI) biosorption from natural wastewater.

Uptake of nickel (II) by Serratia marcescens.

Bioaccumulation and biosorption of various nickel salts by Serratia marcescens (NCIM 2078) were investigated Biosorption of nickel was found maximum for the nickel nitrate and nickel chloride as 28.08 and 25.51 mg-1 nickel was obtained in dry biomass of S. marcescens, respectively. The possible role of pigment prodigiosin in uptake of nickel is discussed.

Assessment of industrial effluent and its impact on soil and plants.

The present study deals with the assessment of industrial water of an electronic component manufacturing unit with electroplating and its subsequent effects on soil and plants receiving the effluent. The physico-chemical parameters of the effluent samples showed higher value than that of ground water. The treated effluent was within the permissible limit. Microtox test was conducted and determined the degree of toxicity of untreated, treated effluents as well as the water sample collected at effluent discharge point of receiving river (confluence point). The physico- mechanical parameters of the soil samples were not changed due to irrigation of the treated effluent, but the concentration of metals were comparatively higher than the control soil. Higher accumulation of metals was found in the plant parts in naturally growing weeds and cultivated crop plant irrigated with treated effluent. Elevated accumulation of metals in Eichhornia crassipes and Marsilea sp. growing along the effluent channel has been identified as a potential source of biomonitoring of metals particularly for Cu and Ca and can be utilised for the removal of heavy metal from wastewater.

Antibiotic resistance of coliforms in drinking water in rural areas.

The antibiotic sensitivity of 197 coliform sp. isolated from drinking water in five rural areas was studied. Twelve strains (6.1%) showed multiple antibiotic resistance, three (1.5%) of which were able to transfer the resistances to an Escherichia coli K-12 recipient. It seems unlikely that the occurrence of transmissible multiple antibiotic resistance among coliforms in drinking water in the areas studied poses a significant public health risk.