European Journal of Experimental Biology Libre accès

Abstrait

Bacterial chromate uptake by chemoautotrophic and myxotrophic free and embedded cells in enrichments obtained from rock samples

Aditi Bhattacharya

Rocks, mineral ores, sediments or soil are often associated with inorganic matter such as metals. Thus inherent  organisms are exposed to the toxicity of many of these metals. Chromate uptake was observed in enrichment cultures. Since organisms do not exist in natural habitat as pure culture, therefore the study was conducted in native consortia. Almost 30% of the chemoautotrophic enrichments did not show any chromate uptake. The chromate uptake was 10 % or less in 23% of the samples. The highest uptake was 34% at 50 μg/ml (phosphate buffer pH 6.8) in the enrichment obtained from haematite. Only 6% of the enrichments showed uptake less than 1% or no uptake at all at 100μg/ml of chromate. The uptake at 100μg/ml in the enrichment obtained from haematite was further reduced by about 50% when compared with 50 μg/ml chromate uptake. The uptake in myxotrophic free living cells in enrichments ranged from 17 to 96%. The highest uptake in myxotrophic biofilms on glass coupons was found to be 56% at 50μg/ml chromate in phosphate buffer pH 6.8.