Showing papers by "Ashoke Ranjan Thakur published in 2006"

Microbial genetic resource mapping of East Calcutta wetlands

Abstract: East Calcutta Wetland (ECW) is the world's largest natural treatment plant for solid and soluble waste, where bioremediation and biodegradation of complex compounds is mainly based on microbial activity and is recognized as a potential source of bacteria of biotechnological impact. Here we discuss the microbial resource mapping of this important Ramsar site. Culture-independent analysis of the microbial population from soil and water through community DNA isolation, amplification, cloning and partial sequencing (320 clones) of 16Sr RNA gene sequence and finally secondary structure-based phylogenetic analysis of the novel sequences (292 GenBank submissions) using ARB software indicated the presence of microorganisms from 12 different main bacterial phyla, thus revealing the rich natural microbial resource at ECW.

Microbial DNA extraction from samples of varied origin

Abstract: The impact of four different soil DNA extraction methods on the quantity and quality of isolated community DNA was evaluated using agarose gel electrophoresis, DNA spectrum study and PCR-based 16S ribosomal DNA analysis. The modified direct lysis method was optimized for environmental water samples (wastewater fed-fisheries and raw liquid sewage canal) as well as diagnostic samples like urine from humans, thus opening up a new arena for fast culture-independent detection of causative pathogens in pathological manifestations like urinary tract infections. The same method was independently found to be effective for isolation of genomic DNA from both Gram-positive and Gram-negative bacteria. Thus a uniform method of DNA extraction from environmental samples (different types of soil and water), pathological samples as well as varied kinds of bacteria was obtained.