Costus pictus, belonging to the family Costaceae, is one of the valuable medicinal plants with its antidiabetic property. Despite ever-increasing demand from the pharmaceutical industry, this species is being less exploited at molecular level. Hence, an effort has been made in the present study to characterize the 15 accessions of C. pictus collected from different geographical regions of India through random amplified polymorphic DNA (RAPD) and inter-simple sequence repeats (ISSR) markers. A total of 25 RAPD and 20 ISSR primers were used in the present study. The RAPD analysis generated 343 loci, of which 124 were polymorphic with an average of 4.96 loci per primer. While, ISSR primers produced 177 loci, of which 77 were polymorphic with an average of 3.85 loci per primer. The similarity coefficients ranged from 0.86-0.99, 0.84-0.95 and 0.86-0.96 for RAPD, ISSR and combined RAPD-ISSR, respectively. The UPGMA dendrogram generated using these data showed low level of divergence among the accessions from South and West regions. Further, accession-specific bands were also revealed by RAPD and ISSR markers which might be contributed to specific trait. This investigation was an understanding of genetic variation within the C. pictus accessions. The present finding indicates that both the marker tools RAPD and ISSR combined or individually can be used in determining the genetic relationship between the accessions. It may be concluded that data of hereditary differences appeared among the C. pictus accessions could be utilized for their conservation and reproducing programs.

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Nitrite-oxidizing bacteria (NOB) are Gram-negative microorganisms, which pick up their energy by changing nitrite over to nitrate. Nitrification is a microbially catalyzed process whereby ammonia (NH 3 ) is oxidized to nitrite (NO 2 À ) and thusly to nitrate (NO 3 À). NOB convey the second phase of the nitrification cycle, that of oxidation of nitrite to nitrate. Since the microorganisms liable for nitrification are fundamentally autotrophic, nitrification gives an interesting connection between the carbon and nitrogen cycles. An unadulterated culture of a nitrite-oxidizing bacterium can be gotten by density gradient centrifugation and a conventional dilution technique. For the enrichment of predominant nitrifiers, combination of the most probable number technique followed by the serial dilutions strategy is recommended. In the highest dilutions, nitrite oxidation can be distinguished simply following a while as a result of the slow growth of the nitrite oxidizers.

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