Streptomyces have been reported to exhibit significant genomic divergence and unique metabolic gene content. Present study was designed to explore the genetic diversity in cellulolytic Streptomyces from same natural ecological niche. Nineteen Streptomyces spp. cultures were isolated from decomposing rural and urban wastes collected from different parts of Western Maharashtra. Random amplified polymorphic DNA (RAPD) tool was used for assessment of genetic diversity between cellulolytic Streptomyces isolates. Genomic DNA from 19 isolates and one reference strain were amplified using 16 random primers. The PCR amplification products of the isolates with different primers produced 507 bands out of which 323 were polymorphic, while 127 were unique. Electrophoretic and cluster analysis of the amplification products revealed incidence of polymorphism among the isolates and none of them was identical to the reference strains although there were some common amplification bands. The average polymorphism observed was 98.22%. The genetic similarity index based on the pooled data of RAPD profiles ranged from 0.19 to 0.70. The dendrogram constructed from the pooled data of Streptomyces spp. had two major groups showing wide genetic diversity between isolates. The results highlights RAPD as an efficient method for discriminating and studying genetic diversity among Streptomyces isolates. The protocol was found useful to detect similarities and differences in different isolates but it is not possible to gain further information on the biochemical parameters which are correlated with diversity amongst each other. Further genomic research will help in understanding the actual differences in biochemical parameters, enzyme production levels and functional potential within closely related population.

Streptomyces, genetic diversity, RAPD-PCR, decomposing waste

There was a significant genetic diversity among Streptomyces isolates at genus level though they were from same ecological niche, may be due to the genetic differences in the strains due to differences at species level, differential expression of genes or diversification of metabolism. RAPD PCR protocol was found useful to detect similarities and differences in different isolates. Data generated by RAPD might help in further genomic research on differences in enzyme production levels within closely related population. Further studies can be correlated with the functional potential and genomic diversity within same group of closely related microorganisms.

B.C. Game, V.P. Chimote and S.B. Latake (2023). Genetic Diversity of Cellulolytic Streptomyces spp. Isolated from Decomposing Waste. Biological Forum – An International Journal, 15(11): 57-63.