A comparative study of the bacterial and fungal diversity in the gut and cast of Glyphodrillus tuberosus, isolated from organic and conventional rice fields in Orissa state, India was done in different seasons for a period of two years from 2007 to 2009. Isolation of the strains was done by serial dilution method on incubation of the inoculated plates at 28°C for 72 h for fungi and at 37°C for 24 h for bacteria. Isolated strains were identified as Bacillus sp., Pseudomonas sp., Staphylococcus sp., Bacillus subtilis, Bacillus lentus, Azotobacter sp., Micrococcus sp., Flavobacterium sp., Acinetobacter sp., Brevibacterium sp. and Thiobacillus sp., while the molds identified were Aspergillus niger, Aspergillus flavus, Fusarium sp., Penicillium sp. and Rhizopus sp. Microbial load was observed significantly higher (p<0.01) in gut sections and cast of the worm than in un-ingested soils. The earthworm was found to constitute a microhabitat enriched in microbes capable of growth and activity. Numbers of bacteria and fungi were observed significantly higher (p<0.01) in the gut section, worm cast and undigested soil of organic rice field in comparison to conventional one. Soil pH and percent moisture did not show significant differences between the two management systems. Season wise comparison showed that irrespective of farming systems bacterial and fungal load were maximum in rainy season than in the other and was attributed to high soil moisture content, which is an important limiting factor in tropical soil.
Debasmita Chhotaray, C.S.K. Mishra and P.K. Mohapatra, 2011. Diversity of Bacteria and Fungi in the Gut and Cast of the Tropical Earthworm Glyphodrillus tuberosus Isolated from Conventional and Organic Rice Fields. Journal of Pharmacology and Toxicology, 6: 303-311.