Tuesday, Apr. 21, 2015
70 ° Fair
|Student||Matthew Boyce, '13|
|Course||BIO 489: Research in Natural Sciences|
Eisenia foetida, commonly known as ‘red wigglers’, is the most widely used worm species in the organic recycling process known as vermicomposting. Vermicompost is a valuable soil amendment often reported to contain microbes beneficial for agriculture. Precisely which microbes are beneficial and how microbial composition may vary with the type of compost is not known. There is a small vermicompost project at Virginia Wesleyan, with the worms recycling vegetable scraps from the dining facility. In this study we examined the microbiomes from vermicompost, normally fed worms, and worms that had been starved for 24 hours. DNA was extracted from each source and subjected to PCR for 16 rRNA, followed by 454 sequencing of the amplified products. A BLAST search revealed considerable differences between the samples, though some species were common to all samples. The search generated over 6000 operation taxonomic units (OTU’s). Of these, about 180 were named species. Surprisingly Methylibium petroleiphilum, a bacterial species found in soil contaminated with aromatic hydrocarbons, was present in all three samples and represented the major bacterial species from the vermicompost. Another species found in all three samples was Sorangium cellulosum,a cellulose degrading organism, known to produce a variety of antibacterial and antifungal compounds. Chitinophaga arvensicola present in all three samples similarly is reported to have antifungal activity. The presence of organisms such as these leads credence to the ‘beneficial microbes’ claims for vermicompost.