Effects of roxarsone on the functional diversity of soil microbial community

To investigate the effects of roxarsone (3-nitro-4-hydrroxyphenylarsonic acid) on indigenous microbial community in soil, the functional diversity and overall activity of microbial communities in vegetable field soil with the addition of roxarsone were assessed with Biolog-ECO plate method. Results of average well color development (AWCD) showed after the addition of roxarsone, AWCD of samples decreased immediately and distinctly. The cluster analysis of the principal component also suggested samples could be separated due to the addition of roxarsone. The kinetic characteristic of microorganism using different categories carbon sources indicated amino acids was the main carbon source of the sample soil and roxarsone sharply decreased the potential utilization of two substrate groups (polymers and amino acids) more strongly than that of the other groups (carboxylic acids and carbohydrates). These results implied roxarsone had a significant detrimental effect on indigenous microbial community diversity and metabolic activity in soil.