Sequential degradations of Dananhu lignites by Nocardia mangyaensis and Bacillus licheniformis

The sequential degradation of coal by two bacterial species was one of the effective methods to improve the coal biodegradation rates. In this paper, two bacteria N. mangyaensis and B. licheniformis were selected to degrade Dananhu lignite sequentially. The biodegradation rates and products of Dananhu lignites by two degradation ways were investigated and characterized, respectively. The results indicated the best way for sequential degradation of Dananhu lignite was to use N. mangyaensis first and then B. licheniformis (represented as N. mangyaensis-* B. licheniformis order), in which the highest degradation rate reached 82.1%. On the contrary, the degradation rate attained 75.5% with the order of B. licheniformis-* N. mangyaensis. The compositions and structures of solid and liquid bioproducts by two ways were analyzed. The side chains in oxidized lignite were prone to be degraded by N. mangyaensis and the aromatic skeletons were attacked by B. licheniformis. Therefore, the sequential degradation order of N. mangyaensis-* B. licheniformis was the effective way for Dananhu lignite.

Automated summary

This paper investigated the sequential degradation of Dananhu lignite by two bacterial species, N. mangyaensis and B. licheniformis. The results showed that the most effective way for degradation was to use N. mangyaensis first and then B. licheniformis. The compositions and structures of the bioproducts generated by the two ways were analyzed, revealing that N. mangyaensis mainly degraded the side chains, while B. licheniformis attacked the aromatic skeletons.