Effect of native microorganism Rhodococcus spp. SL-9 for dibenzothiophene degradation and its application towards clean coal approach

Combustion of coal emits many harmful gases, causing huge environmental problems. Harmful gases are, sulfur dioxide, nitrogen oxides and carbon dioxide, which disturbing eco-condition of environment. Apart from all other emissions sulfur emissions has significant effect on environment as well as on human health. To remove sulfur from coal various methods had been proposed as well as investigated by various researchers. It is necessary to utilize economic as well as ecofriendly technique, which is nothing but the microbial technique. Current study focus on removal of organic sulfur from coal using novel Rhodococcus spp. (SL-9). From literature and previous studies, it was proving that the amount of higher content of type of sulfur present in coal is organic sulfur, which can be found in the form of dibenzothiophene (DBT). Rhodococcus spp. (SL-9). was utilized as bio-catalyst for degradation of DBT via 4S-Pathway. Rhodococcus spp. (SL-9) degrade 0.26 mM DBT within 6 days via 4S pathway. Impact of various process parameters on bio-desulfurization were studied, which are temperature, pH, agitation intensity and different carbon source, which have considerable effect on degradation of DBT. The efficiency of Rhodococcus spp. (SL-9) for maximum degradation and conversion of DBT into 2-HBP (2-hydroxybiphenyl) at optimized parameters are 30 °C, 160 rpm, and glucose as carbon source. This could suggest that Rhodococcus spp. (SL-9) had ability to degrade DBT compound from coal. [Display omitted] •Novel bacteria Rhodococcus spp. (SL-9) for organic sulfur removal has been isolated from petroleum polluted soil.•Rhodococcus spp. (SL-9) was successfully tested for model organic sulfur compounds.•Effect of temperature and pH were successfully analyzed.•The total sulfur removal from lakhra coal is about 31 ± 1.7%.•The highest organic sulfur removal from coal is about 69 ± 1.5%, at 30 °C, and glucose as carbon source.