Biodegradation and Phytotoxicity of Biodiesel,Diesel, and Petroleum in Soil

Biogas must be pretreated before its use; thus, both physical and chemical methods have been implemented to remove the fuel’s principal pollutants (CO₂ and H₂S). Additional removal methods that use microorganisms’ biological processes to eliminate pollutants have also emerged. A selection was made from six bacterial isolates to obtain consortia that removed CO₂ and eventually H₂S through the enrichment of cultures and the construction of clone libraries of gene 16S ribosomal DNA (rDNA). The results indicate that the principal differences between consortia were determined in the culture medium. C5 and C6 consortia had photosynthetic biomass 1.42 and 1.52 μg/ml, respectively, and concentration of dissolved CO₂ 100.6 and 99.1 mg/l, respectively. The clone libraries showed that Rhodopseudomonas sp. had percentages 46.6, 42.5, and 86.8 % in C4, C5, and C6, respectively; Xanthobacter sp., 24.5 %, Castellaniella sp., 18 % in C5, and Sphingobium sp., 39.2 % in C4.