Followed by the identification of the metabolites, the study has been reversed back to examine the isolate for the specific
genes responsible for the anthracene catabolism. As described in Section 1, the presence of dissolution agents is the primary requirement of the microorganisms to attack or encounter the lipophilic molecule. Though, the isolate displayed surface-active agents during the growth, the gene responsible for the production of surface-active agent was examined using molecular techniques. Fig. 4a illustrates CB-839 mw the PCR amplified product of licA3 gene determined with 0.26 kb and Fig. 4b depicts the PCR amplified product of catechol 2,3 dioxygenase (C23O) gene obtained using primers designed specific for hydrocarbon degradation yielded an amplified product of the expected size of 1.27 kb respectively. Conserved regions of MTCC 5514 were selected to design oligonucleotide primers for detection of the genes. Thus, it has been confirmed that the chosen isolates catabolize anthracene through dioxygenase pathway. The sequences of the PCR products obtained were verified in the NCBI databases for the gene/species confirmation and thus validating the presence of the genes in the selected strains of Bacillus. Fig. 4c depicts Selleckchem Rigosertib the aligned sequence of PCR products respective to licA3 and C23O genes encoded
for surface active agent and degradative enzyme of MTCC 5514. Fig. 5 depicts the proposed degradation pathway elucidated based on the metabolites identified. The indented anthracene molecule
may be degraded in two different ways. The left hand side pathway suggested selleck chemical that the primary attack of anthracene after day 15 (because synthesize of catabolizing enzymes triggers only after nutrient depletion) was through a dioxygenase enzyme system, which leads to the formation of di-hydroxy anthracene, which, further and immediate attack by the same enzyme system transformed to anthraquinone. However, the right side reactions demonstrated that, the generation of phthalic acid via naphthalene (as evidenced from GC–MS analysis) and may further degraded as shown and enter in to TCA cycle. Fig. 6 depicts the SEM micrograph of biomass obtained at scheduled time intervals of 10, 16 and 22 days showed interesting observations. The filamentous growth was extensive with increased cell volume with reference to the incubation period and in the presence of the test compound anthracene. The maximum increase in cell volume was observed on day 16 samples, and further on day 22, high filamentous growth leads to aggregation of cells in the form of biofilm and showed a clumsy mass. In the present study, a potential marine isolate MTCC 5514 was tested for its anthracene degradation efficacy and the results of the study further confirmed the degradation of anthracene. The isolate MTCC 5514 displayed the production of surface-active agents and it showed tolerance up to pH 12.0 during the degradation process.