Enrichment, Isolation and phylogenetic identification of fluoranthene and nonylphenol-degrading bacteria

Abstract

Polycyclic aromatic hydrocarbons (PAHs) and Endocrine disrupting chemicals (EDCs) are man-made chemicals that cause cancer and alter the function of endocrine systems in both humans and wildlife, respectively. PAHs and EDCs are considered as one of the priority pollutants and world-wide research is on-going to develop bioremediation strategies to remove these toxic xenobiotics from environment. Understanding indigenous microorganisms is important to design efficient bioremediation strategies. However, much of the information available on PAHs and EDCs has been generated from developed regions. In this direction, recent studies revealed presence of different PAHs and EDCs in South African natural resources. However, to date, study on analysis of microorganisms capability to utilize/degrade EDCs has not been reported and studies on PAHs are scares from South Africa. Soil samples collected at the different coal-fired power stations in and around Mpumalanga province, South Africa was used for enriching microorganisms. Enrichment method employed for isolating fluoranthene (as a model compound for PAHs) or nonylphenol (as a model compound for EDCs) degrading microorganisms. Identification of microorganisms was carried out using 16S rRNA gene analysis. Phylogenetic analysis of isolates was carried out using MEGA5. For each substrate, six pure and distinct bacterial cultures were successfully enriched. Pseudomonas dominated the strains enriched on nonylphenol, with 5 of the 6 isolates belonging to this genus. All four of these isolates however belong to different species. Highest diversity observed when fluoranthene was used as a carbon source. Strains of Pseudomonas, Stenotrophomonas, Cupravidus and Ochrobactrum were isolated using fluoranthene as a carbon source. Study results are the beginning of identification of microorganisms capable of degrading carcinogenic and endocrine disruptors and pave the way for exploring PAHs and EDCs degrading microorganisms from South Africa. An article on EDCs utilization organisms and their capability to degrade nonylphenol is submitted to South African Journal of Sciences. Here the details: 􀁸 Qhanya LB et al. (2016) Isolation and characterization of endocrine disruptor nonylphenol-using bacteria from South Africa. SAJS-2016-0287 (under review). Apart from my Masters study, I also supervised four B. Tech student projects and managed to publish an article with students. Furthermore, I also worked on few bioinformatics projects and earned co-authorship in two manuscripts listed below: 􀁸 Parvez M, Qhanya LB, Mthakathi NT, Kgosiemang IKR, Bamal HD, Pagadala NS, Xie T, Yang H, Chen H, Theron CW, Monyaki R, Raselemane SC, Salewe V, Mongale BL, Matowane RG, Abdalla SMH, Booi WI, van Wyk M, Olivier D, Boucher CE, Nelson DR, Tuszynski JA, Blackburn JM, Yu J-H, Mashele SS, Chen W, Syed K. (2016) Molecular evolutionary dynamics of cytochrome P450 monooxygenases across kingdoms: Special focus on mycobacterial P450s. Scientific Reports | 6:33099 | DOI: 10.1038/srep33099. 􀁸 Qhanya LB, Matowane G, Chen W, Sun Y, Letsimo EM, Parvez M, Yu J-H, Mashele SS, Syed K. (2015) Genome-wide annotation and comparative analysis of cytochrome P450 monooxygenases in basidiomycete biotrophic plant pathogens. PLoS ONE 10(11): e0142100. doi:10.1371/journal.pone.0142100. 􀁸 Sello MM, Jafta N, Nelson DR, Chen W, Yu J-H, Parvez M, Kgosiemang IKR, Monyaki R, Raselemane SC, Qhanya LB, Mthakathi NT, Mashele SS, Syed K. (2015) Diversity and evolution of cytochrome P450 monooxygenases in Oomycetes. Scientific Reports 07/2015; 5. DOI:10.1038/srep11572 · (Discovered novel P450 fusion protein). In addition to the above credits, I was featured on national TV and in newspapers for discovering a novel drug target. I also presented work at both national and international (Canada) conferences.