Biodegradation and adsorption of benzo[a]pyrene by fungi-bacterial coculture

In this work, the relationship and kinetics of biodegradation and bio-adsorption of benzo[ a ]pyrene (BaP) by Bacillus and Ascomycota were explored, and the metabolites of BaP under mixed microbial coculture were analyzed and characterized. The results show that BaP was removed through both biosorption and biodegradation. Under mixed microbial coculture, biosorption played a significant role in the early stage and biodegradation was predominant in the later stage. During the removal of BaP, the fungi exhibited remarkable adsorption capabilities for BaP with an adsorption efficiency (AE) of 38.14 %, while bacteria had a best degradation for BaP with a degradation efficiency (DE) of 56.13 %. Under the mixed microbial culture, the removal efficiency (RE) of BaP by the synergistic action of fungi and bacteria reached up to 76.12 % within 15 days. Kinetics analysis illustrated that the degradation and adsorption process of BaP were well fit to the first-order and the pseudo-second-order kinetic models, respectively. The research on the relationship between degradation and adsorption during microbial removal of BaP, as well as the synergistic effects of fungi and bacteria, will provide a theoretical guidance for two or even synthetic microbial communities. • In the process of the removal of BaP, fungi dominated by adsorption, while mixed bacteria dominated by degradation. • Quasi-second-order kinetics can better describe the adsorption process of BaP by microorganisms. • The quasi-first-order kinetic model can better describe the biodegradation process.