Optimization and Interaction Analysis of Bacterial and Fungal Growth in the Presence of Benzo(A) Pyrene in Wastewater

Abstract

In wastewater treatment plant, an aerobic approach is adopted in the system which utilize the ability of bacteria in the wastewater to reduce biochemical oxygen demand (BOD) and other organic pollutants. High molecular weight of polycyclic aromatic hydrocarbons (HMW-PAHs) are type of organic persistence and insoluble pollutants which hard to be removed from wastewater by bacteria. Owing to the HMW-PAHs tolerant characteristic and abundancy of fungi in wastewater, the bacteria and fungi interaction is anticipated to degrade the HMW-PAHs in wastewater. Thus, this study is carried out as a preliminary study to understand the interaction by optimized the bacterial and fungal growth in the presence of benzo[a]pyrene (BaP). Bacteria and fungi used in this study were Sphingobacterium spiritovorum and Aspergillus brasiliensis ATCC 16404. The response surface methodology (RSM) in Design-Expert® Version 7.0.0 software was used to analysed two factors which are pH and temperature on the bacterial and fungal growth. The growth of bacteria and fungi in co-culture and existence of BaP also been studied. The optimization study showed the growth of S. spiritovorum and A. brasiliensis was optimized at pH 6.2, temperature of 32 °C, and pH 6.5 and temperature of 33 °C, respectively. Synergy interaction was observed in the co-culture condition and with the existence of BaP. The present study provides beneficial information about the bacteria and fungi interaction which has the potential to be applied in the wastewater treatment plant.