Recent advance of biofilm mediated polycyclic aromatic hydrocarbons (PAHs) degradation

Abstract

Polycyclic aromatic hydrocarbons (PAHs) has shown threat to ecosystem and human being due to their mutagenicity and carcinogenicity, and worldwide concern for PAHs degradation has increased in the past decades. Biofilm is proved to be more efficient than planktonic cells in PAHs degradation process, due to their high tolerance to harsh environments and regulation mechanisms. Therefore, biofilm, as an eco-friendly and efficient method, has been widely and successfully used for PAHs degradation. This review discussed biofilm’s composition and formation, mechanism of biofilm-mediates PAHs degradation. Furthermore, the main factors influencing biofilm-mediated PAHs degradation are described, these factors can affect PAHs degradation by influencing metabolic pathway and/or biofilm growth. Physical factors, like pH and temperature, are directly influencing microorganisms’ activity, while nutrient supplements and bioavailability also play critical role in the degradation process. The current applications of biofilm-mediates PAHs degradation are also reviewed, including various biofilm reactors and in-situ methods. However, there are some problems that needs to be addressed for large-scale application of biofilm, such as limited research conditions. Overall, this article reviews biofilm-mediated PAHs degradation in many aspects, and provides some ideas of future research direction.