Hydrophobicity of diverse bacterial populations in activated sludge and biofilm revealed by microbial adhesion to hydrocarbons assay and high-throughput sequencing.
Cell hydrophobicity is one of the key physicochemical properties of bacteria in activated sludge (AS) and biofilms can influence the efficient operation of wastewater treatment plants (WWTPs). In the present study the cell hydrophobicity of diverse bacterial populations in AS and biofilms from the Shatin and Stanley WWTPs of Hong Kong was characterized by combining the microbial adhesion to hydrocarbons (MATH) assay with the Illumina high-throughput sequencing. The results indicated that, at the phylum level, a majority of bacteria in AS and biofilms showed medium hydrophobicity. Most of the top 20 bacterial genera in the AS samples were hydrophilic. However, the top 20 genera in biofilms showed higher hydrophobicity than in the top 20 genera in AS samples, suggesting more hydrophobic bacteria existed in biofilms than in AS. Meanwhile, the hydrophobicity of two specific bacterial groups, including foaming and biosurfactant-producing bacteria, were also evaluated. The results demonstrated that, by combining the MATH assay with the Illumina sequencing approach, bacterial hydrophobicity could be evaluated with high efficiency and coverage in complex systems with high microbial diversity, e.g. AS and biofilms in WWTPs.
Environmental Biotechnology Lab, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
Yuanqing
Y
Chao
Environmental Biotechnology Lab, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
Feng
F
Guo
Environmental Biotechnology Lab, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
Herbert H P
HH
Fang
Environmental Biotechnology Lab, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China. Electronic address: zhangt@hkucc.hku.hk.
Tong
T
Zhang
D001419:Bacteria / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D001422:Bacterial Adhesion / Q000187:drug effects*; D018441:Biofilms / Q000187:drug effects*; D001681:Biological Assay / Q000379:methods*; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D006838:Hydrocarbons / Q000494:pharmacology*; D057927:Hydrophobic and Hydrophilic Interactions / Q000187:drug effects*; D010802:Phylogeny; D012722:Sewage / Q000382:microbiology*
D006838:Hydrocarbons; D012722:Sewage
Activated sludge; Bacterial hydrophobicity; Biofilm; Illumina sequencing; MATH assay