Relationship between the extracellular polymeric substances and surface characteristics of Rhodopseudomonas acidophila.
The relationship between the extracellular polymeric substances (EPS) and surface characteristics of Rhodopseudomonas acidophila in its different growth phases was established. The equilibrium constant of partition (K par) and the Gibbs energies of partition (DeltaG par) between hexadecane and aqueous phases were also calculated according to the microbial adhesion to hexadecane (MATH) testing. The EPS content decreased with cultivation time at the logarithmic phase, but kept almost unchanged around 22.9 mg g(-1) dry cell at the stationary phase. The EPS production of R. acidophila had a significant effect on its surface characteristics. The relative hydrophobicity and the K par values of R. acidophila before EPS extraction were both lower than those after extraction. Both EPS content and ratio of proteins to carbohydrates had a negative effect on the water contact angle of the bacterium, but had a positive influence on the bacterial surface free energy and its polar component. On the other hand, the EPS were not related with MATH% or the Gibbs energy of partition between hexadecane and aqueous phase.
Sheng
Guo-Ping
GP
Lab of Environmental Biotechnology, School of Chemistry, University of Science & Technology of China, Hefei, Anhui, 230026, China.
Yu
Han-Qing
HQ
Lab of Environmental Biotechnology, School of Chemistry, University of Science & Technology of China, Hefei, Anhui, 230026, China. hqyu@ustc.edu.cn.
D001422:Bacterial Adhesion / Q000502:physiology; D001704:Biopolymers / Q000096:biosynthesis* / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D012241:Rhodopseudomonas / Q000502:physiology*; D013499:Surface Properties; D013816:Thermodynamics
D001704:Biopolymers