title: Streptococcus suis sorption on agricultural soils: role of soil physico-chemical properties.
abstract: Understanding pathogen sorption on natural soil particles is crucial to protect public health from soilborne and waterborne diseases. Sorption of pathogen Streptococcus suis on 10 agricultural soils was examined, and its correlations with soil physico-chemical properties were also elucidated. S. suis sorption isotherms conformed to the linear equation, with partition coefficients (Ks) ranging from 12.7 mL g(-1) to 100.1 mL g(-1). Bacteria were observed to sorb on the external surfaces of soil aggregates by scanning electron microscopy. Using Pearson correlation and linear regression analysis, solution pH was found to have significant negative correlations with Ks. Stepwise multiple regression and path analysis revealed that pH and cation exchange capacity (CEC) were the main factors influencing sorption behaviors. The obtained overall model (Ks=389.6-45.9×pH-1.3×CEC, R(2)=0.943, P<0.001) can accurately predict Ks values. However, the variability in Ks was less dependent on soil organic matter, specific surface area, soil texture and zeta potential, probably due to the internal-surface shielding phenomenon of soil aggregates. Additionally, the sorption trends cannot be interpreted by interaction energy barriers calculated using the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, suggesting the limits of DLVO theory in describing pathogen sorption on natural soils. Our results also indicated soil pH and CEC should be preferentially considered when modeling S. suis sorption process.
authors: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
authors: Wenqiang
authors: W
authors: Zhao
authors: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
authors: Xing
authors: X
authors: Liu
authors: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Arable Land Conservation in Middle and Lower Reaches of Yangtse River, Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China.
authors: Qiaoyun
authors: Q
authors: Huang
authors: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Arable Land Conservation in Middle and Lower Reaches of Yangtse River, Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: cp@mail.hzau.edu.cn.
authors: Peng
authors: P
authors: Cai
mesh_terms: D000327:Adsorption; D000383:Agriculture; D002412:Cations / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D008956:Models, Chemical; D012044:Regression Analysis; D012987:Soil / Q000737:chemistry*; D017011:Streptococcus suis / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D002412:Cations; D012987:Soil
keywords: Partition coefficient; Soil properties; Sorption; Statistical correlation; Streptococcus suis