Histo-Blood Group Antigen (HBGA) Positive Bacteria in the Mixed Liquor Reduces the Human Rotavirus Concentration in Membrane Filtration Effluent

摘要

Blood group-active bacteria, which can produce HBGA-like substances as components of lipopolysaccharide (LPS) or extracellular polymeric substances (EPS) are ubiquitously present in wastewater. Human noroviruses have displayed genotype-dependent removal during the microfiltration in the presence of these HBGA-positive bacteria. In the current study, we analyzed the variation of the effluent rotavirus (HAL 1166 strain which recognizes the A-type antigen) concentration in the presence of HBGA positive Enterobacter cloacae SENG-6. Trypsin-treated (proteolytic cleavage of VP4 to produce VP8* which interacts with HBGAs) and non-trypsin treated HAL1166 is mixed with E. cloacae SENG-6 (5×10~8 cells/ml) at 4℃ for 50 min, and then applied to a cross-flow membrane filtration device installed with a 0.2 µm PTFE membrane having a surface area of 2000 mm2. In the presence of HBGA-positive bacteria, trypsin-treated HAL1166 concentration reduced with time (R~2>0.75, all 3 trials) while the non-trypsin treated HAL1166 concentration reduction had a lower correlation (R~2<0.5, all 3 trials). Specific interactions between the HBGA-positive bacteria and trypsin-treated HAL 1166 have shown to be responsible for lower effluent concentration of HAL 1166. Manipulation of reactor bacterial community using HBGA-positive bacteria may improve the virus removal efficiency and provide microbiologically safe reclaimed water for beneficial reuse purposes.