Lower temperature or polyphosphate limitation is the favorable condition to enrich polyphosphate-accumulating organisms (PAOs) or glycogen accumulating organisms (GAOs) in biological phosphorus removal process. In thi...Lower temperature or polyphosphate limitation is the favorable condition to enrich polyphosphate-accumulating organisms (PAOs) or glycogen accumulating organisms (GAOs) in biological phosphorus removal process. In this study,a sludge highly enriched in PAOs was used to investigate the metabolic pathways and carbon transformation in batch tests under the two conditions for elucidating the contradiction. The results showed that the PAOs are able to take up acetate and store it as polyhydroxyalkanoates (PHA) in anaerobic phase although the poly-P pool is emptied through washing with negligible P release. The stoichiometric ratios of the PHB and PHV production and glycogen degradation to the acetate uptake combined with the Nile blue staining indicated that the PAOs possess the anaerobic metabolism of GAOs using glycogen as the sole energy source,but no transformation of PAOs to GAOs is observed. After reconverting to the normal operation,phosphorus uptake and release are recovered the same as the parent reactor.展开更多
Pseudomonas aeruginosa,recognized for its biofilm production and secretion of virulence factors,posing a severe threat in areas such as clinical infections,food contamination,and marine biofouling.To address this,a ne...Pseudomonas aeruginosa,recognized for its biofilm production and secretion of virulence factors,posing a severe threat in areas such as clinical infections,food contamination,and marine biofouling.To address this,a new type of zinc-binding peptide(CSSP-Zn)was prepared from crimson snapper scales peptides(CSSP)and goslarite,and its antibacterial and anti-quorum-sensing activities toward P.aeruginosa PAO1 were exploited.Results indicated that CSSP-Zn induced planktonic strain PAO1 membrane injury via inhibiting expression levels of cell integrity genes,targeting microbial-specific membrane constituents,disrupting proton motive force,and causing metabolic disturbances.Meanwhile,CSSP-Zn decreased virulence factors pyocyanin,protease and rhamnolipid secretion,while considerably inhibiting quorum sensing-related genes(las,pqs and rhl)expression and decreasing bacterial abundance and pathogenicity in fish models.Moreover,CSSP-Zn not only effectively hindered biofilm formation but also disassembled preformed ones,thus disrupting biofilm topology.Taken together,utilizing food byproducts to obtain CSSP-Zn could help recycle food resources and provide insight into controlling planktonic and biofilm strain PAO1 contamination.展开更多
基金Sponsored by the Major Science and Technology Program for Water Pollution Control and Treatment (Grant No.2008ZX07207-005-02)
文摘Lower temperature or polyphosphate limitation is the favorable condition to enrich polyphosphate-accumulating organisms (PAOs) or glycogen accumulating organisms (GAOs) in biological phosphorus removal process. In this study,a sludge highly enriched in PAOs was used to investigate the metabolic pathways and carbon transformation in batch tests under the two conditions for elucidating the contradiction. The results showed that the PAOs are able to take up acetate and store it as polyhydroxyalkanoates (PHA) in anaerobic phase although the poly-P pool is emptied through washing with negligible P release. The stoichiometric ratios of the PHB and PHV production and glycogen degradation to the acetate uptake combined with the Nile blue staining indicated that the PAOs possess the anaerobic metabolism of GAOs using glycogen as the sole energy source,but no transformation of PAOs to GAOs is observed. After reconverting to the normal operation,phosphorus uptake and release are recovered the same as the parent reactor.
文摘Pseudomonas aeruginosa,recognized for its biofilm production and secretion of virulence factors,posing a severe threat in areas such as clinical infections,food contamination,and marine biofouling.To address this,a new type of zinc-binding peptide(CSSP-Zn)was prepared from crimson snapper scales peptides(CSSP)and goslarite,and its antibacterial and anti-quorum-sensing activities toward P.aeruginosa PAO1 were exploited.Results indicated that CSSP-Zn induced planktonic strain PAO1 membrane injury via inhibiting expression levels of cell integrity genes,targeting microbial-specific membrane constituents,disrupting proton motive force,and causing metabolic disturbances.Meanwhile,CSSP-Zn decreased virulence factors pyocyanin,protease and rhamnolipid secretion,while considerably inhibiting quorum sensing-related genes(las,pqs and rhl)expression and decreasing bacterial abundance and pathogenicity in fish models.Moreover,CSSP-Zn not only effectively hindered biofilm formation but also disassembled preformed ones,thus disrupting biofilm topology.Taken together,utilizing food byproducts to obtain CSSP-Zn could help recycle food resources and provide insight into controlling planktonic and biofilm strain PAO1 contamination.
