Biofilm-associated microorganisms play crucial roles in terrestrial and aquatic nutrient cycling and in the biodegradation of environmental pollutants. Biofilm formation was determined for a total of 18 bacterial isol...Biofilm-associated microorganisms play crucial roles in terrestrial and aquatic nutrient cycling and in the biodegradation of environmental pollutants. Biofilm formation was determined for a total of 18 bacterial isolates obtained from the biofilms of wastewater treatment systems and of little carpolite in soil. Among these isolates, seven showed strong biofilm-forming capacity. The phylogenetic affiliation of the isolates showing high biofilm formation capacity was determined through 16S rDNA sequencing and the isolates were grouped into 7 bacterial species including Pseudornonas sp., Pseudomonas putida, Aeromonas caviae, Bacillus cereus, Pseudornonas plecoglossicida, Aeromonas hydrophila, and Comamonas testosteroni. The biofilm-forming capacity was closely related with flagella, exopolysaccharide, and extracellular protein. According to the coefficient of determination, the relative importance of the five biological characteristics to biofilm formation was, in order from greatest to least, exopolysaccharide 〉 flagella 〉 N-acyl-homoserine lactones （AHLs） signaling molecules 〉 extracellular protein 〉 swarming motility.展开更多
The aim of this work was to see whether Pseudomonas putida NWU12, Pseudomonas fluorescence NWU65, Vibrio fluvialis NWU37 and Ewingella americana NWU59 are beneficial to plants and are able to promote plant growth and ...The aim of this work was to see whether Pseudomonas putida NWU12, Pseudomonas fluorescence NWU65, Vibrio fluvialis NWU37 and Ewingella americana NWU59 are beneficial to plants and are able to promote plant growth and development when inoculated as plant growth-promoting rhizobacteria (PGPR). The four rhizobacteria were tested in vitro for PGPR activities and on spinach and pepper in pot experiments. The inoculants are all positive for ammonia (NH3 ), catalase, hydrogen cyanide (HCN), phosphate solubilization and siderophore production. Among the inoculants, E. americana NWU59 is oxidase negative. P. putida NWU12 and P. fluorescence NWU65 are producing indole-3-acetic acid (IAA). The inoculants exhibit some PGPR activities and thus tested in the screen-house. Treatments are control (water) and the four inoculants. Rhizobacterial inoculants increase spinach (17.14%-21.43%) and pepper (15.0%-37.5%) plant heights over the control. Such inoculants have the potential of improving plant yield components and may be used as biofertilizer.展开更多
基金supported by the National Natural Science Foundation of China (No.30600016)the Environment Protection Department of Jiangsu Province,China (No.2004007)
文摘Biofilm-associated microorganisms play crucial roles in terrestrial and aquatic nutrient cycling and in the biodegradation of environmental pollutants. Biofilm formation was determined for a total of 18 bacterial isolates obtained from the biofilms of wastewater treatment systems and of little carpolite in soil. Among these isolates, seven showed strong biofilm-forming capacity. The phylogenetic affiliation of the isolates showing high biofilm formation capacity was determined through 16S rDNA sequencing and the isolates were grouped into 7 bacterial species including Pseudornonas sp., Pseudomonas putida, Aeromonas caviae, Bacillus cereus, Pseudornonas plecoglossicida, Aeromonas hydrophila, and Comamonas testosteroni. The biofilm-forming capacity was closely related with flagella, exopolysaccharide, and extracellular protein. According to the coefficient of determination, the relative importance of the five biological characteristics to biofilm formation was, in order from greatest to least, exopolysaccharide 〉 flagella 〉 N-acyl-homoserine lactones （AHLs） signaling molecules 〉 extracellular protein 〉 swarming motility.
基金supported by National Research Foundation of South Africa
文摘The aim of this work was to see whether Pseudomonas putida NWU12, Pseudomonas fluorescence NWU65, Vibrio fluvialis NWU37 and Ewingella americana NWU59 are beneficial to plants and are able to promote plant growth and development when inoculated as plant growth-promoting rhizobacteria (PGPR). The four rhizobacteria were tested in vitro for PGPR activities and on spinach and pepper in pot experiments. The inoculants are all positive for ammonia (NH3 ), catalase, hydrogen cyanide (HCN), phosphate solubilization and siderophore production. Among the inoculants, E. americana NWU59 is oxidase negative. P. putida NWU12 and P. fluorescence NWU65 are producing indole-3-acetic acid (IAA). The inoculants exhibit some PGPR activities and thus tested in the screen-house. Treatments are control (water) and the four inoculants. Rhizobacterial inoculants increase spinach (17.14%-21.43%) and pepper (15.0%-37.5%) plant heights over the control. Such inoculants have the potential of improving plant yield components and may be used as biofertilizer.
