Survival of the plant-growth promoting rhizobacteria （PGPR） strain Pseudomonasfluorescens 92 in two batches ofbiosolids and soil amended with them and functional and structural shifts occurring in the resident bacte...Survival of the plant-growth promoting rhizobacteria （PGPR） strain Pseudomonasfluorescens 92 in two batches ofbiosolids and soil amended with them and functional and structural shifts occurring in the resident bacterial communities were assessed. Viability of the rifampicin resistant gfp-tagged P. fluorescens 92RTcgfp, inoculated in microcosms consisting of biosolids, soil amended with biosolids and soil, drastically decreased 3-7 days after inoculation in treatments containing biosolids and soil amended with them. The PGPR counts in biosolids were always lower than in soil throughout the experiment whereas, in soil amended with biosolids, were similar or higher depending on the batch of biosolid. Analysis of the community-level physiological profiling （CLPP） revealed a strong impact of the strain on the metabolic activities, as seen in a general uniformity of the inoculated microcosms profiles. According to single-strand conformation polymorphism （SSCP） analysis, the presence of the PGPR had no effect on the resident soil and biosolid eubacterial population, whereas it induced a transient shift in the composition of the resident pseudomonads. In conclusion, biosolids themselves are not suitable as inoculum vehicle for the PGPR nevertheless, their combined incorporation into soil increases the inoculum survival and buffers the competition effects with the resident communities.展开更多
文摘Survival of the plant-growth promoting rhizobacteria （PGPR） strain Pseudomonasfluorescens 92 in two batches ofbiosolids and soil amended with them and functional and structural shifts occurring in the resident bacterial communities were assessed. Viability of the rifampicin resistant gfp-tagged P. fluorescens 92RTcgfp, inoculated in microcosms consisting of biosolids, soil amended with biosolids and soil, drastically decreased 3-7 days after inoculation in treatments containing biosolids and soil amended with them. The PGPR counts in biosolids were always lower than in soil throughout the experiment whereas, in soil amended with biosolids, were similar or higher depending on the batch of biosolid. Analysis of the community-level physiological profiling （CLPP） revealed a strong impact of the strain on the metabolic activities, as seen in a general uniformity of the inoculated microcosms profiles. According to single-strand conformation polymorphism （SSCP） analysis, the presence of the PGPR had no effect on the resident soil and biosolid eubacterial population, whereas it induced a transient shift in the composition of the resident pseudomonads. In conclusion, biosolids themselves are not suitable as inoculum vehicle for the PGPR nevertheless, their combined incorporation into soil increases the inoculum survival and buffers the competition effects with the resident communities.
