Diversity of propanil-degrading bacteria  isolated from rice rhizosphere and their potential for plant growth promotion.
The herbicide propanil has long been used in rice  production in southern Brazil. Bacteria isolated from contaminated soils in  Massaranduba, Santa Catarina, Brazil, were found to be able to grow in the  presence of propanil, using this compound as a carbon source. Thirty strains  were identified as Pseudomonas (86.7%), Serratia (10.0%), and Acinetobacter (3.3%), based on phylogenetic analysis of 16S rDNA. Little genetic  diversity was found within species, more than 95% homology, suggesting that  there is selective pressure to metabolize propanil in the microbial community.  Two strains of Pseudomonas (AF7 and AF1) were selected in bioreactor  containing chemotactic growth medium, with the highest degradation activity of  propanil exhibited by strain AF7, followed by AF1 (60 and 40%, respectively).  These strains when encapsulated in alginate exhibited a high survival rate and  were able to colonize the rice root surfaces. Inoculation with Pseudomonas strains  AF7 and AF1 significantly improved the plant height of rice. Most of the Pseudomonas strains produced indoleacetic acid, soluble mineral phosphate, and fixed  nitrogen. These bacterial strains could potentially be used for the  bioremediation of propanil-contaminated soils and the promotion of plant  growth.
Embrapa Meio Ambiente, Jaguariúna, SP, Brasil.
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D000464:Alginates; D001419:Bacteria / Q000235:genetics* / Q000302:isolation & purification* / Q000378:metabolism / Q000648:ultrastructure; D001483:Base Sequence; D001673:Biodegradation, Environmental / Q000187:drug effects; D018914:Cells, Immobilized / Q000166:cytology / Q000187:drug effects / Q000648:ultrastructure; D004275:DNA, Ribosomal / Q000235:genetics; D014644:Genetic Variation; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D008863:Microspheres; D012275:Oryza / Q000187:drug effects / Q000254:growth & development* / Q000382:microbiology*; D010802:Phylogeny; D011411:Propanil / Q000378:metabolism* / Q000494:pharmacology; D011549:Pseudomonas / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000648:ultrastructure; D058441:Rhizosphere; D014170:Transformation, Genetic / Q000187:drug effects
D000464:Alginates; D004275:DNA, Ribosomal; D006603:Hexuronic Acids; D011411:Propanil; D020723:Glucuronic Acid