Résumé
120 strains of endophytic bacteria identified by ERIC-PCR were isolated from wild and cultivated Glycyrrhiza uralensis plants which collected from Erdos Innermongolia province.The identified results indicated that Glycyrrhiza uralensis plants has plenty of endophytic bacterium in density and population,and the density is higher in root and leave than in stem.Partial sequence analysis of 16S rDNA gene of 82 strains indicated that these strains were in a high similarity with 19 known genus which belong to?、?、 ?-Proteobacteria、Firmicutes and Actinobacteria.The dominant genus were Bacillus sp.,Pseudomonas sp., Pantoea sp.and Serratia sp..
Résumé
Using 16S rDNA clone library method, the bacteria composition of the Organic Matter-decomposing Inoculants A and B were investigated. The results indicated that: Sample A was clustered into 14 taxonomic operational units (OTUs),the dominant communities are Weissella confuse, Bacillus subtilis and Bacillus pumilus, which accounted for 28.6%,30.4% and 23.2%;Sample B was clustered into 43 OTUs,the dominant communities are Lactobacillus buchneri, Lactobacillus farciminis and Lactobacillus acetotolerans, which accounted for 18.03%,18.86% and 13.12%, respectively. The results had much difference from the samples' labels:there were not bacteria in the lable of sample A and only Bacillus pumilus was the same with the lable of sample B.This study showed that 16S rDNA clone library method has nicer application perspectives in analying the bacteria of microbial inoculant and its quality control.
Résumé
98 endophytic bacteria strains were isolated from different internal tissues of Glycyrrhiza uralensis plants collected from Innermongolia region. Results indicated that the population densities of endophytic bacteria ranged from 5.0?104cfu/g～2.9?107cfu/g fresh weight although it varied depending on tissue of the plant. Among these strains, Bacillus sp. was the most prevalent endophytic bacterium, which was amount to 30%.Of the 98 isolates, 6 strains exhibited extensive antagonistic activities against pathogenic bacteria. Characterization showed that these bacteria were Bacillus atrophaeus、Paenibacillus polymyxa、Bacillus subtilis、Paenibacillus ehimensis. This study indicated that selected 6 endophytic bacteria strains have potential for biological control of plant disease.
Résumé
Pesticides, especially chemistry pesticides with high toxicity, high residue, and difficult degradation are a kind of important environment pollutants and pesticide degradation by microorganisms is one of the powerful means to treat pesticide pollution. Many researchers conducted lots of studies on it. Types of pesticide degraders, construction of genetically engineered microorganisms, degrading mechanisms, degradation characteristics, influencing factors, applying effect and so on were summarized in this article. The research trend of degradation of pesticides by microorganisms and problems to be solved were also put forward.