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Iron-reducing bacteria is a general term for a class of microbes ferric reducing function. Reduction of iron bacteria in the bioremediation of heavy metal pollution in the biodegradation of organic pollution, microbial cell development and global physical chemistry cycle has application value. Research under anaerobic conditions carbon source type and quantity of iron restore paddy soil bacterial community diversity changes will restore the dissimilatory iron of reaction principle iron-reducing bacteria in heavy metal pollution applications provide a theoretical basis. As technology continues to progress in molecular microbial ecology, it is found that the organic matter in the environment will significantly affect the iron-reducing bacteria community structure. This test uses organic matter depletion paddy soil samples, add synthetic iron oxide and mixed carbon source for anaerobic incubation, with RFLP and other technical means to study the anaerobic enrichment culture in paddy soil iron reduction bacteria group diversity compare different incubation time reduction of iron bacteria group differences in the structure, and by pure culture experiments, isolates the iron reduction rate compared to explore the different culture phase separation iron reduction iron reduction of microorganisms. 0d, 1d, 7d, 14d, 21d, 28d and 50d, seven different sampling points were set, sealing film anaerobic culture method, respectively the strains 108,113,112,75,80,80 and 80 anaerobic dryer culture method, respectively, the strain 87,72,15,75,80,80 and 80; 1135 bacterial 16S rDNA genes were amplified, and 7 deal with a total of 682 clones, RFLP analysis were obtained 18,5 , 6,2,6,8 and 6 digested type, a total of 27 kinds of digested types, including 11 kinds of advantages type and 14 a single clone. Test for the following results: (1) paddy soil enrichment culture 0d, 1d, 7d, 14d, 21d, 28d and 50d, respectively, resulting OTU were 18,5,6,2,6,8 and 6, the storage capacity, respectively 88.5%, 100%, 97.1%, 98.2%, 95.2% and 96.2%, on behalf of the paddy soil better able dissimilatory iron-reducing bacteria community diversity. (2) from the PIE index, diversity index (index of H and D) and evenness 0d gt; 28d gt; 1d gt; 50d gt; 7d gt; 21d gt; 14d. 0d rich in species composition and community structure is complex, its diversity index is the highest in seven treatments, 14 d minimum and 14 d of community structure is relatively single. Species richness the index (dMa and the R2 index) results: 0d gt; 28d gt; 50d = 7d gt; 1d gt; 21d gt; 14d. 7d and 28d richness, index, respectively, higher than before and after two periods, 7d and 28d when iron-reducing bacteria on carbon source utilization activity is relatively high. 50d diversity index found that the diversity index and richness index were lower, anaerobic enrichment culture process of adding exogenous iron and mixed carbon source so that the advantages of the type of increase in the proportion, the decrease in the total number of groups, paddy soil 0d control iron-reducing bacteria diversity, evenness and richness were reduced. (3) compare the the anaerobic culture iron reduction rate of iron-reducing bacteria of different times found to use anaerobic dryer cultured 7d, iron reduction ability the highest proportion of bacterial growth, the best growth activity. (4) Add the mixed carbon source anaerobic enrichment in paddy soil iron reduction bacteria communities of advantages type Bacillus, Bacillus aureus and class. Anaerobic enrichment culture of iron reduction ability strains are mainly distributed in the dominant type T1, the advantages of type T1 and Staphylococcus aureus, Bacillus ceroid-like Bacillus subtilis and Bacillus megaterium high similarity. By the above results, it can be concluded, adding a mixed carbon source of the artificial synthetic hydrated iron, as well as glucose, lactate and acetate for anaerobic enrichment culture, paddy soil iron-reducing bacteria community structure larger change: the proportion of iron-reducing bacteria increased use of enhanced carbon source, iron reduction capacity enhancements; iron-reducing bacteria community structure to increase stability; dominant position in the growth of Bacillus and Staphylococcus.
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