Select Breeding And Structure Optimization Of Syntrppuic Acetogens Coculture B6

Hydrogen-producing acetogens (HPA) whose trophic niche is between acidogenes and methanogens is very difficult to be separated and purified due to their syntrophism with hyddrogy-consuming bacteria. Resources scarce of hydrogen-producing acetogens has restricted the development of new anaerobic organic wastewater treatement process with high efficiency, based on inhancing their metabolic capability.In order to research into its physiological and ecological characteristics and to lay the scientific basis for the development of highly efficient anaerobic biological treatment technology,the syntrophic acetogen cocultures were enriched and Selective bred by the Selective medium which is mixed by the Propionic acid and butyric acid from the anaerobic activated sludge with methanogens.The paper firstly aimed at the rejuvenation of the seven syntrophic acetogen cocultures from anaerobic baf?ed reactor (ABR) and drew up the growth diagram of curves of syntrophic acetogen cocultures to determination the best vaccination time is 48-96 h. According its growth and metabolism to select a syntrophic acetogen coculture named B₆.To Optimize the conditiong of syntrophic acetogen coculture, study and design based.culture medium of B₆. The influence of ecological factors on the growth and metabolism of the co-cultures was investigated farther more. With butyrate as carbon source (10 g/L), tryptone and the yeast extract as nitrogen source, B₆ could present an excellent performance in growth and metabolism at 42.5℃with a initial pH 7.2, free-vented,ratio of inoculated is 4:10.From the perspective of design culture medium to strengthen the advantaged colony of B₆, The culture medium provide nutrients to favorable growth and metabolism of HPA and restrain the associated bacteria. Consider adding sulfate to provide hydrogen acetogen receptor, weaken the role of associated bacteria.The nitrogen source use needs to consider to the benefit of HPA and avoids to strengthen the associated bacteria. PCR-DGGE technique analysis showed that each business cultures of B₆-8c were only four kinds of bacteria are present, and B₆ were seven kinds. The 16S rDNA sequences of all the clones from the bandings showed that B₆-8c was a new syntrophic acetogen cocultures with non-methanogens as the associated bacteria. They contain obligate HPA Peptococcus sp. in B₆-8c and B₆ camp.The associated bacteria is ferric iron reducers Clostridium sp, which could utilize the formate and the H₂. There were no CH4 or H₂S being evolved in both culture systems, while hydrogen and acetic acid were detected. B₆-8c removed the associated bacteria of HPA in original B₆ that is acetic acid and hydrogen Sedimentibacter sp. And can degrade the amino acid, benzoic acid, toluene and other bacteria Clostridium hydroxybenzoicum.