title: Characterisation of microbial floras and functional gene levels in an anaerobic/aerobic bio-reactor for the degradation of carboxymethyl cellulose.
abstract: The current study determined the carboxymethyl cellulose (CMC) degradation efficiency, dominant microbial flora, eubacteria and archaebacteria characteristics, and expression levels of genes cel5A, cel6B, and bglC in an anaerobic/aerobic bio-reactor consisting of two-stage UASB (U1 and U2) and two-stage BAF (B1 and B2). The results showed that under three CMC loads, the CMC degradation efficiency of the UASB-BAF system was 91.25%, 80.44%, and 78.73%, respectively. At higher CMC loads, the degradation of cellulose and transformation to cellobiose in U1 was higher, while the transformation to glucose was lower. The results of DGGE and real-time PCR indicated that cellulose degradation bacteria are dominant in U1, cellulose degradation bacteria and cellulose degradation symbiosis bacteria are dominant in B1, and non-cellulose degradation symbiosis bacteria are dominant in both U2 and B2. The rate-limiting enzyme gene of cellulose degradation in U1, B1, and B2 is cel6B, but it is cel5A in U2.
authors.affiliation: Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing, China, 100871. jiguodong@pku.edu.cn
authors.forename: Guodong
authors.initials: G
authors.lastname: Ji
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.forename: Feng
authors.initials: F
authors.lastname: Guo
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001105:Archaea / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology*; D058448:Biota; D001711:Biotransformation; D002266:Carboxymethylcellulose Sodium / Q000378:metabolism*; D058645:Denaturing Gradient Gel Electrophoresis; D020869:Gene Expression Profiling; D054892:Metagenome; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D002266:Carboxymethylcellulose Sodium