Two-step fermentation process and the corresponding study on its enzymology characteristics

CHANG Yu-guang^1,2, MA Fang², GUO Jing-bo²

1.School of Municipal and Environmental Engineering,Harbin Institute of Technology,Harbin 150090,China;2.School of Biochemical and Environmental Engineering,Nanjing Xiaozhuang University,Nanjing 211171,China



Abstract:

Strain HIT-3,which has good performances in cellulose degradation,was isolated from the campus soil. Based on the identification of conservative sequences 16S rDNA and the analysis of physiological-biochemical characteristics,HIT-3 was identified as Achromobacter xylosoxidans. Denitrificans. A two-step fermentation process was conducted by adopting compound-bioflocculant-producing flora constructed by cellulose-degrading bacterium HIT-3 and flocculating bacterium F2. The cellulose degradation metabolites of HIT-3 was taken as substrates by flocculating bacterium F2,by which excellent compound bio-flocculant was obtained. In addition,the enzymology characteristics of HIT-3 were investigated when cultured in cellulose media,which utilized CMC-Na as its sole carbon. The results show that HIT-3 achieves a climax of 67.6 U/mL of enzyme production after incubation for 6 d,and the organic carbons produced are sufficient as the substrates required by the fermentation of flocculating bacterium F2(flocculating efficiency of 85.6%),which makes it feasible to reuse bioenergy.

Key words:  two-stage fermentation  cellulose degrading bacterium  flocculating bacterium  cellulase activity

DOI：10.11916/j.issn.1005-9113.2010.03.005

Clc Number:TQ925

Fund: