Screening and Enzymatic Study of a Composite Microbial System FH3

Ano: 2009 | Volume: 52 | Número: 1

Autores: Yi-Min Zhang, Xue-Bin Lu, Han-Bin Dan, Ya-Kai Sun

Palavras-chave: cellulose-degrading bacterium, composite microbial systems, enzyme properties

Resumo Inglês:

Five strains of fungi and 18 strains of bacteria were isolated from the soil and horse manure with cellulose as the
sole carbon source. Among them, two fungal, F9 and F13, and two bacterial, B16 and B21, showed the highest filter
paper activities, which were 7.79 U g-1, 9.84 U g-1, 7.34 U g-1 and 9.68 U g-1, respectively. Four microbial systems,
designed as FH1 (F13+B21), FH2 (F13+B16+B21), FH3 (F9+B16+B21) and FH4 (F13+F9+B16+B21) were developed.
The fermentation studies showed that the filter paper activity of the composite microbial system FH3 was higher
than the others, which was 21.34 U g-1. The medium with bran and filter paper as the carbon source and peptone as
nitrogen source was optimal and the maximum cellulase activity was reached at 30~35ºC and pH 6.0~6.5 when
FH3 was incubated for 48 h. The enzymatic reaction conditions were estimated at 45~55 ºC, pH 4.5~5.5 and the
thermal stability temperature was up to 60 ºC.