[Objective] This study aimed to identify a maunanase-producing strain isolated from soil. [Method] With kanjac powder as the substrate, a man- nanase-producing dominant strain was iselated from the soil samples collec...[Objective] This study aimed to identify a maunanase-producing strain isolated from soil. [Method] With kanjac powder as the substrate, a man- nanase-producing dominant strain was iselated from the soil samples collected from Kunyu Mountain by using plate selection method. Sequence analysis of the 16SrDNA fragment of the strain was conducted, and the strain was identified as Bacillus subtilis. Fermentation conditions and enzymatic characteristics were studied preliminarily. [ Result] Experimental result showed that enzyme yield of this strain was different in different medium and in the same medium at different tempera- ture. Enzyme yield of this strain in LB medium was higher when incubated at 27 ℃ than at 30 ℃ ; however, incubation at 30 ℃ was more conducive to the enzyme production than incubation at 27 ℃ in SOC medium. The optimal reaction pH was 7.0 and the optimal reaction temperature was 55 ℃ for enzyme production of this strain. When the temperature was above 55 ℃, enzyme activity declined sharply with the raise of temperature. Under the optimum conditions, enzyme activity could achieve 95.3 U. [ Conclusion] This study provided reference for the industrial application of degradation products of mannan.展开更多
基金Supported by Science and Technology Project from Binzhou Medical College(BY2007KJ14)
文摘[Objective] This study aimed to identify a maunanase-producing strain isolated from soil. [Method] With kanjac powder as the substrate, a man- nanase-producing dominant strain was iselated from the soil samples collected from Kunyu Mountain by using plate selection method. Sequence analysis of the 16SrDNA fragment of the strain was conducted, and the strain was identified as Bacillus subtilis. Fermentation conditions and enzymatic characteristics were studied preliminarily. [ Result] Experimental result showed that enzyme yield of this strain was different in different medium and in the same medium at different tempera- ture. Enzyme yield of this strain in LB medium was higher when incubated at 27 ℃ than at 30 ℃ ; however, incubation at 30 ℃ was more conducive to the enzyme production than incubation at 27 ℃ in SOC medium. The optimal reaction pH was 7.0 and the optimal reaction temperature was 55 ℃ for enzyme production of this strain. When the temperature was above 55 ℃, enzyme activity declined sharply with the raise of temperature. Under the optimum conditions, enzyme activity could achieve 95.3 U. [ Conclusion] This study provided reference for the industrial application of degradation products of mannan.
