초록
<P>The proper culture conditions for producing cellulase of <I>Bacillus amyloliquefaciens</I> S1, isolated from the cecum of goose was optimized by single-factor experiment combined with orthogonal test. The properties of the cellulase were investigated by DNS method. The appropriate doses of <I>B. amyloliquefaciens</I> S1 were obtained by adding them to goose feed. It indicated that the suitable culture conditions of producing cellulase were the culture temperature of 37°C, the initial pH of 7.0, the incubation time of 72 h and the loaded liquid volume of 75 ml per 250 ml. The effects of each factor on producing cellulase by <I>B. amyloliquefaciens</I> S1 were as follows: initial pH > incubation time = culture temperature > loaded liquid volume. The optimum reaction temperature and pH were 50°C and 7.0, respectively. This enzyme is a kind of neutral cellulase that possesses resistance to heat and acidity. It showed high activity to absorbent cotton, soya bean meal and filter paper. By adding different doses of <I>B. amyloliquefaciens</I> S1 to the goose feed, it was found that the egg production, average egg weight, fertilization rate and the hatching rate were promoted both in experiment 1 (1.5 g kg<SUP>−1</SUP>) and experiment 2 (3 g kg<SUP>−1</SUP>). Also the difference of egg production, fertilization rate and hatching rate between experiment 1 and control group was obvious (<I>p</I> < 0.05), and the average egg weight was significantly increased in experiment 2 (<I>p</I> < 0.05).</P>