동물사료 첨가용 생균제에 사용할 활성소화효소 생산 bacillus species의 분리

Isolation of bacillus species producing active dietary enzymes available for probiotics for animal feed additive

Bacillus species producing dietary enzymes of α-amylase, preteases, β-glucanase, lipase and phytase available for feed additive probiotics were isolated from swine gastrointestinal contents and feces, soil, soybean and fermented soybean, and the productivities of dietary enzymes were screened by simple hydrolysis zone (mm) around giant colonies grown on agar medium containing specific substrates. The productivity of α-amylase was predominant with B. circulans HD 7312(14.0mm) isolated from swine intestine. The productivities of three protenses, caseinase, gelatinase and albuminase, were dominant with B. circulans HD 7312 (11.6mm), B. subtilis HD 7913 (35.0mm) and B. sphaericus HD 7833 (14.1mm), respectively. However, the three proteases were produced simultaneously by B. circulans HD 7312 (11.6mm/25.2mm/11,0mm). The productivities of β-glucanase and lipase were predominant with B. subtilis HD 7923 (21.5mm) isolated from swine intestine and B. subtilis HD 7912 (10.5mm) isolated from soil, respectively. The productivity of phytase based on the reactive zone diameter was predominant with B. circulans HD 7321 (31.3mm/2+) isolated from soybean, whereas that based on the coloration density was dominant with B. coagulans HD 7212 (24,8mm/4+) isolated from fermented soybean. Five Bacillus spp. strains, B. circulans HD 7312 and 7321, B. coagulans HD 7212, and B. subtilis HD 7912 and HD 7923, selected for feed additive probiotics, were not pathogenic to mice with spore numbers from 1.54×10⁷ to 5.9x10⁹.