白孢链霉菌(Streptomyces albosporeus)CT—86几丁质酶研究

STUDIES ON THE CHITINASE IN STREPTOMYCES ALBOSPOREUS CT—86

应用磷酸膨胀几丁质双层平板,从土壤中篩选到48株分解几丁质的链霉菌。经紫外线诱变后,得到一株能强烈分解磷酸膨胀几丁质的突变株CT—86。在1～1.5％的磷酸膨胀几丁质、1％豆饼粉的营养盐培养基中,30℃培养8～10天,酶活达到0.4mg N—乙酰葡萄胺/h。在几丁质浓废为0.5～1％范围内,单位酶活随几丁质浓度的增加而提高。以葡萄糖和N—乙酰葡萄糖胺为碳源时,在上述培养条件下,无酶活捡出。磷酸膨胀几丁质为底物,酶作用的最适温度是48℃,最适pH为6.5;酶液在60℃保温2小时后,酶活力丧失70％左右。

A total of 48 strains, Streptomyces spp. which produced chitinase were isolated from soil by the doable layer agar plate containing phosphate swollen chitin (PSC) as the sole carbon source. A nyperchitinase producer-mutant CT86 was obteiaed by mutating with UV Enzyme activity of culture filtrate of the mutant CT86 was 0.4mg N- Acetylglucosamiae (NAG)/h^(-1) in the nutrient salt medium containing 1～1.5%(W/V) PSC and 1% soy-bean cake meal, at 30℃ on rotary shaking culture for 8～10 days. Further studies showed that enzyme activity was increased as the chitin concentration increased in the medium within the range tested (0.5～1%). ln addition, when CT-86 was grown on a medium con- taining glucose or NAG as the sole carbon source, the enzyme activity was not detected at above culture conditions, and the optimum temperature and pH on PSC were 48℃ arid 6.5, respectively; The residual activity was about 30% after incubated at 60℃ for 2h.