Frändberg E, Schnürer J
Swedish University of Agricultural Sciences, Department of Microbiology, Uppsala.
J Appl Bacteriol. 1994 Apr;76(4):361-7. doi: 10.1111/j.1365-2672.1994.tb01641.x.
The chitinolytic properties of Bacillus pabuli K1 isolated from mouldy grain was studied. Chitinase activity was measured as the release of p-nitrophenol from p-nitrophenyl-N,N'-diacetylchitobiose. Influences of substrate concentration and different environmental variables on growth and chitinase activity were determined. The optimum environmental conditions for chitinase production were: 30 degrees C, initial pH 8, initial oxygen 10% and aw > 0.99. Chitinase production was induced when B. pabuli K1 was grown on colloidal chitin. The smallest chito-oligosaccharide able to induce chitinase production was N,N'-diacetylchitobiose, (GlcNAc)2. Production was also induced by (GlcNAc)3 and (GlcNAc)4. When the bacterium was grown on glucose or N-acetylglucosamine, no chitinases were formed. The highest chitinase production observed was obtained with colloidal chitin as substrate. The production of chitinases by B. pabuli K1 growing on chitin was repressed by high levels (0.6%) of glucose. The production was also repressed by 0.6% starch, laminarin and beta-glucan from barley and by glycerol. The addition of pectin and carboxymethyl cellulose increased chitinase production.
对从霉变谷物中分离出的巴氏芽孢杆菌K1的几丁质分解特性进行了研究。几丁质酶活性通过对硝基苯基 - N，N'-二乙酰壳二糖中对硝基苯酚的释放量来测定。确定了底物浓度和不同环境变量对生长和几丁质酶活性的影响。几丁质酶产生的最佳环境条件为：30℃，初始pH值8，初始氧气含量10%，水分活度>0.99。当巴氏芽孢杆菌K1在胶体几丁质上生长时可诱导产生几丁质酶。能够诱导几丁质酶产生的最小壳寡糖是N，N'-二乙酰壳二糖，(GlcNAc)2。(GlcNAc)3和(GlcNAc)4也能诱导产生几丁质酶。当该细菌在葡萄糖或N - 乙酰葡糖胺上生长时，不形成几丁质酶。观察到以胶体几丁质为底物时几丁质酶产量最高。在几丁质上生长的巴氏芽孢杆菌K1产生几丁质酶受到高水平(0.6%)葡萄糖的抑制。0.6%的淀粉、海带多糖、大麦β - 葡聚糖和甘油也会抑制其产生。添加果胶和羧甲基纤维素可提高几丁质酶产量。
