摘要
芽孢杆菌 E_2菌株(Bacillus sp.strain E_2)能在55℃下良好生长并在培养液中大量积累胞外纤维素酶(190 mu/ml 培养液),所产生的纤维素酶为单一的 CMCase。对芽孢杆菌 E_2菌株产酶条件进行了研究.该菌产酶的最适培养基装量为200ml/500ml 三角瓶,最适起始pH 为6.5,最适产酶温度为45℃,产酶高峰在培养时间8—12小时。E_2菌株不能利用单一的无机氮源形成纤维素酶。酩蛋白是试验过的供 E_2菌株形成纤维素酶的最好氮源,其用量为3g/L。CMC-Na,纤维二糖,能作为碳源供芽孢杆菌 E_2菌株形成纤维素酶。高浓度的葡萄糖(8g/L)对芽孢杆菌 E_2菌株纤维素酶的形成有抑制作用。天然纤维素不能作为芽孢杆菌 E_2菌株形成纤维素酶的碳源。
Bacillus sp.strain E_2,a thermophilic bacterium,isolated from compost,was able to growwell at 55℃ and accumulated large amount of extracellular cellulase(190mu/ml)in cultureborth Bacillus sp.strain E_2 produced only CMCase.The conditions for enzyme productionwere examined.The optimal temperature and pH for enzyme formation were 45℃ and pH6.5.Mineral N was not suitable nitrogen source for cell growth and enzyme formation.Caseinwas the best nitrogen source tested for cell growth and enzyme production.CMC-Na,cello-biose and glucose were suitable carbon sources for enzyme production.The enzyme formationwas inhibited by glucose in high concentration(8g/L).Native celluloses,absorbent cotton,avi-cel were not able to induce the CMCase formation of Bacillus sp.strain E_2.
出处
《微生物学报》
CAS
CSCD
北大核心
1992年第6期412-417,共6页
Acta Microbiologica Sinica
