摘要
碱性纤维素酶在洗涤、饲料、纺织和食品等领域具有较大的应用潜力。为获得产低温碱性纤维素酶的菌种,于冬季从桑树根际土壤中分离到16株纤维素酶产生菌,通过纤维素刚果红选择培养基分离及酶活性测定,筛选出1株能产酶活较高的纤维素酶的菌株BJ-XH,依据形态特征和生理生化特性初步认为该菌株为诺卡氏菌属(Nocardia)的放线菌。BJ-XH菌株的最佳产酶条件为:培养温度28℃,培养液pH 8.5,接种量6%,培养时间6～8 d。该菌株产生的纤维素酶主要为内切β-1,4葡聚糖酶(Cx酶),其酶活力可达5.6 IU/mL,酶最适催化温度为28℃,最适催化pH 9.0,属于低温碱性纤维素酶。此外,金属离子Fe3+、Mn2+和Co2+对该酶的活性有促进作用,Cu2+和Pb2+对酶的活性有抑制作用。研究结果表明,BJ-XH菌株是能生产低温碱性纤维素酶的菌株,具有进一步研究开发利用的潜力。
Alkaline cellulase has shown great applicative potential in detergent,forage,textile and food industries.Aimed to obtain microbial strains producing cold-active alkaline cellulase,we isolated 16 cellulase producing microbial strains from mulberry rhizospheric soil in winter.A microbial strain BJ-XH producing high activity cellulase was obtained through isolation with cellulose Congo red selection medium and determination of cellulase activity.Based on the morphological,physiological and biochemical properties,BJ-XH was identified to be an actinomycete belonging to Nocardia.The optimal condition for cellulase production of BJ-XH was culture temperature 28 ℃,culture medium pH 8.5,inoculation quantity 6%,and culture time 6 to 8 days.The major cellulase produced by this strain was endo-β-1,4-glycanase（Cx enzyme）.Activity of this enzyme could reach 5.6 IU/mL with optimal catalytic temperature 28 ℃ and optimal catalytic pH 9.0,showing typical property of cold-active alkaline cellulases.In addition,metal ions Mn2＋,Fe3＋ and Co2＋ could improve its activity,while Cu2＋ and Pb2＋ inhibit its activity.These results indicated that microbial strain BJ-XH could yield cold-active alkaline cellulase which has great potential for further exploration and utilization.
出处
《蚕业科学》
CAS
CSCD
北大核心
2012年第6期1086-1092,共7页
ACTA SERICOLOGICA SINICA
基金
江苏省自然科学基金项目(No.BK2011527)
江苏科技大学引进人才项目(No.35211003)
关键词
低温碱性纤维素酶
菌株分离
产酶条件
酶活力
最适温度
最适PH
Cold-active alkaline cellulase
Microbial str-ain isolation
Enzyme producing condition
Enzyme activity
Optimal temperature
Optimal pH
