摘要
β-甘露聚糖酶是一类能够水解甘露聚糖、葡甘露聚糖、半乳甘露聚糖的半纤维素酶类,广泛存在于动植物和微生物中,此酶在食品、医药、饲料、造纸、石油等方面已得到广泛应用;近年来,其作为食品和饲料添加剂方面倍受关注。对采自土壤和树皮的样品通过富集培养、平板初筛和摇瓶复筛,得到1株具产β-甘露聚糖酶能力的曲霉属菌株LQ21,结合形态特征、培养特征及18S rRNA基因序列分析,将该菌株鉴定为Aspergillussp.真菌。考察了培养时间、起始pH、培养温度、碳源和氮源对该菌株产酶的影响。初步确定了其最适产酶培养基组成:魔芋粉0.5%,蛋白胨1%,NaNO30.2%,K2HPO40.1%,KCl 0.05%,MgSO4.7H2O 0.05%,FeSO4.7H2O 0.001%;最适培养条件:初始pH4.5,温度35℃,转速200 r/min,培养60 h发酵液上清中酶活达到最高。
Belonging to hemicellulases,β-mannanase could hydrolyze β-1,4-D-manno-pyanosyl linkages of mannans with main product manno-oligosaccharide.It has been found in plants,animals and microorganisms and widely applied in industries such as foodstuff,pharmaceutical,feed,paper making,textile and petroleum.Recently,many researchers focus on the enzyme and its applications as food and food additives.Aspergillus sp.LQ21 which produces β-mannanase was obtained from the samples collected from soil and bark by enrichment,flat screening and shake flask screening.Based on the morphological features,cultural characteristics and 18S rRNA gene sequence similarity analysis,the strain was confirmed and identified as Aspergillus sp.The factors that influence the expression level of β-mannanase containing initial cultural pH,temperature,carbon and nitrogen sources were studied.The optimum of medium components was preliminary determined as follow： Konjaku flour 0.5%;peptone 1%;NaNO3 0.2%;K2HPO4 0.1%;KCl 0.05%;MgSO4·7H2O 0.05%;FeSO4·7H2O 0.001%.The optimal culture conditions： initial cultural pH 4.5,agitation speed 200 r/min,incubation at 35℃ for 60 h with the highest enzyme activity in supernatant of the fermentation broth.
出处
《微生物学杂志》
CAS
CSCD
2010年第5期12-18,共7页
Journal of Microbiology
基金
教育部新世纪优秀人才支持计划(NECT-06-0691)
国家自然科学基金创新研究群体科学基金(50621063)
