玉米皮固态培养混合益生菌的研究
2016-09-21刘建玲戴建英修志龙大连理工大学生命科学与技术学院沈阳大连116024
刘建玲,牟 英,戴建英,修志龙(大连理工大学生命科学与技术学院,沈阳大连116024)
玉米皮固态培养混合益生菌的研究
刘建玲,牟英,戴建英,修志龙*
(大连理工大学生命科学与技术学院,沈阳大连116024)
本试验以玉米皮为主要原料,通过单因素试验和正交试验对黑曲霉与酿酒酵母的混合固态培养进行了研究。以蛋白酶、纤维素酶、活菌数为主要考察指标,优化得出的最佳培养条件为:尿素添加量0.5%(P<0.05)、含水量60%、麸皮添加量15%(P<0.05)、黑曲霉接种量20%、培养天数7 d;混菌培养接种比(黑曲霉∶酿酒酵母)为3∶1,混菌共培养1 d。在此条件下,纤维素酶的酶活为622.11 U/g,蛋白酶的酶活为606.55 U/g,每克发酵物含益生活菌总数超过百亿。
玉米皮;固态培养;纤维素酶;蛋白酶;益生菌
[Abstract]Solid-state culture of Aspergillus niger and Saccharomyces cerevisiae was studied by using corn bran as main material.Single-factor and orthogonal experimentwere used to optimize the nutritional and environmental conditions for improving the activity of protease,cellulase and the number of living cells.The optimized cultivation conditions for As鄄pergillus niger were as follows:urea content 0.5%(P<0.05),water content 60%,wheat bran adding level 15%(P<0.05),inoculation amount 20%,cultivation period 7 days.When co-culture of two strains was conducted,the ratio of As鄄pergillus niger to Saccharomyces cerevisiae was 3∶1,and co-culture time was 1 day.Under the above conditions,the cellulase activity reached to 622.11U/g,the protease activity achieved 605.55U/g,and the total number of living probiotic cells reached tomore than ten billion per gram.
[Key words]corn bran;solid-state cultivation;cellulase;protease;probiotics
玉米皮是玉米深加工的副产物,其本身含有大量的纤维素和半纤维素,适口性差,不利于非反刍类家畜消化(王伟伟等,2013)。相关研究通过益生菌固态培养制备蛋白质饲料来提高玉米皮的利用率和营养价值。研究表明,细菌、真菌、放线菌等都能产生纤维素酶 (刘洁丽和王靖,2008),其中黑曲霉所产酶系丰富,可产十余种酶类,并且自身也是生物安全菌,动物利用后能促进消化吸收(吕玉丽等,2012)。有研究表明,黑曲霉在培养过程中能水解出过量的还原糖,可以接入酿酒酵母进行混菌培养。酵母菌在培养过程中产生的代谢产物能提高瘤胃中有益菌的数量和活力,调节瘤胃的发酵功能,另外酵母菌还能产生维生素,这样既能减轻还原糖对纤维素酶活性的抑制,又能进一步提高活菌饲料的性能。……
