首页|产蛋白酶兼性厌氧菌株的筛选、酶学性质及发酵豆粕应用探究

产蛋白酶兼性厌氧菌株的筛选、酶学性质及发酵豆粕应用探究

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  • 国家科技期刊平台
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为筛选得到1株或几株深层发酵豆粕效果较好的菌株,以透明圈法从自然发酵的豆豉中筛选出4株兼性厌氧且产蛋白酶菌株,同时发现菌株B-1、B-12在厌氧条件下产蛋白酶能力好于好氧条件,对此现象较明显且平板水解圈直径较大的菌株B-1进行形态学、生理生化和分子生物学实验,鉴定为甲基营养型芽孢杆菌.进一步对菌株B-1的蛋白酶酶学性质进行研究后发现,酶活力在pH 6.0～9.0的范围内能够维持一个较高的水平,酶反应和酶稳定最适条件为pH 7.0和40℃,加入Mn2+对酶反应的促进作用较大.将甲基营养型芽孢杆菌B-1以6％的接种量接种于豆粕固态发酵培养基中堆积(20 cm)发酵,以枯草芽孢杆菌A-12好氧浅层发酵和未发酵豆粕作为对照,发酵结束后测得豆粕中小肽含量和水解度分别高达28.37％和29.55％,比枯草芽孢杆菌固态发酵对照组分别高出了9.04％和16.07％,与未发酵豆粕相比,菌株B-1发酵后豆粕的小肽含量和水解度也分别提高了27.22％和29.13％.
Screening of Protease-Producing Bacterium in Facultative Anaerobic Conditions, Studies on Its Enzymatic Characterization and Application for Fermenting Soybean Meal
An efficient protease--producing and facultative anaerobic bacterium B-1 was isolated from naturally fermented Douchi by transparent inhibition zone plate assay.The diameter of inhibition zones in anaerobic conditions was found to be bigger than in aerobic conditions.Based on physiological and biochemical identification and 16S rRNA sequence analysis,it was identified as Bacillus methylotrophicus.Meanwhile,this study revealed that the optimal pH and temperature for protease activity and stability from Bacillus methylotrophicus B-1 were pH 7.0 and 40 ℃,respectively.The protease activity was activated by Mn2+.In addition,Bacillus methylotrophicus B-1 and Bacillus subtilis A-12 were used at an inoculum size of 6％ on raw soybean meal to study the effect of fermentation on the contents of crude protein and small peptides and hydrolysis degree.The results showed that the content of small peptides and hydrolysis degree of soybean meal fermented by Bacillus methylotrophicus B-1 were 28.37％ and 29.55％,which were 9.04％ and 16.07％ higher than those of that fermented by Bacillus subtilis A-12,and 27.22％ and 29.13％ higher than those of raw soybean meal,respectively.

proteasefacultative anaerobicBacillus methylotrophicusidentificationenzymatic propertiesfermented soybean meal

熊涛、唐晓星、黄涛、李啸

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南昌大学生命科学与食品工程学院,食品科学与技术国家重点实验室,江西南昌 330047

蛋白酶 兼性厌氧 甲基营养型芽孢杆菌 鉴定 酶学性质 发酵豆粕

国家高技术研究发展计划(863计划)项目国家重点实验室目标导向项目江西省教育厅高校科技落地计划项目

2011AA100904SKLF-ZZA-201303赣财教[2011]243号

2014

10.7506/spkx1002-6630-201409033

食品科学
北京食品科学研究院

食品科学

CSTPCDCSCD北大核心
影响因子：1.327
ISSN：1002-6630
年,卷(期)：2014.35(9)
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