陈龙军 林程 林陈强 张慧 贾宪波 方宇 陈济琛

摘要：【目的】以麥饭石为载体，制备高效的纳豆芽胞杆菌同体菌剂，为纳豆芽胞杆菌的规模化应用奠定基础。【方法】运用酸、碱、盐等方法探索麦饭石进行改性条件，扩大麦饭石孔隙度及比表面积，提升其吸附能力;并通过添加保护剂（葡萄糖、糊精、淀粉）增加保藏期固体菌剂的有效活菌数残留率，为长期保藏固体粉剂提供技术支持。【结果】 （1）确定了纳豆芽胞杆菌最适培养温度为40℃，最适培养pH为7.5。（2）经氯化钠、盐酸、硫酸和氢氧化钠溶液改性后的麦饭石吸附最大有效活菌数分别为13.17. 12.6、12.7和11.9（×108 CFU-g-1）。其中0 5mol L-1氯化钠溶液改性效果最好，吸附有效活菌数达到13.17（×108 CFU·g-1）。（3）对照组、添加保护剂组（2%糊精、2%葡萄糖、2%淀粉）保藏至6个月时，有效活菌数分别为2.91. 4.1、5.42和4.63（×108 CFU·g-1）。活菌数残留率为初始活菌数的22%、31%、41%和35%，其中2%葡萄糖保护剂比对照组有效活菌数残留率提高了1.86倍。【结论】改性麦饭石能极大提升麦饭石的吸附能力，同时保护剂的添加有利于麦饭石固体芽胞杆菌粉剂的长期保藏，本研究为麦饭石在微生物菌剂制备工艺的应用提供了一定的技术支持。

关键词：纳豆芽胞杆;麦饭石;改性;保护剂;吸附

中图分类号：Q 939.96

文献标志码：A

文章编号：1008-0384（ 2021） 07-0855-06

Functional Improvements on Immobilization Carrier of

Bacillus Culture for Natto Fermentation

CHEN Longjun1， LIN Cheng2. LIN Chenqiang1， ZHANG Hui1. JIA Xianbo1. FANG Yu1. CHEN Jichen1*

（ I. Soil and Fertilizer Institute， Fujian Acaderiy of Agricultural Sciences. Fuzhou. Fujian

350003. China;

2. Fuzhou Agricultural and Rural Bureau， Fuzhou， Fujian

350003. China ）Abstract： 【Objective】The physical properties of maifanshi. a volcanic rock. were modified to improve its porosity andadsorption to be used as an immobilization carrier for natto fermentation bacteria that was further added with protective agentsto extend the shelf life of viable Bacillus natto. 【Method】 Maifanshi was treated by acid. alkali. or salt to modify the porosityand surface adsorption property as a microbial carrier. Various protective agents， such as glucose. dextrin. and/or starch wereincorporated to help prolong the viability of the imbedded B. natto powder. 【Result】 （1） The optimum conditions for B. nattoculture included 40℃ and pH 7.5. （2） The maximum viable bacteria count was the highest at 13.17X 108 CFU·g-I on themaifanshi carriers modified by 0.5 mol·L-1sodium chloride solution. It was followed by a count of 12.7 X 108 CFU·g-1 0nmaifanshi treated by sulfuric acid. 12.6 X 108 CFU·g-l on maifanshi treated by hydrochloric acid. and 1 1 .9 X 108 CFU. g-l onmaifanshi treated by sodium hydroxide. （3） The viable B. natto counts after 6 months in storage on control was 2.91 X 108CFU·g-l as compared to those immobilized on the carriers with addition of 2% dextrin. 2% glucose， or 2% starch being4.1 X 108 CFU·g-1， 5.42X 10 8 CFU·g-1， and 4.63 X lOs CFU·g-1， respectively. The retention of viable B. natto on the NaCI-treated maifanshi with the addition of dextrin was 31%. that of glucose 41%. that of starch 35%. and that of control 22%.【Conclusion】 As a bacteria carrier. maifanshi could be significantly further improved on the adsorption capacity bymodification such as NaCI treatment. With an addition of 2% glucose on the immobilized system. the retained viable B. nattocount could rise l .86 times over control in 6 months of storage. It appeared that this study had paved the way of developing apractical application of maifanshi for natto fermentation industry.

2 结果与分析

2.1温度对纳豆芽胞杆菌生长的影响

为了研究适宜纳豆芽孢杆菌生长的最佳温度，在pH 7.0、150 r·mm_1条件下，设置温度分别为30、35、40、45，50℃进行发酵培养18 h（对数生长末期）。由图1可以看出，不同温度下，纳豆芽胞杆菌培养至对数生长末期，进入稳定期后，有效活菌数各不相同，随着培养温度升高（ 25～40℃），有效活菌数逐渐升高，当培养温度为40℃时，有效活菌数达到最大值12.88×lOb CFU·mL-l。……