摘要
为筛选到可高效降解淀粉且安全的乳杆菌菌株,本研究首先对5株供试菌株(植物乳杆菌JYI-3913和AS1.555、食淀粉乳杆菌CGMCC1.3395、嗜淀粉乳杆菌CGMCC1.3394和副干酪乳杆菌CGMCC1.12731)开展了产淀粉酶能力初筛、复筛及产酶曲线与生长曲线测定实验,以挑选出产淀粉酶能力最佳的菌株,随后对该菌进行了详细的安全性评价,包括药敏试验、耐药基因检测、质粒检测、溶血试验、产硝基还原酶、产偶氮还原酶及产生物胺能力检测与小鼠急性经口毒性试验等。结果表明:相同培养条件下,食淀粉乳杆菌CGMCC1.3395的淀粉降解透明圈明显,淀粉降解率可达97.28%,淀粉酶活性大小为36.94 U/mL,且该菌株的生长延滞期短而对数期和稳定期长,在供试菌中其综合产淀粉酶能力最佳。该菌株对22种参试抗生素多表现为敏感或中介,仅对其中氨苄西林、卡那霉素及4种氟喹诺酮类抗生素耐药,不含相关耐药基因,不含质粒,因此不具有转移抗生素耐药性基因风险;无溶血性,不产硝基还原酶、偶氮还原酶、组胺和酪胺等有害代谢物;小鼠在14 d喂养期间,正常生长、体重增加,该菌株为无毒级。综上,食淀粉乳杆菌CGMCC1.3395具有极强的产淀粉酶能力和良好的安全性,本研究可为该菌株在富淀粉类食品发酵上的安全应用奠定理论依据。
In order to identify a Lactobacillus sp.strain with efficient and safe in starch degradation,this study analyzed five distinct strains:Lactiplantibacillus plantarum JYI-3913 and AS1.555,Lactobacillus amylovorus CGMCC1.3395,Lactobacillus amylophilus CGMCC1.3394,and Lactobacillus paracasei CGMCC1.12731.The preliminary screening and re-screening for amylase production capabilities,the determination of enzyme production curve and growth curve were carried out to select the strain with the best ability to produce amylase.Subsequently,a detailed safety evaluation of the strain was carried out,including drug sensitivity test,drug resistance genetic testing,plasmid detection,hemolysis test,nitroreductase production,azoreductase production and amine production capacity detection,and acute oral toxicity test in mice.Results showed that,under the same culture conditions,the starch degradation transparent zone of L.amylovorus CGMCC1.3395 exhibited a clear transparent zone of starch degradation.Its starch degradation rate and amylase activity were 97.28%and 36.94 U/mL,respectively.And this strain displayed a relatively brief lag phase,while extending the log phase and stationary phase.Overall,this strain demonstrated superior integrated amylase production capabilities when compared to the other strains under investigation.In terms of antibiotic sensitivity,the selected strain exhibited sensitivity or intermediate sensitivity to the majority of the 22 tested antibiotics,with resistance observed for ampicillin,kanamycin,and four fluoroquinolone antibiotics.Moreover,this strain showed no associated drug-resistance genes and plasmids,thereby eliminating the risk of antibiotic-resistance gene transmission.It also lacked a hemolytic effect and did not produce potentially harmful metabolites such as nitroreductase,azoreductase,histamine,and tyramine.Mice displayed normal growth and weight gain over a 14 day feeding period,indicating the non-toxicity of the strain.In conclusion,L.amylovorus CGMCC1.3395 demonstrated a potent and safe capability for amylase production.These findings provide a theoretical foundation for the safe employment of this strain in the fermentation of starch-rich foods.
作者
杨小雨
郭晓燕
龙佩霖
雷静
赵珩
杨成龙
刘凡值
YANG Xiaoyu;GUO Xiaoyan;LONG Peilin;LEI Jing;ZHAO Heng;YANG Chenglong;LIU Fanzhi(Guizhou Institute of Subtropical Crops,Guizhou Academy of Agricultural Sciences,Xingyi 562400,China;Key Laboratory of Crop Genetic Resources and Germplasm Innovation in Karst Mountainous Areas,Guizhou Academy of Agricultural Sciences,Guiyang 550025,China;Institute of Crop Sciences,Chinese Academy of Agricultural Sciences,Beijing 100081,China;College of Life Sciences,Guizhou University,Guiyang 550025,China)
出处
《食品工业科技》
CAS
北大核心
2023年第19期158-166,共9页
Science and Technology of Food Industry
基金
黔农科院青年科技基金([2021]20号)
黔农科院国基后补助([2021]12号)
黔农科种质资源([2023]08号)
贵州省中药材现代产业体系建设(GZCYTX2023-0208)。
