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Effects of heat shock treatment on the survival rate of Lactobacillus acidophilus after freeze-drying
被引:22
|作者:
Zhen, Ni
[1
,2
]
Zeng, Xiaoqun
[1
,2
]
Wang, Huijun
[1
,2
]
Yu, Jing
[1
,2
]
Pan, Daodong
[1
,2
]
Wu, Zhen
[1
,2
]
Guo, Yuxing
[1
,3
]
机构:
[1] State Key Lab Managing Biot & Chem Threats Qual &, Ningbo 315211, Peoples R China
[2] Ningbo Univ, Coll Food & Pharmaceut Sci, Key Lab Anim Prot Food Proc Technol Zhejiang Prov, Ningbo 315800, Peoples R China
[3] Nanjing Normal Univ, Sch Food Sci & Pharmaceut Engn, Nanjing 210097, Peoples R China
基金:
中国国家自然科学基金;
关键词:
Lactobacillus acidophilus;
Heat shock treatment;
Freeze-drying;
Embden-Meyerhof-Parnas pathway;
Glycogen biosynthetic pathways;
Polysaccharides;
LACTIC-ACID BACTERIA;
LACTOCOCCUS-LACTIS;
STRESS-TOLERANCE;
MONOSACCHARIDE COMPOSITION;
ANTIOXIDANT ACTIVITY;
DRIED LACTOBACILLUS;
GANODERMA-LUCIDUM;
PROTEIN LO18;
EXOPOLYSACCHARIDE;
OPTIMIZATION;
D O I:
10.1016/j.foodres.2020.109507
中图分类号:
TS2 [食品工业];
学科分类号:
0832 ;
摘要:
Herein we investigated the effects of heat shock treatment on the resistance of Lactobacillus acidophilus ATCC4356 to freeze-drying and the underlying mechanisms. We assessed the survival rate, cell morphology, enzyme activities, and metabolites in glycometabolism and energy metabolism. Heat shock treated at 45 degrees C for 30 min has increased the survival rate from 39.1% to 56.3% and had a certain protective effect on the integrity of the cell wall and membrane after freeze-drying. Activities of key enzymes, namely glucose-6-phosphate isomerase and lactate dehydrogenase in the glycolytic pathway; phosphoglucomutase, UDP-glucose pyrophosphorylase, and glycosyltransferases in the glycogen biosynthetic pathway; and Na+ -K+ -ATPase in energy metabolism were significantly altered. Further, the utilization rate of extracellular glucose in the broth decreased 7.59% but the conversion rate of intracellular glucose increased 24.04%, which led to the production of lactic acid and energy. Meanwhile, the production of polysaccharides with potential protectant function was increased by 47.6% and the proportion of glucose in the monosaccharide fraction decreased from 21% to 17%. However, the production of galactose increased from 17% to 26%, consequently enhancing the activities and survival rate of bacterial cells in a freeze-drying environment. This is the first study to determine the potential mechanisms and metabolic changes induced by heat shock treatment that make LAB tolerant to freeze-drying, and providing a new insight on the anti-adversity for LAB during the process.
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页数:10
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