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Novel Bifidobacterium promoters selected through microarray analysis lead to constitutive high-level gene expression
Yan Wang1, Jin Yong Kim, Myeong Soo Park
1Department of Food and Nutrition, Research Institute of Human Ecology, Seoul National University, Seoul 151-742, Republic of Korea.
Journal of Microbiology (Seoul, Korea)
|August 28, 2012
Summary
Researchers developed a novel promoter screening system for Bifidobacterium, identifying strong promoters like P919 for high-level gene expression in food-grade applications.
Area of Science:
- Microbiology
- Molecular Biology
- Biotechnology
Background:
- Development of food-grade expression systems in Bifidobacterium requires strong promoters for high-level gene expression.
- A promoter screening host-vector system is essential for identifying suitable promoters.
Purpose of the Study:
- To establish a promoter screening host-vector system for Bifidobacterium.
- To identify and characterize novel strong promoters for use in Bifidobacterium expression systems.
Main Methods:
- Utilized a β-glucosidase reporter system with Bifidobacterium bifidum BGN4 as the host.
- Employed microarray analysis to select putative promoters from the B. bifidum BGN4 genome.
- Cloned selected promoters upstream of the β-glucosidase gene and transformed into Escherichia coli DH5α and B. bifidum BGN4.
- Assessed promoter activity by measuring β-glucosidase activity in both host strains.
Main Results:
- Seven putative promoters exhibiting constitutive high-level expression were identified.
- Promoter activities showed growth-associated characteristics in both E. coli and B. bifidum.
- P919 demonstrated the strongest promoter activity in B. bifidum BGN4, peaking at 18 hours.
- P895 showed the strongest activity in E. coli DH5α, with maximum activity at 7 hours.
Conclusions:
- Identified novel strong promoters, including P919, suitable for high-level foreign gene expression in Bifidobacterium.
- The developed system and identified promoters are valuable for constructing efficient food-grade Bifidobacterium expression systems.
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