1. Construction of transgenic Bacillus mucilaginosus strain with improved phytase secretion.
- Author
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Li, X., Yang, S. H., Yu, X. C., Jin, Z. X., Li, W. D., Li, L., Li, J., and Li, M. G.
- Subjects
BACILLUS (Bacteria) ,PHOSPHORUS ,PHYTASES ,TRANSPOSONS ,MOBILE genetic elements - Abstract
Aims: To construct a transgenic Bacillus mucilaginosus strain to increase the secretion capability of a wild-type isolate of B. mucilaginosus D
4 B1 to hydrolyse phytate phosphorus, which can be used as a microbial fertilizer in field application. Methods and Results: We constructed a phytase secreting expression vector pSP43 with a mini-Tn5 transposon and a Aspergillus fumigatus phytase expression cassette. The vector pSP43 was successfully transferred into the wild-type B. mucilaginosus using the particle bombardment method, and three transgenic strains with a stable copy of phytase expression cassette integrated into the chromosome of the B. mucilaginosus by Tn5 transposition were selected. The phytase activity of the engineered strains increased 36โ46-fold when compared with the wild-type strain of D4 B1 . Conclusions: The A. fumigatus phytase gene can be expressed under the direction of p43 promoter in B. mucilaginosus. The expression protein is secreted extracellularly and newly constructed strains showed a high phytase activity. Significance and Impact of the Study: A transgenic Bacillus strain by the particle bombardment method was constructed. [ABSTRACT FROM AUTHOR]- Published
- 2005
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