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Improved production of insecticidal proteins in Bacillus thuringiensis strains carrying an additional cry1C gene in its chromosome
Author(s) -
Yue Chaoyin,
Sun Ming,
Yu Ziniu
Publication year - 2005
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.20396
Subject(s) - bacillus thuringiensis , exigua , biology , spodoptera , recombinant dna , gene , plutella , microbiology and biotechnology , genetics , botany , larva , bacteria
A cryIC gene, whose product is active against Spodoptera exigua , was introduced into wildtype Bacillus thuringiensis kurstaki strain YBT1520 using an integrative and thermosensitive vector, pBMB‐FLCE, which was developed based on B. thuringiensis transposon Tn4430 harboring a tnpI‐tnpA gene. With the mediation of TnpI‐TnpA, the cry1C gene was integrated into the chromosome of the host strain. To prevent secondary integration, the integrative vector was eliminated by moving recombinant cultures to 46°C for generations. Two integrative recombinant B. thuringiensis strains BMB1520‐E and BMB1520‐F were obtained. In recombinant BMB1520‐F, the cry1C gene was expressed stably at a significant level and did not reduce the expression of endogenous crystal protein genes. Bioassay results indicated that BMB1520‐E and BMB1520‐F showed a higher level of activity against S. exigua third‐instar larvae than did their parent strains, in addition to the high toxicity to Plutella xylostella third‐instar later larvae. © 2005 Wiley Periodicals, Inc.