Expression of chitinase-encoding genes in Bacillus thuringiensis and toxicity of engineered B. thuringiensis subsp. aizawai toward Lymantria dispar larvae.
Chitinase genes from Aeromonas hydrophila and Bacillus circulans No.4.1 were cloned into the plasmid pHY300PLK and designated as pHYA2 and pHYB43, respectively. Both plasmids were introduced into various strains of B. thuringiensis by electroporation. Plasmid pHYB43 was generally structurally stable, but showed lower segregrational stability than pHYA2 in B. thuringiensis subsp. aizawai when grown under nonselective conditions. The production of chitinase from B. thuringiensis subsp. aizawai harboring pHYB43 or pHYA2 could be detected after native polyacrylamide gel electrophoresis by using 4-methylumbelliferyl beta-D- N,N'- diacetylchitobioside as the substrate. Moreover, B. thuringiensis subsp. aizawai harboring pHYB43 gave 15 times higher chitinase activity than when harboring pHYA2, as determined by means of a colorimetric method using glycol chitin as the substrate. In addition, B. thuringiensis subsp. aizawai harboring pHYB43 was more toxic to gypsy moth larvae ( Lymantria dispar) than parental B. thuringiensis subsp. aizawai or its clone harboring pHYA2.
Lertcanawanichakul
Monthon
M
Institute of Allied Health Sciences and Public Health, Walailak University, Thasala District, Nakhon Si Thammarat 80160, Thailand. lmonthon@wu.ac.th
Wiwat
Chanpen
C
Bhumiratana
Amaret
A
Dean
Donald Harry
DH
D016980:Aeromonas hydrophila / Q000201:enzymology / Q000235:genetics*; D000818:Animals; D001407:Bacillus / Q000201:enzymology / Q000235:genetics*; D001413:Bacillus thuringiensis / Q000201:enzymology / Q000235:genetics*; D001427:Bacterial Toxins / Q000633:toxicity; D002686:Chitin / Q000031:analogs & derivatives* / Q000378:metabolism; D002688:Chitinases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D003001:Cloning, Molecular; D018274:Electroporation; D015870:Gene Expression; D005798:Genes, Bacterial; D006923:Hymecromone / Q000031:analogs & derivatives* / Q000378:metabolism; D007814:Larva / Q000254:growth & development / Q000382:microbiology; D009036:Moths / Q000254:growth & development* / Q000382:microbiology*; D009844:Oligosaccharides / Q000378:metabolism; D010572:Pest Control, Biological / Q000379:methods*; D020161:Physical Chromosome Mapping; D010957:Plasmids / Q000235:genetics / Q000502:physiology; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012641:Selection, Genetic
D001427:Bacterial Toxins; D009844:Oligosaccharides; D011994:Recombinant Proteins; D002686:Chitin; D006923:Hymecromone; C033855:4-methylumbelliferyl-N,N-diacetylchitobioside; C031610:glycolchitin; D002688:Chitinases