title: Molecular characterization of chitinase genes from a local isolate of Serratia marcescens and their contribution to the insecticidal activity of Bacillus thuringiensis strains.
abstract: The chitinase B (chiB) and C (chiC) genes and flanking regions from a local isolate of Serratia marcescens were cloned individually and sequenced. Results showed that these chiB and chiC genes have a 96 % maximum similarity with chiB and chiC from different S. marcescens species (GenBank numbers Z36295.1 and AJ630582.1, respectively). The amplified chiB fragment, including some upstream and downstream regions, is 1,689-bp long with an open reading frame of 1,500 bp. The amplified fragment of chiC is 1,844 bp with an open reading frame of 1,443 bp. These sequences were submitted to the GenBank with accession numbers JX847796 (chiB) and JX847797 (chiC). Putative promoter regions and Shine-Dalgarno sequences were identified in both genes. The genes were cloned into a shuttle vector and the constructs were designated as pHYSB and pHYSC, respectively. Both plasmids were introduced separately into kurstaki and israelensis strains of Bacillus thuringiensis and the insecticidal activities of the engineered B. thuringiensis strains were assayed in larvae of Galleria mellonella and adult of Drosophila melanogaster. Engineered B. thuringiensis strains showed higher insecticidal activity than parental strain and the parental S. marcescens. In addition, pHYSB and pHYSC were stable over 16 daily passages under non-selective conditions in transformed B. t. israelensis 5724 strain.
authors.affiliation: Department of Biology, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon, Turkey.
authors.forename: Arzu
authors.initials: A
authors.lastname: Ozgen
authors.forename: Kazim
authors.initials: K
authors.lastname: Sezen
authors.forename: Ismail
authors.initials: I
authors.lastname: Demir
authors.forename: Zihni
authors.initials: Z
authors.lastname: Demirbag
authors.forename: Remziye
authors.initials: R
authors.lastname: Nalcacioglu
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism / Q000633:toxicity; D001681:Biological Assay; D002688:Chitinases / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D004331:Drosophila melanogaster / Q000187:drug effects / Q000254:growth & development / Q000382:microbiology; D004731:Endotoxins / Q000235:genetics / Q000378:metabolism / Q000633:toxicity*; D015870:Gene Expression; D006460:Hemolysin Proteins / Q000235:genetics / Q000378:metabolism / Q000633:toxicity*; D007814:Larva / Q000187:drug effects / Q000254:growth & development / Q000382:microbiology; D008969:Molecular Sequence Data; D009036:Moths / Q000187:drug effects / Q000254:growth & development / Q000382:microbiology; D012706:Serratia marcescens / Q000201:enzymology* / Q000235:genetics
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D002688:Chitinases