title: Effective trapping of fruit flies with cultures of metabolically modified acetic acid bacteria.
abstract: Acetoin in vinegar is an attractant to fruit flies when combined with acetic acid. To make vinegar more effective in attracting fruit flies with increased acetoin production, Komagataeibacter europaeus KGMA0119 was modified by specific gene disruption of the acetohydroxyacid isomeroreductase gene (ilvC). A previously constructed mutant lacking the putative ligand-sensing region in the leucine-responsive regulatory protein (KeLrp, encoded by Kelrp) was also used. The ilvC and Kelrp disruptants (KGMA5511 and KGMA7203, respectively) produced greater amounts of acetoin (KGMA5511, 0.11%; KGMA7203, 0.13%) than the wild-type strain KGMA0119 (0.069%). KGMA7203 produced a trace amount of isobutyric acid (0.007%), but the other strains did not. These strains produced approximately equal amounts of acetic acid (0.7%). The efficiency of fruit fly attraction was investigated with cultured Drosophila melanogaster. D. melanogaster flies (approximately 1,500) were released inside a cage (2.5 m by 2.5 m by 1.5 m) and were trapped with a device containing vinegar and a sticky sheet. The flies trapped on the sticky sheet were counted. The cell-free supernatant from KGMA7203 culture captured significantly more flies (19.36 to 36.96% of released flies) than did KGMA0119 (3.25 to 11.40%) and KGMA5511 (6.87 to 21.50%) cultures. Contrastingly, a 0.7% acetic acid solution containing acetoin (0.13%) and isobutyric acid (0.007%), which mimicked the KGMA7203 supernatant, captured significantly fewer flies (0.88 to 4.57%). Furthermore, the KGMA0119 supernatant with additional acetoin (0.13%) and isobutyric acid (0.007%) captured slightly more flies than the original KGMA0119 supernatant but fewer than the KGMA7203 supernatant, suggesting that the synergistic effects of acetic acid, acetoin, isobutyric acid, and unidentified metabolites achieved the efficient fly trapping of the KGMA7203 supernatant.
authors.affiliation: Department of Bioscience, Graduate School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Ishii
authors.affiliation: Institute of Applied Microbiology, Marukan Vinegar Co. Ltd., Kobe, Hyogo, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Akasaka
authors.affiliation: Department of Bioscience, Graduate School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo, Japan.
authors.forename: Itsuko
authors.initials: I
authors.lastname: Goda
authors.affiliation: Institute of Applied Microbiology, Marukan Vinegar Co. Ltd., Kobe, Hyogo, Japan.
authors.forename: Hisao
authors.initials: H
authors.lastname: Sakoda
authors.affiliation: Department of Bioscience, Graduate School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo, Japan Research Center for Intelligent Bio-Materials, Graduate School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo, Japan fujiwara-s@kwansei.ac.jp.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Fujiwara
mesh_terms: D016947:Acetobacteraceae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D000093:Acetoin / Q000378:metabolism*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002630:Chemotactic Factors / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004331:Drosophila melanogaster / Q000187:drug effects* / Q000502:physiology; D004772:Entomology / Q000379:methods*; D017353:Gene Deletion; D050540:Ketol-Acid Reductoisomerase / Q000235:genetics; D060847:Metabolic Engineering; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA
chemical_list: D002630:Chemotactic Factors; D003470:Culture Media; D004269:DNA, Bacterial; D000093:Acetoin; D050540:Ketol-Acid Reductoisomerase