Monday, July 27, 2009
P126

Bioproduction of diRhamnolipids for control of green peach aphid (Myzus persicae) by diesel oil-degrding Pseudomonas resinovorans SG3

Seul Ki Kim1, Hyang Yeon Kim1, Seon Hwa Kim1, Myung Ryeol Park1, Sunwoo Lee2, Young Cheol Kim3, Jin Cheol Kim4, and In Seon Kim1. (1) Division of Applied Bioscience and Biotechnology, Chonnam National University, Yongbong Dong 300, Gwangju, South Korea, (2) Department of Chemistry, Chonnam National University, Yongbong Dong 300, Gwangju, South Korea, (3) Division of Plant Biotechnology, Chonnam National University, Yongbong Dong 300, Gwangju, South Korea, (4) Chemical Biotechnology Research Center, Korea Research Institute of Chemical Technology, Yusong PO Box 107, Daejeon, South Korea

Biosurfactant-producing microorganism is a potential for the control of plant pathogens and pest insects alternative to synthetic pesticides in agriculture. Much study has been done in order to examine biosurfactant-producing microorganisms for the control of plant pathogens, but little study has been performed on the control of pest insects by biosurfactant-producing microbial cultures. In this study, we examined bacterial cultures capable of producing biosurfactants for the control of green peach aphid (Myzus persicae) in cabbage. Microorganisms capable of degrading diesel oil were isolated from agricultural soil contaminated with machine oils. A microorganism that exhibits a high surface tension value of 30 mN/m was chosen for further studies. The isolate was identified as Pseudomonas strain by 16r-RNA sequence analysis. The cultures grown on LB or 0.2% (v/v) soybean oil showed aphid mortality higher than 90%. In order to determine microbial metabolites that exhibit insecticidal activity, the cultures were extracted with organic solvents followed by column chromatography analyses. NMR and mass spectrometer analyses identified rhamnolipid B as a main active metabolite against the insect, giving C32H58O13 with molecular weight of 650.7951 and C34H62O13 with molecular weight of 678.8433. The rhamnolipids showed a LC50 value (50% aphid mortality) of aphid mortality at a level of about 40 mg/L. This is the first to report rhamnolipid as a control agent against aphids.


Web Page: altair.chonnam.ac.kr/~epsl/

See more of Poster Session 2
See more of Posters

See more of The Annual Meeting and Exhibition 2009 (July 26 - 30, 2009)