Characterization of Bacteria Isolated from Pine Wood Nematodes in Korea

국내 20개 지역의 소나무재선충병에 감염된 소나무와 잣나무에서 분리된 소나무재선충으로부터 총 110개의 세균을 분리하여 동정한 결과 Cedecea neteri(64균주)가 가장 높은 빈도로 검출되었으며, 다음으로 Ewingella americana(21균주), Pseudomonas sp.(15균주), Flavobacterium sp.(8균주), Rahnella aquatilis (2균주) 순으로 분리되었다. 분리된 세균의 phytotoxin 생성능을 조사한 결과 Pseudomonas sp.(Ba2) 세균은 해송 유묘에 갈변과 고사를 유발하였다. 21개의 항생물질을 이용하여 분리된 3개의 세균, Pseudomonas sp.(Ba2), E. ameircana(Ba4), C. neteri(Ba10)에 대한 감수성 조사 결과 carbenicillin, doxcycline, tetracycline에서 생장억제 효과가 높게 나타났다. A survey of bacterial species associated with Korean isolates of pine wood nematode (PWN) was performed. A total of 110 bacterial isolates were obtained from the PWN isolates that were previously isolated from Pinus densiflora and P. koraiensis. Among the bacterial isolates, Cedecea neteri was most frequent (64 isolates) followed by Ewingella americana (21 isolates), Pseudomonas sp. (15 isolates), Flavobacterium sp. (8 isolates) and Rahnella aquatilis (2 isolates). Both E. americana and Pseudomonas sp. which are assumed to be closely associated with PWN were examined for their phytotoxicity to P. thunbergii seedlings. Ethyl acetate extracts of Psuedomonas sp. (Ba2 strain) cultures were found to induce wilting and mortality in the tested seedlings. The three bacterial species, Pseudomonas sp. (Ba2 strain), E. ameircana (Ba4 strain) and C. neteri (Ba10 strain) were examined in vitro for their sensitivity to 21 kinds of antibiotics. All of the strains were highly susceptible to carbenicillin, doxcycline and tetracycline.