摘要
水霉病是淡水和咸淡水鱼类被水霉菌感染引起的常见疾病。该研究从多个养殖水体中分离得到6株水霉拮抗菌,SZK15、XL03、TG08、DJ12、HD05和DS08,以SZK15的拮抗作用最强。对SZK15研究发现,在PDA平板上,其对水霉菌丝抑制距离为11.5 mm,对水霉孢子抑制圈直径为29.7 mm,其10倍浓缩的无细胞发酵液的抑水霉菌圈直径达30.2 mm;在液体培养条件下,SZK15无细胞发酵原液能完全抑制水霉菌丝和孢子的萌发生长,其5倍稀释液中,水霉菌丝生长受抑制而长度稳定在2.0 mm,有30%的孢子萌发,且萌发后菌丝受抑制而未形成菌丝网,其10倍稀释液中水霉菌丝生长慢于对照组。SZK15分泌的拮抗活性物质对121℃高温敏感,对80℃、100℃高温、蛋白酶K和胰蛋白酶均部分敏感。本研究为水霉病害的生物防治提供了潜在新途径。
Saprolegniasis is a common disease of fresh water and brackish water fish. The pathogens are water molds, belonging to the genus Saprolegnia. In this study, six bacterial isolates from multiple fish farm ponds could inhibit the growth of the molds, which were named as SZK15, XL03, TG08, DJ12, HD05 and DS08, and the strain SZK15 showed the strongest anti-mold efficacy. In PDA media, the SZK15 presented an inhibition distance of 11.5 mm on the hyphae and an inhibition zone of 29.7 mm on the spores. The 10 times concentrated cell-free extract of the SZK15 fermentation culture gave an inhibition zone of 30.2 mm on the spores. In the broth assay, the undiluted cell-free culture supernatant of the SZK15 could completely inhibit the hyphal growth and spores germination. The hyphae were inhibited at the length of 2.0 mm and just 30% spores germinated in the 1/5 diluted supematant. The hyphal growth from germinated spores was also inhibited, and could not form into hyphal nets. The antagonistic substance of SZK15 was sensitive for 121 ℃ high temperature, and was partly sensitive for 80 ℃, 100 ℃ high temperature, protease K and trypsinase. This study provides a potential new bio-control pathway for saprolegniasis in aquaculture in future.
出处
《生态科学》
CSCD
北大核心
2013年第2期189-193,共5页
Ecological Science
基金
国家高技术研究与发展规划("863"计划)(2011AA10216-2)
广东省教育部产学研结合项目(2011B090400063)
广东省海洋与渔业科技推广专项(A201001H01)
中央高校基本科研业务费专项资金资金资助(21612111)
关键词
水霉
拮抗菌
拮抗物
生物防治
Saprolegnia
antagonistic bacteria
antagonistic substance
bio-control
