Isolation of a chitinase producing bacterium from mycorrhizospheric soil of tomato and its chitinase activity | 番茄菌根根际土壤产几丁质酶细菌的分离及其几丁质酶活性研究

Chinese. 对盆栽试验根际土壤微生物数量计数结果表明，接种丛枝菌根（AM）真菌苏格兰球囊霉菌（Glomuscaledonium）的番茄菌根根际土壤的细菌、真菌、放线菌和产几丁质酶细菌总数显著高于非菌根根际土壤。从番茄菌根根际土壤中分离得到1株产几丁质酶细菌，该菌能够抑制黄瓜尖镰孢的生长。经16SrDNA和生理生化鉴定，该菌为芽孢杆菌属（Bacillussp．）菌株。该菌在pH6―8范围几丁质酶活性没有显著差异，产酶的最适温度为35℃，最适装液量为1／5（250mL三角瓶）。在几丁质液体培养基中摇床培养125h后酶活性与蛋白质含量达到平衡。表明：该菌株具有稳定的产几丁质酶能力，因此具有潜在的生物防治功能。[著者文摘]

English. Counting of the microbes in rhizospheric soil of tomato （Lycopersicon esculentum Miller） from a pet experiment in this study showed that total numbers of bacteria, fungi, actinomycetes and chitinase producing bacteria （CPB） in the mycorrhizospheric soil with inoculation of arbuscular mycorrhizal （AM） fungus G/omus caledonium were significantly higher than those in non-inoculation rhizospher- ic soil. A strain of CPB, which was able to suppress the growth of cucumber Fusarium oxysporium, was isolated from the mycorrhizos- pheric soil. Identification by 16S rDNA gene procedure and physiological and chemical analysis showed that the strain belonged to genus Bacillus species （Bacillus sp. ）. Chitinase activities were not significantly changed from pH 6 to pH 8, while optimized at 35 ℃ and at one fifth of loading volume. Chitinase activity and total protein content reached a balance 125 h after fermentation at liquid chitin medi- um. It showed that the isolate has stable ability to produce chitinase and hence could potentially be used in bio-control.