Division of Biotechnology, College of Environmental and Bioresource Sciences, Chonbuk National University, Iksan, Korea.
J Basic Microbiol. 2010 Apr;50(2):200-5. doi: 10.1002/jobm.200900171.
The enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase cleaves the ethylene precursor ACC into alpha-ketobutyrate and ammonia. The decreased level of ethylene allows the plant to be more resistant to a wide environmental stress including plant pathogens. In the present study, we characterized the ACC deaminase activity of a Pseudomonas entomophila strain PS-PJH isolated from the red pepper rhizosphere region of red pepper grown at Jinan, Korea. The isolate produced 23.8 +/- 0.4 micromol of alpha-ketobutyrate/mg of protein/h during ACC deamination under in vitro conditions. Polymerase chain reaction for acdS gene showed that the isolated P. entomophila strain PS-PJH carry sequences similar to the known acdS genes. Results of the multiple sequence alignment revealed >99% identity (nucleotide and amino acid) with acdS gene of Pseudomonas putida strains AM15 and UW4. The isolated bacteria promoted 43.3 and 34.1% of growth in Raphanus sativus and Lactuca sativa plants, respectively. Based on the 16S-23S internal transcribed spacer region sequences, the isolate was identified as P. entomophila. To the best of our knowledge this is the first study to report the acdS gene in P. entomophila.
酶 1-氨基环丙烷-1-羧酸 (ACC) 脱氨酶将乙烯前体 ACC 切割成α-酮丁酸和氨。乙烯水平的降低使植物能够更好地抵抗包括植物病原体在内的广泛环境胁迫。在本研究中，我们从韩国济州种植的红辣椒根际区域分离出的根瘤假单胞菌 PS-PJH 菌株中表征了 ACC 脱氨酶活性。该分离物在体外条件下进行 ACC 脱氨时产生 23.8 +/- 0.4 微摩尔的α-酮丁酸/毫克蛋白/小时。acdS 基因的聚合酶链反应表明，分离的根瘤假单胞菌 PS-PJH 菌株携带与已知的 Pseudomonas putida 菌株 AM15 和 UW4 的 acdS 基因相似的序列。多重序列比对的结果显示与 Pseudomonas putida 菌株 AM15 和 UW4 的 acdS 基因具有 >99%的同一性（核苷酸和氨基酸）。分离的细菌分别促进了萝卜和莴苣植物的 43.3%和 34.1%的生长。根据 16S-23S 内部转录间隔区序列，该分离物被鉴定为根瘤假单胞菌。据我们所知，这是首次在根瘤假单胞菌中报道 acdS 基因的研究。
