摘要
【目的】从大豆根瘤中筛选具ACC(1-氨基环丙烷-1-羧基)脱氨酶活性的内生细菌,对活性菌株的抗盐碱性、系统分类地位以及代表菌株的促生长作用进行研究,为发掘和应用抗逆、促生优良菌种资源提供理论基础。【方法】以ACC作为唯一氮源测定菌株产ACC脱氨酶特性,采用标准曲线法测定α-丁酮酸含量,比色法定量测定ACC脱氨酶活力,固体平板筛选法对活性菌株进行抗性分析,通过菌体形态及生理生化特性测定、16S rRNA基因序列同源性分析鉴定菌株分类地位,采用盆栽试验验证代表菌株的促生作用。【结果】从河南省13个市(地区)36个点采集的大豆根瘤中筛选出8株ACC脱氨酶内生细菌,其中菌株DD132的酶活性最高(15.712 U/mg)。筛选菌株可耐受4%–6%NaCl,其中菌株DD165、DD132可耐受9%NaCl盐浓度。在pH 11时5株(DD14、DD132、DD67、DD141、DD131)生长良好,说明这些菌株有较强耐碱性。8株产ACC脱氨酶菌株分属于4属,即芽孢杆菌属(Bacillus)、肠杆菌属(Enterobacter)、寡养单胞菌属(Stenotrophomonas)和泛菌属(Pantoea)。接种试验表明内生菌DD132对小麦幼苗生长具有明显促生长作用。【结论】大豆根瘤内具ACC脱氨酶高活性菌株有较强耐盐碱性,其中菌株DD132对小麦幼苗生长有明显促生长作用。为发掘和应用抗逆、促生的优良菌种资源提供理论基础。
[Objective] We screened endophytic bacteria containing ACC(1-aminocyclopropane-1-carboxylate)deaminase from soybean nodules, and evaluated salt-alkaline resistance, phylogenetic status and the growthpromoting of representative strain. [Methods] The features of strains producing ACC deaminase were determined by using the ACC as a sole nitrogen source, adopting standard curve method, colorimetric method, solid medium screening method, bacterial morphology, physio-biochemical characteristics, similarity analysis of 16 S rRNA gene,inoculation tests. [Results] Eight endophytic bacteria containing ACC deaminase were screened from soybean nodules collected from 36 points of 13 cities(regions)in Henan province. Enzymaticactivity of DD132 was the highest(15.712 U/mg). Screened strain tolerated to medium of 4%–6% Na Cl concentration. Among of them, DD165 and DD132 could tolerate 9% NaCl concentration. Five bacteria growing well under pH 11, showing that these strains had stronger alkali resistance. Eight strains containing ACC deaminase activity were affiliated to four genera: Bacillus,Enterobacter, Stenotrophomonas and Pantoea. Inoculation test showed that DD132 had a significant growthpromoting effect on wheat seedlings. [Conclusions] Endophytic bacteria containing high ACC deaminase activity from soybean nodules have stronger salt-alkaline resistance. DD132 has obvious growth-promoting effect on wheat seedlings.
出处
《微生物学报》
CAS
CSCD
北大核心
2016年第6期1009-1021,共13页
Acta Microbiologica Sinica
基金
国家自然科学基金(U1204301)
河南省高等学校青年骨干教师项目(2012GGJS166)~~
关键词
ACC脱氨酶
根瘤内生菌
抗性
系统发育
促生作用
1-aminocyclopropane-1-carboxylate deaminase
nodule endophytic bacteria
resistance
phylogeny
growth-promoting effect