摘要
采用改进的CAS检测平板从东湖中筛选得到了一株高产铁载体细菌sp-f,并用CAS检测液定量检测其分泌铁载体量,发现其As/Ar仅0.09(OD680),Su(Siderophore Unit)为90%,达到产铁载体菌最高级。用BIOLOG检测板,结合细菌生理生化反应、形态观察和16S rDNA序列比对分析等分类鉴定方法,确定sp-f为一株荧光假单胞菌。P.fluorescenssp-f生长过程中胞外铁载体的量在对数生长前期累积达到最高后有所减少,至稳定期时菌液中铁载体量达到稳定。在已知铁载体特异吸收峰波长下,用反向高效液相色谱检测无铁环境和高铁环境下培养液上清,比较发现sp-f上清含有3种含儿茶酚胺类基团铁载体,其中包括荧光和非荧光性的脓菌素,200μmol/L Fe2+可完全抑制荧光性质脓菌素的分泌,但非荧光脓菌素的分泌不受抑制,并且对非脓菌素的儿茶酚胺类铁载体的合成分泌反而具有一定的诱导作用。
Strain sp-f was isolated, a siderophores over producing bacterium, using an improved universal Chrome Azurol S(CAS)-agar plate method from Donghu Lake. The result of the CAS solution siderophores quantitative determination showed the lowest As/AГ(OD680) ratio could be as low as 0.09 with Su (Siderophore Unit) of 90%. Some more experiments were made to make out the pertinence between siderophores quantity reached maximum amount during the concentration stopped accumulating and turned to be morphology, cultivation, physiology, (G + C) mol % its growth and siderophores production, indicating that its prophase of logarithmic growth. After then, siderophores stable at stationary phase. Based on the characteristics of content, 16S rDNA sequence and BIOLOG station system analysis, it was identified as Pseudomonas fluorescens sp-f strain. RP-HPLC analysis showed there exist at least 3 kinds of catecholate siderophores, including fluorescent and non-fluorescent pyoverdins. But only fluorescent pyoverdin' s excretion was completely repressed by the 200 μmol/L Fe^2+ in the medium. And the non-pyoverdin siderophores excretion was induced at the same time, contrarily.
出处
《微生物学报》
CAS
CSCD
北大核心
2006年第5期691-695,共5页
Acta Microbiologica Sinica
基金
武汉市青年科技晨光计划(20015005051)~~
关键词
高产铁载体
荧光假单胞菌
细菌鉴定
脓菌素
Over excreting siderophore
Pseudomonas fluorescens
Bacterial identification
Pyoverdins