Cr(III) Oxidation and Cr Toxicity in Cultures of the Manganese(II)-Oxidizing Pseudomonas putida Strain GB-1
Cr(III) Oxidation and Cr Toxicity in Cultures of the Manganese(II)-Oxidizing Pseudomonas putida Strain GB-1
复制标题
DOI：
10.1080/01490450590945988
复制
发表时间：
2005-04
影响因子：
2.3
通讯作者：
Karen J. Murray;Mylene L. Mozafarzadeh;B. Tebo
中科院分区：
文献类型：
--
作者：
Karen J. Murray;Mylene L. Mozafarzadeh;B. Tebo
摘要锰氧化物一直被认为是Cr（III）的主要环境氧化剂，然而，由于环境中大多数活性锰氧化物被认为是生物来源的，微生物可以间接介导Cr（III）的氧化，并加速在纯非生物系统中看到的速率。在这项研究中，我们研究了锰（II）氧化细菌，恶臭假单胞菌菌株GB-1，氧化铬（III）的能力。结果表明，GB-1不能直接氧化Cr（III），但在Mn（II）存在下，Cr（III）能被迅速完全氧化。生长研究表明，在含有少量有机物的生长培养基中，所得的Cr（VI）对恶臭假单胞菌GB-1的毒性可能低于Cr（III），而Cr（III）通常被认为是危害较小的。此外，在恶臭假单胞菌GB-1生长期间存在的Cr（III）似乎引起铁胁迫，如通过荧光铁载体绿脓菌荧光素的产生所确定的。当受到Fe限制或Cr（III）毒性的胁迫时，GB-1对Mn（II）的氧化被抑制。
Abstract Mn oxides have long been considered the primary environmental oxidant of Cr(III), however, since most of the reactive Mn oxides in the environment are believed to be of biological origin, microorganisms may indirectly mediate Cr(III) oxidation and accelerate the rate over that seen in purely abiotic systems. In this study, we examined the ability of the Mn(II)-oxidizing bacterium, Pseudomonas putida strain GB-1, to oxidize Cr(III). Our results show that GB-1 cannot oxidize Cr(III) directly, but that in the presence of Mn(II), Cr(III) can be rapidly and completely oxidized. Growth studies suggest that in growth medium with few organics the resulting Cr(VI) may be less toxic to P. putida GB-1 than Cr(III), which is generally considered less hazardous. In addition, Cr(III) present during the growth of P. putida GB-1 appeared to cause iron stress as determined by the production of the fluorescent siderophore pyoverdine. When stressed by Fe limitation or Cr(III) toxicity, Mn(II) oxidation by GB-1 is inhibited.