Trivedi Vikas D, Bharadwaj Anahita, Varunjikar Madhushri S, Singha Arminder K, Upadhyay Priya, Gautam Kamini, Phale Prashant S
Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
Arch Microbiol. 2017 Aug;199(6):907-916. doi: 10.1007/s00203-017-1363-4. Epub 2017 Apr 3.
Pseudomonas sp. strain C7 isolated from sediment of Thane creek near Mumbai, India, showed the ability to grow on glucose and carbaryl in the presence of 7.5 and 3.5% of NaCl, respectively. It also showed good growth in the absence of NaCl indicating the strain to be halotolerant. Increasing salt concentration impacted the growth on carbaryl; however, the specific activity of various enzymes involved in the metabolism remained unaffected. Among various enzymes, 1-naphthol 2-hydroxylase was found to be sensitive to chloride as compared to carbaryl hydrolase and gentisate 1,2-dioxygenase. The intracellular concentration of Cl ions remained constant (6-8 mM) for cells grown on carbaryl either in the presence or absence of NaCl. Thus the ability to adapt to the increasing concentration of NaCl is probably by employing chloride efflux pump and/or increase in the concentration of osmolytes as mechanism for halotolerance. The halotolerant nature of the strain will be beneficial to remediate carbaryl from saline agriculture fields, ecosystems and wastewaters.
从印度孟买附近的塔纳河沉积物中分离出的假单胞菌属菌株C7，分别在含有7.5%和3.5%氯化钠的条件下，表现出在葡萄糖和西维因上生长的能力。在无氯化钠的情况下，它也表现出良好的生长，表明该菌株具有耐盐性。盐浓度的增加影响了在西维因上的生长；然而，参与代谢的各种酶的比活性并未受到影响。在各种酶中，与西维因水解酶和龙胆酸1,2 -双加氧酶相比，1 -萘酚2 -羟化酶对氯离子敏感。无论有无氯化钠，在西维因上生长的细胞中氯离子的细胞内浓度保持恒定（6 - 8 mM）。因此，适应不断增加的氯化钠浓度的能力可能是通过利用氯离子外流泵和/或增加渗透溶质的浓度作为耐盐机制。该菌株的耐盐性将有利于从盐渍农田、生态系统和废水中修复西维因。
