Institut für Ingenieurbiologie und Biotechnologie des Abwassers, Karlsruher Institut für Technologie, Am Fasanengarten, 76131 Karlsruhe, Germany.
Appl Microbiol Biotechnol. 2010 Dec;88(6):1363-71. doi: 10.1007/s00253-010-2856-0. Epub 2010 Sep 7.
Anaerobic growth of a newly isolated Pseudomonas putida strain WB from an arsenic-contaminated soil in West Bengal, India on glucose, L: -lactate, and acetate required the presence of arsenate, which was reduced to arsenite. During aerobic growth in the presence of arsenite arsenate was formed. Anaerobic growth of P. putida WB on glucose was made possible presumably by the non-energy-conserving arsenate reductase ArsC with energy derived only from substrate level phosphorylation. Two moles of acetate were generated intermediarily and the reducing equivalents of glycolysis and pyruvate decarboxylation served for arsenate reduction or were released as H(2). Anaerobic growth on acetate and lactate was apparently made possible by arsenate reductase ArrA coupled to respiratory electron chain energy conservation. In the presence of arsenate, both substrates were totally oxidized to CO(2) and H(2) with part of the H(2) serving for respiratory arsenate reduction to deliver energy for growth. The growth yield for anaerobic glucose degradation to acetate was Y (Glucose) = 20 g/mol, leading to an energy coefficient of Y (ATP) = 10 g/mol adenosine-5'-triphosphate (ATP), if the Emden-Meyerhof-Parnas pathway with generation of 2 mol ATP/mol glucose was used. During growth on lactate and acetate no substrate chain phosphorylation was possible. The energy gain by reduction of arsenate was Y (Arsenate) = 6.9 g/mol, which would be little less than one ATP/mol of arsenate.
印度西孟加拉邦受砷污染土壤中分离到的一株新的恶臭假单胞菌（Pseudomonas putida）WB 菌株在以葡萄糖、L: -乳酸和醋酸盐为碳源进行厌氧生长时需要砷酸盐的存在，砷酸盐在此过程中被还原为亚砷酸盐。在存在亚砷酸盐的情况下进行好氧生长时会形成砷酸盐。恶臭假单胞菌 WB 以葡萄糖进行厌氧生长可能是由于存在非能量守恒的砷酸盐还原酶 ArsC，其能量仅来自底物水平磷酸化。在此过程中会生成 2 摩尔醋酸盐，糖酵解和丙酮酸脱羧的还原当量用于砷酸盐还原或作为 H2 释放。显然，由于存在与呼吸电子链能量守恒偶联的砷酸盐还原酶 ArrA，所以该菌能够以醋酸盐和乳酸盐为碳源进行厌氧生长。在砷酸盐存在的情况下，两种底物均完全氧化为 CO2 和 H2，其中部分 H2 用于呼吸砷酸盐还原，以提供生长所需的能量。以葡萄糖为碳源进行厌氧降解生成醋酸盐的生长产率为 Y（葡萄糖）= 20 g/mol，如果采用生成 2 摩尔 ATP/mol 葡萄糖的 EMP 途径，则导致 Y（ATP）= 10 g/mol 腺苷-5'-三磷酸（ATP）。在以乳酸盐和醋酸盐为碳源生长时，无法进行底物链磷酸化。砷酸盐还原获得的能量增益为 Y（砷酸盐）= 6.9 g/mol，略低于每摩尔砷酸盐 1 个 ATP。
