Anguita Javiera M, Rojas Claudia, Pastén Pablo A, Vargas Ignacio T
Department of Hydraulic and Environmental Engineering, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Macul, 7820436, Santiago, Chile.
Centro de Desarrollo Urbano Sustentable (CEDEUS), Santiago, Chile.
Biodegradation. 2018 Feb;29(1):59-69. doi: 10.1007/s10532-017-9813-x. Epub 2017 Nov 16.
Biological arsenic oxidation has been suggested as a key biogeochemical process that controls the mobilization and fate of this metalloid in aqueous environments. To the best of our knowledge, only four aerobic chemolithoautotrophic arsenite-oxidizing (CAO) bacteria have been shown to grow via direct arsenic oxidation and to have the essential genes for chemolithoautotrophic arsenite oxidation. In this study, a new CAO bacterium was isolated from a high Andean watershed evidencing natural dissolved arsenic attenuation. The bacterial isolate, designated TS-1, is closely related to the Ancylobacter genus, in the Alphaproteobacteria class. Results showed that TS-1 has genes for arsenite oxidation and carbon fixation. The dependence of bacterial growth from arsenite oxidation was demonstrated. In addition, a mathematical model was suggested and the kinetic parameters were obtained by simultaneously fitting the biomass growth, arsenite depletion curves, and arsenate production. This research increases the knowledge of chemolithoautotrophic arsenic oxidizing microorganisms and its potential role as a driver for natural arsenic attenuation.
生物砷氧化被认为是控制这种类金属在水环境中迁移和归宿的关键生物地球化学过程。据我们所知，仅四种好氧化能自养型亚砷酸盐氧化（CAO）细菌已被证明可通过直接砷氧化生长，并拥有化能自养型亚砷酸盐氧化的必需基因。在本研究中，从安第斯山脉高处一个显示出天然溶解砷衰减的流域分离出一种新的CAO细菌。分离出的细菌命名为TS - 1，与α-变形菌纲中的Ancylobacter属密切相关。结果表明TS - 1具有亚砷酸盐氧化和碳固定的基因。证明了细菌生长对亚砷酸盐氧化的依赖性。此外，提出了一个数学模型，并通过同时拟合生物量生长、亚砷酸盐消耗曲线和砷酸盐生成来获得动力学参数。这项研究增加了对化能自养型砷氧化微生物的认识及其作为天然砷衰减驱动因素的潜在作用。
