Biswas Rimi, Sarkar Angana
a Department of Biotechnology and Medical Engineering , National Institute of Technology Rourkela , Odisha.
Prep Biochem Biotechnol. 2019;49(1):30-37. doi: 10.1080/10826068.2018.1476883. Epub 2018 Jun 11.
High arsenic groundwater contamination causes serious health risks in many developing countries, particularly in India and Bangladesh. The arsenic fluxes in aquifers are primarily controlled by bacterial populations through biogeochemical cycle. In this present study, two gram-positive rod-shaped bacteria were isolated from shallow aquifers of Bhojpur district in Bihar during the early winter season, able to withstand arsenite (As) concentration upto 70 mM and 1000 mM of arsenate (As) concentration. They showed high resistance to heavy metals up to 30 mM and utilized some complex sugars along with different carbon sources. Growth at wide range of temperature, pH and salinity were observed. Both these isolates showed high efficiency in converting As into less toxic concentrations of As respectively from arsenic enriched culture media. Along with superior arsenic transformation and arsenic resistance abilities, the isolates showed a wide variety of metabolic capacity in terms of utilizing a variety of carbon sources under aerobic conditions, respectively. This study reports the potential As-oxidizing bacteria that can play an important role in subsurface arsenic transformation that will aid in designing future bioremediation strategy for the arsenic affected areas.
高砷地下水污染在许多发展中国家造成了严重的健康风险，尤其是在印度和孟加拉国。含水层中的砷通量主要通过生物地球化学循环由细菌种群控制。在本研究中，在初冬季节从比哈尔邦博杰布尔区的浅层含水层中分离出两种革兰氏阳性杆状细菌，它们能够耐受高达70 mM的亚砷酸盐（As）浓度和1000 mM的砷酸盐（As）浓度。它们对高达30 mM的重金属表现出高抗性，并利用一些复合糖以及不同的碳源。观察到在广泛的温度、pH值和盐度下生长。这两种分离株分别在富含砷的培养基中显示出将As转化为毒性较低浓度的As的高效率。除了具有卓越的砷转化和抗砷能力外，这些分离株在好氧条件下利用多种碳源方面分别表现出广泛的代谢能力。本研究报道了潜在的砷氧化细菌，它们可以在地下砷转化中发挥重要作用，这将有助于为受砷影响地区设计未来的生物修复策略。
