Abstract：
Rhodococcus erythropolis bacterium is known for its remarkable resistance characteristics that can be useful in several biotechnological processes, such as bioremediation. However, there is scarce knowledge concerning the behavior of this strain against different metals. This study sought to investigate the behavior of R. erythropolis ATCC 4277 against the residue of chalcopyrite and e-waste to verify both resistive capacities to the metals present in these residues and their potential use for biomining processes. These tests were carried out in a stirred tank bioreactor for 48 h, at 24ºC, pH 7.0, using a total volume of 2.0 L containing 2.5% (v/v) of a bacterial pre-culture. The pulp density of chalcopyrite was 5% (w/w), and agitation and oxygen flow rates were set to 250 rpm and 1.5 LO2 min-1, respectively. On the other hand, we utilized a waste of computer printed circuit board (WPCB) with a pulp density of 10% (w/w), agitation at 400 rpm, and an oxygen flow rate of 3.0 LO2 min-1. Metal concentration analyses post-fermentation showed that R. erythropolis ATCC 4277 was able to leach about 38% of the Cu present in the chalcopyrite residue (in ~ 24 h), and 49.5% of Fe, 42.3% of Ni, 27.4% of Al, and 15% Cu present in WPCB (in ~ 24 h). In addition, the strain survived well in the environment containing such metals, demonstrating the potential of using this bacterium for waste biomining processes as well as in other processes with these metals.
摘要：
红球菌以其显着的抗性特征而闻名，可用于几种生物技术过程，比如生物修复。然而,关于这种菌株对不同金属的行为的知识很少。这项研究旨在研究R.remorypolisATCC4277对黄铜矿和电子废物残留物的行为，以验证对这些残留物中存在的金属的抵抗能力及其在生物沉积过程中的潜在用途。这些测试在搅拌釜生物反应器中进行48小时，在24ºC，pH7.0,使用含有2.5%(v/v)的细菌预培养物的2.0L的总体积。黄铜矿的矿浆密度为5%(w/w),以及搅拌和氧气流速分别设定为250rpm和1.5LO2min-1。另一方面,我们利用浪费的计算机印刷电路板（WPCB），纸浆密度为10％（w/w），以400rpm的速度搅拌，和3.0LO2min-1的氧气流量。发酵后的金属浓度分析显示，R.restarypolisATCC4277能够浸出黄铜矿残留物中存在的约38％的Cu（在〜24小时内），和49.5%的铁，42.3%的Ni，27.4%的铝，WPCB中存在15%的Cu(在~24小时内)。此外,菌株在含有这种金属的环境中存活良好，证明了使用这种细菌进行废物生物处理过程以及使用这些金属进行其他过程的潜力。
