Food Security and Safety Niche, Faculty of Natural and Agricultural Sciences, North-West University, Mmabatho, South Africa.
J Basic Microbiol. 2019 Jan;59(1):62-73. doi: 10.1002/jobm.201800011. Epub 2018 Oct 4.
In this study, the myco-reduction potential of fungi isolated from soil was ascertained by Norkrans shake flask experiment contaminated with chromium(VI). Fungal tolerance assay and induced tolerance training of the fungi were also carried out. Aspergillus niger, Penicillium, and Saccharomyces strains were isolated from the soil samples using culture based technique. Norkrans samples were collected and analyzed for Cr(VI) concentration using diphenylcarbazide spectrophotometric method. Penicillium strain was observed to be most effect at Cr(VI) concentrations of 16.1 and 8.1 mg L since it was able to reduce Cr(VI) more than Saccharomyces strain and A. niger on day 20. Bio-sorption kinetics for this study was better described by pseudo second order model while Langmuir isotherm model fitted better to the equilibrium data. There was virtually steady increase in fungal growth for all the treatments through-out the experimental period. Significant negative correlation (p < 0.05) was observed between fungal growth and Cr(VI) reduction rate. The results from the induced tolerance training showed that Penicillium had the highest tolerance index (TI) values at 18, 20, and 25 mg L concentrations of Cr(VI) compared to A. niger and Saccharomyces strain. These results demonstrated that these fungi have the potential to bio-absorb Cr(VI) and if properly harnessed, could be used in place of conventional remediation technology to clean-up the Cr(VI) contaminant in the field.
在这项研究中，通过 Norkrans 摇瓶实验（用铬(VI)污染）确定了从土壤中分离出的真菌的还原潜力。还进行了真菌的耐受性测定和诱导耐受训练。采用基于培养的技术从土壤样品中分离出黑曲霉、青霉和酿酒酵母菌株。采集 Norkrans 样品并使用二苯卡巴肼分光光度法分析 Cr(VI)浓度。青霉菌株在 Cr(VI)浓度为 16.1 和 8.1 mg/L 时效果最为显著，因为它在第 20 天能够比酿酒酵母菌株和黑曲霉菌株更有效地还原 Cr(VI)。本研究的生物吸附动力学更符合拟二级模型，而 Langmuir 等温线模型更适合平衡数据。在整个实验期间，所有处理的真菌生长都呈实际上的稳定增长。真菌生长与 Cr(VI)还原率之间存在显著负相关（p<0.05）。诱导耐受训练的结果表明，与黑曲霉和酿酒酵母菌株相比，青霉在 18、20 和 25 mg/L Cr(VI)浓度下具有最高的耐受指数（TI）值。这些结果表明，这些真菌具有生物吸收 Cr(VI)的潜力，如果得到妥善利用，它们可以替代传统的修复技术，用于清理现场的 Cr(VI)污染物。
