Institute of Bio-IT Selangor, Universiti Selangor, Shah Alam, Selangor Darul Ehsan, Malaysia.
Department of Chemistry, Imperial College London, London, UK.
Environ Technol. 2020 Jan;41(1):71-85. doi: 10.1080/09593330.2018.1491634. Epub 2018 Jun 28.
In the present study, locally isolated strains were attempted as biological tools for methyl red removal, a mutagenic azo dye posing threat to the environment if left untreated. strain UCC 0016 demonstrated superior methyl red-decolourizing activity of 100% after 24 h at static condition in comparison to strain UCC 0008 which recorded 65% decolourization after 72 h. Optimization of physicochemical parameters at 30°C, pH 7 and supplementing glucose as the carbon source resulted in improved methyl red-decolourizing activity at static condition and reduced the time taken to achieve complete decolourization by 80%. Higher concentration of methyl red (5 g/L) was able to be decolourized completely within 10 h by adopting the technology of immobilization. The encapsulated cells of strain UCC 0016 demonstrated higher substrate affinity (K = 0.6995 g/L) and an accelerated rate of disappearance of methyl red ( = 0.3203 g/L/h) compared to the free cells. Furthermore, the gellan gum beads could be reused up to nine batches without substantial loss in the catalytic activity indicating the economic importance of this protocol. Analysis of methyl red degradation products revealed no germination inhibition on and demonstrating complete toxicity removal of the parent dye after biological treatment. The occurrence of new and altered peaks (UV-Vis and FTIR) further supported the notion that the removal of methyl red by strain UCC 0016 was indeed through biodegradation. Therefore, this strain has a huge potential as a candidate for efficient bioremediation of wastewater containing methyl red.
在本研究中，尝试将本地分离的菌株用作去除甲基红的生物工具，因为如果未经处理，这种具有诱变作用的偶氮染料会对环境造成威胁。与菌株 UCC 0008 相比，菌株 UCC 0016 在静态条件下 24 小时后对甲基红的脱色活性达到 100%，而菌株 UCC 0008 则在 72 小时后记录到 65%的脱色率。在 30°C、pH 7 的理化参数优化，并补充葡萄糖作为碳源，可提高静态条件下的甲基红脱色活性，并将达到完全脱色所需的时间缩短 80%。采用固定化技术，可在 10 小时内完全去除 5 g/L 的较高浓度甲基红。与游离细胞相比，菌株 UCC 0016 的包埋细胞对基质的亲和力更高（K=0.6995 g/L），甲基红的消失速率更快（=0.3203 g/L/h）。此外，甘聚糖珠粒可重复使用九批次以上，而催化活性没有明显损失，这表明该方案具有经济重要性。对甲基红降解产物的分析表明，和均未显示出发芽抑制作用，表明母体染料经生物处理后完全去除了毒性。新峰和改变峰（UV-Vis 和 FTIR）的出现进一步支持了菌株 UCC 0016 通过生物降解去除甲基红的观点。因此，该菌株作为含有甲基红的废水高效生物修复的候选物具有巨大的潜力。
