Aké Aké Henri Joël, Rochdi Nabil, Jemo Martin, Hafidi Mohamed, Ouhdouch Yedir, El Fels Loubna
Laboratory of Microbial Biotechnologies, Agrosciences and Environment, Labeled Research Unit-CNRST N°4, Faculty of Sciences Semlalia, Universiry Cadi Ayyad, Marrakesh, Morocco.
Laboratory of Innovative Materials, Energy and Sustainable Development (IMED-Lab), Cadi Ayyad University, Marrakesh, Morocco.
Front Microbiol. 2024 Jul 1;15:1423741. doi: 10.3389/fmicb.2024.1423741. eCollection 2024.
Hexavalent chromium removal from the environment remains a crucial worldwide challenge. To address this issue, microbiological approaches are amongst the straightforward strategies that rely mainly on the bacteria's and fungi's survival mechanisms upon exposure to toxic metals, such as reduction, efflux system, uptake, and biosorption. In this work, scanning electron microscopy, energy-dispersive X-ray spectrophotometry, Fourier transform infrared spectroscopy, and zeta potential measurements were used to investigate the ability of chromium adsorption by sp., and strains isolated from tannery wastewater. Scanning electron microscopy combined with energy dispersive X-ray spectroscopy revealed alterations in the cells treated with hexavalent chromium. When exposed to 50 mg/L Cr, and cells become rough, extracellular secretions are reduced in , and sp. cells are tightly bound and exhibit the greatest Cr weight percentage. In-depth analysis of Fourier transform infrared spectra of control and Cr-treated cells unveiled Cr-microbial interactions involving proteins, lipids, amino acids, and carbohydrates. These findings were supported by zeta potential measurements highlighting significant variations in charge after treatment with Cr(VI) with an adsorption limit of 100 mg/L Cr for all the strains. sp. showed the best performance in Cr adsorption, making it the most promising candidate for treating Cr-laden wastewater.
从环境中去除六价铬仍然是一项全球性的关键挑战。为解决这一问题，微生物学方法是直接的策略之一，主要依赖细菌和真菌在接触有毒金属时的生存机制，如还原、外排系统、摄取和生物吸附。在这项工作中，使用扫描电子显微镜、能量色散X射线光谱法、傅里叶变换红外光谱法和zeta电位测量来研究从制革废水中分离出的 菌和 菌株对铬的吸附能力。扫描电子显微镜与能量色散X射线光谱法相结合揭示了经六价铬处理的细胞的变化。当暴露于50 mg/L Cr时， 菌和 菌的细胞变得粗糙， 菌的细胞外分泌物减少， 菌的细胞紧密结合并表现出最大的Cr重量百分比。对对照细胞和经Cr处理的细胞的傅里叶变换红外光谱进行深入分析，揭示了涉及蛋白质、脂质、氨基酸和碳水化合物的Cr-微生物相互作用。zeta电位测量结果支持了这些发现，突出了用Cr(VI)处理后电荷的显著变化，所有菌株对Cr的吸附极限为100 mg/L。 菌在Cr吸附方面表现出最佳性能，使其成为处理含Cr废水最有前途的候选菌株。
