Thongpitak, J., J. Pekkoh, and C. Pumas.
Frontiers in Microbiology 10:2605(2019)

This study evaluated the potential of microalgal Mn remediation of water under three different water conditions: filtrated water obtained from a rehabilitated lignite coal mine in Thailand, non-filtrated water that was sterilized with an autoclave, and non-treated water from the mine. Pediastrum duplex AARLG060 microalga was cultured with a modified medium consisting of N, P, C, and Mg nutrients. The remediated Mn concentration present in the cultures was detected by atomic absorption spectroscopy. The precipitated Mn was collected as a result of biooxidation, and EDTA was used to wash Mn from the biomass. Characterization of biosorption was evaluated by employing the Langmuir and Freundlich models. Results demonstrated that >97% of the Mn was removed in every treatment. The adsorption characteristics revealed a close similarity to the Langmuir isotherm of monolayer adsorption. The scanning electron microscope-energy dispersive spectroscopy indicated precipitation of Mn oxide on the cell surface, while transmission electron microscopy revealed that the nanoparticles of Mn were scattered mainly in the chloroplast and throughout the vacuoles of the cells. This article is Open Access at https://www.frontiersin.org/articles/10.3389/fmicb.2019.02605/full