Zeta potential of anoxygenic phototrophic bacteria and Ca adsorption at the cell surface: Possible implications for cell protection from CaCO3 precipitation in alkaline solutions

► Anoxygenic phototrophic bacteria can metabolically control their surface potential. ► This regulation is necessary to electrostatically attract the nutrients at alkaline pH. ► It can be also related to rejecting Ca ions to prevent CaCO3 precipitation in the vicinity of cell surface.