“…The differences in the growth capacity and Se bioaccumulation of the studied strains ( L. paracasei CH135,and L. paracasei CH139) in the growth and tolerance tests (Tables 1 and 2 and Figures 1 and 2) and the divergences or similarities (or both) compared with data from the literature (Calomme et al, 1995a;Xia et al, 2007;Zhang et al, 2009;Pieniz et al, 2011Pieniz et al, , 2017Deng et al, 2015;Palomo-Siguero et al, 2016) are plausible given that the binding of metal or metalloid ions, such as Se, to the cell wall of LAB and their transport and storage in the cell are mediated by complex processes that depend on the characteristics of the element, the specific physiological properties of each LAB strain, and the physical chemical characteristics of the environment in which the bacteria are grown (Mrvčić et al, 2012). The bioaccumulation process does not depend on temperature or the presence of metabolic energy or metabolic inhibitors but instead depends on the functional groups available on the cell surface, the nature of the ions, and their concentrations and surface charges, cations, and metal ligands, which can occur through 2 different mechanisms: biosorption, which is a passive binding process of the metal to the bacterial cell wall that is not metabolically mediated, and bioaccumulation, which is an active metabolic binding process during which metal ions cross the cell membrane and accumulate within the cell (Vijayaraghavan and Yun, 2008).…”