Inhibition of phototrophically growing Chromatium vinosum D by glycine

Abstract

The effect of glycine on phototrophically growing Chromatium vinosum D was investigated in the presence and absence of various amino acids. Inhibition of autotrophic cells was more pronounced than that of heterotrophic cells. Cells of growth-inhibited cultures were misshaped, showing vacuolation and partial protoplast formation. Cells exposed to glycine in the presence of equimolar amounts of either d- or l-alanine did not show any inhibition of growth. Neither serine, leucine, valine, isoleucine nor α-aminoisobutyric acid could counteract the inhibition of growth by glycine. The inhibitory effect of glycine on growth is thus likely to be caused by a competition between glycine and alanine during cell wall synthesis. The possible functions of glycine transport system(s) in the natural habitat of C. vinosum are discussed.