The effects of amino acids on production and transport of alpha-amylase through bacterial membranes

Bacillus subtilis was grown in media containing various amino acids. The ef fects of these aminoacids on the production of secreted alpha-amylase and m embrane-bound alpha-amylase were investigated. Their effects on the transpo rt of alpha-amylase through membranes were also determined. The synthesis r ate of alpha-amylase isolated from bacterial membranes was stimulated by gr owth in media separately containing Ala and Arg, all other amino acids bein g inhibitory. Cys, Arg and Leu increased the transport of alpha-amylase thr ough the membrane, while Ala, Asp and Ser inhibited it. Secreted alpha-amyl ase activity was appreciably stimulated by Ala, Arg, Gin, Gly, Leu, Phe, Pr o, and especially Cys while it was repressed by Asp, Asn, Glu, Lys, Met, Se r, Thr and Trp.