The Redistribution of Nitrogen in Silage by Lactic-Acid-Producing Bacteria

Abstract

Consideration is given to the part played by the lactic-acid-producing bacteria in nitrogen redistribution during ensilage. In suitable media, silage strains of Lactobacillu8 plantarum, Lactobacillu8 brevi8, and Pediococcu8 sp. were shown to have a net uptake of ammonia during growth, but this uptake was considered to have small effect on the net production of ammonia during ensilage. Cell suspensions of Lb_ plantarum produced ammonia from serine, and those of Lb. brevi8 and Pediococcu8 sp. ammonia from arginine. These reactions were studied particularly as regards the influence of pH and the physiological age of cells, and their likely contribution to ammonia production during ensilage is discussed. During growth of the lactic acid bacteria in media of defined amino acid composition, ornithine derived from arginine was the only ninhydrin-positive substance produced in significant amount.