Abstract
As a part of microbiological studies on nitrate disappearance, the culture conditions for the growth of nitrate reducing bacteria in silages were investigated. In this paper, effect of the medium added with the water extract of the silage on the growth of nitrate reducing bacteria was espeically studied. The results obtained were as follows: 1. The composition of basal medium was 0.5% meat extract, 0.5% polypepton and 0.1% KNO_3 with an initial pH value of 7.0. The numbers of nitrate reducing bacteria increased at 28℃ for 3 days culture in the medium added with 5% water extract of silage, but further increase in added water extract of silage did not affect on the growth of bacteria. 2. The growth of bacteria was promoted by increasing level of added KNO_3. 3. The optimum pH and temperature for the growth were 7.0 to 7.9 and 28℃, respectively. There were no marked difference in the growth of bacteria among stationary culture, stationary culture after the shaking culture for 6hr and stationary culture covered with fluid parafin.
