Extraction of the 260 nm-absorbing material from Group N streptococci as a method for estimating cell growth

Abstract

SummaryA method is described for estimating the growth of Group N streptococci in milk and other media by measuring the 260 nm-absorbing material extracted from the cells with 0·1 M-NaOH at 100°C. A good correlation between the absorbance at 260 nm of the hot alkali extracts and the dry weight of the cells was obtained for cultures of Streptococcus lactis during the logarithmic and early stationary phases of growth.