ISSN:
1432-072X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Minimal growth-limiting concentrations of different nitrogen sources were tested in liquid cultures of Flavobacterium aquatile, Aerobacter aerogenes, and Bacillus subtilis in population densities of approximately 5000 cells/ml. Evidence of multiplication was given by plate counts and microscopic counts on membrane filters. The lowest nitrogen concentrations at which multiplication occured (threshold concentrations) ranged from 〈1 to 500 γ/l and depended upon both the kind of nitrogen source and the organism used (Table3). A. aerogenes proved to require larger concentrations of nitrogen than the two other organisms. Nitrogen of ammonia and of hydrolysed peptone showed lower threshold concentrations than nitrogen of nitrate and untreated peptone, respectively. Microscopic measurement of the cell size indicated formation of cell material of B. subtilis at concentrations of ammonia-nitrogen lower than those necessary for multiplication.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00409970
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