prototrophicadj.

1900 A. C. Jones tr. A. Fischer Struct. & Functions Bacteria v. 48 A better classification would be to divide the bacteria, according to their mode of life, into three biological groups, prototrophic, metatrophic, and paratrophic.

1900 A. C. Jones tr. A. Fischer Struct. & Functions Bacteria v. 48 Prototrophic species are those which either require no organic compounds at all for their nutrition (nitrifying bacterium), or which, given the smallest quantity of organic carbon, can derive all their nitrogen from the atmosphere (bacteria of root-nodules). With them may be classed..sulphur and iron bacteria.

1940 Nature 26 Oct. 541/2 If virus was the first form of life, it ought to be possible to find prototrophic viruses which feed on inorganic materials.

1946 F. J. Ryan & J. Lederberg in Proc. National Acad. Sci. U.S.A. 32 172 We propose to designate as a prototroph any strain which has the nutritional requirements of the ‘wild type’ from which it was derived irrespective of how it became prototrophic.

1963 F. J. Ryan in W. J. Burdette Methodol. in Basic Genetics 57 The average number of mutations per liquid culture may be determined from the fraction of a series of similar but independent auxotrophic cultures which become overgrown by prototrophic mutants when there is a limited supply of the required growth factor.

2003 Proc. National Acad. Sci. U.S.A. 10 6634/2 Transformant yeast cells are rendered prototrophic for tryptophan biosynthesis and harbor a 13-kb minichromosome.

1957 Proc. National Acad. Sci. U.S.A. 43 950 Prototrophically growing colonies were of heterokaryotic origin, carrying both types of parental nuclei.

1978 Nature 20 Apr. 731/1 These cells..now grow prototrophically at a reduced rate identical to that of the spermidine-deficient cells.

1990 Current Genetics 17 163 Fusion heterokaryons between the complementary mating types, which grew prototrophically, were selected.