| 释义 |
auxotroph Genetics.|ˈɔːksəʊtrəʊf, -trɒf|
[f. L. aux-ilium help + -o + Gr. τροϕή nourishment.]
A mutant bacterium, fungus, etc., which has an additional nutritional requirement compared with the original strain; a naturally occurring bacterium with a requirement for a specific nutrient.
1950Davis & Mingioli in Jrnl. Bacteriol. LX. 17 The terms ‘auxotrophic’..and the corresponding noun ‘auxotroph’ are suggested for convenience in denoting biochemical mutants with increased nutritional requirements. 1953Ann. N.Y. Acad. Sci. LVI. 844 Algae, like autotrophic bacteria, may be divided into auxotrophs and non-auxotrophs. 1971M. Alexander Microbial Ecol. v. 109 Auxotrophs are ubiquitous, and though their proliferation denotes that their needs are satisfied, the level of growth factors in nature and their significance..have been the subject of only modest inquiry, except in water and soil. 1976Ann. Rev. Microbiol. XXX. 92 Other auxotrophs such as those requiring amino acids, purines, and pyrimidines do not assume a colonial or semicolonial growth habit if the biochemical supplement in the medium is limiting. 1980Nature 3 Jan. 106/1 The fact that we were able to detect auxotrophs among the bacterial strains tested suggests that certain vitamin and amino acid requirements do not necessarily represent a selective disadvantage to the bacteria that possess them.
Also auxoˈtrophic a., of, pertaining to, or being an auxotroph; auxoˈtrophically adv.; auˈxotrophy, the state or condition of being auxotrophic.
1950Auxotrophic [see above]. 1953Ann. N.Y. Acad. Sci. LVI. 839 The relative incidence of auxotrophy in coastal and oceanic phytoplankton species. 1968W. Hayes Genetics of Bacteria & their Viruses (ed. 2) x. 210 Auxotrophic mutants of bacteria are..widely used in biochemical as well as in genetic research. 1973R. G. Krueger et al. Introd. Microbiol. xv. 412/2 Each of the auxotrophic strains was spread separately in large numbers..on plates of synthetic medium lacking the necessary nutritional supplements needed for the repair of defects caused by auxotrophy. 1976Ann. Rev. Microbiol. XXX. 45 Since many exoproteins lack cysteine, starvation of cys- mutants for their auxotrophic requirement appears to offer a potential method for separating exoprotein synthesis from general cellular protein synthesis. Ibid. 395 A problem that has long hampered Caulobacter workers in the efficient isolation of auxotrophically marked strains is the relative resistance to mutagenesis exhibited by several Caulobacter species. 1977R. Y. Stanier et al. Gen. Microbiol. (ed. 4) 35 Auxotrophy, represented by an absolute requirement for one or more vitamins, is characteristic of many photoautotrophic algae and bacteria. 1982Jrnl. Bacteriol. CLI. 708 Mutants of Escherichia coli K-12 auxotrophic for thiamine phosphates were produced in stepwise fashion. |