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251.
F. B. Cor Witteveen Peter van de Vondervoort Klaas Swart Jaap Visser 《Applied microbiology and biotechnology》1990,33(6):683-686
Summary A colony staining method was used to isolate mutants inAspergillus niger which showed altered glucose oxidase induction. The mutants were isolated under weakly or non-inducing conditions. A stable glucose-oxidase-negative mutant and a series of overproducing mutants were found. Among the overproducing mutants, different phenotypes were found with respect to glucose oxidase induction. The mutants were tested for glucose oxidase production in surface and submerged cultures, indicating a fair correspondence between those methods. From the characteristics of the mutants it can be concuded that oxygen- and carbonsource-dependent induction are mediated by different factors. 相似文献
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Leilani A. Walker Cor J. Vink Gregory I. Holwell Thomas R. Buckley 《New Zealand journal of zoology.》2020,47(3):187-205
ABSTRACT Spider webs vary in size to meet the nutritional requirements of the resident spider with the resident’s body size strongly informing these requirements. In this way, the effect of body size on web-building behaviour should be apparent across species. To determine whether the size of analogous web structures scales with body size across closely related species, we first measured mainsheet area and adult female body size of 12 sheet-web spider species (Cambridgea). Using these species, we then generated alignments from the cytochrome c oxidase subunit I (COI) and histone 3 (H3) gene regions. These alignments were phylogenetically analysed using Bayesian inference and maximum likelihood methods. While phylogenetic trees for the COI gene suggested that Cambridgea is monophyletic relative to sampled outgroups, H3 did not. Combining our COI phylogenetic tree’s branch lengths with data on web-building behaviour, we used phylogenetic least squares to determine whether web size scales with spider size across species. While we found evidence that larger species generally build larger webs, the variation in web size across even similarly sized species suggests that environmental characteristics which influence site selection and prey type may play a role in determining the optimal web size for different species. 相似文献
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Stefanie J.W.H. Oude Elferink Piet N.L. Lens Cor Dijkema Alfons J.M. Stams 《FEMS microbiology letters》1996,142(2-3):237-241
Abstract The isomerization of butyrate and isobutyrate was investigated for the sulfate reducer Desulforhabdus amnigenus . Nuclear magnetic resonance (NMR) studies with 13 C-labelled butyrate showed that isobutyrate was formed by migration of the carboxyl group, in conformity with the butyrate isomerization reaction reported for methanogenic consortia. In addition to D. amnigenus , several other butyrate-degrading sulfate reducers ( Desulfobacterium vacuolatum, Desulfoarculus baarsii and Desulfotomaculum sp.) were capable of butyrate isomerization. 相似文献
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