English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

SUMMARY: A wild-type strain of the yeast Kluyveromyces fragilis was grown in continuous culture on inulin-, fructose- and glucose-limited media. In the presence of organic nitrogen, all three carbon sources supported an extremely rapid changeover to a homogeneous mutant cell population that exhibited hyperproduction of β-fructofuranosidase (exo-inulase). The non-specific role of the carbon substrate in the takeover suggested co-regulation of inulase synthesis and early glycolytic pathway enzymes such as hexokinase, resulting in gratuitous hyperproduction of inulase. The rate of mutant appearance increased linearly with a decrease in dilution rate as well as carbon/nitrogen ratio, implying that the responsible forces were related to the residual concentration of the limiting carbon substrate. Under optimum conditions, mutant cells were detected within only 40 h (2.9 generations) from the start of continuous culture, at least 6.5 times faster than predicted. The maximum rate of displacement was as high as 54% per generation, or more than 12 times greater than predicted from the differential growth rate between the wild-type and mutant strain. These extraordinarily rapid takeovers point to a very fast and ongoing genetic change triggered by growth under severe stress.

Extraordinarily Rapid Appearance of a -Fructofuranosidase (Exo-inulase)-hyperproducing Mutant in Continuous Culture of Kluyveromyces fragilis