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

Background  Efficient xylose alcoholic fermentation is one of the key to a successful lignocellulosic ethanol production. However, regulation of this process in the native xylose-fermenting yeasts is poorly understood. In this work, we paid attention to the transcriptional factor Cat8 and its possible role in xylose alcoholic fermentation in  Ogataea (Hansenula) polymorpha.  In  Saccharomyces cerevisiae,  organism, which does not metabolize xylose, gene  CAT8  encodes a Zn-cluster transcriptional activator necessary for expression of genes involved in gluconeogenesis, respiration, glyoxylic cycle and ethanol utilization. Xylose is a carbon source that could be fermented to ethanol and simultaneously could be used in gluconeogenesis for hexose synthesis. This potentially suggests involvement of  CAT8  in xylose metabolism.    Results  Here, the role of  CAT8  homolog in the natural xylose-fermenting thermotolerant yeast  O. polymorpha  was characterized. The  CAT8  ortholog was identified in  O. polymorpha  genome and deleted both in the wild-type strain and in advanced ethanol producer from xylose. Constructed  cat8 Δ strain isolated from wild strain showed diminished growth on glycerol, ethanol and xylose as well as diminished respiration on the last substrate. At the same time,  cat8 Δ mutant isolated from the best available  O. polymorpha  ethanol producer showed only visible defect in growth on ethanol.  CAT8  deletant was characterized by activated transcription of genes  XYL3, DAS1  and  RPE1  and slight increase in the activity of several enzymes involved in xylose metabolism and alcoholic fermentation. Ethanol production from xylose in  cat8 Δ mutants in the background of wild-type strain and the best available ethanol producer from xylose increased for 50 and 30%, respectively. The maximal titer of ethanol during xylose fermentation was 12.5 g ethanol/L at 45 °C. Deletion of  CAT8  did not change ethanol production from glucose. Gene  CAT8  was also overexpressed under control of the strong constitutive promoter  GAP  of glyceraldehyde-3-phosphate dehydrogenase. Corresponding strains showed drop in ethanol production in xylose medium whereas glucose alcoholic fermentation remained unchanged. Available data suggest on specific role of Cat8 in xylose alcoholic fermentation.    Conclusions  The  CAT8  gene is one of the first identified genes specifically involved in regulation of xylose alcoholic fermentation in the natural xylose-fermenting yeast  O. polymorpha .    Electronic supplementary material  The online version of this article (doi:10.1186/s12934-017-0652-6) contains supplementary material, which is available to authorized users.

Transcriptional activator Cat8 is involved in regulation of xylose alcoholic fermentation in the thermotolerant yeast Ogataea (Hansenula) polymorpha