Discovery of the target genes inhibited by formic acid in Candida shehatae

Abstract:

Abstract:［Objective］At transcriptional level，the inhibitory effects of formic acid was investigated on Candida shehatae，a model yeast strain capable of fermenting xylose to ethanol． Thereby，the target genes were regulated by formic acid and the transcript profiles were discovered．［Methods］ On the basis of the transcriptome data of C. shehatae metabolizing glucose and xylose，the genes responsible for ethanol fermentation were chosen as candidates by the combined method of yeast metabolic pathway analysis and manual gene BLAST search．These candidates were then quantitatively detected by RQ-PCR technique to find the regulating genes under gradient doses of formic acid．［Results］By quantitative analysis of 42 candidate genes，we finally identified 10 and 5 genes as markedly down-regulated and up-regulated targets by formic acid，respectively.［Conclusion］With regard to gene transcripts regulated by formic acid in C．shehatae，the markedly down-regulated genes ranking declines as follows: xylitol dehydrogenase (XYL2)，acetyl-CoA synthetase (ACS)，ribose-5-phosphate isomerase (RKI)，transaldolase (TAL)，phosphogluconate dehydrogenase (GND1)，transketolase (TKL)，glucose-6-phosphate dehydrogenase (ZWF1)，xylose reductase (XYL1)，pyruvate dehydrogenase (PDH) and pyruvate decarboxylase (PDC); and a declining rank for up-regulated gens as follows: fructose-bisphosphate aldolase (ALD)，glucokinase (GLK)，malate dehydrogenase (MDH)，6-phosphofructokinase (PFK) and alcohol dehydrogenase (ADH)．