Project description:In this study, the recombinant Trichoderma reesei strain HJ48 was employed to investigate the differences between anaerobic and aerobic fermentation of glucose, through genome-wide transcription analysis.Analysis of the genes induced under fermentation condition has revealed novel features in T. reesei. Our results how that many genes related to ribosome were expressed more highly under aerobic condition in HJ48.
Project description:Equol is one of major isoflavones with an affinity to endoplasmic reticulum and has an estrogen-like biological activity. Equol-producing bacteria have been isolated and characterized, however fermentation has been performed in an anaerobic condition with soybean-based products as substrates. Pueraria lobata has been reported as a plant with a higher content of isoflavones, such as daidzein, daidzin, and puerarin.
Project description:All organisms have evolved elaborate physiological pathways that regulate growth, proliferation, metabolism, and stress response. These pathways must be properly coordinated to elicit the appropriate response to an ever-changing environment. While individual pathways have been well studied in a variety of model systems, there remains much to uncover about how they are integrated to produce global changes in a cell. Past work from our lab, focused on engineering the budding yeast Saccharomyces cerevisiae for fermentation of the non-native pentose sugar xylose, discovered that hyperactivation of the RAS/Protein Kinase A (PKA) pathway was needed for rapid anaerobic xylose fermentation. Interestingly, the mechanism of PKA hyperactivation has a dramatic impact on growth and metabolism on xylose; deletion of the RAS inhibitor IRA2 permits rapid growth and fermentation, while deletion of the PKA regulatory subunit BCY1 allows for fermentation without growth on xylose. To understand how a single deletion in the PKA pathway can decouple growth and metabolism, we performed transcriptomic analysis of these strains, predicting that altered PKA activity would impact global gene expression and identify pathways important for growth and metabolism coordination. Notably, we found enriched differential expression of lipid metabolism genes, targets of the phospholipid biosynthetic gene transcription factor Ino4, and genes containing the Aft1/2 consensus motif. These results suggested that dysfunctional lipid homeostasis may be responsible for decoupling growth and metabolism in the bcy1∆ strain. In parallel work, we also directly evolved the bcy1∆ strain to grow anaerobically on xylose and found point mutations in TPK1, OPI1, RIM8, and TOA1 permitted growth. Interestingly, Opi1 is the inhibitor of Ino4, further supporting the role of lipid homeostasis in growth and metabolism coordination. This work shows that a single genetic change can have dramatic impacts on multiple aspects of cellular physiology.
Project description:Anaerobic digestion is a popular and effective microbial process for waste treatment. The performance of anaerobic digestion processes is contingent on the balance of the microbial food web in utilizing various substrates. Recently, co-digestion, i.e., supplementing the primary substrate with an organic-rich co-substrate has been exploited to improve waste treatment efficiency. Yet the potential effects of elevated organic loading on microbial functional gene community remains elusive. In this study, functional gene array (GeoChip 5.0) was used to assess the response of microbial community to the addition of poultry waste in anaerobic digesters treating dairy manure. Consistent with 16S rRNA gene sequences data, GeoChip data showed that microbial community compositions were significantly shifted in favor of copiotrophic populations by co-digestion, as taxa with higher rRNA gene copy number such as Bacilli were enriched. The acetoclastic methanogen Methanosarcina was also enriched, while Methanosaeta was unaltered but more abundant than Methanosarcina throughout the study period. The microbial functional diversity involved in anaerobic digestion were also increased under co-digestion.
Project description:Transcriptome analysis in natural Saccharomyces cerevisiae as function of fermentation stage. Strains used were the reference strain S288C, two (06L3FF02 and 06L6FF20) isolates from the Bairrada wine region, Portugal, three (Lalvin EC-1118, Lalvin ICV D254 and AEB Fermol Rouge) wine yeast obtained commercially and one (J940047) isolate from a human patient. Fermentation was carried out in synthetic must MS300, in semi-anaerobic conditions. Cells were harvested at six time-points during fermentation: early exponential growth (T1), mid-exponential growth (T2), diauxic shift (T3), early stationary growth (T4) Mid-stationary growth (T5) and end of fermentation (T6). Hybridizations were carried out using a common reference design, using RNA obtained from S288C at T2, in dye-swap replicates, and four self-self hybridizations were performed using the common reference sample for control of the experiment background, in a total of 88 hybridizations.