The 13th International Congress on Yeasts that was held at the Monona Terrace Convention Center in Madison, Wisconsin, USA, Aug. 26-30, 2012, was one of the largest and most successful yeast conferences organized by the International Yeast Commission since its inception in 1964. Over 400 delegates representing 46 countries participated in the congress. Professor Steve Oliver of the University of Cambridge (UK) gave the keynote address entitled “A Yeast For All Reasons: Functional Genomics and Systems Biology,” Six plenary talks were given by speakers Teun Boekhout (CBS, The Netherlands) on Taxonomy, Systematics and Rapid Identification; Sakkie Pretorius (Australian Wine Research Institute, Australia) on Food, Beverages and Agriculture; Merja Penttila (VTT, Finland) on Industrial Applications; Jens Nielsen (Chalmers University, Sweden) on Yeast Systems Biology; Joseph Heitman (Duke University, USA) on molecular aspects of Clinical, Immunologyand Diagnostics; and Bernard Dujon (Institute Pasteur, France) on Genome Diversity, Function and Comparative Analysis.
In addition to the keynote and 6 plenary talks, the scientific program consisted of 9 major topic areas that included yeast taxonomy, systematics and rapid identification, clinical, immunological and diagnostics for yeasts, ecology and biogeography of yeasts, genome diversity function and comparative analysis of yeasts, cell biology physiology and metabolism of yeasts, yeasts systems biology, transcription, translation and signaling in yeasts, food beverage and agriculture applications of yeasts, and biotechnological applications of yeasts. Topic areas were subdivided into 5 parallel sessions with a record total of 55 sessions organized with 3-4 speakers giving 25-minute oral presentations.
Two of the studies reported in this special issue investigate important aspects of yeast physiology and genetics with potential implication in bioenergy research. The paper from Meneghin et al. [ref] reports detailed analysis of the fermentation profile of a strain of Dekkera (Brettanomyces) bruxellensis isolated from water in an alcohol-producing unit. This species is regarded as a contaminant in the winemaking industry due to the production of off-flavor compounds and blamed for ethanol loss during fuel fermentation. Given the co-existence of this species with S. cerevisiae in these industrial settings, the authors investigated fermentative performance by co-culturing D. bruxellensis and S. cerevisiae in several different media conditions. Moreover, the authors investigated the effect of sequential batch cultivation, somewhat mimicking the practice of re-pitching in Brazilian biofuel production, showing how this practice can favor expansion of D. bruxellensis populations.
In a second paper, Antonangelo et al. report a wide survey of S. cerevisiae strains isolated from Brazilian sugar cane mills. Microsatellite analysis was used to investigate the population structure and dynamic of a large number of strains obtained from different sugar cane mills across Brazil. The analyses reveal a complex community of S. cerevisiae isolates present during the fermentation process with distinct populations characteristic of different sugar cane mills and seasons. Further analysis using next generation sequencing will be required to resolve the complexity of these populations. However, this untapped biodiversity has high potential for developing and improving novel biofuel strains.
Finally, a third paper in this issue by López-Martínez et al., characterized an important molecular aspect of yeast cell desiccation. This trait is of primary biotechnological relevance since active dry yeasts are commercialized worldwide for conventional biotechnological applications. The authors investigate the role of SIP18, a phospholipid binding hydrophilin, a gene essential to overcome the desiccation stress. The overexpression of this gene in different S. cerevisiae strains background genetics (both wild and wine making strains) has a beneficial impact on cell viability of desiccated yeasts by reducing ROS accumulation. Fermentation profiling of these strains for winemaking metabolites indicate that this genetic modification does not impact on oenological properties.