Support for the UC-Davis Wine Microbiology Culture Collection

The primary objective of this proposal was to increase both the diversity and total number of wine related bacteria in the culture collection. We have used 2 methods to accomplish this goal. First we have obtained interesting isolates from other collections (see Appendix A). From these collections we have been able to obtain some unusual isolates that will be of use for further research. For example, 2 isolates of the acid tolerant Lactobacillus suebicus are being used for a study of malo-lactic fermentations by a masters student, Cameron Parry. These strains may be a commercial alternative to Oenococcus. We also now have in the collection 2 strains of Allicyclobacillus, a spoilage organism from apple juice. These organisms have not been found in grape juice but we may now be able to look for this type of spoilage organism.

Our second method of enhancing the bacterial collection has been to isolate interesting wine-related bacteria directly from wine and must. We worked with a winery that does not use inoculation for malo-lactic fermentaion to obtain isolates of Oenococcus from 5 wine varieties; Zinfandel, Cabernet Sauvignon, Chardonnay, Merlot, and Carignane. We have purified over 600 putative Oenococcus isolates from these wines and are in the process of determining how many different strains they represent. We have also isolated more then 300 other bacteria from these samples and are attempting to determine the genus and species as well as the genetic variety of these organisms. An additional request was made to several wineries to provide us with examples of wines that they felt had microbial spoilage organisms present. We have isolated approximately 20 bacterial spoilage organisms from a variety of such wines at this point. We are currently working in conjunction with the Wine Microbiology class (VEN 128) to obtain more isolates that will be added to the collection.

Over the duration of the granting period we have added 68 well characterized strains to the collection from various collections around the world. We have added an additional 20 spoilage isolates from California. Over the next year we should be able to analyze and characterize many of the other isolates we have collected. We can not as yet put a number on those isolates we will add to the collection. Overall, we have made substantial progress in bringing the bacterial portion of the culture collection up to the level where it can be of substantial use for instructional, research, and industry purposes.

PDF: Support for the UC-Davis Wine Microbiology Culture Collection