Pyrosequencing reveals regional differences in fruit-associated fungal communities

We know relatively little of the distribution of microbial communities generally. Significant work has examined a range of bacterial communities, but the distribution of microbial eukaryotes is less well characterized. Humans have an ancient association with grape vines (Vitis vinifera) and have been making wine since the dawn of civilization, and fungi drive this natural process. While the molecular biology of certain fungi naturally associated with vines and wines is well characterized, complementary investigations into the ecology of fungi associated with fruiting plants is largely lacking. DNA sequencing technologies allow the direct estimation of microbial diversity from a given sample, avoiding culture-based biases. Here, we use deep community pyrosequencing approaches, targeted at the 26S rRNA gene, to examine the richness and composition of fungal communities associated with grapevines and test for geographical community structure among four major regions in New Zealand (NZ). We find over 200 taxa using this approach, which is 10-fold more than previously recovered using culture-based methods. Our analyses allow us to reject the null hypothesis of homogeneity in fungal species richness and community composition across NZ and reveal significant differences between major areas. © 2014 The Authors

Yeast strains and methods of use thereof

The present invention relates to yeast strains and, in particular, to yeast stains for use in fermentation processes. The invention also relates to methods of fermentation using the yeast strains of the invention either alone or in combination with other yeast strains. The invention thither relates to methods for the selection of yeast strains suitable for fermentation cultures by screening for various metabolic products and the use of specific nutrient sources

A distinct population of Saccharomyces cerevisiae in New Zealand: evidence for local dispersal by insects and human-aided global dispersal in oak barrels

Humans have used S. cerevisiae to make alcoholic beverages for at least 5000 years and now this super-model research organism is central to advances in our biological understanding. Current models for S. cerevisiae suggest that its population comprises distinct domesticated and natural groups as well as mosaic strains, but we generally know little of the forces which shape its population structure. In order to test the roles that ecology and geography play in shaping the S. cerevisiae species we examined nine variable microsatellite loci in 172 strains of S. cerevisiae isolated from two spontaneous grape juice ferments, soil, flowers, apiaries and bark in New Zealand. Bayesian analysis shows that the S. cerevisiae in NZ comprise a subdivided but interbreeding population that out-crosses �20 of the time. Some strains contributing to spontaneous ferments cluster with NZ soil/bark isolates, but others cluster with isolates from French oak barrels. It seems some strains have been globally dispersed by humans in oak barrels while some are locally vectored by insects. These data suggest geography is more important than ecology in shaping S. cerevisiae's population structure. © 2009 Society for Applied Microbiology and Blackwell Publishing Ltd

Yeasts associated with the New Zealand Nothofagus honeydew system

New Zealand honeydew beech forests are the only natural ecosystem where large quantities of above-ground labile carbon are added year-round. Microbes can potentially play an important role in the flux of nutrients through food webs; because of their potential for specialisation to sugar-rich niches we tested for the presence of yeasts in the honeydew system. We found at least two abundant species (Hanseniaspora osmophila and Candida railenensis), as well as two species (Zygosaccharomyces cidri and Z rouxii) likely present at lower frequencies. Only Candida railenensis is known to be associated with Nothofagus, but the other species are associated with fruits and winemaking/fermentation. These other species found in honeydew may be indigenous, but it is also possible that they represent microbial examples of invasive species and consequently add to the considerable list of human-introduced species that have invaded New Zealand's ecosystem. © New Zealand Ecological Society