Management and optimisation of the AWRI Wine Microorganism Culture Collection
The AWRI Wine Microorganism Culture Collection (AWMCC) contains over 10,000 yeast and bacterial strains including yeast genome deletion libraries, proprietary strains, and natural isolates from Australian wineries. In addition, the collection is a largely untapped resource of microbial diversity which, if properly characterised, has the potential to greatly enhance microbial strain development projects.
Ongoing use of the culture collection is expected for future Wine Australia-funded projects, which will lead to the generation and/or isolation of many novel yeast and bacteria. Efficient use of the collection will require a reorganisation of storage facilities (including the off-site duplicate collection), and an update of the existing collection database into a format that is amenable to high throughput screening and characterisation. In addition, quality control (QC) of new depositions and existing strains within the collection, will be required on an ongoing basis, and technological advances may provide opportunities to improve existing QC regimes. Once the collection has been organised for high throughput screening, large scale genotyping and phenotyping will be feasible.
Identification, storage and distribution of microbial strains
In 2019/2020, a total of 393 individual yeast and bacterial strains were submitted to the AWMCC by researchers and wineries. During the year, the AWMCC distributed 617 microbial strains from cryogenic stocks to AWRI researchers, wineries and external research partners. In addition, another 3,100 microorganisms were collected from wineries for the bioprospecting project and are housed in the collection, bringing the total number of available microorganisms to around 22,000.
Many of the strains are stored in specialised individual vials which have been designed to ensure the long-term viability of microorganisms stored at ultra-low temperature. Storage in individual vials reduces the risk of cross-contamination that can occur when using multi-well storage systems and is therefore best practice for ensuring the long-term integrity and traceability of critical microbial germplasm. However, storage in individual tubes is labour-intensive and not amenable to high-throughput screening methods. For this reason, several screening populations representing commonly studied subsets of the collection have been prepared in 96-well format, which is accessible to robotic handling equipment. More than 3,000 yeast and more than 1,000 bacteria previously stored in individual tubes have been assembled into seven populations: Saccharomyces, Brettanomyces and non-Saccharomyces yeast (excluding Brettanomyces), Oenococcus, lactic acid bacteria and acetic acid bacteria. These populations are now available for high-throughput screening for characteristics of interest.