Recent content by suregork

All single colony isolates of WLP099 I have tested are STA- and unable to use maltotriose. We've also whole-genome sequenced one such colony, and the strain is a POF-, STA- wine strain. I have never tested extracting DNA directly from a WLP099 package and testing for STA1 by PCR. Since people...

Yeah I saw this earlier today, very cool! Will see what I can do, don't have that much extra time at the moment and that is quite a lot of data :)

Never tried it, but one of the White Labs wine strains included in this study (Domestication and Divergence of Saccharomyces cerevisiae Beer Yeasts - PubMed) contains the STA1 gene (A deletion in the STA1 promoter determines maltotriose and starch utilization in STA1+ Saccharomyces cerevisiae...

I haven't tested very many no. I do have a load of White Labs (including WLP540) and Fermentis strains in the -80 freezer though, so can try to test them at some point when I have time later this spring. Currently out of office on parental leave.

Yes, very unlikely that strains in a blend would cross-mate and a hybrid would take over the population in a can. Especially since we are talking about brewing yeast, which are quite challenging to breed with as they are sterile (i.e. do not form viable spores) and polyploid. However, if one...

They've inactivated one of the genes required for the POF phenotype with CRISPR/Cas9 editing. In theory it could be done at home, but in practice it requires some lab equipment and experience (e.g. confirming a successful modification). Genetic engineering in yeast nowadays is super easy. Hoping...

As Northern Brewer says, and I mentioned a few pages back, do we know for sure they use dry yeasts? If yes, then one can be quite confident the 'S04-like' isolate is S04, as I'm not sure there are that many other Beer 1 - UK dried strains. If liquid yeasts are an option, you'll see that most...

Did some interdelta fingerprints (delta12/delta21 and Phusion polymerase) of some Escarpment and White Labs strains at work today. I'm not sure if they are of any help in IDing the strains . One observation is that the fingerprints of WB06, WLP570 and WLP644 are identical (and genome data...

The Dunham Lab tree, looking at only strains in a specific group and with high quality sequence data, is definitely more accurate than the my big tree!

A potentially relevant poster abstract at this year's WBC: "Can we rescue Beer infected with Diastaticus during fermentation: A profile in killer yeast and the effect of co-fermentation on the superattenuative characteristics of diastaticus."...

I'd say it's quite unlikely your problem is 2,3-pentanedione. Diacetyl (2,3-butanedione) and 2,3-pentanedione are formed as byproducts of the same amino acid synthesis pathway. Typically a fermentation will produce similar amounts of both compounds, and these are also removed from the wort/beer...

I haven't tested long term stability, but the hybrid is likely to be less stable than the parent strains. Hybrids within a species (e.g. here between two S. cerevisiae strains) are often more stable than hybrids between species). However, as the hybrid is probably hexaploid (from the tetraploid...

WB-06 has the deletion in the STA1 promoter, so STA1 is not expressed very actively. It can still ferment dextrins, but it happens very slowly.

WB-06 is STA1+, but it has a deletion in the STA1 promoter. This deletion is common in many of the STA1+ strains (which is probably why many went unnoticed for such a long time). This significantly reduces the activity of STA1 (see our recent paper...

If someone has the TH isolates left, and an extra 125 USD per strain, then I recommend the whole genome sequencing route. MiGS does 625 Mb Illumina sequencing (50x coverage for yeast) for 125 USD. https://www.migscenter.com/sequencing I'd be happy to do the analysis and figure out the closest...