A better yeast?

by pointnshoot
Brewing better beer: Scientists determine the genomic origins of lager yeasts:
[Via Eureka! Science News - Popular science news]

Yeast, the essential microorganism for fermentation in the brewing of beer, converts carbohydrates into alcohol and other products that influence appearance, aroma, and taste. In a study published online today in Genome Research (www.genome.org), researchers have identified the genomic origins of the lager yeast Saccharomyces pastorianus, which could help brewers to better control the brewing process.

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Very nice. Ale yeast, the ‘original’ is a top fermenting yeast, while lager is a bottom-fermenting. Because of these characteristics, lagers are more easily produced for mass consumption but usually do not have the taste complexities found in ales. ALes can also be easily produced at room temperatures while lagers need cooler temps.

This looks like an interesting report, with the mystery of where lager yeast came from being closer to a solution. What I found really interesting is that the yeast from different breweries looked like they had been under selective pressure for that specific brewery.

So it may not just be the water that makes the same brand of beer produced at different sites to taste differently. The yeast may actually be diverging at the two sites.

Technorati Tags: Health, Science

The two best

Tricked out hurricane websites:
[Via Deep Sea News]

Naturally, one of the favorite pastimes here in the Cone of Probability is to monitor as many websites as possible for different forecasts and projections of Hurricane Ike. The more the models stray away from Corpus Christi the less anxious you feel. Currently three models veer to the north before landfall, so CC has a small chance of escaping the storm.

The image above is from my favorite hurricane web interface so far, called Stormpulse. It’s full screen, and very interactive, almost like a video game. If you’re looking for in-depth analysis, grab a cup a’ joe and dig in to Jeff Masters WunderBlog. It’s a great resource from a PhD storm chaser. Jeff predicted a chain of atmospheric disturbances following Gustav two weeks ago. For Ike, he overlays the trajectory on maps of heat potential, which is very cool.

These are two of the best sites. Stormpulse give you the data and Jeff Master’s gives you the analysis. Plus the comments to the Wunderblog are chock full of amateur weather experts who, amongst all the discussion, provide more data and insight.

If you want to see what realtime data coupled with expert advice looks like, these are the two places. Plus, they also link out to other useful sites.

Technorati Tags: Environment, Science

Molds that are slimey

The Diversity of Slime Moulds:
[Via Catalogue of Organisms]

How could you not love an organism that manages to combine both slime and mould? Slime moulds are saprobic organisms (i.e. they gain their nutrients by breaking down dead organic matter) that spend most of their life cycle feeding as separate amoeboid cells or disaggregated plasmodium. However, when conditions become right all the cells or plasmodium near each other will stream together to form a fungus-like fruiting body that releases spores, as shown in the diagram above borrowed from here. Because slime moulds thus resemble protozoa for part of their life cycle but fungi at other times, they were an early protagonist in the destruction of the idea that all organisms could be divided between plants and animals. Slime moulds, it turns out, are mostly not related to plants or animals. As our understanding of organismal phylogeny has progressed, it has become clear that not all slime moulds are even related to other slime moulds. Instead, the term has been used to cover a number of phylogenetically disparate organisms with little in common other than similar life cycles. However, the majority of references to slime moulds out there fail to mention this, focusing on only a small part of “slime mould” diversity, so I thought I’d give a brief overview of the full diversity of organisms with a slime mould-type life cycle.
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One of the really wonderful things about attending CalTech was the opportunity to have Leading scientists, even Nobel Prize winners teach the undergraduates. In my freshman year introductory biology class we had a lecture by Max Delbruck, shortly before he retired.

As the physicists had Feynman, the biologists had Delbruck. It was a very memorable lecture because he talked about slime molds. I had never heard of them and could not really understand why someone of his stature was studying them.

By the end of the lecture, I was fascinated by them. It is nice to get a chance to get reacquainted.

Technorati Tags: Science