Über alkoholische Gärung ohne Hefezellen

In my last submission to “The Giants’ Shoulders” blog carnival, we saw how the famous surgeon Dr. Joseph Lister deftly demonstrated definitively that fermentation processes were caused by live microbes rather than some sort of mysterious soluble substance that just happened to be associated with microbes. In today’s episode, we will see how Eduard Buchner definitely demonstrated that fermentation was caused by a soluble substance that was associated with microbes, and no microbes are actually needed.

Better still…they’re both right. “Wait…what?” Read on, O Seeker of Microbiological Knowledge, and be enlightened by this month’s entry: Continue reading Über alkoholische Gärung ohne Hefezellen

Saccharomyces cerevisiae – Shameless Libertine!

I’ve been wondering about starting my own little yeast-breeding operation. I haven’t yet figured out where you can by the necessary teeny, tiny yeast-sized versions of the Implements of Extremely Impolite Probing that breeders of other species use, but even before that, I need to understand yeast reproduction better in the first place.

I had gotten an impression from some of the stuff that I’d read in a Genetics textbook and online that yeasts were normally haploid, and only became diploid briefly during mating (you see, when an “?” haploid yeast cell and an “a” haploid yeast cell fall in love, sometimes they’ll…). On the other hand, while reading a review of yeast virology[1], the author explicitly wrote that yeast cells are normally diploid. How to resolve this issue? Plus, I was wondering how, if I happened to have a pure culture of a haploid yeast, how could I tell if it was “a” or “?”?

I recently realized that there was one Dr. Bryk in the department where I work who specifically researches yeast chromosomes…so I asked her…

Continue reading Saccharomyces cerevisiae – Shameless Libertine!

Nerd Reading Spasm!

Did I mention the place I work has some amazingly spiffy perks for a nerd like me?

Last night, I was poking around pubmed looking for references to yeast and erythritol (namely, do yeast interact with it, and will they metabolize it?) I found precisely one relevant reference. From 1975. In a Czechoslavokian microbiology journal. A no-longer-existent Czechoslovakian microbiology journal. Even though it was a journal published in English, I didn’t figure I’d be able to find the article I was looking for. It did turn out that the greedy (insert long string of profanity here) anti-open-access “SpringerLink®” Netherlands organization has an electronic copy of the article…which I can get limited access to for a short time for a mere $34.00. Not going to happen, obviously.

Just in case the college had a subscription that would let me get to the article at no extra cost, I checked. No such luck. But…

…The campus medical science library just two buildings over from where I work has dead-tree editions of essentially the entire journal! Im name des Nudelmonster! Instead of paying $34.00, I got a photocopy of the article for about $0.50. Bonus: As I had hoped, the article[1] reports that erythritol is not metabolized by yeasts, although it is taken up to a small extent. That means I can add erythritol (or xylitol or sorbitol or whatever) to must or wort, and it’ll still be there when the yeast finish, leaving the resulting beverage still sweet. Hooray!

Plus, I was also able to get access to an electronic copy of a review of the uses of poly-?-glutamate[2], which I was bemoaning not having access to over on an interesting Small Things Considered post recently.

Speaking of reading, one thing I really could use are any worthwhile books on the general subject of applied/industrial microbiology, bioprocess engineering, fermentation, and so on. “Worthwhile” here means practical texts that are A)primarily about microbiological processes (as opposed to, say, bioengineering of plants) B)Reasonably technical, and C)Either “not very old” or “very old indeed” (I collect old science books).

I’m not a fan of Amazon.com’s abuses of the patent system, but I’m in a hurry since it’s past my bedtime already. Therefore, purely as a sampling of the kinds of books that sounded interesting to me, here is a selection in more or less random order of books that came up in a quick search on amazon.com. Anybody out there have any other suggestions?

Continue reading Nerd Reading Spasm!

“Top Ten Favorite Microbes” proto-meme…

Dr. Joseph over on the “(It’s a…) Micro World (…after all)” blog posted a list of his ten favorite microbes. After showing up in the comments of his post and being a wiseass about E.coli and Gram staining, the least I can do is participate here. Besides, it’s a great idea. Therefore here are ten of my current favorite microbes:

Continue reading “Top Ten Favorite Microbes” proto-meme…

“On the lactic fermentation and its bearings on pathology.”

Lunchtime – time to get this posted…(Let me know if this page is loading way too slowly…)

For this month’s “Giant’s Shoulders” I offer you mouthwash and yogurt.

Indirectly, at least.
Continue reading “On the lactic fermentation and its bearings on pathology.”

Stir-Fried Random Ep 02:Sex, Violence, and Cinnamon Bears, y’all!

Only about five more days until the next “Giant’s Shoulders” blog carnival. I still need to pick a paper. ARGH!
(UPDATE 20081126: I’ve removed the embedded flash player – it seems to ignore me when I explicitly tell it NOT to automatically start playing rather than waiting until you intentionally hit “play”. Sorry for anyone annoyed by the autoplay. The embedded player will not return until I solve this.)

Meanwhile, here’s this week’s episode of “Stir-Fried Random”, weighing in at a MASSIVE 12 WHOLE MINUTES or so. As before, there’s an “<audio>” tag pointing directly at the Ogg Vorbis audio for those of you running a beta of the Firefox 3.1 series, a recent version of Opera, or (I believe) the current Safari on a system with the Ogg Vorbis Quicktime component installed. There is also the usual embedded Flash®-based mp3 player and direct download links for both versions.

Somebody please let me know if I’m making a fool of myself here… Anyway, here are the show notes:
Continue reading Stir-Fried Random Ep 02:Sex, Violence, and Cinnamon Bears, y’all!

Stir-Fried Random: Alferbeetagama!

(Update 20081104T1050: added a minimal embedded flash-based player at the bottom of the post, if you’re willing to settle for mp3 quality and want to listen from your web browser…)
(Update again 20081126: I wish I had realized before that the stupid thing was autoplaying despite explicitly including “autoplay=false” in the parameters. I’ve removed the embedded player again until I find a way to prevent autoplaying. Sorry about anyone that was annoyed by this.)

I was going to post this last night, but there appears to have been another bout of database connection errors again at my ISP (“host blocked due to too many connection errors”). I’m guessing either someone is DOS’ing the database server or one of the other users had some very badly behaved custom code running. They’ve got it fixed now, so here we go…

After staying up too (insert profanity here) late again despite having to get up extra-early this morning to vote before work…here’s the first real episode of Stir-Fried Random. Still only about 10 minutes long – I’d like to make it longer, but it’ll still probably take a few episodes of building up to it. An actual shiny new <audio> tag is included for those with bleeding-edge browsers that support it (let me know if it works – hypothetically the 3.1 Beeta[sic] version of Firefox and I believe the most recent Opera support this.). Otherwise, direct-download is available below the show notes:
Continue reading Stir-Fried Random: Alferbeetagama!

Phylogenetic structure of the prokaryotic domain: the primary kingdoms.

Ike’s comin’ right for us, so I don’t know when the my power and internet access will die, and if so how long it’ll be before it comes back. However, while I’m still connected I wanted to contribute something again to this month’s The Giant’s Shoulders blog carnival. Since it’s in three days and there’s a chance our power might be out when the deadline passes, I figured I’d better hurry. Because of the hurry there are no fancy graphics nor even too much explanatory text here, but I’ll do what I can. Fortunately, the basics of today’s post isn’t too complex.

Depending on how rigorous your biology education was, there are a variety of ways that you might tend to categorize the fundamental types of living things. You might vaguely recall something about “five kingdoms”, which as I recall were “Animals, Plants, Fungi, Protozoa [e.g. amoeba], and Bacteria”. You might just segregate everything into either “animal” or “plant”. If your memory of biology education is a bit stronger, you might remember that “bacteria” are a separate group from the true plants and animals. A step more precise and you may split living things into the two domains of “prokaryote” and “eukaryote”.

The “plant” and “animal” distinction is pretty classic – until comparatively recently, bacteria were assumed to be “plants”, just as fungi (“plants” that lacked chlorophyll) were. Non-photosynthetic bacteria were referred to as “schizomycetes” (literally “fission” [splitting in two] fungi, because they reproduce by splitting from one cell into two rather than forming spores), while bacteria with chlorophyll (cyanobacteria or “blue-green” algae, and possibly the “green sulfur bacteria”) were designated “schizophyta” (“fission plants”).

Within the last fifty years or so, though, it’s become obvious that bacteria were a different type of life from fungi, chlorophyll-containing plants, or animals. The latter critters have cells that in turn contain “organelles”, which are more or less very specialized “mini-cells” within themselves. The nucleus, for example, is a compartment within the cell where the cell’s DNA is kept and processed. Bacteria, it turned out, don’t have any of these organelles (in fact there’s good evidence that at least some if not all organelles used to be bacteria, but this post’s long enough already so I won’t go into that), and life was re-organized into the bacterial “prokaryotes” (“before nucleus”) and the “eukaryotes” (having a “true nucleus” – i.e. everything that isn’t bacteria).

Then, along comes Carl Woese, who spoils this nice simple dichotomy. In 1977, he published (along with G.E. Fox) the subject of today’s post:
Continue reading Phylogenetic structure of the prokaryotic domain: the primary kingdoms.

“Ueber die isolirte Faerbung der Schizomyceten in Schnitt- und Trockenpraeparaten”

The Giant’s Shoulders blog carnival is coming up in two days, and I just realized I still haven’t gotten a post up for it yet. So, here it is.

I put up some quick reviews of several classic microbiology-methods papers for the previous edition of this blog carnival, but didn’t actually get around to putting up the one for what is almost certainly the most well-known microbiology technique: “The Gram Stain”. So, this post is about it:

Gram HC: “Ueber die isolirte Faerbung der Schizomyceten in Schnitt- und Trockenpraeparaten”; Fortschritte der Medicin; 1884; vol 2, pp 185-189

That’s “Regarding the Isolational(?) Coloring of Schizomycetes in Cut- [i.e. tissue sections] and Dried Preparations” in “Medical Progress”. The translation hosted by the American Society for Microbiology uses the word “Differential” where I’ve put “Isolational” – which is probably not quite right either but it’ll have to do for now – but I’ll get to that in a moment.

If you’ve ever been exposed to microbiology labwork before, you’ve almost certainly done or at least watched a procedure referred to as a “Gram stain”. In brief, you smear your sample with bacteria on a glass slide and bake it on, then you dump some purple stuff on it, them some brown stuff, then you rinse it briefly with alcohol, then you dump on some pink stuff, and then rinse it in water and look at it under a microscope. Bacteria that stay the original dark purple-blue color of the original purple/brown stuff are considered “Gram Positive”, and those that don’t instead appear the pink color of the last stain, and are considered “Gram Negative”. Many textbook authors and microbiology instructors will breathlessly proclaim that the Gram Stain reveals two “fundamental” categories of bacteria, but I’ll spare you my rant about that.

Properly speaking, this isn’t actually Gram’s stain, as described in his original paper. The modern variations that we’re all taught in microbiology class were developed later, and I believe they are nowadays based mainly on Victor Burke’s 1922 paper on the subject[1].

Regarding the title of the paper: “schizomycete” is what they used to call most kinds of bacteria. “Mycete” meaning “fungus”, as bacteria were assumed to be “plants without chlorophyll” just like molds and mushrooms, and “Schizo-” meaning “split in two”, since bacteria reproduce by splitting into two cells rather than by producing spores like “other” fungi. I say “most” because things like cyanobacteria (“blue-green algae”) or Green Sulfur Bacteria would have been referred to as “Schizophyta” (“fission-plants”). What Gram was originally trying to do wasn’t to differentiate one kind of bacteria from another, either, but to make it easy to tell bacteria from from the nuclei of cells in bacteria-infected tissue.

For that matter, Gram was really metaphorically standing on the shoulders of Koch and Erhlich, as he was building on their technique for staining “tubercle bacteria” – that is, tuberculosis-causing members of the genus Mycobacterium. Gram mentions that you need to stain this type of bacteria for the “usual” 12-24 hours to make this work, incidentally, as opposed to a few minutes for other “schizomycetes”. This suggests that you are expected to have some idea of what you’re going to find before you use the stain, as opposed to the modern implementation which is supposed to tell you something about what kind of bacteria you’re finding.

Still, Gram does report that some bacteria take the stain and some don’t, giving us a preview of the “differential” character of the modern version. He specifically notes typhoid and some causes of bronchial pneumonia fail to hold the stain. Given that Typhoid Fever is caused by a strain of the “Gram-negative” butt-bacter Salmonella enterica, and there are a number of “Gram negative” bacteria as well as “Gram positive” that can cause pneumonia, this makes sense. He also does mention the use of Bismarck Brown R a.k.a. Vesuvine as a counterstain in order to make the nuclei of the infected cells brown in contrast to the dark blue of the infectious bacteria in the tissue.

For much of the century-and-a-quarter since Gram’s publication, the question of why the Gram stain works was thoroughly investigated, and even today I occasionally hear or read assertions to the effect that the Gram Stain isn’t well understood. I disagree with this just as I think its importance to bacterial identification is grossly overblown, and if you want to know why, I have a previous post all about why the Gram stain works and how we know. You may or may not also be interested in an older post regarding whether or not “acid-fast” bacteria like the ones that cause tuberculosis (which don’t stain at all when using the modern version of the Gram stain) are “Gram Positive” or not. As always, if you spot any errors or have any questions, please let me know…

[1] Burke V: “Notes on the Gram Stain with Description of a New Method.” J Bacteriol. 1922 Mar;7(2):159-82.

(Tap Tap Tap) Is this thing on?…

Move is underway. Here’s a quick update / test.

Cornelia and Monk(eymutt), the Laser Dogs

On the way home (to Texas, that is, with a load of furniture from House v1.0 in Idaho) we adopted a co-dog. Now Cornelia isn’t the only official dog in the house.

Yeah, I know, pretty frivolous stuff. What do you want – this is mainly a test post. You guys ARE seeing this post, right? (Please comment and let me know). I’ve finally found and jumped through the hoops necessary to migrate the bigroom.org website over to the new host. It’s also running on the old server in House v1.0 on the DSL line as well, but this post isn’t getting put on it. If I’ve done everything correctly, hosting for bigroom.org should now be handled by Eskimo North. Just a few other minor tweaks and I’ll be set to return to House v1.0 and shut down the old server so I can move it down here to Texas.

I’ve gone from about 4400ft elevation down to about 250ft, but the plastic bottles of Mountain Dew® Wine seem to have positive pressure, so it would appear there is still some live yeast left in there and the priming sugar is slowly doing its job. I’m pretty sure the benzoic acid is what’s slowing down the activity so drastically, but it hasn’t killed it off yet.

I’ve also got a couple of entries in mind already for the next The Giants’ Shoulders blog carnival, and hopefully some more crazed brewing project news to offer sometime. And, of course, the promised post on why benzoic acid works. Stay tuned.