Tag: industrial microbiology

Amateur Soap Microbiology and my new Friend

I thought soap was supposed to be *clean*!

lumpy yellow microbial colonies growing on the soap inside of a hand-soap dispenser
People usually assume soap gets rid of funky microbes that might grow on things, so I was very amused several months ago when I spotted something growing on top of the soap in one of the household hand-soap dispensers. As of today, it looks as pictured at left. That lumpy yellow and brown mass atop the the soap looked to me like some sort of soap-sodden mold, and have been saving the dispenser specifically in the hopes that someday I’d have a microscope and could take a look at it. Meanwhile, the mass spread, and slowly started releasing some kind of yellow pigment into the soap.

Incidentally, I kind of doubt this indicates some sort of failure on the part of the manufacturer of the soap. I don’t recall for certain, but I think I may have opened the dispenser at one point to transfer some of the soap to another nearly-empty dispenser. When the mass started growing originally, it was a single spot, which suggests a single spore or speck of dust floating in and landing on the surface. Hey, it happens. Anyway, I’ve therefore blanked out the name of the manufacturer since I don’t think they really have anything to do with this.

VWR VistaVision Microscope
This mysterious growth upon my soap remained mysterious until today. Thanks to the Minister of Domestic Affairs and VWR (who managed to find me a really good deal), I finally got to actually get a close look at that lumpy mass. Meet my new friend Minnie (pictured at right). I could gaze into those eyes for hours. I couldn’t afford a darkfield condenser, and I sure as heck couldn’t afford to upgrade to phase-contrast gear, but I can add either one later if the opportunity presents itself. I also can’t afford the overpriced proprietary digital camera attachments either, though working around that is a whole other project. Until I identify an affordable model that plays well with Linux or work out how to modify a webcam into an ocular attachment,
I’ll have to settle for a trick…

It turns out if you take a digital camera and set it for close-up photos, you can actually stick the camera lens right up to the eyepiece and often get a serviceable picture.. Now, I had to subject the pictures I got today to moderately heavy processing to bring out the detail a bit better, but at least part of that is just me working on learning how to optimize the camera settings for this kind of use.

Equipped with some surplus slides and cover-slips donated by a kind professor who had some extra packages, I opened up the soap container and smeared a little of the yellow crud on a couple of them. One I just slapped a coverslip on for direct observation – the other I smeared over a slide and let dry with the intention of staining using the tiny, previously-unused vial of methylene blue left over from a very old plastic toy microscope. While the latter dried, I took a look at the wet mount hoping to finally see the mold mycelia that I had been expecting…

There wasn’t enough contrast to bother trying to get a photo, but it was obvious at 400x that what I was looking at was bacteria, not mold. Nerdly joy at learning something by looking in the microscope that I wouldn’t have otherwise known ensued, along with happiness as I realized this meant I had a perfect excuse to dig out my recent shipment from the Maker Shed – materials for doing a “Gram Stain”. Incidentally, the “Maker Shed” had the supplies on the way to me within hours of my ordering it, and they have lots and lots of cool stuff. I highly recommend it. Anyway, I got to do a “Gram Stain” for the first time in a couple of years (and the first time ever outside of a school lab). Want to see?

Mystery Microbe, I see you!

Gram-stained bacteria
Here it is – the nasty yellow goo that infected my bottle of hand-soap. My staining technique was a little off since I’m out of practice – the way I interpret the results is that what I’ve got here is neither a member of the Firmicutes (i.e. “Gram positive”) nor – probably – Actinobacteria. I really can’t guess at more than that, though. I think the few “Gram-positive”-looking cells there are artifacts of insufficient decolorization. I know I still had a surplus of the purple “Crystal Violet” stain still on the slide at the end. (How did I know? I’ll show you at the end…). The irregular bluish bits towards the bottom are, I believe, just bits of stuff from the soap itself.

Meanwhile, this pretty much satisfies my curiousity about the Mystery Soap-Infecting Microbe. There’s certainly a lot more I could investigate, but my developing Hillbilly Biotech lab is really intended to support my interest in intentional food microbiology and perhaps evenutally some small-scale non-food industrial microbiology. I have some remaining curiousity about the yellow pigment and whether or not it might be useful for something, but I’m doubting there is any food or beverage I might want to grow this stuff in and therefore don’t have much use for it. Still, I’ll keep the bottle around for a while before I throw it out in case I think of something fun to do with it. If I end up being really interested in the identity of the bug growing on it, I should be able to find a liquid that I can grow a big mess of it in, then run it through a simple DNA extraction process. Then all I need to do is find someone who can supply PCR primers, a thermocycler, and sequencing services cheap. It might sound like I’m being facetious, but I wouldn’t be surprised these days if I manage to find somewhere that’d do it for $20/sample or less. I may eventually do this will the Mystery Soap Bug anyway, since I hope to be running through this process with cultures of sourdough, yogurt, cheese, vinegar, and brewing microbes that I develop myself. For now, though, it’s just nice to be playing with microbiology equipment again. And now fully independently! Wheeeeeeee!!!!!!

Yes, I’m a nerd. And proud of it!

What’s next?

Now that I finally have a microscope, I no longer have any excuse for not getting to work on the rest of my Hillbilly Biotech lab. Just this weekend I was pricing out Hillbilly Autoclaves. I picked up a cheap air pump and air stone
for potentially building an aerobic bubble-column fermenter (for quick growth of yeast starters or a working model of a “Fring’s Acetator®”-style vinegar generator. I still want to build an ozone generator for sanitization and to get a pH meter. I’d like to also get my hands on some wheat, barley, and rye seeds to sanitize, sprout, and grow here as the first stage of developing a truly local sourdough culture, plus arrange to have several pounds of plain flour irradiated to sterilize it.

I’m also like summer to be over. Yes, I’m writing this in Winter, but it’s not until later in the summer to autumn that locally-grown fruits will start becoming available, and locally grown fruits ought to be an ideal source of local brewing and baking yeasts and bacteria. Finally, I’d like to find a wealthy patron (or matron, I’m no sexist…) who would sponsor me so I could just pursue food-microbe bioprospecting and research full-time…

Oh, yes, and I need to get around to finishing Episode 4 of my little podcast project, especially since episode 4’s topic is a fundamental microbiology technique.

Comments welcome below – thanks for reading!

Oh, and as a reward for getting all the way to the end, here’s a picture that I thought was pretty – crystals of “Crystal Violet” and iodine. I told you I had too much left on the slide…
Crystallized dye left on the slide

“Improvements in the Fermentation and Maturation of Beers”

Judging by my webserver’s logs, almost nobody actually bothers to click through the blog-carnival host’s site to read my Giant’s Shoulders” posts. This could be due to a secret conspiracy involving famous bloggers and several shadowy government agencies. I suppose, though, that there’s a chance that simply nobody but me is that interested in non-medical microbiology. Well…today’s post is an attempt to disprove that concept, for what aspect of non-medical microbiology could be more universally appealing than beer?

Unfortunately, in the middle of trying to assemble this posting, I see the February host has decided to put the carnival up a day early, undercutting my experiment. See, I told you it was a conspiracy! I suspect the Secret Cabal of Popular Bloggers was getting pressure from the Trilateral Comission, the NSA, and Pepsico® to silence me, so they had to do it. At least being forced to miss one, I am now free from the “I’ve been posting to these since the beginning, I can’t miss one now!” treadmill.

That means, loyal readers, that you get to see this post a month before everyone else! Hooray! Stick it to The Man™! Comically paranoid rantings aside, it also means I can split this up into more than one post, which may be more readable considering how much ground the article in question actually covers. Today’s Classic Scientific Paper is:

Nathan, L:”Improvements in the fermentation and maturation of beers.”; 1930; J. Inst. Brewing; 36; pp538-550

I ran across this reference recently while working my way through an industrial microbiology text[1] that I checked out of the campus library. According to the author of this text, “The use of cylindro-conical vessels in the brewing of lager was first proposed by Nathan (1930)[…]”, referring to the now-ubiquitous style of metal fermenter seen in small brewpubs and “MegaBladderwashCo” large-scale industrial breweries alike. Based on this I had expected the reference to be a digression on the design, construction, and testing of the fermenter. When inter-library loan managed to get me a copy of the paper, I found something much more involved.

The paper is a presentation made by Dr. Leopold Nathan in 1930 to the Scottish section of the Institute of Brewing. The topic was not simply a fermenter design but the entire “Nathan System” of brewing which appears to be the basis of modern large-scale brewing, especially for Lager-type beers. At this point, Dr. Nathan had apparently already been developing this system for about thirty years (apparently starting with a German patent in 1908, which I’ve yet to find a copy of), so as you might guess it was not just a single invention but a whole collection of them. Compared to the more rustic techniques frequently in use at the time, the “Nathan System” of brewing promised to provide faster production, more consistent results, and a better final product. It does this mainly by improving the removal of “trub” (the cloudy bits of protein and such that settle out of the malt-water – the “wort” – after you boil it), preventing infection of the beer with undesirable organisms during the cooling, hops-infusion, and aeration, and by eliminating the need to “age” the brew to make it palatable. The most important improvement in the “Nathan Process” seems to be how he treats the wort between boiling and “pitching”.

—
For anyone unfamiliar with the brewing process, here’s a Grossly Oversimplified review of the steps:

  • Boil some malt-sugar dissolved in water to sterilize it and to help coagulate the “trub” proteins so they’ll settle out of the liquid.
  • Cool the malt solution and aerate it so that the yeast will grow in it.
  • “Pitch” your yeast into the now-cooled-and-aerated malt-water, in a container that will keep air out while letting out the carbon dioxide bubbles that the yeast will give of during the fermentation
  • Wait until the yeast get done fermenting, then put the resulting liquid into bottles/kegs/casks/whatever.

—

Diagram showing the containment vessel, cooling system, and sterile-air generator for the 'Nathan method' of brewing
I’ve added a couple of labels to that image from the paper, which I’m guessing was itself copied from a contemporary patent of Dr. Nathan’s. There are two purposes to this part of the Nathan Process – To cool and aerate the wort quickly without exposing it to risk of contamination, and to move trub and volatile sulfur compounds that would otherwise make the brew taste and smell funny. The hot boiled wort is pumped directly into an insulated vat (labelled “A” in the diagram) from the boiling kettle. At this stage the wort is hot enough to prevent anything from landing in it and growing. Then, the hot wort is pumped from the top of this vat into a clean-room containing a cooling device that the wort is poured on, cooling and aerating it as it flows through. Infection is prevented here by the fact that the room has a continuous stream of “sterilized” (or at least well-filtered) air, which is exhausted through the vent in the ceiling. The cooled, aerated wort is then pumped back out of the room and into the bottom of the insulated container below the still-hot wort.

Because of the large open cooling room with its constant stream of clean air, the cooling and aeration step also allows the volatile sulfurous compounds of “jungbukett” (The “Bouquet of Youth”; the unpleasant smells and tastes of immature beer, described in this paper as ‘onion-like’) to evaporate off and be carried away. Since waiting for these compounds to break down was apparently a primary reason for having to “age” lager before selling it, this not only improves the quality but eliminates the need to store the beer for months after fermentation.

The now-chilled wort then rests back in vat “A” and the trub settles out onto horizontal plates inside the vat, where it stays behind when the clarified wort is pumped out to the fermenters.

I did some poking around, and this appears to be what is described in US Patent# 1,581,194 (application filed in August of 1921), in case you are bored and want to look that up. If not, or if you don’t want to deal with the frustrating hassle of trying to view TIFF files in your browser, I intend to provide a followup post with some more details of the process and some interesting bits I found in it, and I’ll include a pdf of the patents, assuming anyone wants them.

Oh, one last thing – I’ve had no luck getting any biographical information about Dr. Leopold Nathan. Unfortunately when you search for “Leopold Nathan”, the results are clogged with references to a murdering smartass named “Nathan Leopold” instead. Doesn’t Google™ realize that brewmeisters are far more important than obscure murderers? No pictures of him, either, so I can’t even say whether his hairstyle is cooler than Eduard Buchner’s or not.

[1] Stanbury PF, Whitaker A, Hall SJ:”Principles of Fermentation Technology (2nd edition)”; 1995; Elsevier Science, Ltd; Tarrytown NY

Ewwwwwwwwwwwwww……

They say “When life gives you lemons, make lemonade”. What if life gives you snot instead?

Someone's slime-covered handNow, see, this is what happens when I’m too poor to buy nice distracting new toys for myself. (No, not the hand in the picture – that’s not mine, it’s just there for illustration.)

I found a pot that I’d rinsed well but then left filled with water in the sink to soak, to help remove the last of the rice bits stuck to it. It hadn’t gotten stinky or fuzzy or anything, but it had gone…viscous. Like a light sewing-machine oil. Naturally, I took appropriate action to deal with it.

I fed it.

Glucose (“dextrose”), to be precise. It’s since been dumped into an old glass jar and the original pot thoroughly scrubbed with hot soapy water. At this point (a day later) the slime is closer to the viscosity of vegetable oil now. And I fed it again.

I wonder what it is? I mean, obviously it’s bacteria-snot, but what kind? I suppose if I had some iodine I could check to see if it’s a polysaccharide (evidently this test works on polysaccharides besides starch). If only I had a microscope, I could at least get some basic hints as to what’s producing the slime. Maybe I can maintain a culture and figure it out later, if I can ever afford a real microscope. Perhaps I could even attempt a strain-improvement program to increase the production rate…

Uh…I did mention I was a nerd, right? Okay then.

I wonder if anyone at work has a bacteriological microscope setup that I could use?…

Since I’m sure you’re all aching to know:

According to the nutrition information on the back of the bag and some quick calculations, powdered Xanthan Gum has a density of a little over 610mg/ml (or about 10 slugs/hogshead).

I think I may be an Applied Microbiology nerd.

See, when I put dirty dishes in the sink to wash later, I often fill them up with water to soak. I didn’t see this much in Idaho, but down here in Texas I notice that if I leave them too long, the water will sometimes end up turning into a thick slime.

And here I am, wondering what kind of slime it is and if I could find a way to produce it in quantity and purify it (and then find something useful to do with it).

I’m also wondering if this delightfully simple gel electrophoresis technique might be scaled up for more production-type purposes.

Obscure scientific papers, Mad Science, Travel, and other randomness

First – an amazingly astute observation that I’m ashamed to have not previously noticed myself (click image to go to it’s original site and see it full-size…):
Most 'Mad Scientists' are actually just 'mad engineers'...

I’m proud to say that I think testing Mad Hypotheses is great, and will continue to try to be a Mad Scientist. And a “Dirty Old Man” someday, but that’s a whole separate issue.

Second – I am really loving the perks of my new job – namely access to the college library system. I had previously mentioned (see last couple of paragraphs) a certain article that I wanted to get my hands on:

Greenberg LA:”The Definition of an Intoxicating Beverage”;Q J Stud Alcohol. 1955 Jun;16(2):316-25

Not only does the medical library have copies of a Czechoslovakian microbiology journal, the main library had a set of this old journal, too. I have my bedtime reading for tonight…

Thirdly – Another Giant’s Shoulders carnival has come and gone. I now believe that Eduard Buchner had hit upon not only a useful truth of living systems, but also a nifty alternative “mad scientist” hairstyle. Now I need to come up with one for next month. It’s been getting me thinking, though. That blog carnival is intended for “Classic” papers. Implied is that the papers are somehow important to the development of some scientific field or other. I’d like to see a variation on the “old papers” theme focussing on random old papers (where “old” might mean a few years or decades, depending on the subject) that people have found useful or interesting. Stuff that isn’t necessarily ground-breaking and has perhaps been forgotten or lost to obscurity but still has useful things to teach us. Naturally, I’m thinking especially Microbiology (and especially Microbiology other than Medicine) and Food Science. The Carnival could be called something like “Second Chance Science” or something of the sort. Just a thought.

Fourth – speaking of “Microbiology Other Than Medicine” and Food Science, apparently The National Academies of Science want to know what scientific topics people most want to read about. As usual, “microbiology” appears to have been relegated in their breakdown to merely a subset of either medicine/diseases, “biology”, and perhaps a small subset of “energy” and “Feeding the World” (no, seriously). The survey includes space to tell them what they’re missing – I heartily encourage anyone who cares to make sure you take the survey, and mention industrial and environmental microbiology and food science as subjects they shouldn’t continue to neglect.

And, finally – next week I need to make a very-long-overdue run back up to Idaho to grab some things from the old house and make sure it’s still standing, the water’s really turned off, nothing unnecessary is running, etc. 1600 miles of driving each way. Ugh. Anybody got any good recommendations for things to listen to on the trip? Other than having a chance to finally grab some things that I am missing, maybe I’ll at least have a chance to visit New Belgium Brewing Company again, since my route goes right past it. So long as I’m not driving by on Christmas day (when I assume they’ll be closed) I may have a chance.

“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…