One Fish, Two Fish, Orange Fish and a slightly off-white one with dark coloring that resembles a moustache.

My fish came in this week. I've got 3 Gold Fish to work with - two have names. Most of the related research I've seen involves much larger fish like catfish. They've got a relatively large tank to live in, but no privacy. I put a tray in front of the tank to at least give them privacy from the human activity going on in the lab for now. This should extend their life and comfort. I also have a small bowl I'm going to be using to transfer then to while I attempt to collect their fecal matter. I'm hoping the excitement of moving into a new environment will encourage to cooperate and make my collection easier. I've seen some overly complex methods of collection in my research. I'll begin with simply using a net or screen hanging down to catch it. I'm also wondering if I could feed them something that would make the consistency of their fecal matter more conducive to collection.

It's interesting to note that some Lactobacillus species naturally produce bacteriocins that are harmful to bacteria like MRSA.

Growing lactobacilli in fish with varying diet.

I'm still focusing in on a specific research question, however, I have come up with a general idea. I'll be using at least two fish (probably goldfish) in the same tank. I'll either use some sort of dividing structure to keep them separated but keep the environments basically the same (water flow between). I won't have to do this if I can obtain fish which are uniquely identifiable; we'll see. I'll have two food sources, both of which will be inoculated with lactobacilli (need to choose species - there's quite a few). One food source will be mixed/enriched with a nutrient like fructooligosaccharide. Basically something that should encourage lactobacilli growth. One fish will get the food with the nutrient/bacteria and the other will get food with no nutrient and the same amount of bacteria.

Why would anyone do this? Just like as in the human gut, fish have a wide variety of bacteria. Some are beneficial, some not. The idea is to encourage dominance of beneficial bacteria in the fish so that when consumed by humans, the risk of food-borne illness is reduced. There's still going to be bacteria on the outside of the fish, but I believe (have to research more) the gut bacteria in the fish pose a larger problem. I'll be testing to see whether the nutrient enriched food yields more growth.

I inoculated a TSA plate with store bought yogurt containing probiotics and after two days this grew:

 I didn't see any other colonies other than this one. Gram Positive, catalase-negative rods. No glucose fermentation or motility results yet. But, most likely Lactobacillus casei.

On related note, supposedly goldfish aren't picky eaters. I might see if they will eat Labneh. I do, and I seem to stay healthy!

Fish and a polluted environment.

At the moment, I'm collecting and isolating different bacteria off of crickets. I've only got as far as gram staining them but, the stains look pretty interesting under the microscope. The most interesting so far are gram negative cocci which form colonies that look like flowers under the dissecting stereo-microscope (good for colony morphology). Their structure is really interesting (to me anyway) when stained and observed at 100x; they are bunched together to form pentagons (roughly) with space in the middle and the cells forming the boundaries. Maybe this is common, but I've never seen it; it seems very ordered and symmetric. I made a permanent slide of it today with cytoseal which should be ready to view tomorrow via oil immersion and maybe the video scope. I'll be sure to post some photos. FYI, if you're trying to collect bacterial samples my best results were with Peptone using 100-300 microL dilutions worked well to gather bacteria from the crickets. The direct swabs yield a useless mass of growth where it was too difficult to isolate anything.

I was speaking with one of our instructors today about the focus of my research this semester and he suggested perhaps working with either fish and a polluted (with one specific pollutant) environment vs unpolluted. If we can't get fish in the lab, I'll try crickets with polluted water sources or maybe even plants. One possible pollutant could be 4-Methylcyclohexanemethanol - which was in the news recently from West Virginia as a side effect of coal processing. It's not entirely understood how this affects humans. I'll do some reading how it might affect anything else. A fun side note - we just learned how to name organic compounds like this in o-chem, which isn't as bad as it looks. I could also continue working from 182 with eutrophication. Maybe I could test how it affects bacterial growth in organisms with in the waters. 

I also identified my unknown bacteria today: Micrococcus luteus. I did an extra motility test because although it wasn't needed, I read they are highly motile and wanted to see this. Also, I'm going to try to extract dna from the sample and see if it matches. Below are photos of my sample of Micrococcus luteus. on isolation TSA, lawn TSA, MSA (negative for manitol fermentation) plate, and a pre-iodine starch plate (was negative).

Lactose Intolerant crickets aided by probiotics?

I was thinking of various ideas relating to crickets and their microbiomes. Specifically, in their digestive tract. Many people are lactose intolerant, so I'm assuming crickets haven't evolved an efficient way to break down dairy products. But what if they ingested bacteria that could? Could the bacteria survive within the cricket? Would the crickets that were fed diary and had the beneficial bacteria thrive more than those without the bacteria that ate dairy? Also, how would the crickets that never dairy at all do compared with the ones that did? I'm not sure if this is a practical experiment yet, but we'll see.

I also noticed in reading some anecdotal reports that bearded dragons could be fed yogurt and not have any ill-effects. I wonder if any creature that doesn’t normally have enzymes to digest lactose and related proteins could acquire certain bacteria that could and live relatively well. Lifespan and activity level might be good variables that would be affected by their diary diet.

At the moment, I’m simply trying to find a good way to collect bacteria samples from a very small cricket without creating a huge mess. I’ve literally streaked the plate with a cricket, embedded a cricket into agar, and finally used peptone to separate the cricket into a solution that was distributed onto a TSA plate.