Bensmom Posted February 24, 2014 Share Posted February 24, 2014 Can you please help identify our bacteria? We collected bacteria and have our samples growing in agar in Petri dishes, but I am having trouble identifying them. I have looked online, but have not found a simple kid-friendly picture identification site. Here is what we are growing: 1. Pink/red smooth-edge circles 2. Dark yellow elongated, slight raised (some circular and some are long, thin, worm-like shape) 3. Smooth-edge, white circles, small 4. Fuzzy, white, snowflake looking, round with ruffled edges (like fuzz on food left in the fridge) 5. Irregular shaped, cream/tan, raised, wrinkly, crusty 6. Fuzzy, mold-looking, round, dark gray/black centers with white outer circle. Are numbers 4 & 6 bacteria or mold? Just as a side note ds collected 12 samples from around town. Walmart checkout buttons have grown the most. The only two sample locations with the red/pink bacteria are from the playground equipment at the park and the library entrance buttons. I am really curious. (And a little afraid to know...) Anything you can help identify would be appreciated. Quote Link to comment Share on other sites More sharing options...
madteaparty Posted February 24, 2014 Share Posted February 24, 2014 No idea, but 1. Bump, 2. Could you tell me what lesson plan/process you followed on this project? I am so not hands on with science and really want to be! Many thanks! Quote Link to comment Share on other sites More sharing options...
alef Posted February 24, 2014 Share Posted February 24, 2014 Fuzzy sounds like mold, I don't know about the others. Quote Link to comment Share on other sites More sharing options...
Bensmom Posted February 24, 2014 Author Share Posted February 24, 2014 I continued to search online and found a nice kid-friendly page at science buddies. We ordered the sterile swabs, Petri dishes, and nutrient agar from Home Science Tools. They have awesome kits and supplies. The bacteria kit offers several possible experiments and directions. We went on a bacteria scavenger hunt around our town. Ds swabbed surfaces such as the indoor McDonalds playground, Walmart shopping cart handle, Walmart checkout buttons (the grossest of samples. I am never touching them with my hands again!), park playground equipment, local museum bathroom, library computer keyboard, library entrance buttons, our tv remote, and just for fun, our dog's mouth. We will use the same supplies to test the bacteria fighting effectiveness of different soaps ans cleaners. We are also considering doing a dog vs. human bacteria test by having out pet-owning friends swab their dog's mouth and swabbing their own mouth and seeing if the human mouth really is dirtier. Lots of fun :) Quote Link to comment Share on other sites More sharing options...
Mom22ns Posted February 24, 2014 Share Posted February 24, 2014 You really can't identify bacteria by a description of their colony. You really have to look at the individual bacteria under a microscope and run a variety of tests on them. However, you really shouldn't do that. From your question, I am going to assume you have not had a microbiology class or anything where you were taught to deal safely with bacteria. You may have colonies there that are potentially lethal, especially for your children. Please keep them tightly closed and dispose of them soon. Re-reading that it sounds a bit condescending, and I don't mean to. I just want you to be careful. Touching a few of those nasties while checking out at Wal-Mart is bad enough. Letting them colonize in your home is truly potentially dangerous and I want you to be safe. Quote Link to comment Share on other sites More sharing options...
Dicentra Posted February 25, 2014 Share Posted February 25, 2014 You really can't identify bacteria by a description of their colony. You really have to look at the individual bacteria under a microscope and run a variety of tests on them. However, you really shouldn't do that. From your question, I am going to assume you have not had a microbiology class or anything where you were taught to deal safely with bacteria. You may have colonies there that are potentially lethal, especially for your children. Please keep them tightly closed and dispose of them soon. Re-reading that it sounds a bit condescending, and I don't mean to. I just want you to be careful. Touching a few of those nasties while checking out at Wal-Mart is bad enough. Letting them colonize in your home is truly potentially dangerous and I want you to be safe. I just wanted to second what Momto2Ns has said - please, please, please be careful! I know that growing your own bacterial colonies can sound like a wonderful way to approach biology from a hands-on perspective but you can end up culturing some virulent stuff. Look at it this way - if the tiny bit of contact you have from touching a door handle in a store that someone else has just sneezed on has enough bacteria on it to make you sick, then culturing a petri dish full of them at home and exposing you and your children to the colonies could make all of you very, very sick. Even when we cultured bacteria at the high school where I taught, the students swabbed surfaces, innoculated the agar, closed the petri dishes, and sealed them shut with tape. They were only allowed to look at the colonies through the sealed plastic lids of the dishes which were then autoclaved before they were thrown away. The high school has actually stopped doing this lab because of safety issues. If I might please make a suggestion? Take your petri dishes, seal them shut right now with tape, and take them to your local hospital or medical facility at your earliest convenience. Before they autoclave them for you (I'm hoping they will), the lab techs could probably help you with identification. If you don't want to do that, please at least seal them shut. For disposal, you could either put them outside for a few days if you live somewhere really, really cold before you throw them away or you could put the open dishes in a bucket of strong bleach solution which would kill the bacteria and destroy any mold spores that you've grown. Like Momto2Ns, I don't mean to sound harsh - I just worry about safety. :) Quote Link to comment Share on other sites More sharing options...
Kevin'sMom Posted February 25, 2014 Share Posted February 25, 2014 http://microbiologyinpictures.com/ This might help...you've already grown them, so it would be nice to identify them. BTW, you may have saved us all from something: I will NEVER touch the buttons at WalMart again without sanitizing my hands afterward, seriously. Yuck!!!!! Quote Link to comment Share on other sites More sharing options...
stripe Posted February 25, 2014 Share Posted February 25, 2014 I have always wondered about doing this after reading warnings about not breathing the samples. I saw a lab like this and have been avoiding doing it for fear of contaminating my house! Thanks for the warning. I think we have enough moldy food unintentionally growing in our home to avoid adding to the situation. Quote Link to comment Share on other sites More sharing options...
Bensmom Posted February 25, 2014 Author Share Posted February 25, 2014 Thanks for your safety concerns. They have had lids on since the samples were swabbed. (Ds wore disposible gloves when handling samples). I haven't let my son handle them since the samples were collected. They are on a high shelf where they wont be accidentally bumped. I pick them up and let him look at the bacteria through the clear lid. I did however wait three days to seal them with tape as I read that they need oxygen to grow. (Bacteria was visible at the end of the third day). If we conduct another bacteria test, should I seal them immediately or is some amount of oxygen required? I am not sure that the samples received much oxygen as is, but the lids do not screw on, they just sit on top. Would it be better to put any future samples (with lids) in clear ziplock bags? The info. from Home Science Tools didn't mention this. I am probably scaring you ladies, but I really would like to conduct the next experiment where you test the bacteria fighting effectiveness of different products. Anything I need to consider first to improve our safety? Quote Link to comment Share on other sites More sharing options...
Dicentra Posted February 25, 2014 Share Posted February 25, 2014 Thanks for your safety concerns. They have had lids on since the samples were swabbed. (Ds wore disposible gloves when handling samples). I haven't let my son handle them since the samples were collected. They are on a high shelf where they wont be accidentally bumped. I pick them up and let him look at the bacteria through the clear lid. I did however wait three days to seal them with tape as I read that they need oxygen to grow. (Bacteria was visible at the end of the third day). If we conduct another bacteria test, should I seal them immediately or is some amount of oxygen required? I am not sure that the samples received much oxygen as is, but the lids do not screw on, they just sit on top. Would it be better to put any future samples (with lids) in clear ziplock bags? The info. from Home Science Tools didn't mention this. I am probably scaring you ladies, but I really would like to conduct the next experiment where you test the bacteria fighting effectiveness of different products. Anything I need to consider first to improve our safety? So glad to hear from you, Bensmom! I was thinking about my post afterwards - science is my passion and my intent wasn't to scare everyone into never trying any hands-on stuff but I do want everyone to be safe when they do the hands-on stuff. :) I would think there would be enough oxygen in the air space above the agar that sealing them with tape right after swabbing would be fine. As a safer alternative for everyone, though, I would suggest purchasing cultures from Home Science Tools to inoculate and grow your own bacterial colonies. Here's a link: http://www.hometrainingtools.com/introductory-bacteria-set/p/LD-BACINTR/ They also sell individual cultures so you don't have to buy the set of three. If you want to do the anti-bacterial lab, Bensmom, you should purchase one of the cultures from Home Science Tools or another science supply store. There are two reasons - first, it's much, much safer to work with those cultures (none of the bacteria they sell are pathogens) and second, in order to get accurate results you have to have only one variable in your experiment. If what you will be changing are the different anti-bacterial substances, then all other conditions must be controlled. If you used bacterial swabs from your environment, you wouldn't always be testing the anti-bacterial substances against the same species of bacteria so you won't know what factor the effectiveness of the anti-bacterial substances is due to. Using bacterial cultures from your environment would mean that you have two variables that aren't controlled so you can't tell if your results are due to changes in the anti-bacterial substances or changes in the bacterial species themselves. Does that all make sense? :) Forgive me if you know all of this already - I get into "science teacher" mode and I'm like a runaway train. ;) Home Science Tools also has antibiotic discs you can use to test for antibiotic sensitivity in bacteria. Here's a link: http://www.hometrainingtools.com/antibiotic-disc-set/p/LM-ANTIKIT/ I always thought it would be a cool science fair project to culture a bunch of pure, safe bacteria (from a bought culture) and then have the student test the anti-bacterial properties of the antibiotic discs as well as different over-the-counter substances that are said to be anti-bacterial (anti-bacterial soaps, tea tree oil, other essential oils, etc.). If you choose to do this, Bensmom, let us know how it turns out - I think it would be awesome! What's your disposal plan for the cultures that you've grown, Bensmom? Even using the safer, bought cultures, one should always have a disposal plan to make sure the cultures are destroyed before putting them in the trash. It's good lab procedure. :) Quote Link to comment Share on other sites More sharing options...
Mom22ns Posted February 25, 2014 Share Posted February 25, 2014 I am probably scaring you ladies, but I really would like to conduct the next experiment where you test the bacteria fighting effectiveness of different products. Anything I need to consider first to improve our safety? Not a microbiology teacher, but I did take it in college and did these labs (enjoyed them too). We've swabbed and grown bacteria, I'm really not against the idea. If you want to test killing agents, lift the lids only slightly, just enough to get whatever you are putting in, into the petri dish. Keep your face away so you don't breathe in the little beasties. Wash hands when you are finished. If you don't get the beasties out to play, they aren't likely to do too much to you from inside the petri dish. Identifying them requires getting them out to play, that is where you increase your exposure and risk exponentially. When I finished with mine, I just tossed them in the trash and took the bag to the dumpster. Maybe I should apologize to my trash man, but there it is. Quote Link to comment Share on other sites More sharing options...
Bensmom Posted March 1, 2014 Author Share Posted March 1, 2014 Somewhat OT, but how did you prepare your petri dishes? I tried to grow bacteria and nothing grew. So I really would like to try again. Did you buy them already made? As a previous poster mentioned, I bought the agar, melted it and poured it in the dishes. The instructions said it will set in 1 hour. I prepared the dishes and then we went on our scavenger hunt. When we returned nearly 2 hours later, they were ready for our samples. Not sure why your experiment didn't work. Maybe one of the science moms here can offer some explanation. Quote Link to comment Share on other sites More sharing options...
Bree Posted March 2, 2014 Share Posted March 2, 2014 For what it's worth my micro final was to find the unknown bacteria through a process of elimination by performing a bunch of tests...half of us never figured out what we had, but there is some type of flow chart you can use to determine what you have, usually first by determining if it is a rod or cocci... I'm not sure where to find the right chart and all, but I hope you can figure it out :) Quote Link to comment Share on other sites More sharing options...
Mom22ns Posted March 2, 2014 Share Posted March 2, 2014 Our Micro lab final was being given a mixture of two unknowns which had to be cultured, separated and identified. One cultured up neatly, but I thought the other one was going to make me fail the class. I had to start over twice, trying to get it isolated because all my results kept coming back as not one of the list of possibilities. It was so stressful! I loved and hated microbiology. Quote Link to comment Share on other sites More sharing options...
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