Do I need to use freshly grown culture of isolates if I am to test their hemolysis activity on sheep blood agar plate? I am quite confused because references did not specify 🥲 Thank you!!!

I’m in a microbiology class currently and am trying to figure out what to sample for a group project. Part of the project is obtaining a sample from the environment and identifying what bacteria is present. We had a similar project recently but struggled to find research articles for our sample. So far my ideas include yakult, raw chicken, and tap water. If anyone has any ideas for things that can be sampled with decent research that would be very helpful!

Greetings!

I am a 3rd year microbiology student from the Philippines formulating an undergraduate thesis title. We focused on microbial ecology. Our initial title is "Screening Klebsiella sp. for its potential plant growth promotion properties on [Plant] under stress conditions"

Plants that are advised to us are slow-growing --- which could not match the provided duration for conducting the experiment.

So, just in case we cannot find a plant with soil problems, what are the possible test organisms should we used aside from plant?

Every suggestion is highly appreciated. Thank you!

Greetings!

I am a 3rd year microbiology student formulating an undergrad thesis title. Me and my groupmates are stuck at choosing the right variable or issue to address for the thesis concept, which is generally related to microbial ecology. 

So, we are looking for a crop production issue that has been prevalent in the country recently, aside from overproduction and el niño. 

As much as possible, the issue should relate to a problem in the soil (e.g., pH, salinity, contamination with heavy metals, or any stressor). At the same time, the crop involved shouldn't be slow-growing in order to match the provided duration for conducting the experiment.  Every suggestion is highly appreciated. Thank you!

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Hey everyone, I'm in my undergraduate program and could use some help. I'm struggling with streaking without scraping the agar, and it's hard for me to see my streak on opaque agars like BAP. Any tips for streaking well, especially for someone with tremors?

With the show the Last of us talking about fungi, check out this great episode about Cordyceps

Specifically Bacillus subtilis. I don't need a pure suspension, just any suspension with a good amount of viable spores that I could use later to grow more B. subtilis will suffice. I'm not a microbiologist and I don't have lab equipment except a bunch of Petri dishes and an inoculation loop. Also I could probably make a simple magnetic stirrer. And of course I have B. Subtilis spores in a powder form to start from (I bought them).

What I have learned so far:

• Sporulation of B.Subtulis responds to stress conditions and a lack of nutrition;
• Heating to 80°C will kill remained vegetative cells, but spores will survive.

But first of all I need a nutrient broth I suppose. Is it even possible to grow cells in a liquid medium? I mean B.Subtilis is aerobe. Although stirrer could possibly help with aeration (but increasing the risk of contamination?). I could prepare some kind of potato dextrose liquid medium. Will it work? But at what concentration? And how many ml?

Anyway, if someone thinks it is possible, I would appreciate any suggestions and/or instructions.

Fellow Microbiologists, In your opinion, how accurately can spectrophotometers measure optical density of a culture in dark coloured medias( such as MacConkey) and would you still use 600nM as the wavelength for the cells? I came across a few articles that suggest multiwavelength measurements but they didnt mention anything about intensely coloured broths. I would appreciate any opinion and/or references and curious to hear about what the community has to say. Thanks in advance! Edit: I guess reading the comments so far, I realised I should specify why I am asking, I work in a QC micro lab where we do presence absence tests so see if our media lot is okay to be used, and we had an incident where a dark coloured media(EEBM which is dark green had really low growth when inoculated). Thus the question, if the Spec would solve the problem, i.e., if we can measure low turbidity and not have to rely on eyesight.

Hi everyone, hope this is the right place to post this question but I work in a brewery and we are expanding our yeast program. From our research, we need a hemocytometer and looking through our storage we have a hemacytometer. Is there a difference?/what is the difference? And I apologize if this is a dumb question Lmao

Does anyone know of any books that talk about or just mention spores? Brock has about endospores, but I also need fungal spores and haven't found anything useful yet.

If I were running a membrane filtration for total coliforms (presence/absence) using single use filter funnels and m-ColiBlue, in what order would I check the sterility of items?

For the Petri dish, Would you simply pour proven sterile TSB in and out when it is clear after 24 hours of incubation, clear it sterile?

Would you repeat this process then with a pad and filter on top to show the filter is sterile next?

I think I’m most confused about proving the sterility of the single use membrane funnel. Would you do this using TSB, but without actual filtration - for instance, coating sides and bottom with TSB then incubating WITHOUT doing any filtration? Or would filter proven sterile water through the filter membrane, coating the sides, and then place this proven sterile filter in our proven sterile petri dish with our proven sterile TSB to prove the membrane was sterile?

I think once all of this is done, I understand you can run a sterile blank and incubate on the m-ColiBlue for it’s proven sterility. And then I would also run a QC using E Coli and two other known organisms.

Would the order then be: -Petri dish and pad -Filter -membrane funnel -m-ColiBlue?

I would have already proven TSB and water sterility prior as we do batch checks on those already and I use them for our QC of our primary method Colilert P/A.

hello, has anyone here working as Food Quality Assurance in a meat products? what you guys doing?

and for others, what is/was your work in a field of microbio and what do you do in your work?

Hi y’all. I’m considering getting a PhD because right now I am a research tech and I would like to do more than just be a technician. I really enjoy being in the lab and running my own project and so I am planning on applying to grad school. I would love some insight on why people did a phd and if it paid off for them. Also does it really help in industry or will I probably end up staying in academia if I get a Phd?

Hi! I’m looking for help in preparing bacteriophage stock for my undergraduate thesis. I can’t wrap my head around the method, so I was hoping to see some advice and answers here. Any recommendations for protocols and such are highly welcomed!

I am trying to plan a phenotypic assay stress experiment to study the phenotype of mutant line ( my t-DNA) and compare it with negative and positive control ( WT and atg5) ,; I am working with arabidposis.

If I want to study the impact of salt and sucrose or carbon starvation stress in the mutant line, could someone please help me start and build a plan?

what should I do and for how long and how many days and when to collect the data?

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thanks

Can anyone suggest a good resource for Biosafety and Research Ethics?

I know that c. botulinum and c.tetani are super rare now particularly in wealthier nations but I’m having a hard time deciding which is more of a risk overall to public health between c.diff & c.perf.

I’ve got an assignment about clostridia with regards to food safety & im trying to decide which is the most notable species to discuss in one of the sections. I’ve researched some recent outbreaks and although there’s very few of either outside of hospital settings I’m just unsure.

Any tips from those with experience with these pathogens would be appreciated.

Apologies for formatting and grammar I’m rapidly typing this on my lunch break.

Hi everyone, I am a teacher in Canada who is looking to do experiments with my students. I am hoping to culture petri dishes with different types of bacteria to learn more about our environment.

The real goal is to generate a curiosity behind science.

Nutrient agar online is tremendously expensive and this is all coming out of my own pocket. I wanted to know if anyone could recommend where I could buy Nutrient Agar in a larger quantity. Alternatively, can anyone recommend a recipe for home made nutrient agar (and where to buy those ingredients)?

Thank you all so much, although I know nothing about science, I know my students would have a great time and most certainly pursue more knowledge.

I want to start with saying I'm not a biologist of any kind.

Because of the situation i have detailed below, I would like to know how long should an aquarium be isolated to ensure all fish infecting pathogens have died off. There are no fish in the aquarium, only plants and sand.

I have an aquarium that I had introduced some wild caught fish into. Over the course of about 4 weeks every fish died, usually about one death per day. They would present as asymptomatic until the final 24ish hours where they became lethargic, with no external symptoms, shortly before dying.

I had treated for bacterial infections via amoxicillin laced food. Also treated external parasites and fungal infections with malachite green.

I ruled out acute toxicity via constant water parameter monitoring. I also ruled out chronic toxicity due to their asymptomatic nature prior to death and the extended time frame they died across. Lastly I didn't bother treating for internal parasites after considering the short time untill death of the unknown disease.

After all of this, I have made an assumption that it was an unknown viral infection of some kind considering no fish were able to survive even with treatment. If any of yall have any thoughts on what it probably was, or if I was wrong on my assumptions please let me know.

What do you guys do with the mashed potatoes remaining after preparing potato infusion for PDA?