FUNGI VS BACTERIA

Who’s better? Fungi or Bacteria?

Well, what is a fungus? A fungus (aka mould) is a microbe and is found in many places. Some places could be spoilt food, damp areas and many more. A fungus has a very unique appearance. Most fungi look a bit fuzzy. Fungi come in many different colours and some fungi are even toxic. Anyway, enough about fungi, more about bacteria… Bacteria (aka germs) are microscopic and an individual cell can’t be seen by the naked eye. But bacteria like to grow together to make a colony which can be seen by the naked eye. The appearance of bacteria is different from fungi. Unlike fungi bacteria have more of a glossy look when growing on agar. The main bacteria we were interested in for this work was actinomycetes, which like fungi can produce antimicrobials. Actinomycetes almost try to role play as fungi for actinomycetes look a little bit fuzzy. Well, who would you choose as the best antimicrobial producers? The great fungi, the amazing bacteria or the “in-between” fantastic actinomycetes?

What we did

At the start of this term we set out to trap some actinomycetes from a number of different types of soils.

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This term we used lots of different techniques such as patch plating, lawn plating and the dilution series, and had to master these.

What is patch plating?

Patch plating is when you draw up a grid on the bottom of your plate then number it and put the selected microbes you want to have in your grid (Figure 3).

To do a patch plate you need a marker, agar plate, toothpicks and a discard container.

 

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What is lawn plating?

Lawn plating is when you get a swab and spread a microbe of choice (Figure 4). In our case it was different Tester bacteria.

To do a lawn plate you need a sterile cotton swab, an agar plate and a microbe of your choice.

FIGURE 5: WE COMBINED LAWN PLATING AND PATCH PLATES TO CHECK FOR ZONES OF INHIBITION TO SEE IF ANY OF OUR SOIL ISOLATES PRODUCED ANTIMICROBIALS.

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What is a serial dilution?

The dilution series is when you get a substance, like soil, and put it in tubes and then put water in and then dilute it by making the soil less concentrated (Figure 6). We use this method because it can make sure that there are not too many microbes on each plate. From each dilution tube we took a sample out and put it on a spread plate.

You need a pipettor, tubes and diluent.

What we found

In the beginning of this short journey we wanted to see the difference between wet, dry, shady and sunny dirt and the impact of that on actinomyces. Once we started our traps, we realised that it did!  Some of our traps didn’t work too well because the dirt was too dry or too wet. In our first trap our agar dried up when we had dry soils and this caused the trap not to work well.

But we also discovered that having wet dirt did not produce as many actinomycetes. The shadiness or sunniness of the dirt did not really matter, but the wet or dryness of the dirt impacted the way the trap worked and the actinomycetes we were able to isolate.

In the end we isolated 10 different actinomycetes from three soil samples. The soils collected by Josh, Jemma and Dieter had the best results, but we all shared and saw some of these actinomycetes causing inhibition by producing antimicrobials against some other bacteria.

So, in conclusion, from this term, we now know what texture and place to collect from and learning new ways of creating traps and the best way to isolate actinomycetes. However, one thing stood out for all of us, was, how much fun it was to do this amazing and fun experience and educational short journey.

All content produced by The Budding Scientists collaborative of Aoife, Dieter, Eshwari, Jemma, Josh, Kieran, Lachlan, Natalia, Natasia, Pranav, Tom, Tori and Varun.