I took the opportunity today to try out my new Bresser Mikrocam 9.0 camera on the Zeiss IM microscope. Last Saturday I exposed a Petri dish of Nutrient Agar to the air outside for 4 hours and this has grown a diverse culture of bacteria and fungi.
Both cameras performed well – the Mikrocam though allowed me to zoom in for a higher magnification shot. I used GIMP2 software to sharpen the image and bring out the colours a little to compensate for limitations in illumination.
All pictures taken using Phase 1 annulus on the microscope.
No stains – live culture.
Both Rhys and Hannah had friends around to the house – so they found themselves with an unexpected biology lesson half way through their half term holidays!
Air-exposure-@-4-days-261017-x4-x32-objectives-Ph1-VIII-bacteria-x32-Mikrocam-9-0v4.bmp (below) – I used GIMP2 on following to bring out the detail in the image (brightness, contrast, sharpen, despeckle):
Air-exposure-@-4-days-261017-x4-x32-objectives-Ph1-VIII-bacteria-x32-Mikrocam-9-0v4-small-area-interest.bmp (this is a small area of above image to allow magnification on this website, making use of the 9MB resolution of the camera – individual bacterial cells can now be seen):
In the following image I have taken the area of interest above and changed it to greyscale then used curves to stretch the data – my first attempt at this so please let me know what you think?
Video of protozoa found in culture from air exposed Petri dish – exposed for 4 hours – this sample from 4 days later (AVI):
Hannah and I looked at some flour which had altered in appearance – it looked more clumpy. It had been around for some time. We wondered if it was still edible.
To compare, we looked initially at “good” (i.e. relatively new) white and wholemeal flour, and then compared images of the altered clumpy flour under the microscope.
Zeiss IM microscope, Bresser MikrOkular camera.
Andy and Hannah
White flour x4 objective 310817 – the following images show that good white flour is white/black/grey in colour with small amount of residual brown (residual wholemeal we assume not removed during cleaning process implemented to make flour white):
White flour x20 objective 310817:
Wholemeal flour x4 objective 310817 – the following photos show that wholemeal flour is very similar to white flour, except there is a lot more brown colour (wholemeal) in it – in both white and wholemeal flour circular carbohydrate areas are present in abundance and there is some clumpiness:
Wholemeal flour x20 objective 310817:
Altered white flour x20 objective. In the following photos, it becomes clear why the flour is altered in texture. Under a microscope the flour stands out from good white and wholemeal flour by having large amoutn green colouration in it (which immediately made us think that it was contaminated with fungal growth as this looked similar to our previous images of the green mold on bread). In addition, the clumps are significantly larger, as are the oval carbohydrate inclusions. The green fuzz appears to be located around the edge of the inclusions, suggesting fungal growth around the food source. We have been able to identify mycelia (fungal elements) confirming the diagnosis. We suspect that this is a form of penicillin – in any case no bacteria were seen, suggesting that the fungi are producing anti-bacterial substances which are killing off the bacteria. So, is the bread fit to eat? It could well be entirely fit to eat given its anti-bacterial properties but it does have fungal growth and we therefore recommended it was thrown away to be safe.
I popped into the kitchen one hour ago to make my lunch and found the following……
Some people would go “urrrhhhh……” – but for me I thought what a great opportunity to look at this under the microscope!
Observations of non-affected part of cheese as comparison with affected part
I was shocked when I looked at a part of the cheese that appeared not to be affected by mould – in fact the section of cheese used for this came from INSIDE the cheese! I knew that cheese was effectively rotten milk but when I looked I saw active diplococci bacteria and another ciliated round organism which I could not identify. I did not realise the cheese was just so alive! These bacteria became visible at 32x objective (with standard 10x ocular this would equal 320x – however I was using the Bresser camera instead of the an ocular).
All photos and videos below taken with Bresser MikrOkular HD camera.
Video of microscopy of “normal” cheese from the sample showing bacteria that look like small dumbbells moving around (below) – I think these are lactobacilli as on this link – http://blog.microscopeworld.com/2014/11/lactobacillus-under-microscope.html
Video of apparently normal cheddar cheese sample 32x Zeiss long distance objective – initially video is in bright field then changes after a while to phase contrast using Phase 1 annulus that this objective was designed to be used with (below). There is an air bubble in top right of video and the background is out of focus material in different image plane. Bacteria are visible moving in the video. It is worth blowing this up to full screen to view the bacteria.
Two images below are phase contrast images using 32x Zeiss LD objective and phase 1 annulus that it was designed to be used with. Note the rainbow-coloured segment of a circle in upper right each image is an air bubble:
Microscopy of fungal sample from cheese
I scraped off a sample from the edge of the same cheese as above which as infected with green fungi – photos below show that this did not show bacteria. Instead, there were masses of fungal spores – and virtually nothing else. I think this might mean that the fungi were penicillin types – producing the antibiotic penicillin and killing off any bacteria in its vicinity. Even 1cm into the cheese, the “normal” cheese still had some green in it and those areas had no bacteria but the areas without green tinge were where the bacteria were found. Shows how far the fungi stretches into the cheese – yipes! However if it is penicillin then it is probably the safest bit of the cheese to eat…….