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== | =Spot the antibiotics producer: STREPTOMYCES= | ||
[[File:Micro.png|800px]] | |||
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''Antibiotics''. | |||
The human gets ill, goes downhill, forgets the dollar bill, ''takes a pill'', regains will, re-feels the thrill. | |||
It’s simply the recuperation cycle. | |||
But, do you ever think about the fundamentals of having the chance of recuperation from infections? | |||
'' | Sure. | ||
It’s thanks to the pill - the antibiotic. | |||
Good job! | |||
Now, zoom in deeper… | |||
Do you actually know where this savior comes from? | |||
Think no further than ''the soil''. | |||
''Streptomyces''. | |||
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===ISOLATION OF STREPTOMYCES=== | |||
====1st step: Air dry the soil samples for 3-4 h at 45° for the selection of Actinomyces spores, considering that many other bacteria die during this pre-treatment==== | |||
<gallery> | |||
File:Soil1.png | |||
File:Soil.png | |||
</gallery> | |||
====2nd step:Dilute 1-3g of soil in 10 ml saline solution (NaCl 0,9%) and let the solution stand for 15 min==== | |||
<gallery> | |||
File:NACL.png | |||
File:Solution .png | |||
</gallery> | |||
====3rd step: Prepare 3 dilutions (1:10, 1:100, 1:1000) out of it==== | |||
<gallery> | |||
File:Diluting.png | |||
File:Dilutions&Solution.png | |||
</gallery> | |||
====4th step: Prepare the Mannitol Soy Agar (MSA) petri dishes==== | |||
<gallery> | |||
File:Mannitol.png | |||
File:Plates.png | |||
</gallery> | |||
''MSA RECIPE:'' | |||
In a 250 mL conical flask mix: | In a 250 mL conical flask mix: | ||
* 2g Agar | *2g Agar | ||
* 2g Mannitol | *2g Mannitol | ||
* 2g Soya flour (Holland and Barrett) | *2g Soya flour (Holland and Barrett) | ||
* 10 mM CaCl2 | *10 mM CaCl2 | ||
* 100 mL Deionised water | *100 mL Deionised water | ||
<tt> | |||
Medium alternative: Inorganic Salt Starch Agar (ISSA) | |||
</tt> | |||
====5th step: Plate an aliquot of 0.1ml of each dilution on the medium (MSA)==== | |||
<gallery> | |||
File:Put.png | |||
File:Spread.png | |||
</gallery> | |||
<tt> | |||
The loop used for spreading the solution on the medium (shown on the 2nd photo) is a DIY loop, created from paper clips | |||
</tt> | |||
====6th step: Incubate at 30° for 5-7 days==== | |||
'''Important:''' Use parafilm to fortify the covers of each petri dish, in order to avoid evaporation, as it can lead to contamination. | |||
[[File:Incubation.png|800px]] | |||
Optional: Supplementation with cyclohexamide (50 μg/ml) and nystatin (50 μg/ml) to further remove competing bacteria | Optional: Supplementation with cyclohexamide (50 μg/ml) and nystatin (50 μg/ml) to further remove competing bacteria | ||
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==3-DAY OUTCOMES== | |||
<gallery> | |||
File:After3days.png | |||
File:After3dayss.png | |||
</gallery> | |||
'''Observations:''' | |||
The no-dilution petri dish shows a tendency towards contamination. Other petri dishes seem on the right track by far. The small white powdery looks like a good sign. | |||
==6-DAY OUTCOMES== | |||
<gallery> | |||
File:Sample1.png|1:10 | |||
File:Sample2.png|1:100 | |||
File:Sample3.png|1:1000 | |||
File:Sample4.png|1:1000 (2) | |||
</gallery> | |||
'''Observations:''' | |||
There has been overgrowing a hybrid of organisms, but assumingly the pinky/white powdery dots are streptomyces colonies.Such colonies are mostly to be found on the 1:100 and 1:1000 dilution plates. In this case, creating subcultures is the best solution, in order to get a unified-type of biotope in the petri dish! | |||
Only one sample has been contaminated, as it was the first one to get done during the isolation process. | |||
==== | ==FINAL DAY MICROSCOPICAL VIEWS== | ||
[[File:Micro2.png|800px]] | |||
==Insight== | |||
'''Streptomyces''' species are the most abundant source of antibiotics. More specifically, they produce the two-thirds of all existent antibiotics. Except that, this genus produces a rife scope of bioactive compounds. It usually inhabits the soil and plays a significant role in decomposing. | |||
So, next time when you get ill, decide to take another pill, in order to re-feel the thrill... | |||
'' | '''...take a minute to think and ''praise the genus of good welfare.''''' | ||
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'''Inspiration''': | |||
http://annadumitriu.tumblr.com/ - Anna Dumitriu | |||
https://exploringtheinvisible.com/ - Dr. Simon Park |
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