Antimicrobials

teal · 03-26-08, 23:27

For last semester bio lab we did an experiment where we took a liquid culture of non-pathogenic E. coli and spread it around on agar. Then we took sterile paper disks and dipped them in various solutions and placed them on the agar and let it incubate. The purpose was to see the effectiveness of various antimicrobials. We even tried different spices (the lab was really about the effectiveness of spices, but they tried various commercial products too). Well anyways, here's the result of the lab.

The first number is the size of the zone of inhibition, which is the circle around the disk where bacteria was not found growing. The next number is the number of bacterial colonies (bacteria grows is clumps) that are found within the zone of inhibition. So a big zone of inhibition and little or no colonies is good. No zone of inhibition (even with 0 colonies found in it) means the substance did not work at all (marked with just 1 zero). These are the averages from the 6 trials (per each category).

Antibiotics
Neomycin 3.83, 0
Penicillin 1.83, 0
Streptomycin 5.33, 1
Ampicillin 8.17, 1.5
Control 0

Disinfectants
Ammonia 0.67, 0
Lysol 4.25, 0
70% Ethanol 1.73, 21.5
10% Bleach 1.33, 0
Control 0

Antiseptics
Hydrogen Peroxide 12.00, 1 (I assume it was %3 and only one plate showed 1 colony)
Listerine 4.00, 0 (one plate showed 299, but only 1, so it was excluded)
Antibacterial Soap 26.83, 0
Regular Soap 0
Control 0

Spices (just for fun, note that 1 zero means no zone of inhibition)
Garlic 6.60, 50
lemon 4.00, 0
mustard 0
oregano 0
ginger 0
onion 0
chili 0
lime 4.00, 0
allspice 0
control 0
pepper 0
control 0

Winner: Antibacterial soap, followed by hydrogen peroxide.
Loser: Ethanol and spices.

Now the main reason I've looked back at this old bio lab is that I have two LCs, one of which is already cloudy and another that is clear but is starting to get that disagreeable smell that the other one has. I've added a cap full of peroxide to one and doubled the volume of the other one with peroxide and was wondering if this would inhibit bacteria growth? I was thinking that I could transfer a small amount of it to another clean jar saturated with peroxide in it and get a clean culture.

Hippie3 · 03-26-08, 23:38

very doubtful.
were yeasts tested as well ?

teal · 03-27-08, 00:09

No yeasts, only E. coli.

teal · 03-27-08, 18:04

Today the LC looked like this. I'm not sure whether this is healthy mycelium, metabolized honey or something else. It doesn't quite look like the large chunks I see in other pics. Also, the smell is still present. It was inoculated with spores a bit less than a week ago.

Om shanti · 03-27-08, 18:27

Is there any air exchange at all?
I am probably not the fastest animal in the forest around here.

...I have managed to have a few jars of LC go alcoholic, because of too little fresh air. It smells foul, actually worse than some bacterial infestations. Just an idea from the slow animal

Good luck.

laughingsamsdice · 03-27-08, 18:34

Tea tree oil i think is an interresting product...

aumbrellaforainydays · 03-31-08, 16:27

that antibacterial soap, was it salicylic acid or trilosan as the primary ingredient?

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03-26-08, 23:27	#1 (permalink)
teal Mycophiliac Join Date: May 2007 Posts: 4	Antimicrobials For last semester bio lab we did an experiment where we took a liquid culture of non-pathogenic E. coli and spread it around on agar. Then we took sterile paper disks and dipped them in various solutions and placed them on the agar and let it incubate. The purpose was to see the effectiveness of various antimicrobials. We even tried different spices (the lab was really about the effectiveness of spices, but they tried various commercial products too). Well anyways, here's the result of the lab. The first number is the size of the zone of inhibition, which is the circle around the disk where bacteria was not found growing. The next number is the number of bacterial colonies (bacteria grows is clumps) that are found within the zone of inhibition. So a big zone of inhibition and little or no colonies is good. No zone of inhibition (even with 0 colonies found in it) means the substance did not work at all (marked with just 1 zero). These are the averages from the 6 trials (per each category). Antibiotics Neomycin 3.83, 0 Penicillin 1.83, 0 Streptomycin 5.33, 1 Ampicillin 8.17, 1.5 Control 0 Disinfectants Ammonia 0.67, 0 Lysol 4.25, 0 70% Ethanol 1.73, 21.5 10% Bleach 1.33, 0 Control 0 Antiseptics Hydrogen Peroxide 12.00, 1 (I assume it was %3 and only one plate showed 1 colony) Listerine 4.00, 0 (one plate showed 299, but only 1, so it was excluded) Antibacterial Soap 26.83, 0 Regular Soap 0 Control 0 Spices (just for fun, note that 1 zero means no zone of inhibition) Garlic 6.60, 50 lemon 4.00, 0 mustard 0 oregano 0 ginger 0 onion 0 chili 0 lime 4.00, 0 allspice 0 control 0 pepper 0 control 0 Winner: Antibacterial soap, followed by hydrogen peroxide. Loser: Ethanol and spices. Now the main reason I've looked back at this old bio lab is that I have two LCs, one of which is already cloudy and another that is clear but is starting to get that disagreeable smell that the other one has. I've added a cap full of peroxide to one and doubled the volume of the other one with peroxide and was wondering if this would inhibit bacteria growth? I was thinking that I could transfer a small amount of it to another clean jar saturated with peroxide in it and get a clean culture.

03-26-08, 23:38	#2 (permalink)
Hippie3 DUNG DEALER Join Date: Feb 2001 Posts: 43,266	very doubtful. were yeasts tested as well ? __________________ visit dial-a-hippie .

03-27-08, 18:34	#6 (permalink)
laughingsamsdice Mycophiliac Join Date: Feb 2006 Posts: 67	Tea tree oil i think is an interresting product... __________________ i believe in Jesus christ you see ! ?

03-31-08, 16:27	#7 (permalink)
aumbrellaforainydays Mycotopiate Join Date: Aug 2006 Posts: 1,329	that antibacterial soap, was it salicylic acid or trilosan as the primary ingredient? __________________ We are all born free and equal.

03-27-08, 00:09	#3 (permalink)
teal Mycophiliac Join Date: May 2007 Posts: 4	No yeasts, only E. coli.

03-27-08, 18:04	#4 (permalink)
teal Mycophiliac Join Date: May 2007 Posts: 4	Today the LC looked like this. I'm not sure whether this is healthy mycelium, metabolized honey or something else. It doesn't quite look like the large chunks I see in other pics. Also, the smell is still present. It was inoculated with spores a bit less than a week ago.

03-27-08, 18:27	#5 (permalink)
Om shanti S.W.I.M. in H.POO Join Date: Jan 2008 Posts: 1,297	Is there any air exchange at all? I am probably not the fastest animal in the forest around here. ...I have managed to have a few jars of LC go alcoholic, because of too little fresh air. It smells foul, actually worse than some bacterial infestations. Just an idea from the slow animal Good luck.

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