Find content
Not Telling
Tween80 as lipid source? Do you add the lipid mixture too?
What bacteria do you use? usually they aren't that lipophilic, except a few that produce a hydrophobic coating, and these are susceptible to the presence of surfactants like Tween80
Tween80 is used as surfactant in media containing hydrophobic substances (e.g. hydrophobic C-sources like PAHs). Did you test the media with only Tween80 to say they can use it?
#154495 Test for production of antimicrobial substances by bacteria
Posted
on 01 May 2013 - 07:13 PM
#154498 Test for production of antimicrobial substances by bacteria
Posted
on 02 May 2013 - 05:16 AM
Tween 80 is used in alot of applications - it's a nonionic surfactant used in drug and cosmetic testing to neutralize preservatives like paraben. Others have used it as media additions to source unsaturated fatty acid (oleic) for mutants that required this in their membranes and I've also seen it reportedly used as substrate- both latter app'spresumed esterase activity to separate the fatty acid from the ethyoxylated sorbitan.
Think the original post reported no inhibition when grown with Tween 80 - only saw it in the bacteria/undescribed "natural lipid" combination. With only this, you really can't separate the two very effectively. You'd have to find some uncontaminated "natural lipid" to test -with this, one way to address this would be to incorporate the clean lipid mixture into an agar medium - inoculating a lawn of the indicator(of inhibition) culture and spot inoculating the bacterium in question.
Think the original post reported no inhibition when grown with Tween 80 - only saw it in the bacteria/undescribed "natural lipid" combination. With only this, you really can't separate the two very effectively. You'd have to find some uncontaminated "natural lipid" to test -with this, one way to address this would be to incorporate the clean lipid mixture into an agar medium - inoculating a lawn of the indicator(of inhibition) culture and spot inoculating the bacterium in question.
#152461 Bacterial Motility
Posted
on 17 March 2013 - 07:20 PM
Few if any lab strains of E. coli are motile. What strain were you trying to use as a positive control?
#152475 Bacterial Motility
Posted
on 18 March 2013 - 04:57 AM
I'm not absolutely certain, but I strongly doubt that the cloning strains such as XL1 are motile. Something more like wild type, such as MG1655 would probably work well. If you have never compared the strains under a microscope, it is a revelation. Lab strains are very very sick, and look it.
#145715 Identification of new species
Posted
on 22 November 2012 - 04:05 PM
Why not? I have a fungal isolate from Australia which has 100% identity with another from Japan and other from China, and based on the ITS which is much more variable.
Did you isolate the second time from dog too? Same medium?
Some species have a plethora of closely related strains or within the same species, almost like a gradient of similarity based on 16S. Others however, may have the exact same 16 S or maybe just one bp different and being different species. The last case is not very common but there are some cases that need extra sequencing of some other genes to confirm.
Did you isolate the second time from dog too? Same medium?
Some species have a plethora of closely related strains or within the same species, almost like a gradient of similarity based on 16S. Others however, may have the exact same 16 S or maybe just one bp different and being different species. The last case is not very common but there are some cases that need extra sequencing of some other genes to confirm.
#145700 Identification of new species
Posted
on 22 November 2012 - 09:30 AM
Perhaps you used highly conserved regions of the DNA within that species.
