2 replies to this topic

[k_josefin]

Hello everyone!

I'm looking for bacterial strains with positive surface charge in neutral or close to neutral pH. According to the litterature, there are some bacteria that has a positive charge. But I can't seem to find any examples.

Does anyone know about this?

[Bluefunk]

k_josefin, on 15 June 2011 - 09:46 PM, said:

Hello everyone!

I'm looking for bacterial strains with positive surface charge in neutral or close to neutral pH. According to the litterature, there are some bacteria that has a positive charge. But I can't seem to find any examples.

Does anyone know about this?

Think about using Staphylococcus aureus. One of the major lipids in staph is lysyl-phosphatidylglycerol. This polar lipid has a positively charged lysine attached. The membrane is subsequently positively charged in an attempt to repel cationic antiomicrobial peptides.

[pito]

Its a bit more complicated then Bluefunk said, but in essence, its ok.

In general: the charge is negative.. for gram - and gram +
This characteristic is used for example to concentrate toxic waste and more specific radioactive waste.

However, under certain circumstances, the charge can be altered by the bacterium in a response on the pH. Its a defence mechanism of the bacterium to survive.

I do not know if you had basic microbial physiology? Of not, try to look it up..


I also included a paper to start .. it gives you an example, Bluefunk  allready mentioned S. A.

Its not so hard to find other examples if you search a bit.

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