[aeacfm]

hello guys,

it is well known sulfate reducing bacteria has two major types in the oil field are :planktonic SRB , sessile SRB the first is wandering bacteria not form slim or biofilm  and the last is Bacteria bound to the walls and specificed by the slim or biofilm formation.

 when our compant carry biological test on bacteria in specialized bio-labs  the report included a third type  of SRB bacteria called pitting forming SRB !!!

do any body know any thing about this type of pitting SRB ?

if yes , what is its species or name ?

also, how it could be cultured ?

thanks in advance 

[rjb]

aeacfm,

Not a subject I know a great deal about, but of all of the SRB microbeasties, the Desulfovibrio species seems to look like your culprit and have been referred to as pit formers in a fair few papers. Try googling Desulfovibrio vulgaris and seeing if you can find anything of interest in your subject area, or sticking it into sciencedirect and having a trawl.

In terms of culturing, you're obviously trying to grow an anaerobic species so an anaerobic chamber with a H2/CO2/N2 or similar atmosphere might be a plan. Try TSB as the growth medium to start off with. The paper below might be of some use...

http://aem.asm.org/cgi/reprint/14/4/529.pdf

Anyhow, good luck!

R

[aeacfm]

rjb , thanks too much

do this mean vugaris specifically could be cultured in this medium or all SRB ?
because we culture SRB in postgate medium B

[Mitch]

http://dx.doi.org/10.1016/S0010-938X(99)00088-8

Effect of iron exposure in SRB media on pitting initiation

Pitting corrosion of iron (99.9%) in Sulphate-reducing bacteria (SRB) media containing 0.09–0.30 g/l sulphides and 0.1–5.0 g/l [Cl−] was studied. Iron electrode immersed in SRB media undergoes fast activation and numerous active sites formed on the surface. Depending on exposure time, pitting was initiated at different potentials. After short period (<2 h) in open circuit potential, when active sites were still exist on the surface, pitting occurred at the potential range of −0.60 to −0.55 V (SCE). Extended exposures resulted in more stable passivity of iron and the pitting potential shifted to positive values. Pit initiation mechanism at the various exposure periods is discussed.

[rjb]

aeacfm,

Postgate B should be ideal for pretty much all of your SRB's. After having a bit of a trawl, I understand that Desulfovibrio isn't all that fussy, but one or two papers suggest that it might be happier on Postgate A, so that might be worth a try.

If you can find it, looking up Postgate's original paper on Dusulfovibrio desulfuricans (Journal of general microbiology) from the 1950's wouldn't be a bad plan. Another point that might be useful to you, is remembering that here in the UK we spell 'Sulfur' as Sulphur, so Desulfovibrio might end up as Desulphovibrio in UK and commonwealth papers. 

Anyhow, good luck

R

 

[aeacfm]

rjb,

thanks very much but i am not looking for medium to SRB in general , specifically i am talking about vulgaris species if i can culture it alone among other SRB's (plantonik , sessile).
or you mean that postgate A is good choice for it ? i didnt understand u .

[rjb]

aeacfm,

Sorry for the confusion. If you're looking for differential culturing of Desulfovibrio vulgaris with other SRB's, maybe give postgate A a try, as I think it tends to suit Desulfovibrio sp. more than than other SRB's. Its also worth considering that Desulfovibrio sp. are more aero tolerant than other SRB's, so this is a parameter that could be used to ensure your less oxygen tolerant species grow pretty feebly.

R

[aeacfm]

aha ,

thats more clear
but other SRB's will included in this medium  according to this tolerance .
any way i will try

 many thanks