I was introduced to PNSB's (purple non sulphur bacteria) in learning about EM cultures (effective micro organisms). PNSB's are one of the three main groups of micro organisms contained in commercial "EM-1" (google) cultures along with yeasts and lactic acid bacteria (LAB). The latter are easy to culture and are predominantly used in the home made versions of commercial EM-1 as direct substitutes for the bottled product. As far as I know, I've never heard of anyone other than lab coats having the ability top culture them. From that literature, it seems far from trivial. Anyways, I found it very interesting in my research that PNSB have the ability to clean up toxic wastes and are also being explored for their ability to produce hydrogen energy... Very interesting stuff even for the layman like myself.
https://en.wikipedia.org/wiki/Purple_bacteria
1. ) Potentials of phototrophic bacteria in treating pharmaceutical wastewater
http://www.bioline.org.br/request?st10018
2.) Photobiological production of hydrogen gas as a biofuel
http://www.sciencedirect.com/science/article/pii/S0958166910000285
3.) The use of rice straw broth as an appropriate medium to isolate purple nonsulfur bacteria from paddy fields
http://www.scielo.cl/scielo.php?pid=S0717-34582012000600007&script=sci_arttext&tlng=e
4.)Molecular Hydrogen Production Using Purple Non- sulfur Bacteria Enriched from Anaerobic Digester Sludge
http://uwyo.coalliance.org/fedora/repository/wyu:76/Scarborough.pdf
The last one is pretty cool, killing two birds with one stone- utilizing disaster waste to produce energy. Now we're talkin..
Hope this helps.