Yes. But this does not mean that some cyanobacteria can not survive without light, because some of them are mixotrophic (heterotrophic and autotrophic).

Synechococcus is one example of many.

If you are interested in alternative cyanobacteria in terms of photosynthesis, i recommended you the anoxygenic photosynthesis, where bacteria uses sulfur compounds as electron acceptor. This is very interesting for research.

Recommendation: "Surfur metabolism in phototrophic sulfur bacteria" by Frigaard & Dahl.

See this.

http://www.sciencedaily.com/releases/2008/11/081113181037.htm

or

http://news.ucsc.edu/2008/11/2555.html

This suggest evolution from cynobacteria to non photosynthetic life form.

http://www.sciencedirect.com/science/article/pii/S0960982201006492

http://www.biomedcentral.com/1471-2148/9/197

mentionable references

http://www.sciencedirect.com/science/article/pii/S0065308X03540015

http://rstb.royalsocietypublishing.org/content/358/1429/109.short

http://mbe.oxfordjournals.org/content/21/5/809.full

http://www.pnas.org/content/100/3/765.short

http://www.geol.ucsb.edu/faculty/porter/Papers/Porter_2004_eukdiversific.pdf

Ah, thanks, most interesting, but these are no longer cyanos...

Also the heterotrophic ability so synechococcus does not make it non-photosynthetic.

I'm thinking is there a strain that is defined (say by 16S) as a cyanobacterium, but lacks photosynthetic ability.

Philosophical question: How would you go about searching for such a strain?

Thanks Saurabh, just saw your other input. Excellent.

Yes, but these bacteria can survive under the dark.

Just stumbled upon this paper. The title alone answers my original question, but the rest of the paper is also worth reading.

https://peerj.com/preprints/204v1.pdf