Does it mean you are looking for dehalogenase enzymes? These are often found in species associated with soil contaminated with e.g. halogenated hydrocarbons. Though it might be difficult to connect specific phyla with such environments. A Pseudomonas species from a halogenated environment can be very different from another Pseudomonas species coming from a different environment (i.e. one having the enzyme system, the other not despite being the same species). So I'd suggest to take it from the perspective of proteins: are you looking for oxidative or reductive dehalogenation, mesophilic or thermophilic proteins, etc. and find well characterized examples in the literature. These reviews may help as a start:

Smidt& de Vos: Anaerobic microbial dehalogenation. Annu Rev Microbiol. 2004;58:43-73.

van Peé and Unversucht: Biological dehalogenation and halogenation reactions Chemosphere. 2003 Jul;52(2):299-312.

Good luck!

Thank you very much. To specify: i'm not looking for dehalogenases, but for nucleoside phosphorylases.

You might wish to consider taking a look at some reference books or reviews on extremophiles (or applications). Check the examples below, but you'll likely find better suited sources in their reference list:

http://www.sciencedirect.com/science/article/pii/S1367593100001836

http://www.springer.com/life+sciences/microbiology/book/978-94-007-6487-3

http://www.sciencedirect.com/science/article/pii/S1369527403000602