Anoxygenic phototrophic bacteria, which include purple and green sulfur bacteria, are an ecological group of anaerobic bacteria. Unlike oxygenic phototrophs, they do not use water as an electron donor for photosynthesis. Their most typical electron donor is hydrogen sulfide, which they oxidize to elemental sulfur or to sulfate. This property could be used, for example, in the removal of hydrogen sulfide from wastewater or biogas where it is an unwelcome impurity. In particular, biogas production has a great importance for our sustainability and such a biotechnology would make it even more environmentally friendly. In the presented research, three anoxygenic phototrophic bacteria cultures were isolated from the environment. The dominant bacterial species were identified by microscopy and sequencing of the 16S rRNA gene. Furthermore, their metabolic activity was monitored. This included measuring density of the bacterial suspension, consumption of hydrogen sulfide and production of sulphate. The impure environmental cultures enriched with anoxygenic phototrophic bacteria were compared with a pure culture of Chlorobium limicola from a microorganism collection. All the examined cultures removed hydrogen sulfide effectively, most notably the environmental culture enriched with a purple sulfur bacterium Thiocapsa sp. These results indicate that anoxygenic phototrophs could be an interesting option for biogas desulfurization.