Bacteria purple, brown, green

Even more complicated is the situation in the utilization of non-visible parts of the sun s radiation. Some plants, algae and cyanobacteria have a certain photosynthetic activity also in the upper part of the UV region, for green plants the maximum is at about 360 nm, for brown and red algae it is around 340 nm. Infrared radiation cannot be utilized by green organisms, but some brown and red algae are able to utilize the shortwave part of infrared spectrum quite well. The purple phototrophic bacteria also possess a similar ability [9, 10]. 

The discovery that certain bacteria could carry out photosynthesis opened up a new field of photosynthetic research. It was found that certain green-, red-, purple-, and brown-colored bacteria could produce organic matter from carbon dioxide upon illumination. The formation of organic matter was not accompanied by oxygen evolution. As a result of work with the green sulfur bacteria, van Niel (21) showed that their CO2 assimilation process was in close agreement with the following equation ... 

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