Rhodobacter and pigments in anaerobic digestion of brewery effluent

Brewery wastewater (BWW) was digested anaerobically in mesophilic conditions and batch mode. The presence of a reddish pigmentation associated to the better removal capacity of the BWW digestion (64%), indicates that the treatment and energetic valorisation of an organic effluent can occur at the same time and inside the same unit as the production of a photosynthetic pigment. The reddish pigmentation found in this experiment was mainly attributed to bacteriochlorophyll a, and to carotenoids pigments of the spirilloxantin series (characteristics of purple non-sulfur bacteria). Microbial identification through Next-generation sequencing of 16S rRNA genes showed the presence of bacterial genus Rhodobacter in the inoculum and in anaerobic digestion of BWW.