Isolation and identification of microbial populations from an odour treating biofilter

Complex odour emissions are normally associated to the operation of wastewater treatment plants, composting facilities and agro-industry activities. The most common contaminants are hydrogen sulfide (H2S), organic reduced sulfur compounds (e.g.,CH3SH), and volatile organic compounds (VOCs). These compounds can be treated using biological air treatment systems, such as biofilters. Five different types of material, including pieces of wood and polymeric material, were collected from different locations of a biofilter treating odours at an organic waste treatment plant and subjected to microbiological characterization. Colony forming units (CFU/g) ranged from 107 to 108 CFU/g from each different material analyzed. The different materials showed high heterogeneity of microbial colonization, being the diversity higher in a heather based material. After random amplification of polymorphic DNA (RAPD) analysis, a total of 22 different isolates were identified by 16S rRNA sequencing analysis. Ten isolates demonstrated capacity to grow on solid sulphur oxidizing medium. Their capacity to oxidize sulphur compounds in liquid medium is being further studied