North Carolina hosts ~2300 active swine Concentrated Animal Feeding Operations (CAFOs), which generate 15 million metric tons of pig manure slurry (PMS) annually. PMS is a mixture of urine, feces, and washing water from the hog houses and is stored in earthen lagoons for use on crops as fertilizer. These lagoons generate various problems during storage including the release of offensive odors in the form of volatile organic compounds (VOCs), aerosol formation, and the release of nutrients and pathogenic microorganisms by surface runoff to watersheds. The lagoon microflora consist primarily of purple photosynthetic bacteria, which are capable of producing carotenoids that are used as photoprotection pigments. Carotenoids are well known antioxidants and used in pharmaceuticals, supplements, and food additives. In order to convert hog waste into useful resources, we isolated and characterized bacteria producing carotenoids in hog lagoon wastes. From PMS samples collected from a swine waste lagoon in Burgaw, NC we isolated 49 bacteria. Their taxonomic association was determined based on 16S rRNA gene sequences. The bacteria producing pigments are associated with Rhodococcus sp., Rhodobacter sp., Pseudomonas sp., Thermomonas sp., Comamonas sp., and Hydrogenophaga sp. In addition we detected the pufM gene from the isolates to define their photosynthetic capability. Carotenoids produced from bacterial isolates were characterized based on HPLC purification and spectrometry analysis. Thus, this study demonstrates the presence and diversity of carotenoid producing bacteria from a swine waste lagoon in NC and shows the biotechnological potential of antioxidant discovery from animal manure wastes.
