Production of Cyanobacterial Phycocyanin from Produced Waters
Linear tetrapyyrole bile pigments are potentially high value, naturally occurring products that can be synthesized from cyanobacterial phycocyanin. Desirable properties of bile pigments may include high antioxidant activity, anti- inflammatory properties, and anti-viral activites. The varied and high demand properties of these compounds increase the commercial potential of bile pigments for many areas of application. Current production of desirable bile pigments is very expensive as they are often sourced from animal materials.
Production of phycocyanin from cyanobacteria is a potentially very cost effective and sustainable way to obtain large quantities of this chemical feedstock (phycocyanin) for conversion into desirable bile pigments. Cyanobacteria can naturally accumulate phycobiliprotein such as phycocyanin in quantities of up to a quarter of their dry weight and 40% of the total water-soluble protein. Their extremely large genetic diversity also leaves open the possibility of the production of many other useful bioproducts in addition to phycocyanin.
The wide range of adaptability to different environments that many cyanobacteria demonstrate is a good match to the chemically varied environment that produced water provides. Produced water is wastewater from the oil and natural gas industries that is pumped along with oil and gas to the Earth’s surface. It is by far the largest waste stream generated by the oil and gas industries with 15-20 billion barrels estimated being produced in 2004 on-shore in the USA alone. As hydrocarbon reservoirs mature and hydraulic fracturing of natural gas reservoirs becomes more prevalent, produced water production will likely increase dramatically in the future. The disposal of produced water is a very large problem for the oil and natural gas industries and it is currently a limiting factor for oil and gas production in the Uinta Basin of Utah.
Utilization of the Rotating Algal Biofilm Reactor (RABR) as a growth platform with cyanobacteria and produced water allows for the harvesting of a pre- concentrated biofilm, bypassing costly dewatering procedures and equipment. The rotating nature of the RABR platform allows it to be used in the often-turbid existing produced water ponds allowing the cyanobacteria to grow in a much deeper pond than a traditional algae raceway would allow. In addition to allowing the use of existing ponds, this also reduces the physical footprint of an algae facility allowing for more productivity per unit area of land.