Adriatic cyanobacteria potential for cogeneration biofuel production with oil refinery wastewater remediation

Abstract

Among cyanobacteria isolated from Northern Adriatic five strains were able to grow on oil refinery wastewater. Based on the sequencing of the internal transcribed spacer (ITS region) and morphological features strains were identified as Synechococcus sp. MK568070, Phormidium lucidum MK568072, Neolyngbia sp. MK568073, Pseudanabaena sp. MK568071 and Spirulina subsalsa MK573248. Selected marine cyanobacteria were tested over a range of ammonium (NH4+) concentrations simulating oil refinery effluent conditions. Three strains demonstrated high growth potential in a range 0.8–2.0 mM NH4+. Maximum biomass concentrations in stationary phase were in a range 176–590 mg/l, whereas total lipid yields were in a range 7.63–21.40% of dry weight. Although all species satisfy the criteria for biodiesel production the average degree of unsaturation was lowest in Synechococcus sp. MK568070 and Neolyngbia sp. MK568073. High proportion of polyunsaturated alpha-linolenic acid found in Spirulina subsalsa MK573248 opens up considerations for nutritional, aquaculture or other biotechnology applications of that species.