Evaluation of fatty acid profile and biodiesel properties of microalga Scenedesmus abundans under the influence of phosphorus, pH and light intensities S.K. Mandotra a,b , Pankaj Kumar a , M.R. Suseela a,⇑ , S. Nayaka a , P.W. Ramteke b a Algology Laboratory, CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, Uttar Pradesh 226 001, India b Department of Biological Sciences, Sam Higginbottom Institute of Agriculture, Technology and Sciences, Allahabad, Uttar Pradesh 211 007, India highlights  Phosphate, pH and light intensities have marked effect on the FA profile of alga.  60 mg/L phosphate has favoured high biomass and lipid concentration.  Illumination of 6000 lux was suitable for biomass and lipid production.  Biomass increased at pH 8, whereas pH 6 favoured lipid content.  Favourable phosphate, pH and light conditions resulted in good fuel properties. article info Article history: Received 23 September 2015 Received in revised form 15 November 2015 Accepted 17 November 2015 Available online 23 November 2015 Keywords: Microalgae Light intensity pH Phosphate Biodiesel abstract The present study dealt with biomass, lipid concentration, fatty acid profile and biodiesel properties of microalga Scenedesmus abundans under different phosphate concentrations, pH and light intensities, one at a time. Among different phosphate concentrations, higher biomass (770.10 ± 11.0 mg/L) and lipid concentration (176.87 ± 4.6 mg/L) were at the concentration of 60 mg/L. Light intensity at 6000 lux yielded higher biomass and lipid concentration of 742.0 ± 9.7 and 243.15 ± 9.1 mg/L, respectively. The biomass (769.0 ± 12.3 mg/L) and lipid (179.47 ± 5.5 mg/L) concentration were highest at pH 8 and pH 6, respectively. All the culture treatments showed marked effect on the fatty acid profile and biodiesel properties of the extracted oil. FAME derived biodiesel properties were compared with European biodiesel standards (EN 14214), Indian biodiesel standards (IS 15607) and American biodiesel standards (ASTM D 6751-08) to assess the suitability of algal oil as biodiesel feedstock. Ó 2015 Published by Elsevier Ltd. 1. Introduction The intensive use of fossil fuel due to large-scale energy demand has raised the threat of global energy crises. At present, the use of fossil fuels fulfils 90% of global energy demand and there are estimates that, by the year 2050, most of the fossil fuel reserves will be completely exhausted (Ho et al., 2013; Maity et al., 2014). Besides this, the combustion of fossil fuel is posing serious threat to the environment and human health by the emission of green- house gases. Therefore, it has been realised that both exploration of new energy sources and safety of environment are equally important for sustainable development. There are considerations of biomass as the most promising alternative for fossil fuels, as it is renewable, non-toxic and biodegradable in nature. Worldwide, 10% of energy demand is fulfilled by the alternative sources of energy (biofuels) produced form biomass (Maity et al., 2014). Biofuel in the form of biodiesel and bioethanol has been pro- duced from various edible and non-edible sources, viz., animal fat, waste frying oil, soybean, corn, palm, rapeseed, jatropha and sugarcane, but their production is very less to satisfy the energy demand; moreover, their large-scale production requires huge amount of arable land, which directly competes with the produc- tion of food crops (Ho et al., 2014). Microalgae, on the other hand, are one of the ideal sources for biofuel production; they are photosynthetic organisms and are highly efficient for biomass production. Microalgal oil is rich in long chain polyunsaturated fatty acids, suitable for biodiesel production; the energy content of algal oil is around 35,800 kJ kg 1 , which is more or less equal to the energy content of petroleum fuel (Dasgupta et al., 2015). Apart from biofuel (biodiesel, biohydrogen, bioethanol and methane), microalgae can also be used for the production of high http://dx.doi.org/10.1016/j.biortech.2015.11.042 0960-8524/Ó 2015 Published by Elsevier Ltd. ⇑ Corresponding author. E-mail address: mrsuseela@yahoo.co.in (M.R. Suseela). Bioresource Technology 201 (2016) 222–229 Contents lists available at ScienceDirect Bioresource Technology journal homepage: www.elsevier.com/locate/biortech