Optimisation of carbohydrate, lipid and biomass productivity in Tetradesmus obliquus using response surface methodology

Abstract

Microalgae are known as an alternative source of biomass energy to replace fossil fuels. The aim of the present study is to optimise the growth conditions and increase the lipid, carbohydrate and biomass productivity of Tetradesmus obliquus UPSI-JRM02 using response surface methodology with Design Expert software. Four variables (nitrogen concentration, temperature, pH, and light intensity) were optimised to enhance T. obliquus productivity. The highest lipid (33 ± 1.2mg/L/day), carbohydrate (51 ± 1.5 mg/L/day) and biomass (115 ± 1.4 mg/L/day) productivity were produced at a nitrogen concentration of 400 mg/L NO₃⁻ at 36 °C with pH of 9.8, and light intensity of 23500 lux. The fatty acid methyl ester contains polyunsaturated fatty acid (C18:2, C18:3) and saturated fatty acid (C16:0). These results demonstrate the potential of T. obliquus to produce promising feedstock for biofuel production.

Keywords:

• Microalgae
• biomass
• lipid
• carbohydrate
• Tetradesmus sp.
• response surface methodology

Acknowledgements

The authors wish to thank The Ministry of Higher Education Malaysia (MOHE) for financing this study through the Fundamental Research Grant Scheme (Code: 2015-0161-102-02). We are also grateful to Makmal Pencirian Struktur Molekul (MPSM) at the Centre for Research and Instrumentation Management (CRIM), Universiti Kebangsaan Malaysia (UKM), for their technical assistance.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Ministry of Higher Education Malaysia through Fundamental Research Grant Scheme [2015-0161-102-02].