VOLUME 62 : 2014

Diatoms are unicellular and colonial microalgae which are currently explored as one of the potential algal species for biofuel production since they are known to accumulate high lipid content under different environmental stresses. This paper focuses on the diatom Nitzschia palea subjected under various culture conditions of light intensity, temperature, and pH, using batch culture experiments for optimizing their growth, lipid content and lipid productivity. Nitzschia palea attained a maximum growth of 3.08×10⁶ cells/mL under the optimum conditions of 18 mmol photons m^–2 s^–1 light intensity, temperature of 30°C, and pH 9.

The highest lipid content (1.23 mg mL^–1) was attained at 30°C. Lipid productivity increases with increased light intensity, temperature and pH. This was positively correlated with both lipid content and culture conditions (p <0.05), while growth of N. palea was negatively correlated with lipid content (p <0.05). Nitzschia palea had shown a relatively high growth rate and lipid content which are important characteristics for consideration as a potential for biofuel resource.

Keywords: Nitzschia palea, culture conditions, biofuel resource, lipid content, lipid
productivity