Development of operating process for continuous production of biomass by Tetradesmus obliquus (MT188616.1) in a hollow fiber membrane photobioreactor

• Published in: Journal of biotechnology 2022-11, Vol.359, p.59-64
• Main Authors: Roopashri, Arekal N., Makam, Roshan
• Format: Article
• Language: English
• Subjects: Biomass production; Hollow fiber membrane photobioreactor; Lipid production; Medium flow rate; Tetradesmus obliquus
• ISSN: 0168-1656; 1873-4863
• DOI: 10.1016/j.jbiotec.2022.09.017

An effective prototype of photobioreactor namely hollow fiber membrane bioreactor is employed to produce algal biomass for biofuel production. The effect of two-stage cultivation system on the biomass productivity and lipid production is studied using freshwater green microalga Tetradesmus obliquus MT188616.1. The hybrid system combines exponential biomass production in hollow fiber membrane photobioreactor (HFMPBr) and a coordinated high-lipid stimulation phase in nitrogen-deprived medium by the shake flask method. This work is proposed to examine the usefulness of HFMPBr module to enhance the microalgal growth rate through the effective mass transfer by standardizing the culture medium re-circulation flow rates (5 – 45 mL min−1) through the hollow fiber membranes. Cultivation is carried out at continuous mode in HFMPBr containing polysulfone fabricated membranes at fixed light intensity of 50 µmol m−2 s−1 and temperature at 28 °C. Biomass productivity and specific growth rate obtained are 0.44 g L−1d−1 and 1.61 µ d−1 with a lipid yield of 0.1 g L− 1. The key operating parameter i.e., liquid flow rate is optimized based on biomass production. The highest biomass concentration is produced at the flow rate of 45 mL min−1. The results showed that HFMPBr module is a better choice for the algal-cultivation to obtain higher biomass yield. The effect of two-stage cultivation system on the growth rate, biomass productivity, and lipid yield was studied in freshwater green microalga Tetradesmus obliquus MT188616.1. The hybrid system combines exponential biomass production in hollow fiber membrane photobioreactor (HFMPBr) and a coordinated high-lipid stimulation phase in nitrogen deprived medium by the shake flask method. The algal cultivation was carried out at continuous mode in HFMPBr containing polysulfone fabricated membranes at fixed light intensity of 50 µmol m−2 s−1 and temperature at 28 °C. Biomass productivity and specific growth rate obtained were 0.44 g L−1d−1 and 1.61 µ d−1 with a lipid yield of 0.1 g L− 1. The key operating parameter i.e., liquid flow rate was optimized based on biomass production. The highest biomass concentration was produced at the highest flow rate of 45 mL min−1, whereas the lowest biomass was at the lowest flow rate of 5 mL min−1. The results showed that HFMPBr module was a better choice for the cultivation of Tetradesmus obliquus MT188616.1 to obtain higher biomass yield. [Display omitted] •Integrated HFMPBr and shake flask appr