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Biodiesel production from microalgae oil by lipase from Pseudomonas aeruginosa displayed on yeast cell surface

Raoufi, Zeinab, Mousavi Gargari, Seyed Latif
Biochemical engineering journal 2018 v.140 pp. 1-8
Pichia pastoris, Pseudomonas aeruginosa, biocatalysts, biodiesel, calcium, carboxylic ester hydrolases, cetyltrimethylammonium bromide, copper, detergents, enzyme activity, fuel production, genes, hydrophilicity, ions, iron, magnesium, manganese, microalgae, oils, pH, polysorbates, quantitative polymerase chain reaction, sodium dodecyl sulfate, solvents, temperature, yeasts, zinc
Yeast surface display has become a powerful technology in recent decades and one of the promising areas in this field is the biodiesel synthesis by microbial lipases. Hence, in this study the optimized lipase A (Lip A) gene from Pseudomonas aeruginosa was fused to GPI-anchored protein Gcw61 and successfully displayed on the surface of Pichia pastoris X33. A lipase activity of 85.2 U/mg dry cell weight was obtained from recombinant P. pastoris. The copy numbers of inserted lipase gene were determined 2.09 ± 0.06 by real time PCR absolute quantification method. The enzyme showed the best stability in pH 7.0–10.0 and at temperature 37 °C–40 °C and was also stable in hydrophilic organic solvents. Ca²⁺, Mg²⁺, Mn²⁺ and Cu²⁺ ions enhanced enzyme activity, whereas Fe²⁺ and Zn²⁺ ions and some detergents like SDS, CTAB, Tween 20 and 80 dramatically decreased the activity of the enzyme. The results demonstrate that our whole cell biocatalyst exhibited a good potential for biodiesel production from microalgae oil in 10 repeated batch cycles.