African Journal of Biotechnology

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Experimental design applied to the optimization and partial characterization of pectin-methyl-esterase from a newly isolated Penicillium brasilianum

Jamile Zeni, Jonaína Gomes, Éllin Ambroszini, Geciane Toniazzo, Débora de Oliveira, Eunice Valduga


The objective of this work was to optimize the medium composition for maximum pectin-methylesterase (PME) production from a newly isolated strain of Penicillium brasilianum by submerged fermentation. A Plackett-Burman design was first used for the screening of most important factors, followed by a 2<sup>3</sup> full experimental design, to maximize the enzyme production. The maximum pectinmethyl-esterase activity was 4.0 U/mL at 24 h of bioproduction using a pectin concentration of 32.0 g/L, yeast extract of 30.0 g/L, potassium phosphate of 8.0 g/L, iron (II) sulfate of 0.02 g/L, at 30°C, stirring rate of 180 rpm and initial pH of 5.5. The kinetic evaluation showed that after 27 h of fermentation, a consumption of 15% of total organic carbon and 10% of nitrogen was observed. The crude enzymatic extract kept about 80% of its initial activity after 1848 h under low temperatures. An increase of PME activity was observed after incubation at high temperatures. The residual activity of the extracts after 1728 h of incubation was about 95% for all tested pH values (5, 7, 9 and 11). The application of 0.5% (v/v) of PME crude extract for clarification of peach juice showed a reduction on the viscosity (7.20%) and turbidity (14.11%).

Keywords: Penicillium brasilianum, pectin-methyl-esterase, experimental design, pectin-methyl-esterase (PME).

African Journal of Biotechnology Vol. 12(40), pp. 5886-5896
AJOL African Journals Online