Journal Article

Bioprocess optimization for pectinase production using Aspergillus niger in a submerged cultivation system

Suhaimi, Noorhamizah, El Enshasy, Hesham A., Elsayed, Elsayed Ahmed, Esawy, Mona, Malek, Roslinda Abd

2018

Overview

Background Pectinase enzymes present a high priced category of microbial enzymes with many potential applications in various food and oil industries and an estimated market share of $ 41.4 billion by 2020. Results The production medium was first optimized using a statistical optimization approach to increase pectinase production. A maximal enzyme concentration of 76.35 U/mL (a 2.8-fold increase compared with the initial medium) was produced in a medium composed of (g/L): pectin, 32.22; (NH 4 ) 2 SO 4 , 4.33; K 2 HPO 4 , 1.36; MgSO 4 .5H 2 O, 0.05; KCl, 0.05; and FeSO 4 .5H 2 O, 0.10. The cultivations were then carried out in a 16-L stirred tank bioreactor in both batch and fed-batch modes to improve enzyme production, which is an important step for bioprocess industrialization. Controlling the pH at 5.5 during cultivation yielded a pectinase production of 109.63 U/mL, which was about 10% higher than the uncontrolled pH culture. Furthermore, fed-batch cultivation using sucrose as a feeding substrate with a rate of 2 g/L/h increased the enzyme production up to 450 U/mL after 126 h. Conclusions Statistical medium optimization improved volumetric pectinase productivity by about 2.8 folds. Scaling-up the production process in 16-L semi-industrial stirred tank bioreactor under controlled pH further enhanced pectinase production by about 4-folds. Finally, bioreactor fed-batch cultivation using constant carbon source feeding increased maximal volumetric enzyme production by about 16.5-folds from the initial starting conditions.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Ammonium sulfate / Applied Microbiology / Aspergillus / Aspergillus Niger / Aspergillus niger - genetics / Aspergillus niger - growth & development / Aspergillus niger - metabolism / Batch Cell Culture Techniques - instrumentation / Batch Cell Culture Techniques - methods / Batch culture / Biochemical Engineering / Biomedical Engineering/Biotechnology / Bioprocess optimization / bioprocessing / Bioreactors / Bioreactors - microbiology / Biosynthesis / Biotechnology / Carbon / Carbon - metabolism / Carbon sources / Chemical properties / Chemistry / Chemistry and Materials Science / Citrus fruits / Cultivation / Culture Media - chemistry / Culture Media - metabolism / Dehydrogenases / dipotassium hydrogen phosphate / Enzymes / Fed-batch culture / Feeding / Fermentation / Food / Food industry / Genetic Engineering / Glucose / Hydrogen-Ion Concentration / industrialization / industry / Innovations / Iron sulfates / market share / Medium optimization / Microbial biotechnology / microbial enzymes / Microorganisms / Oil and gas industry / oils / Optimization / Pectin / Pectinase / pectins / pH effects / Plant Breeding/Biotechnology / polygalacturonase / Potassium chloride / Potassium phosphate / Potassium phosphates / Research Article / Scaling / Statistics / Substrates / Sucrose / Sugar / system optimization / Tangerines