초록
Polygalacturonase production by Aspergillus niger LFP-1 was studied in solid state fermentation (SSF) using pomelo (Citrus grandis) peel as a substrate. This local agricultural waste product is rich in lignocellulolytic material, including pectin, which can act as an inducer of pectinase production. Using the parameters of 5 g of 0.75 mm (particle size) pomelo peel as a substrate, moisture content ratio of 1:1 (w/v), inoculum size of <TEX>$1{\times}10^7$</TEX> spores/mL, cultivation temperature of <TEX>$30^{\circ}C$</TEX>, and no mixing, static fermentation conditions with addition of 1.2% ammonium nitrate produced the highest polygalacturonase production rate of 8.90 U/g of substrate and a fungal growth rate of 2.07mg of glucosamine/g of substrate on day 5 of cultivation. A large increase (1,434.5%) in enzyme production occurred after improvement of the growth parameters. Under optimum bioprocess conditions, pomelo peel can be used as solid substrate for production of pectinase.