Optimization of ellagic acid accumulation by Aspergillus niger GH1 in solid state culture using pomegranate shell powder as a support

This report describes an investigation of ellagic acid accumulation (EAA) in solid state culture (SSC) using Aspergillus niger GH1 and powdered pomegranate peel as a support. Various culture conditions (temperature, initial moisture, levels of inoculum and concentration of salts) were evaluated using a Plackett–Burman design (PBD) for screening culture factors followed by a central composite design (CCD) for enhancing the EAA. Temperature, MgSO4 and KCl concentration were identified as significant parameters for EAA in SSC. This enhancement procedure resulted in 15.5-fold increase in EAA (8.48–132.62 mg/g) when the selected culture conditions were evaluated in a kinetic study of biodegradation of ellagitannins to produce ellagic acid. This work proposes a biotechnological alternative to obtain a highly valuable, high-quality compound from agro-industrial wastes through SSC.