An analysis of exo-polygalacturonase bioprocess in submerged and solid-state fermentation by Pleurotus ostreatus using pomelo peel powder as carbon source

BACKGROUND: As there has been an increasing trend in the effective utilization of plant and crop residues for microbial transformation into a desired product, an attempt was made to compare of exo-polygalacturonase production using logistic and Luedeking-Piret kinetic model by Pleurotus ostreatus in submerged (smf) or solid-state fermentation (ssf) using pomelo peel powder, an agro-forestry residue as carbon substrate. RESULTS: Cultures grown in submerged fermentation produced a peak of exo-polygalacturonase activity as 6160 Ul(-1) on the 4th day of culture as compared with 2410 Ul(-1) on the 5th day of fermentation by solid-state fermentation. The enzyme yield coefficient (Y(E/X)) is of higher value in smf vs. ssf system (Y(E/X) = 1.05 × 10(3) vs. 0.622 × 10(3)) indicating the more efficient product yield in smf as compared with ssf. The plots derived fromλ versusζ clearly demonstrate that the secondary product destruction is higher in smf than in ssf. CONCLUSION: P. ostreatus performs much better in submerged fermentation as compared with solid-state fermentation in respect to exo-polygalacturonase production although ssf technique produced a more thermo-stable exo-polygalacturonase in crude extract, which is highly desirable in various industrial applications.