The correlation between mannanase and cellulose activities towards fibre content of palm oil sludge fermented with Aspergillus niger

إنجليزي. Enzyme (mannanase and cellulase) activities and fibre (hemicellulose, cellulose and lignin) contents were determined during the fermentation course of palm oil sludge with Aspergillus niger TL (wild type) and A. niger ES1 (an asporogenous mutant). The analyses were carried out at the incubation time of 3 and 4 days of aerobic fermentation and at 2 days of anaerobic fermentation afterward. The correlations between mannanase activity with hemicellulose content and cellulase activity with cellulose content were calculated by linear regression. The activities of mannanase and cellulase are increasing during the aerobic fermentation, while in the anaerobic fermentation the enzyme activities are decreasing due to instability of the enzymes. THe enzyme activities of ES1 are higher than the TL. The regression coefficient is highly significant for correlation between mannanase and hemicellulose content of fermented product by ES1 (r=0.83; P less than 0.01). While other correlations are not statistically significant (P more than 0.05). Mannanase and cellulase activities were also detected after the fermented product dried at 60 deg. C which indicated the enzymes are quite stable

الأندونيسية. Aktivitas enzim (mananase dan selulase) dan kadar serat (hemiselulosa, selulosa dan lignin) ditentukan selama fermentasi lumpur sawit dengan Aspergillus niger TL (tipe liar) dan A. niger ES1 (mutan asporogenous). Analisis dilakukan pada masa inkubasi fermentasi aerob selama 3 dan 4 hari yang masing-masing diikuti dengan 2 hari fermentasi anaerob. Korelasi antara aktivitas mananase dengan kadar hemiselulosa dan selulase dengan kadar selulosa dihitung dengan analisis regresi linear. Aktivitas mananase dan selulase mengalami kenaikan selama fermentasi aerob, sedangkan pada fermentasi anaerob menurun karena ketidakstabilan enzim. Aktivitas enzim ES1 lebih tinggi dari TL. Koefisien regresi hanya bernilai sangat nyata pada hubungan mananase dengan kadar hemiselulosa produk fermentasi menggunakan ES1 (r=0,83; P lebih kecil dari 0,01). Korelasi yang lain tidak nyata secara statistik (P lebih besar dari 0,05). Aktivitas mananase dan selulase juga terdeteksi untuk produk fermentasi yang telah dikeringkan pada 60 derajat C yang menunjukkan aktivitas enzim bersifat cukup stabil