Enzymes with new biochemical properties in the pectinolytic complex produced by Aspergillus niger MIUG 16.
ABSTRACT A comprehensive study on the purification and characterization of pectinolytic enzymes produced by Aspergillus niger MIUG 16 on raw materials solid-state fermentation is reported. Five pectinolytic enzymes were purified using a combination of chromatographic techniques. The properties of these homogenous enzymes were analyzed. The purified enzymes were classified with respect to their biochemical properties and substrate specificity. Among these proteins, one revealed polygalacturonase activity, another appeared to be a pectin methylesterase and three were identified as pectate lyases. The capacity of the fungus A. niger to produce pectate lyases with optimum pH in acidic domain was reported for the first time.
- SourceAvailable from: hrcak.srce.hr[Show abstract] [Hide abstract]
ABSTRACT: Solid-state fermentation of coffee pulp with Aspergillus tamarii V12307 was carried out in laboratory scale reactors (bottle and column) to evaluate the effect of four different mix-ing frequencies (2.0, 2.7, 4.0 and 8.0 day –1) on fungal growth, indirectly determined by car-bon dioxide formation and the production of spores and pectin methylesterase. Coffee pulp was used as the sole source of nutrients. An increase in the fraction of bonded parti-cles was observed in the bottle reactors after 12 h of cultivation when no mixing was ap-plied. The use of any mixing frequency reduced the fraction of bonded particles. However, there was no significant difference in pectin methylesterase production between the mix-ing frequencies at the end of the fermentation. Similarly, there were no significant differ-ences in CO 2 production, oxygen uptake or sporulation, demonstrating that the mycelium was not damaged by intermittent mixing. This strategy of mixing could be used in large scale reactors in order to reduce heat and mass limitations.
- [Show abstract] [Hide abstract]
ABSTRACT: In this study intensified removal of pectins was integrated with microfiltration step to develop in situ self-cleansing biocatalytically active membranes. This method was developed to reduce the severe fouling that occurred during microfiltration (MF) of olive mill wastewater (OMWW) for the recovery of bioactive compounds using integrated membrane processes. As a proof-of-concept, pectinase has been immobilized on the MF membrane surface and flux performances as a function of time has been monitored and compared with inert membrane. For the experiments real OMWW has been used. The steady-state flux through the enzyme immobilized on the membrane surface solo was 50% higher than inert membrane. The mechanism for the better performance of the biocatalytically active on the surface has been explained as based on both degradation of deposited pectins (in situ self-cleansing) and overcome of product inhibition as it is continuously removed from the reaction site. The inhibitory effect has been clearly identified from kinetic study of pectinase. For all types of used membrane systems, analysis of cake resistance, membrane resistance, and membrane fouling index indicated surface biofunctionalized membranes with the least fouling tendency and significantly improved flux.Industrial & Engineering Chemistry Research 04/2013; · 2.24 Impact Factor
Article: Polygalacturonases Produced Under Solid State and Submerged Fermentation Conditions by Two Strains of Aspergillus foetidus (Aspergillus foetidus 'a Ait İki Suş Tarafindan Kati Kültür ve Batik Kültür Fermentasyon Koşullarinda Üretilen Poligalakturonazlar) Research Article (Araştirma Makalesi)[Show abstract] [Hide abstract]
ABSTRACT: Objectives: Polygalacturonases produced by two strains of Aspergillus foetidus (EGEK145, EGEK635) under solid state and submerged conditions were investigated for some of their biochemical characteristics.