The synthesis of pectinase using Aspergillus niger, NCIM 548, has been enhanced by optimizing the carbon and nitrogen sources present in the medium. Enzyme synthesis was about 40% more using the optimized medium than using the unoptimized medium. The study provided information on the appropriate carbon source as well as the optimum ratio of carbon to nitrogen, yielding the highest enzyme levels.

T Panda

Department Of Chemical Engineering

Sushma R. Nair

POLYGALACTURONASE

article

Aspergillus niger

controlled study

culture medium

enzyme synthesis

fungus culture

nonhuman

priority journal

statistical analysis

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Bioprocess Engineering

Pectinases are a complex group of enzymes that degrade various pectic substances present in plant tissues. Pectinases have potential applications in fruit, paper and textile industries. Apart from these industrial applications, these enzymes possess biological importance in protoplast fusion technology and plant pathology. Since applications of pectinases in various fields are widening, it is important to understand the nature and properties of these enzymes for efficient and effective usage. For the past few years, vigorous research has been carried out on isolation and characterization of pectinases. New affinity matrices with improved characteristics and affinity-precipitation techniques have been developed for purification of pectinases. Recently much attention has been focused on chemical modification of pectinases and their catalytic performance by various researchers. These studies are helpful in determining key amino acid residues responsible for substrate binding, catalytic action, and physico-chemical environmental conditions for maximum hydrolysis. This short review highlights progress on purification and understanding the biochemical aspects of microbial pectinases. © 2002 Elsevier Science Ltd. All rights reserved.

Process Biochemistry

Purification and biochemical properties of microbial pectinases - A review

Pectolytic enzymes, viz., polymethylgalacturonase (PMG), polygalacturonase (PG), and pectinlyase (PL) were deactivated at various combinations of pH and temperature. The deactivation process was modelled as first-order kinetics and the deactivation rate constant was found to be minimum at pH 2.2 and 23 °C, respectively for PMG, 4.8 and 28 °C, respectively for PG and 3.9 and 29 °C, respectively for PL. Thermodynamic parameters like ΔG*, ΔH*, ΔS*, and activation energies were evaluated for crude and partially purified enzymes. It was found that entropy values are negative for all the three enzymes. The partially purified enzymes were found to be less stable than the crude enzymes. Hence, the interaction effect among the enzymes and also the effect of protein (BSA) on deactivation were studied. The addition of protein doubled the half-life times of partially purified PMG, PG I and PG II. The interaction effect of pectolytic enzymes on deactivation was found to be significant. © 2003 Elsevier Science B.V. All rights reserved.

Biochemical Engineering Journal

Studies on pH and thermal deactivation of pectolytic enzymes from Aspergillus niger

Stability studies and kinetics of β-1,3-glucanase from Trichoderma harzianum NCIM 1185 are reported. The critical parameters, pH and temperature, affecting the stability of β-1,3-glucanase were optimized using response surface methodology. The optimal combination of pH and temperature were 3.6 and 41 °C, respectively. The stability of β-1,3-glucanase was studied at various conditions of pH and temperature above the optimal conditions. Since the final activity was not zero, a non-first order deactivation model was used to explain the experimental data. Enzyme kinetic studies were carried out with and without inhibitors. Cu2+ behaved as a noncompetitive- uncompetitive mixed inhibitor, whereas EDTA and NH4+ behaved as competitive-noncompetitive type mixed inhibitors during the hydrolysis of β-1,3-glucan. © 2002 Elsevier Ltd. All rights reserved.

Stability and kinetics of β-1,3-glucanse from Trichoderma harzianum

The nutritional requirements for riboflavin production by a UV-mutant of Eremothecium ashbyii UV-18-57 were optimized using indigenous agroindustrial by-products. The medium components considered include molasses as carbon source, sesame seed cake (SSC) as nitrogen source, yeast extract, KH2PO4, NaCl, MgSO4 7H2O and Tween-80 in shake flask experiments. Initial screening using a Plackett-Burman statistical design identified four components, i.e., molasses, SSC, KH2PO4 and MgSO4 7H20 as significantly, influencing riboflavin production (confidence levels above 80%). Response surface methodology was applied to determine the mutual interactions between these four components and optimal levels for riboflavin production. The optimal concentrations for enhanced production of riboflavin were: (g/l) molasses = 30.85; SSC = 39.80; KH2PO4 = 1.484 and MgSO4 7H2O = 0.072. (C) 2000 Elsevier Science Ltd.

Statistical optimization of medium components for enhanced riboflavin production by a UV-mutant of Eremothecium ashbyii

The reaction conditions were optimized for enzymatic hydrolysis of pectic substances using pectolytic enzymes produced by Aspergillus niger NCIM 548. Response surface methodology was used to optimize the reaction parameters and the central composite design was employed for this purpose. Pectin was used as the substrate for polymethylgalacturonase and pectinlyase, whereas polygalacturonic acid was the substrate for polygalacturonase. The volume ratio of reactants for maximum hydrolysis was determined under the assay conditions. The optimum amount of substrate and enzyme were found to be 0.2 cm3 and 0.074 cm3 for polymethylgalacturonase, 0.4 cm3 and 0.086 cm3 for polygalacturonase, and 0.63 cm3 and 0.7 cm3 for pectinlyase. The pH and temperature optima were found to be 5.3 and 30°C for polymethylgalacturonase, 6.6 and 26°C for polygalacturonase, and 4.8 and 35°C for pectinlyase. Under optimized conditions the enzyme activities were higher when compared to unoptimized conditions. Copyright (C) 1999 Elsevier Science Inc.The reaction conditions were optimized for enzymatic hydrolysis of pectic substances using pectolytic enzymes produced by Aspergillus niger NCIM 548. Response surface methodology was used to optimize the reaction parameters and the central composite design was employed for this purpose. Pectin was used as the substrate for polymethylgalacturonase and pectinlyase, whereas polygalacturonic acid was the substrate for polygalacturonase. The volume ratio of reactants for maximum hydrolysis was determined under the assay conditions. The optimum amount of substrate and enzyme were found to be 0.2 cm3 and 0.074 cm3 for polymethylgalacturonase, 0.4 cm3 and 0.086 cm3 for polygalacturonase, and 0.63 cm3 and 0.7 cm3 for pectinlyase. The pH and temperature optima were found to be 5.3 and 30°C for polymethylgalacturonase, 6.6 and 26°C for polygalacturonase, and 4.8 and 35°C for pectinlyase. Under optimized conditions the enzyme activities were higher when compared to unoptimized conditions.

Enzyme and Microbial Technology

Performance of pectolytic enzymes during hydrolysis of pectic substances under assay conditions: A statistical approach

The synthesis of pectinase is investigated using six species of Aspergillus, with five media differing either in their carbon sources or level of carbon source(s). Five of the six species used, synthesized appreciable amounts of pectinase in the media containing sugars. Pectinase synthesis was highest for A. niger, NCIM 548, with all the sugar containing media. A. foetidus, NCIM 510, was the only one among the organisms studied, that responded well to the medium containing pectin in the absence of additional sugars supplied in the medium. © 1995 Springer-Verlag.

Effect of carbon sources on the synthesis of pectinase by Aspergilli

Ullmann's Encyclopedia of Industrial Chemistry

Cereals and Cereal Products

Applied Microbiology and Biotechnology

Effects of different carbon sources on the synthesis of pectinase by Aspergillus niger in submerged and solid state fermentations

Biotechnology Advances

Removal of fiber from vines by solid state fermentation/enzymatic degradation: A comparison of flax and kudzu retting

Effect of temperature on polygalacturonase production by Aspergillus niger

Statistical optimization of medium components for improved synthesis of pectinase by Aspergillus niger

Journal	Bioprocess Engineering
ISSN	0178515X
Open Access	No