Debaryomyces nepalensis was previously isolated, which is capable of producing pectin lyase and pectate lyase using pectin as sole source of carbon. The parameters affecting the activity of these enzymes are categorized into two, viz., chemical (amount of substrate and enzyme) and physical (pH of reaction mixture and temperature of incubation). The effect of these parameters on pectin lyase and pectate lyase was studied using central composite design. The optimal conditions of amount of substrate and enzyme (culture broth) were found to be 545 μl (∼1 g/l pectin) and 123 μl for pectin lyase and 707 μl (∼1.1 g/l polygalacturonic acid) and 96 μl for pectate lyase. The optimum pH and temperature for reaction was found to be 6.4 and 35 °C for pectin lyase and 7.5 and 32 °C for pectate lyase. After optimization, the activity of pectin lyase and pectate lyase was increased by 1.3- and 1.4-fold, respectively. © 2006 Elsevier B.V. All rights reserved.

Sathyanarayana Naidu Gummadi

Department Of Biotechnology

Dinesh J.R.S.S. Kumar

carbon

Optimization

pH effects

Reaction kinetics

Statistical methods

Central composite design

chemical parameters

PECTATE LYASE

Pectin

PECTIN LYASE

Physical parameters

POLYGALACTURONIC ACID

Response surface methodology

TRANSELIMINATION REACTION

Enzymes

article

Biotechnology

composite material

DEBARYOMYCES NEPALENSIS

enzyme activity

enzyme substrate

enzyme synthesis

fungal metabolism

Fungus

fungus culture

nonhuman

pH measurement

priority journal

process design

Process optimization

reaction analysis

statistical analysis

temperature dependence

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

Biochemical Engineering Journal

Debaryomyces nepalensis, osmotolerant yeast isolated from rotten apple, is known to utilize both hexoses and pentoses and produce industrially important metabolites like ethanol, xylitol and arabitol. In the present study, the effect of different growth substrates, trace elements, nitrogen concentration and initial pH on growth and formation of ethanol and arabitol were examined. Optimum conditions for maximizing the product yields were established: glucose as carbon source, an initial pH of 6.0, 6 g/L of ammonium sulphate and addition of micronutrients. Under these best suited conditions, a concentration of 11g/L of arabitol and 19 g/L of ethanol was obtained in shake flask fermentations. The fermentation was scaled up to 2.5 L bioreactor and the influence of aeration, agitation and initial substrate concentration was also determined. Under optimal conditions (150 g/L glucose, 400 rpm and 0.5 vvm) ethanol concentration reached 52 g/L, which corresponds to a yield of 0.34 g/g and volumetric productivity of 0.28 g/L/h, whereas arabitol production reached a maximum of 14 g/L with a yield and volumetric productivity of 0.1 g/g and 0.07 g/L/h respectively. © 2013 Kumdam et al.; licensee Springer.

Fulltext

AMB Express

Production of ethanol and arabitol by Debaryomyces nepalensis: Influence of process parameters

Previously, we isolated caffeine degrading Pseudomonas strain from soil of coffee plantation area, which could utilize caffeine as sole carbon and nitrogen source and could tolerate caffeine up to 20 g/L. In this study, caffeine degradation by immobilized cells of this strain was investigated. Various matrices were considered and agar-agar was chosen based on degradation rate (0.08 g/(L h)), bead stability and reusability. Further, immobilization parameters, viz., bead size (mm), agar-agar concentration % (w/v) and cell concentration (g/L) were optimized using central composite design. The optimal conditions of cell concentration, agar-agar concentration and bead size were 7.8 g/L, 5% (w/v) and 6.2 mm. Under optimal conditions, caffeine degradation rate was found to 0.15 g/(L h), which closely agrees with the model predicted values. This is the first report on caffeine degradation at high concentrations (10 g/L) by immobilized cells of Pseudomonas sp. Immobilization efficiency was 80%. Damköhler number is very much higher than 1, suggesting that mass transfer is the rate limiting process. © 2008 Elsevier B.V. All rights reserved.

Enhanced degradation of caffeine by immobilized cells of Pseudomonas sp. in agar-agar matrix using statistical approach

Polysaccharide degrading enzymes are hydrolytic enzymes, which have a lot of industrial potential and also play a crucial role in carbon recycling. Pectinases, chitinases and glucanases are the three major polysaccharide degrading enzymes found abundantly in nature and these enzymes are mainly produced by fungal strains. Production of these enzymes by yeasts is advantageous over fungi, because the former are easily amenable to genetic manipulations and time required for growth and production is less than that of the latter. Several yeasts belonging to Saccharomyces, Pichia, Rhodotorula and Cryptococcus produce extracellular pectinases, glucanases and chitinases. This chapter emphasizes on the biological significance of these enzymes, their production and their industrial applications. © 2009 Springer Netherlands.

Yeast Biotechnology: Diversity and Applications

Industrially important carbohydrate degrading enzymes from yeasts: Pectinases, chitinases, and β-1,3-glucanases

The effect of various parameters such as pH, agitation and aeration was studied for maximum production of pectin lyase (PL) and pectate lyase (PGL) by a novel yeast strain Debaryomyces nepalensis in bioreactor. The optimal levels of pH, aeration and agitation rate was found to be 7.0, 300 rpm and 1 vvm, respectively. Under these conditions, D. nepalensis produced 14,200 U/L of PL and 12,000 U/L of PGL corresponding to a productivity of 600 U/L h and 500 U/L h of PL and PGL, respectively. Fed-batch production was studied by feeding inducer (lemon peel), carbon source (galactose) individually and in combination at 12 h of growth for enhanced production of PL and PGL. Combined feeding of inducer and carbon source at 12 h was found to be the best strategy for enhanced production of PL and PGL. Under these conditions, production of PL and PGL increased to 23,300 U/L and 22,400 U/L, respectively which corresponded to a productivity of 728 U/L h of PL and 700 U/L h of PGL, respectively. The production was increased by 1.6- and 1.8-fold and productivity by 1.2- and 1.4-fold for PL and PGL, respectively when compared to batch culture. © 2007 Elsevier Ltd. All rights reserved.

Bioresource Technology

Batch and fed batch production of pectin lyase and pectate lyase by novel strain Debaryomyces nepalensis in bioreactor

Bacillus sp. KCA102 capable of producing thermostable amylase in a short fermentation time (∼18-20 h) has been isolated from a soil sample. The performance of amylase during hydrolysis of starch has been studied using response surface methodology. The parameters under study have been categorized into two, viz., physical parameters (pH, temperature and time) and chemical parameters (amounts of substrate and enzyme). The optimal conditions of pH, temperature and time at which maximum amount of glucose formed were found to be 7.1, 57.5°C and 25 min, respectively. The optimal amounts of substrate and enzyme for maximum hydrolysis were found to be 0.5% starch and 94 mU/ml of amylase, respectively. © 2004 Elsevier Ltd. All rights reserved.

Process Biochemistry

Hydrolysis of starch by amylase from Bacillus sp. KCA102: A statistical approach

Pectic transeliminases, also known as pectic lyases or pectinases, are involved in the degradation of pectic substances. They have a wide range of applications in food and textile processing. Although Aspergillus and Penicillium spp. produce pectin lyases, bacteria are the major producers of polygalacturonate lyase. The yields of pectic transeliminases are less than other pectinases. Since new applications for pectic transeliminases are emerging, an improved process for the production of these enzymes is necessary. © Springer 2005.

Biotechnology Letters

Microbial pectic transeliminases

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.

Purification and biochemical properties of microbial pectinases - A review

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

Pectolytic enzymes play an important role in food processing industries and alcoholic beverage industries. These enzymes degrade pectin and reduce the viscosity of the solution so that it can be handled easily. These enzymes are mainly synthesized by plants and microorganisms. Aspergillus niger is used for industrial production of pectolytic enzymes. This fungus produces polygalacturonase, polymethylgalacturonase and pectinlyase. This review mainly concerns with the production of pectolytic enzymes using different carbon sources. It also deals with the effect of operating parameters such as temperature, aeration rate, agitation and type of fermentation on the production of these enzymes.

Bioprocess Engineering

Production of pectolytic enzymes - A review

Optimization of chemical and physical parameters affecting the activity of pectin lyase and pectate lyase from Debaryomyces nepalensis: A statistical approach

Journal	Biochemical Engineering Journal
ISSN	1369703X
Open Access	No