Effect of carbon sources on the synthesis of pectinase by Aspergilli
TL;DR: 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.
Abstract: 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.
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01 Apr 2016
TL;DR: In this paper, pektin liyaz (PL) yerel su kaynaklarından izole edilen Aspergillus fumigatus 2101 suşundan elde edildi, amonyum sülfat çöktürmesi, jel filtrasyon ve iyon değişim kromatografisi kullanılarak saflaştırıldı.
Abstract: Bu çalışmada, pektin liyaz (PL) yerel su kaynaklarından izole edilen Aspergillus fumigatus 2101 suşundan elde edildi. PL, amonyum sülfat çöktürmesi, jel filtrasyon ve iyon değişim kromatografisi kullanılarak saflaştırıldı. Bu saflaştırma basamaklarından sonra, 12.4 saflaştırma katsayısı elde edildi. PL’nin optimum pH ve sıcaklığı sırasıyla 8.0 ve 40 ̊C’de 70 dakikadır. PL’nin molekül ağırlığı 11.5 kDa’dur. Sıvı besi ortamında maksimum PL aktivitesi meyve pulpları ile elde edilmiştir. Stabilite deneyleri, PL’nin 4 ̊C’de 20 aya kadar kararlı olduğunu göstermiştir. En yüksek PL aktivitesi karbon kaynağı olarak sitrus pectin kullanıldığında elde edilmiştir. PL, FeSO 4 , FeCl 3 ve askorbik asit tarafından güçlü bir şekilde aktive edilmiştir.
1 citations
Cites background from "Effect of carbon sources on the syn..."
...Aspergillus and Penicillium genus are preferred for industrial applications [7]....
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01 Jan 2023
TL;DR: In this paper , the authors classified the enzymes involved in the degradation of pectin as polysaccharide, polygalacturon, lyases, and protopectinase based on their mode of action.
Abstract: Enzymes are considered the backbone of green technology. Enzymes of microbial origin are being exploited in various industrial and environmental processes. They are used to degrade low-value polymers into valuable products or improve industrial processes. Pectin, the substrate of pectinase, is a polysaccharide usually found in the plant cell walls that acts as a cementing substance for binding the microfibrils of cellulose, hemicellulose, and protein. Structurally pectin is a diverse and complex polymer. Therefore, the enzymes involved in its degradation have evolved according to its structure and complexity. They are classified as pectin esterase, polygalacturonase, lyases, and protopectinase based on their mode of action. For industrial applications, they are classified as acidic and alkaline pectinases which find application in various industrial processes including fruit juice, tea, plant fiber retting, cotton fiber bioscouring, plant virus recovery, deinking of recycled paper, processing of pectin industry effluent from fruit juice industries and paper production, and a feed supplement. Due to their diverse nature and applications, various attempts have been made to optimize their production in submerged and solid-state fermentations in order to meet the industrial demand. Fungi are prime producers; therefore, the diversity, production, characterization, and applications are discussed.
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TL;DR: Three assay procedures are described that permit quantitative assay of hydrolytic and β-eliminative pectic enzymes, respectively, and can guide purification strategies, particularly when used in conjunction with titration curves.
Abstract: Publisher Summary The characterization and purification of a pectic enzyme is often complicated by the presence of other pectic enzymes produced by the source microorganism. This chapter describes three assay procedures that address this problem. Pectic enzymes from Erwinia spp. is used as examples in the chapter. The assays are readily adapted to the analysis of pectic enzyme complexes of other organisms and can be used with crude preparations. Results from plant tissue extracts should be interpreted cautiously, however, because of the prevalence of pectic enzyme inhibitors. The activity stains in the first procedure enable rapid approximation of the number and type of pectic enzymes in the sample and can guide purification strategies, particularly when used in conjunction with titration curves. The second and third procedures permit quantitative assay of hydrolytic and β-eliminative pectic enzymes, respectively. The action patterns of purified pectic enzymes are determined by viscometric and reaction product analyses; oligogalacturonides are resolved by paper chromatography or thin-layer chromatography and detected with bromphenol blue or thiobarbituric acid spray reagent.
303 citations
TL;DR: Results indicate that regulatory phenomena, such as induction-repression or activation-inhibition, related to pectinase synthesis by A. niger CH4 are different in the two types of fermentation.
Abstract: A study was made to compare the production of pectinase by Aspergillus niger CH4 in solid-state (SSF) and submerged (SmF) fermentations. Production of endo- (endo-p) and exo-pectinase (exo-p) by SSF was not reduced when glucose, sucrose or galacturonic acid (up to 10%) were added to a culture medium containing pectin. Moreover, both activities increased when concentrations of the carbon sources were also increased. In SmF, these activities were strongly decreased when glucose or sucrose (3%) was added to culture medium containing pectin. The addition of galacturonic acid affected endo-p activity production to a lesser extend than exo-p. Final endo-p and exo-p activities in SSF were three and 11 times higher, respectively, than those obtained in SmF. The overall productivities of SSF were 18.8 and 4.9 times higher for endo-p and exo-p, respectively, than those in SmF. These results indicate that regulatory phenomena, such as induction-repression or activation-inhibition, related to pectinase synthesis by A. niger CH4 are different in the two types of fermentation.
218 citations
TL;DR: A process was developed for the production of polygalacturonase by Aspergillus niger and its mutant VTT-D-77050 and the enzyme mixture produced in one pilot fermentation was used successfully for improving the cloud stability of fruit nectars.
106 citations
"Effect of carbon sources on the syn..." refers background in this paper
...Although many yeasts, some bacteria and a large variety of filamentous fungi are known to synthesize pectic enzymes, the most preferred industrial choice rests on fungi of the genus Aspergillus [ 1 , 2]. Another important factor influencing the synthesis of pectic enzymes in the mixture is the medium composition, particularly the carbon and nitrogen sources [3, 4]. Studies have been conducted by different workers using both synthetic and ......
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TL;DR: This review deals mainly with the literature which has appeared since the discovery of pectin lyases in 1960 and it is emphasized that the choice of substrates and reaction conditions, as well as that of methods of analysis, to a large extent influence the values found for a number of enzyme properties.
Abstract: This review deals mainly with the literature which has appeared since the discovery of pectin lyases in 1960. Those papers have been selected which are reports of investigations carried out with purified enzyme preparations and rather well defined substrates. According to their action on high polymer pectic substances, the enzymes are placed in one of six different groups. Mutual relationships of some of the groups are discussed. It is emphasized that the choice of substrates and reaction conditions, as well as that of methods of analysis, to a large extent influence the values found for a number of enzyme properties. Trends for future research are outlined.
80 citations
01 Mar 1978
TL;DR: It is suggested that catabolite repression of polygalacturonase occurs at the level of translation and that of acid protease at transcription in an adenine-requiring mutant of Aspergillus niger.
Abstract: A comparative study was made on catabolite repression of acid protease and polygalacturonase in an adenine-requiring mutant of Aspergillus niger. Both enzymes are inducible and accumulated extracellularly after cessation of growth caused by adenine starvation. Addition of glucose, fructose, or intermediates of glycolysis, but not tricarboxylic acid cycle intermediates, depressed the formation of both enzymes. Catabolite repression of polygalacturonase by glucose occurred quickly and was almost complete. However, acid protease was only partly repressed even after several hours. Formation of polygalacturonase in the presence of actinomycin S3 or during deinduction was repressed by glucose, whereas that of acid protease was not. In the course of induction of acid protease by peptone, glucose did not affect the length of the induction lag period and the rate of acid protease formation decreased by glucose was not restored by the addition of large amounts of inducer. From these results, we suggest that catabolite repression of polygalacturonase occurs at the level of translation and that of acid protease at transcription.
33 citations