Partial purification of extracellular exo-inulinase from Ulocladium atrum

El-Souod, Soad M Abu; Mohamed, Tarek M.; Ali, Ehab M.M.; El-Badry, Mohammed O; El-Keiy, Mai M.

doi:10.1016/j.jgeb.2014.04.001

Cited by 24 publications

(6 citation statements)

References 26 publications

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“…A similar strong inhibition by Hg 2+ was observed for pre-purified or purified inulinases from A. niger [ 26 ], Penicillium sp. [ 27 ], and Ulocladium atrum [ 28 ], for which residual activities of only 9.0, 21.59, and 18.6% were reported, respectively.…”

Section: Discussionmentioning

confidence: 99%

Production, Biochemical Characterization, and Kinetic/Thermodynamic Study of Inulinase from Aspergillus terreus URM4658

Oliveira¹,

Silva²,

Converti

et al. 2022

Molecules

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Inulinases are enzymes involved in the hydrolysis of inulin, which can be used in the food industry to produce high-fructose syrups and fructo-oligosaccharides. For this purpose, different Aspergillus strains and substrates were tested for inulinase production by solid-state fermentation, among which Aspergillus terreus URM4658 grown on wheat bran showed the highest activity (15.08 U mL−1). The inulinase produced by this strain exhibited optimum activity at 60 °C and pH 4.0. A detailed kinetic/thermodynamic study was performed on the inulin hydrolysis reaction and enzyme thermal inactivation. Inulinase was shown to have a high affinity for substrate evidenced by very-low Michaelis constant values (0.78–2.02 mM), which together with a low activation energy (19.59 kJ mol−1), indicates good enzyme catalytic potential. Moreover, its long half-life (t1/2 = 519.86 min) and very high D-value (1726.94 min) at 60 °C suggested great thermostability, which was confirmed by the thermodynamic parameters of its thermal denaturation, namely the activation energy of thermal denaturation (E*d = 182.18 kJ mol−1) and Gibbs free energy (106.18 ≤ ΔG*d ≤ 111.56 kJ mol−1). These results indicate that A. terreus URM4658 inulinase is a promising and efficient biocatalyst, which could be fruitfully exploited in long-term industrial applications.

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Section: Discussionmentioning

confidence: 99%

Production, Biochemical Characterization, and Kinetic/Thermodynamic Study of Inulinase from Aspergillus terreus URM4658

Oliveira¹,

Silva²,

Converti

et al. 2022

Molecules

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“…Following kinetic parameters were calculated for both experimental kinetics and further validation of the best-selected mathematical models (Equations (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)):…”

Section: Calculation Of Kineticsmentioning

confidence: 99%

Inulinase production and mathematical modeling from carob extract by using Aspergillus niger

Ilgın

Germeç

Turhan

2019

Biotechnology Progress

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The main objectives of the study were to produce inulinase from carob extract by Aspergillus niger A42 (ATCC 204447) and to model the inulinase fermentation in the optimum carob extract-based medium. In the study, carob extract was used as a novel and renewable carbon source in the production of A. niger inulinase. For medium optimization, eight different variables including initial sugar concentration ( Bx), (NH 4 ) 2 HPO 4 , MgSO 4 .7H 2 O, KH 2 PO 4 , NH 4 NO 3 , yeast extract, peptone, and ZnSO 4 .7H 2 O were employed. After fermentations, optimum medium composition contained 1% yeast extract in 5 Bx carob extract. As a result of the fermentation, the maximum inulinase activity, maximum invertase-type activity, I/S ratio, maximum inulinase-and invertasetype activity rates, maximum sugar consumption rate, and sugar utilization yield were 1507.03 U/ml, 1552.86 U/ml, 0.97, 175.82 and 323.76 U/ml/day, 13.26 g/L/day, and 98.52%, respectively. Regarding mathematical modeling, the actual inulinase production and sugar consumption data were successfully predicted by Baranyi and Cone models based on the model evaluation and validation results and the predicted kinetic values, respectively. Consequently, this was the first report in which carob extract was used in the production of inulinase as a carbon source. Additionally, the best-selected models can serve as universal equations in modeling the inulinase production and sugar consumption in shake flask fermentation with carob extract medium. K E Y W O R D S Aspergillus, carob extract, flexible models, fungal inulinase, optimization 1 | INTRODUCTION Developments in the field of biotechnology play an important role in the effective use of all kinds of agricultural products and waste in the world. The agricultural products which are rich in food additive and sugar but limited in evaluation potential are used in the production of high added-value products by biotechnological processes. 1,2 The enzyme industry is the result of a rapid development seen primarily over the past four decades thanks to the evolution of modern biotechnology. This development allowed the introduction of enzymes into true industrial products and processes, for example, within the detergent, textile, and starch industries. 3 Inulinase (2,1-β-D-fructanohydrolase EC 3.2.1.7) targets on the β-2,1 linkage of inulin and hydrolyzes it into fructose. Inulin and inulinase can be used for production of either ultra-high fructose syrups, with D-fructose content over 95% by exo-enzymatic hydrolysis, or for production of oligofructose syrups by endo-enzymatic hydrolysis. 4 Inulinases are classified into endo-and exoinulinases, depending on their mode of action. Endo-inulinases (2,1-β-D-fructan fructanohydrolase; EC 3.2.1.7) are specific for inulin and hydrolyze it by breaking bonds between fructose units that are located away from the ends of the polymer network, to produce oligosaccharides. Exoinulinases (β-D-fructohydrolase; EC 3.2.1.8) split terminal fructose units from the nonreducing end of the inulin mo...

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“…This implies the need for research of new and improved inulinases. The pursuit of novel enzymes has prompted researchers to explore native fungal isolates from different habitats, which is often an important starting point ( 9 , 10 ).…”

Section: Introductionmentioning

confidence: 99%

“…The screening of potential producers among fungi starts with the isolation of fungi from different habitats, cultivation on substrates for inducible enzymes and detection of enzymatic activity in the obtained fermentation extracts, and therefore studies usually analyze a small number of fungal isolates ( 9 , 10 ). Another approach is based on direct selection during fungal growth on substrates for inducible enzymes ( in situ ) where results are evaluated in terms of colony growth by visual analysis of the formed mycelium ( 11 ) or by dyeing of nonhydrolyzed inulin after fungal growth ( 12 ).…”

Section: Introductionmentioning

confidence: 99%

Selection of Non-Mycotoxigenic Inulinase Producers in the Group of Black Aspergilli for Use in Food Processing

Stojanovic

Stepanović

Špirović-Trifunović

et al. 2022

Food Technol. Biotechnol. (Online)

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Research background. Inulinases are used for fructooligosaccharide production and they are research topic for scientific community and for industry too. Black aspergilli represent a diverse group of species which has use for enzyme production, in particular some species are known as potent inulinases producers. Finding new potential producers from the environment is as important as improving production with known strains. Safety use of enzymes provided by aspergilli in food industry is placed ahead of their benefit for inulinase production. Experimental approach. Here we shown specific approach to finding/screening of newly isolated fungal inulinase producers which combine newly developed screening method and an equally important assessment of the toxigenic potential of the fungus. In this study 39 black aspergilli collected from different substrates in Serbia were identified and assessed for inulinases production. Results and conclusions. The most common species were Aspergillus tubingensis (51.2 %), followed by A. niger (23.1 %), A. welwitschiae (23.1 %), and A. uvarum (2.6 %). Selection of the isolates for inulinases production was conducted using a cheap and easy, fast and non-hazardous alternative inulinase screening test developed in this work. For selected inulinases producing strains enzymatic activity was confirmed spectrophotometrically. Since some A. niger and A. welwitschiae are able to produce mycotoxins ochratoxin A (OTA) and fumonisins (FB), the toxigenic potential of selected inulinases producers was assessed analytically and genetically. Fungal enzyme producer could be considered as food safety only after crossing results of both approaches for toxic potential - the direct presence of mycotoxins in the enzyme preparation (analytically) and a presence of genes clusters (genetically). In some strains absence of OTA and FB production capability was molecularly confirmed by absence of complete or critical parts of biosynthetic gene clusters, respectively. The two best inulinases producers and mycotoxin non-producers (without mycotoxin production capability as additional safety) were selected as potential candidates for further development of enzyme production. Novelty and scientific contribution. Presented innovative approach for selection of potential fungal enzyme producer shows that only non-toxigenic fungi could be considered as useful in food industry. Although this study was done on local isolates, the approach is applicable globally.

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Partial purification of extracellular exo-inulinase from Ulocladium atrum

Cited by 24 publications

References 26 publications

Production, Biochemical Characterization, and Kinetic/Thermodynamic Study of Inulinase from Aspergillus terreus URM4658

Production, Biochemical Characterization, and Kinetic/Thermodynamic Study of Inulinase from Aspergillus terreus URM4658

Inulinase production and mathematical modeling from carob extract by using Aspergillus niger

Selection of Non-Mycotoxigenic Inulinase Producers in the Group of Black Aspergilli for Use in Food Processing

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