Immobilization of α-galactosidase on galactose-containing polymeric beads

Properties and applications of α-galactosidase in agricultural waste processing and secondary agricultural process industries

Agriculture products form the foundation building blocks of our daily lives. Although they have been claimed to be renewable resources with a low carbon footprint, the agricultural community is constantly challenged to overcome two post-harvest bottlenecks: first, farm bio-waste, a substantial economic and environmental burden to the farming sector, and second, an inefficient agricultural processing sector, plagued by the need for significant energy input to generate the products. Both these sectors require extensive processing technologies that are demanding in their energy requirements and expensive. To address these issues, an enzyme(s)-based green chemistry is available to break down complex structures into bio-degradable compounds that source alternate energy with valuable by-products and co-products. α-Galactosidase is a widespread class of glycoside hydroxylases that hydrolyzes α-galactosyl moieties in simple and complex oligo and polysaccharides, glycolipids, and glycoproteins. As a result of its growing importance, in this review we discuss the source of the enzyme, production and purification systems, and enzyme properties. We also elaborate on the enzyme's potential in agricultural bio-waste management, secondary agricultural industries like sugar refining, soymilk derivatives, food and confectionery, and animal feed processing. Insight into this vital enzyme will provide new avenues for less expensive green chemistry-based secondary agricultural processing and agricultural sustainability. © 2023 Society of Chemical Industry.

Microbial production and biotechnological applications of α-galactosidase

α-Galactosidase, (E.C. 3.2.1.22) is an exoglycosidase that target galactooligosaccharides such as raffinose, melibiose, stachyose and branched polysaccharides like galactomannans and galacto-glucomannans by catalysing the hydrolysis of α-1,6 linked terminal galactose residues. The enzyme has been isolated and characterized from microbial, plant and animal sources. This ubiquitous enzyme possesses physiological significance and immense industrial potential. Optimization of the growth conditions and efficient purification strategies can lead to a significant increase in the enzyme production. To boost commercial productivity, cloning of novel α-galactosidase genes and their heterologous expression in suitable host has gained popularity. Enzyme immobilization leads to its greater reutilization, superior thermostability, pH tolerance and increased activity. The enzyme is well explored in food industry in the removal of raffinose family oligosaccharides (RFOs) in soymilk and sugar crystallization process. It also improves animal feed quality and biomass processing. Applications of the enzyme is in the area of biomedicine includes therapeutic advances in treatment of Fabry disease, blood group conversion and removal of α-gal type immunogenic epitopes in xenotransplantation. With considerable biotechnological applications, this enzyme has been vastly commercialized and holds greater future prospects.

Enhanced elimination of non-digestible oligosaccharides from soy milk by immobilized α-galactosidase: A comparative analysis

This study compared two immobilization matrices like calcium-alginate and chitosan for immobilization of α-galactosidase and evaluated their potential for the removal of non-digestible raffinose family oligosaccharides from soy milk which cause abdominal discomfort. The pH optima of the free and immobilized enzymes were found to be similar at pH 4.0. The chitosan-immobilized α-galactosidase displayed higher optimal temperature (60°C) compared to alginate-immobilized enzyme (45°C) and free enzyme (50°C). The chitosan-immobilized and alginate-immobilized α-galactosidases displayed 93.7% and 97.6% hydrolysis of raffinose family oligosaccharides, respectively, while the free enzyme hydrolyzed only 30.3% oligosaccharides present in soy milk in 4 hr. Remarkably, both the immobilized enzymes showed complete removal of raffinose family oligosaccharides in 8 hr. Moreover, reusability studies indicate that even after five cycles of reuse, the chitosan and alginate-immobilized enzymes displayed 99% and 60% hydrolysis, respectively. PRACTICAL APPLICATIONS: In this study, we have used two inexpensive and non-toxic matrices for immobilizing α-galactosidase. We report that entrapment of α-galactosidase with chitosan significantly improved the optimal temperature of α-galactosidase, which is advantageous in food industry. The hydrolysis of raffinose family oligosaccharides in soy milk was also greatly enhanced after immobilization with chitosan and alginate. Thus, the results described in this study have relevance for development of safe, cost-effective and efficient method for removal of non-digestible soy oligosaccharides in food industry.

Immobilization of catalase onto chitosan and chitosan-bentonite complex: A comparative study

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Characteristics of free and immobilized catalase.

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The kinetic parameters and stability of free and immobilized catalase were studied.

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FTIR spectra of free and immobilized catalase were studied.

The immobilization of catalase onto chitosan and chitosan–bentonite was investigated and immobilization yield of 95.91 and 95.26 was obtained respectively. The optimum pH and temperature were found as 7.5 and 8.0 at 40 °C for free and immobilized enzyme. The value of V_max decreased by 33,000–26,300, 24,500 μmol (min mg protein)⁻¹ and K_m increased by 12.5–25 and 20 mM for free and immobilized on chitosan and chitosan–bentonite respectively. The thermal stability, half life, FTIR analyses of the beads was also performed in order to characterise the structural differences. The remaining immobilized catalase onto chitosan and chitosan–bentonite activity was 50% and 70% after 20 cycles respectively. The storage stability were found as 22%, 60%, and 70% from its original activity in case of free enzyme and immobilization of chitosan, chitosan–bentonite beads respectively after 60 days.

Modification of chitosan-bead support materials with L-lysine and L-asparagine for α-amylase immobilization

Maltose syrups have got wide-range utilizations in a variety of applications from bakery to drug-development. α-Amylases are among the most widely utilized industrial enzymes due to their high specificity in production of maltose syrup from starch. However, enzymes are not stable in ex vivo conditions towards alteration in pH, temperature, and such other parameters as high salt concentrations and impurities, where immobilization is required to advance the stability of the enzyme with which approach the requirement of isolation of the enzyme from media is eliminated as well. In this study, Termamyl^® α-amylase was immobilized on the none-modified chitosan beads (NMCB), L-lysine-modified chitosan beads (LMCB), and L-asparagine-modified chitosan beads (AMCB) to assess effects of the support material on optimum conditions and kinetic parameters of the α-amylase activity in production of maltose from starch. Immobilization on NMCB, LMCB, and AMCB puts a strong influence on optimum pH, optimum temperature, stability, and kinetic parameters of α-amylase. Modification of chitosan beads with L-lysine and L-asparagine dramatically altered the overall immobilization yield, and enzyme's response to pH and temperature variations and the kinetic parameters. AMCB provided the best immobilization yield (49%), while LMCB only improved the yield by 2% from 22 to 24%.

Response surface methodology-based optimization of production media and purification of α-galactosidase in solid-state fermentation by Fusarium moniliforme NCIM 1099

Response surface methodology was used to enhance the production of α-galactosidase from Fusarium moniliforme NCIM 1099 in solid-state fermentation. Plackett–Burman design was employed for selection of critical media constituents which were optimized by central composite rotatable design. Wheat bran, peptone and FeSO₄·7H₂O were identified as significant medium components using PB design. Further CCRD optimized medium components as wheat bran; 4.62 μg, peptone; 315.42 μg, FeSO₄·7H₂O; 9.04 μg. RSM methodological optimization increased the enzyme production from 13.17 to 207.33 U/g showing 15.74-fold enhancement. The α-galactosidase was purified by 70% fractionation followed by DEAE anion exchange column chromatography which yields 23.33% with 28.68-fold purification. The molecular weight of α-galactosidase was 57 kDa which was determined by SDS-PAGE analysis. Purified enzyme has optimum pH of 4.0 and was found to be stable in wide pH range of 3.0–9.0. Its optimum temperature was 50 °C, whereas its activity remains above 50% up to 2 h at 75 °C. Hg²⁺ was found to be a potent inhibitor and Mg²⁺ acted as an activator of enzyme. No significant change was observed in enzyme activity for galactose concentration, ranging from 1 to 100 mM. The K_m values of enzyme for substrates p-nitrophenyl-α-d-galactopyranoside, melibiose and raffinose were 0.20, 1.36, and 3.66 mM, respectively. Low K_m and stability to various physiological conditions of enzyme represents its potential which can be exploited in various industrial applications.

Hooked on α-d-galactosidases: from biomedicine to enzymatic synthesis

α-d-Galactosidases (EC 3.2.1.22) are enzymes employed in a number of useful bio-based applications. We have depicted a comprehensive general survey of α-d-galactosidases from different origin with special emphasis on marine example(s). The structures of natural α-galactosyl containing compounds are described. In addition to 3D structures and mechanisms of action of α-d-galactosidases, different sources, natural function and genetic regulation are also covered. Finally, hydrolytic and synthetic exploitations as free or immobilized biocatalysts are reviewed. Interest in the synthetic aspects during the next years is anticipated for access to important small molecules by green technology with an emphasis on alternative selectivity of this class of enzymes from different sources.

Molecular imprinting science and technology: a survey of the literature for the years 2004-2011

Herein, we present a survey of the literature covering the development of molecular imprinting science and technology over the years 2004-2011. In total, 3779 references to the original papers, reviews, edited volumes and monographs from this period are included, along with recently identified uncited materials from prior to 2004, which were omitted in the first instalment of this series covering the years 1930-2003. In the presentation of the assembled references, a section presenting reviews and monographs covering the area is followed by sections describing fundamental aspects of molecular imprinting including the development of novel polymer formats. Thereafter, literature describing efforts to apply these polymeric materials to a range of application areas is presented. Current trends and areas of rapid development are discussed.

Immobilization of the Antarctic Bacillus sp. LX-1 α-Galactosidase on Eudragit L-100 for the Production of a Functional Feed Additive

Partially purified α-galactosidase from Bacillus sp. LX-1 was non-covalently immobilized on a reversibly soluble-insoluble polymer, Eudragit L-100, and an immobilization efficiency of 0.93 was obtained. The optimum pH of the free and immobilized enzyme was 6.5 to 7.0 and 7.0, respectively, while there was no change in optimum temperature between the free and immobilized α-galactosidase. The immobilized α-galactosidase was reutilized six times without significant loss in activity. The immobilized enzyme showed good storage stability at 37°C, retaining about 50% of its initial activity even after 18 d at this temperature, while the free enzyme was completely inactivated. The immobilization of α-galactosidase from Bacillus sp. LX-1 on Eudragit L-100 may be a promising strategy for removal of α-galacto-oligosaccharides such as raffinose and stachyose from soybean meal and other legume in feed industry.

Cicer α-galactosidase immobilization onto chitosan and Amberlite MB-150: optimization, characterization, and its applications

Cicer α-galactosidase was immobilized onto chitosan and Amberlite with immobilization efficiency of 62% and 51%, respectively. Compared to soluble enzyme, immobilized enzyme had a broader operational pH range and thermal stability. Temperature optimum for chitosan immobilized enzyme and Amberlite immobilized enzyme was 70°C, whereas it was 50°C for soluble enzyme. After 120days storage at 4°C chitosan immobilized enzyme retained 54% activity and Amberlite immobilized enzyme showed 32% activity. After using the immobilized enzymes 12 times, chitosan immobilized enzyme showed 52% activity, while Amberlite immobilized enzyme retained 22% activity with pNPGal. The immobilized enzyme exhibited higher K(m) compared to the soluble enzyme. Raffinose family oligosaccharides (RFOs) are mainly responsible for flatulence on taking of soybean derived food products. Immobilized enzyme can be used effectively for the hydrolysis of RFOs. After five runs, chitosan and Amberlite immobilized enzyme retained 53% and 34% activity, respectively with soybean RFOs. The easy availability of enzyme source, ease of its immobilization on matrices, non-toxicity and low cost of matrices, increased stability of immobilized enzyme, and effective hydrolysis of RFOs makes it a suitable product with potential applications at industries.