Immobilization of pectin degrading enzyme from Bacillus licheniformis KIBGE IB-21 using agar-agar as a support

Kinetic and thermodynamic investigation of Rhodanese synthesized by enhanced Klebsiella oxytoca JCM 1665 strain: a comparative between the free and immobilized enzyme entrapped in alginate beads

Klebsiella oxytoca JCM 1665 was subjected to extracellular rhodanese production using a submerged fermentation technique. The organism was further engineered for higher cyanide tolerance and rhodanese yield using ethylmethanesulfonate as a mutagen. Mutagenesis resulted in an improved mutant with high cyanide tolerance (100 mM) and rhodanese yield (26.7 ± 0.67 U/mL). This yield was 4.34-fold higher than the wild strain (6.15 ± 0.65 U/mL). At temperatures ranging from 30 to 80 °C, the first-order thermal denaturation constant (Kd) for free enzyme increases from 0.00818 to 0.0333 min-1 while the immobilized enzyme increases from 0.003 to 0.0204 min-1. The equivalent half-life reduces from 99 to 21 minutes and 231 to 35 minutes, respectively. Residual activity tests were used to assess the thermodynamic parameters for both enzyme preparations. For the free enzyme, the parameters obtained were enthalpy (29.40 to 29.06 kJ.mol-1), entropy (-194.24 to -197.50 J.mol-1K-1) and Gibbs free energy (90.20 to 98.80 kJ.mol-1). In addition, for immobilized rhodanese, we obtained enthalpy (40.40 to 40.07 kJ.mol-1), entropy (-164.21 to - 165.20 J.mol-1K-1) and Gibbs free energy (91.80 to 98.40 kJ.mol-1. Regarding its operational stability, the enzyme was able to maintain 63% of its activity after being used for five cycles. Immobilized K. oxytoca rhodanese showed a marked resistance to heat inactivation compared to free enzyme forms; making it of utmost significance in many biotechnological applications.

Immobilization of microbial multienzyme preparation on calcium alginate beads as well as lyophilization with mosambi peel matrix improved its shelf-life and stability

The purpose of the current study was to evaluate the functional activity and storage viability (at 4 °C and 35 °C) of an immobilized as well as lyophilized multienzyme, viz., pectinase, cellulase, and amylase (PCA) that was produced by Bacillus subtilis NG105 under solid state fermentation (SSF) at 35 ℃ for 10 days using mosambi peel as a substrate. After SSF, the culture media was divided into two aliquots. From the first aliquot, the produced ME was extracted, precipitated, and further immobilized on calcium alginate beads (MEICA). In order to immobilize on mosambi peel matrix, the second aliquot was mixed with acetone and subsequently lyophilized (MELMP). Thus, ready MEICA and MELMP extracted 87.5 and 91.5% juice from mango pulp, respectively. In the reusability study, after 5 cycles, MEICA exhibited 23.8%, 24.4%, and 36.5% PCA activity, respectively. The PCA activity of MEICA and MELMP was examined after 60 days of storage at 4 ℃. The result revealed that the PCA for MEICA declined from 100 to 66%, 58.2%, and 64.5%, respectively, while for MELMP, it dropped from 100 to 84.2%, 82.1%, and 69.7%, respectively. Further, after 60 days of storage, the reduction of total protein content (TPC) in free multienzyme (FME), MEICA, and MELMP was 92.2%, 91.5%, and 36.3% observed, respectively. In the localization study, the maximum levels of multienzyme activity were found in cell exudates. This study demonstrated that immobilizing of multienzyme through lyophilization on waste substrates like mosambi peel boosted its stability and shelf-life along with greatly reducing the cost of products.

Application of Immobilized Enzymes in Juice Clarification

Immobilized enzymes are currently being rapidly developed and are widely used in juice clarification. Immobilized enzymes have many advantages, and they show great advantages in juice clarification. The commonly used methods for immobilizing enzymes include adsorption, entrapment, covalent bonding, and cross-linking. Different immobilization methods are adopted for different enzymes to accommodate their different characteristics. This article systematically reviews the methods of enzyme immobilization and the use of immobilized supports in juice clarification. In addition, the mechanisms and effects of clarification with immobilized pectinase, immobilized laccase, and immobilized xylanase in fruit juice are elaborated upon. Furthermore, suggestions and prospects are provided for future studies in this area.

Development of Pectinase Based Nanocatalyst by Immobilization of Pectinase on Magnetic Iron Oxide Nanoparticles Using Glutaraldehyde as Crosslinking Agent

To increase its operational stability and ongoing reusability, B. subtilis pectinase was immobilized on iron oxide nanocarrier. Through co-precipitation, magnetic iron oxide nanoparticles were synthesized. Scanning electron microscopy (SEM) and energy dispersive electron microscopy (EDEX) were used to analyze the nanoparticles. Pectinase was immobilized using glutaraldehyde as a crosslinking agent on iron oxide nanocarrier. In comparison to free pectinase, immobilized pectinase demonstrated higher enzymatic activity at a variety of temperatures and pH levels. Immobilization also boosted pectinase's catalytic stability. After 120 h of pre-incubation at 50 °C, immobilized pectinase maintained more than 90% of its initial activity due to the iron oxide nanocarrier, which improved the thermal stability of pectinase at various temperatures. Following 15 repetitions of enzymatic reactions, immobilized pectinase still exhibited 90% of its initial activity. According to the results, pectinase's catalytic capabilities were enhanced by its immobilization on iron oxide nanocarrier, making it economically suitable for industrial use.

Graphene oxide/chitosan composites as novel support to provide high yield and stable formulations of pectinase for industrial applications

An extracellular pectinase from a mixed consortium of Bacillus sp. (BSP) was immobilized onto graphene oxide/chitosan composite (GO/CS) through covalent binding to enhance its recycling and operational stability features. Different parameters were optimized, including cross-linker concentration (%), time, pH, and GO/CS-pectinase ratios. GO/CS-pectinase was further characterized by FT-IR and XRD. The activity of GO/CS-pectinase was reached up to 804 μmolmin^-1 with an immobilization efficiency of 80.64 ± 1.15 % under optimum conditions. GO/CS-pectinase exhibited a 3.0-folds higher half-life (t_1/2) than free pectinase at 50, 55, and 60 °C, respectively. The V_max and K_M values of GO/CS-pectinase were found to be nearly equal to the free pectinase indicating that conformational flexibility was retained. K_d, t_1/2, ∆G*, ∆H*, and ∆S* of both free pectinase and GO/CS-pectinase was 0.0339 & 0.0721 min^-1, 9.62 and 40.44 min, 81.35, 90.72 kJmol^-1, 47.098 & 63.635 kJmol^-1, -102.86 & -81.340 Jmole^-1 K^-1. SEM morphological analysis further confirmed the successful binding of pectinase with GO/CS, which retained about 92 % of its original catalytic activity after ten consecutive reaction cycles. Finally, GO/CS-pectinase was employed for guava juice clarification which exhibited the turbidity reduction up to 81 % after 75 min of treatment.

Mechano-chemical and biological energetics of immobilized enzymes onto functionalized polymers and their applications

Enzymes of commercial importance, such as lipase, amylase, laccase, phytase, carbonic anhydrase, pectinase, maltase, glucose oxidase etc., show multifunctional features and have been extensively used in several fields including fine chemicals, environmental, pharmaceutical, cosmetics, energy, food industry, agriculture and nutraceutical etc. The deployment of biocatalyst in harsh industrial conditions has some limitations, such as poor stability. These drawbacks can be overcome by immobilizing the enzyme in order to boost the operational stability, catalytic activity along with facilitating the reuse of biocatalyst. Nowadays, functionalized polymers and composites have gained increasing attention as an innovative material for immobilizing the industrially important enzyme. The different types of polymeric materials and composites are pectin, agarose, cellulose, nanofibers, gelatin, and chitosan. The functionalization of these materials enhances the loading capacity of the enzyme by providing more functional groups to the polymeric material and hence enhancing the enzyme immobilization efficiency. However, appropriate coordination among the functionalized polymeric materials and enzymes of interest plays an important role in producing emerging biocatalysts with improved properties. The optimal coordination at a biological, physical, and chemical level is requisite to develop an industrial biocatalyst. Bio-catalysis has become vital aspect in pharmaceutical and chemical industries for synthesis of value-added chemicals. The present review describes the current advances in enzyme immobilization on functionalized polymers and composites. Furthermore, the applications of immobilized enzymes in various sectors including bioremediation, biosensor and biodiesel are also discussed.

Production and immobilization of β-galactosidase isolated from Enterobacter aerogenes KCTC2190 by entrapment method using agar-agar organic matrix

In the present study, Enterobacter aerogenes KCTC2190 was isolated from soil around a cattle shed area, which was capable of producing intracellular β-galactosidase. Partially purified β-galactosidase was immobilized by entrapment method in agar-agar gel matrix. Agar-agar entrapped beads were prepared by dropping the enzyme-agar solution to ice-cooled toluene-chloroform ((3:1 (v/v)). 45.88±0.11% activity of partially purified β-galactosidase was retained after immobilization (bead shape). Maximum immobilization yield was observed in the presence of 2.5% agar-agar concentration. After immobilization, optimum temperature required for the enzyme-substrate reaction was shifted from 50 to 60 °C and the optimum reaction time was shifted from 15 to 25 min. The optimum pH for both free and immobilized β-galactosidase was pH 7. Free enzyme showed lower activation energy in comparison with the immobilized one. For free as well as immobilized β-galactosidase thermal deactivation, rate constant (k_d) increased with increasing temperature while the values of decimal reduction time (D-values) and half-lives (t_1/2) decreased. Immobilization process increased the t_1/2 and D-values of β-galactosidase while it decreased the k_d. Thermostability of immobilized β-galactosidase was higher as they showed higher enthalpy (ΔΗ⁰) and Gibb's free energy (ΔG⁰)value than those of the free β-galactosidase. The negative entropy (ΔS⁰) of free and immobilized β-galactosidase established that both were in a more ordered state within the temperature range (50 to 70 °C) studied. Immobilized β-galactosidase was able to retain 51.65±1.61% of its initial activity after 7 batches of enzyme-substrate reaction. Immobilized β-galactosidase showed 78.09±3.69% of its initial activity even after 40 days of storage at 4 °C.

Biopolymers and nanostructured materials to develop pectinases-based immobilized nano-biocatalytic systems for biotechnological applications

Pectinases are the emerging enzymes of the biotechnology industry with a 25% share in the worldwide food and beverage enzyme market. These are green and eco-friendly tools of nature and hold a prominent place among the commercially produced enzymes. Pectinases exhibit applications in various industrial bioprocesses, such as clarification of fruit juices and wine, degumming, and retting of plant fibers, extraction of antioxidants and oil, fermentation of tea/coffee, wastewater remediation, modification of pectin-laden agro-industrial waste materials for high-value products biosynthesis, manufacture of cellulose fibres, scouring, bleaching, and size reduction of fabric, cellulosic biomass pretreatment for bioethanol production, etc. Nevertheless, like other enzymes, pectinases also face the challenges of low operational stability, recoverability, and recyclability. To address the above-mentioned problems, enzyme immobilization has become an eminently promising approach to improve their thermal stability and catalytic characteristics. Immobilization facilitates easy recovery and recycling of the biocatalysts multiple times, leading to enhanced performance and commercial feasibility.In this review, we illustrate recent developments on the immobilization of pectinolytic enzymes using polymers and nanostructured materials-based carrier supports to constitute novel biocatalytic systems for industrial exploitability. The first section reviewed the immobilization of pectinases on polymers-based supports (ca-alginate, chitosan, agar-agar, hybrid polymers) as a host matrix to construct robust pectinases-based biocatalytic systems. The second half covers nanostructured supports (nano-silica, magnetic nanostructures, hybrid nanoflowers, dual-responsive polymeric nanocarriers, montmorillonite clay), and cross-linked enzyme aggregates for enzyme immobilization. The biotechnological applications of the resulted immobilized robust pectinases-based biocatalytic systems are also meticulously vetted. Finally, the concluding remarks and future recommendations are also given.

A comprehensive review on incredible renewable carriers as promising platforms for enzyme immobilization & thereof strategies

Enzymes are the highly versatile bio-catalysts having the potential for being employed in biotechnological and industrial sectors to catalyze biosynthetic reactions over a commercial point of view. Immobilization of enzymes has improved catalytic properties, retention activities, thermal and storage stabilities as well as reusabilities of enzymes in synthetic environments that have enthralled significant attention over the past few years. Dreadful efforts have been emphasized on the renewable and synthetic supports/composite materials to reserve their inherent characteristics such as biocompatibility, non-toxicity, accessibility of numerous reactive sites for profitable immobilization of biological molecules that often serve diverse applications in the pharmaceutical, environmental, and energy sectors. Supports should be endowed with unique physicochemical properties including high specific surface area, hydrophobicity, hydrophilicity, enantioselectivities, multivalent functionalization which professed them as competent carriers for enzyme immobilization. Organic, inorganic, and nano-based platforms are more potent, stable, highly recovered even after used for continuous catalytic processes, broadly renders the enzymes to get efficiently immobilized to develop an inherent bio-catalytic system that displays higher activities as compared to free-counter parts. This review highlights the recent advances or developments on renewable and synthetic matrices that are utilized for the immobilization of enzymes to deliver emerging applications around the globe.

Biocatalysis in the winemaking industry: Challenges and opportunities for immobilized enzymes

Enzymes are powerful catalysts already being used in a large number of industrial processes. Impressive advantages in enzyme catalysts improvement have occurred in recent years aiming to improve their performance under harsh operation conditions far away from those of their cellular habitat. Production levels of the winemaking industry have experienced a remarkable increase, and technological innovations have been introduced for increasing the efficiency at different process steps or for improving wine quality, which is a key issue in this industry. Enzymes, such as pectinases and proteases, have been traditionally used, and others, such as glycosidases, have been more recently introduced in the modern wine industry, and many dedicated studies refer to the improvement of enzyme performance under winemaking conditions. Within this framework, a thorough review on the role of enzymes in winemaking is presented, with special emphasis on the use of immobilized enzymes as a significant strategy for catalyst improvement within an industry in which enzymes play important roles that are to be reinforced paralleling innovation.

Maltose deterioration approach: Catalytic behavior optimization and stability profile of maltase from Bacillus licheniformis KIBGE-IB4

Maltase is an economically valuable enzyme that is used to catalyze the hydrolytic process of maltose and yields d-glucose as a product. In this study, the catalytic behavior of maltase was optimized under various physicochemical condition. Results indicated that bacterial maltase exhibited maximum catalytic activity at 45 °C and pH-6.5 after 5.0 min. It presented greater stability within 0.1 M K2HPO4 buffer having pH-6.5 and showed 100 % activity even after 1.0 h. It retained 83.6 % and 45.0 % activity at 40 °C after 1.0 and 3.0 h, respectively. The enzyme retained 90.0 % activity at -20 °C even after 60 days. The molecular weight of enzyme was deduced to be 157.2 kDa as calculated using polyacrylamide gel electrophoresis (PAGE) and zymography. It was concluded that the characterized maltase has notable stability profile with reference to temperature, pH and other reaction conditions which anticipates its utilization in various starch and maltose hydrolyzing processes for the synthesis of glucose.

Naturally-derived biopolymers: Potential platforms for enzyme immobilization

Naturally-derived biopolymers such as alginate, chitosan, cellulose, agarose, guar gum/guaran, agar, carrageenan, gelatin, dextran, xanthan, and pectins, etc. have appealed significant attention over the past several years owing to their natural abundance and availability all over the years, around the globe. In addition, their versatile properties such as non-toxicity, biocompatibility, biodegradability, flexibility, renewability, and the availability of numerous reactive sites offer significant functionalities with multipurpose applications. At present, intensive research efforts have been focused on engineering enzymes using natural biopolymers as novel support/composite materials for diverse applications in biomedical, environmental, pharmaceutical, food and biofuel/energy sectors. Immobilization appears as a straightforward and promising approach to developing biocatalysts with improved catalytic properties as compared to their free counterparts. Biopolymers-assisted enzymes are more stable, robust, and recoverable than that of free forms, and can be employed for continuous biocatalytic reactions. The present review highlights the recent developments and use of biopolymers and their advanced composites as support carriers for the immobilization of a variety of different enzymes to develop biocatalysts with desired catalytic activity and stability characteristics for emerging applications.

Transforming food waste: how immobilized enzymes can valorize waste streams into revenue streams

Food processing generates byproduct and waste streams rich in lipids, carbohydrates, and proteins, which contribute to its negative environmental impact. However, these compounds hold significant economic potential if transformed into revenue streams such as biofuels and ingredients. Indeed, the high protein, sugar, and fat content of many food waste streams makes them ideal feedstocks for enzymatic valorization. Compared to synthetic catalysts, enzymes have higher specificity, lower energy requirement, and improved environmental sustainability in performing chemical transformations, yet their poor stability and recovery limits their performance in their native state. This review article surveys the current state-of-the-art in enzyme stabilization & immobilization technologies, summarizes opportunities in enzyme-catalyzed valorization of waste streams with emphasis on streams rich in mono- and disaccharides, polysaccharides, lipids, and proteins, and highlights challenges and opportunities in designing commercially translatable immobilized enzyme systems towards the ultimate goals of sustainable food production and reduced food waste.

Pectinolytic enzymes-solid state fermentation, assay methods and applications in fruit juice industries: a review

A plethora of solid substrates, cultivation conditions and enzyme assay methods have been used for efficient production and estimation of polygalacturonase and pectin methylesterase enzymes. Recent developments in industrial biotechnology offer several opportunities for the utilization of low cost agro-industrial waste in Solid State Fermentation (SSF) for the pectinolytic enzyme production using fungi. Fruit waste mainly citrus fruit waste alone and along with other agro-industrial waste has been explored in SSF for enzyme production. Agro-industrial waste, due to the economic advantage of low procuring cost has been employed in SSF bioreactors for pectinolytic enzyme production. Acidic pectinases produced by fungi are utilized especially in food industries for clarification of fruit juices. This review focuses on the recent developments in SSF processes utilizing agro-industrial residues for polygalacturonase and pectin methylesterase production, their various assay methods and applications in fruit juice industries.

Bacillus Cellulase Molecular Cloning, Expression, and Surface Display on the Outer Membrane of Escherichia coli

One of the main challenges of using recombinant enzymes is that they are derived from genetically-modified microorganisms commonly located in the intracellular region. The use of these recombinant enzymes for commercial purposes requires the additional processes of cell disruption and purification, which may result in enzyme loss, denaturation, and increased total production cost. In this study, the cellulase gene of Bacillus licheniformis ATCC 14580 was cloned, over-expressed, and surface displayed in recombinant Escherichia coli using an ice-nucleation protein (INP). INP, an outer membrane-bound protein from Pseudomonas syringae, was utilized as an anchor linker, which was cloned with a foreign cellulase gene into the pET21a vector to develop a surface display system on the outer membrane of E. coli. The resulting strain successfully revealed cellulase on the host cell surface. The over-expressed INP-cellulase fusion protein was confirmed via staining assay for determining the extracellular cellulase and Western blotting method for the molecular weight (MW) of cellulase, which was estimated to be around 61.7 kDa. Cell fractionation and localization tests demonstrated that the INP-cellulase fusion protein was mostly present in the supernatant (47.5%) and outer membrane (19.4%), while the wild-type strain intracellularly retained enzymes within cytosol (>61%), indicating that the INP gene directed the cellulase expression on the bacteria cell surface. Further studies of the optimal enzyme activity were observed at 60 °C and pH 7.0, and at least 75% of maximal enzyme activity was preserved at 70 °C.

Micro- and nano-capsulated fungal pectinase with outstanding capabilities of eliminating turbidity in freshly produced juice

The present study aimed to compare the pectinase forms produced from Trichoderma viride-free, micro-capsule, and nano-capsule-in sodium alginate to analyze the pectin that causes the turbidity of orange juice. This was performed along with an estimation of viscosity, residual of pectin, and turbidity. The extracted and purified enzyme was 24.35-fold better than that of the crude enzyme. After application of free one, it loses most of the activity on low degrees of acidity and remains constant on the temperatures of pasteurization. Therefore, the tested enzyme was encapsulated by two different ways using the same polymer. The morphology of the three pectinase forms was obtained by transmission electron microscopy, and the micrographs clearly showed the pores on the surface of sodium alginate matrix after encapsulation. The size of the wall (sodium alginate) ranged from 3.24 to 3.76 µm diameter but was 3.15 µm for core of enzyme. Micro-capsuled and nano-capsuled pectinase can be used in the hydrolysis of pectic substances in orange juice with natural ways and maintaining the quality of final product. Consequently, the cost of juice clarifying can be reduced due to reusing the enzyme several times.

Production optimization, purification and characterization of a heat-tolerant acidic pectinase from Bacillus sp. ZJ1407

Medium compositions for a heat-tolerant acidic pectinase production from Bacillus sp. ZJ1407 were optimized via response surface methodology (RSM) and its enzymatic properties were investigated. A 2-level factorial design was used to estimate the main effect of factors, and to screen the significant factors. A central composite design was used to find out the optimal concentrations of screened key factors. Lactose, tryptone and (NH₄)₂SO₄ were found to have a significant influence on the pectinase activity (p <0.05). The optimal medium compositions were as follows: lactose 44.8g/l, tyrptone 30.9g/l, (NH₄)₂SO₄ 1.35g/l, MnSO₄·H₂O 0.2g/l, MgSO₄ 0.4g/l and NaCl 3.5g/l. Pectinase was purified to homogeneity by ammonium sulphate precipitation, DEAE-cellulose ion-exchange chromatography and Sephadex G-100 size-exclusion chromatography. The molecular weight of the purified pectinase determined by SDS-PAGE was about 23kDa, and its final specific activity was 110.47U/mg. Its optimal temperature and pH were 37°C and 5.0, respectively. Pectinase was very stable within a pH range of 3.0-5.0, and showed a high thermo-stability at 80 and 90°C. Ba²⁺ could significantly promote the activity of pectinase, and Mn²⁺ heavily inhibited its activity. This study provides new insight into the future development and use of pectinase from Bacillus sp. ZJ1407.

Production of High Commercial Value Xylooligosaccharides from Meranti Wood Sawdust Using Immobilised Xylanase

The present study explores the utilisation of a new raw material from lignocellulose biomass, Meranti wood sawdust (MWS) for high commercial value xylooligosaccharides (XOS) production using immobilised xylanase. The xylanase was immobilised by a combination of entrapment and covalent binding techniques. The hemicellulosic xylan from MWS was extracted using a standard chlorite delignification method. The production of total and derivatives of XOS from the degradation of the hemicellulosic xylan of MWS were compared to the production from the commercial xylan from Beechwood. The utilisation of the extracted xylan from MWS yielded 0.36 mg/mL of total XOS after 60 h of hydrolysis. During the hydrolysis reaction, the immobilised xylanase released a lower degree of polymerisation (DP) of XOS, mainly X2 and X3, which were the major products of xylan degradation by xylanase enzymes. The production of XOS with a lower DP from MWS demonstrated the biotechnological potential of the MWS in the future. The XOS production retained about 70% of its initial XOS production during the second cycle. This is also the first report on the utilisation of MWS wastes in enzymatic hydrolysis using immobilised xylanase for XOS production.

Utilization of agro waste pectin for the production of industrially important polygalacturonase

In the present study, a variety of agro-industrial wastes have been utilized for meaningful purpose to produce valuable biocatalyst. All wastes used were low cost and easily accessible while, some available throughout the year. A number of bacterial strains isolated from rotten fruits and vegetables were screened for the production of industrially important polygalacturonase (PGase) using pectin present in these agro-industrial wastes. The strain producing maximum PGase was identified as Bacillus licheniformis KIBE-IB3 on the basis of taxonomic studies and 16S rDNA analysis. Among different agro-industrial wastes studied, high yield of PGase was achieved from fermentation broth having wheat bran (1.0%) as a substrate in to the medium supplemented with nitrogen sources in combination of NaNO₃ and yeast extract while KH₂PO₄ was selected as suitable micronutrient. After optimizing fermentation parameters it was noticed that Bacillus licheniformis KIBE-IB3 was capable of producing maximum PGase at 37 °C, pH 7.0 and after 48 h of incubation time. From the current research, wheat bran was proven as a cheap and easily available source throughout the year for hyper production of pectinase. The utilization of the waste will also help to minimize the concerned environmental issues.

Production optimization of a heat-tolerant alkaline pectinase from Bacillus subtilis ZGL14 and its purification and characterization

Alkaline pectinase has important applications in the pretreatment of waste water from food processing and in both the fabric and paper industries. In this study, a 2-level factorial design was used to screen significant factors that affect the activity of alkaline pectinase, and the response surface methodology (RSM) with a Box-Behnken design (BBD) was used to optimize their concentrations. Starch, peptone, KH₂PO₄ and K₂HPO₄·3H₂O were found to significantly affect the activity of alkaline pectinase. Their optimal concentrations were as follows: 4.68% starch, 1.6% peptone, 0.26% KH₂PO₄ and 0.68% K₂HPO₄·3H₂O. Under the above conditions, the activity of alkaline pectinase was significantly improved to 734.11 U/mL. Alkaline pectinase was purified to homogeneity with a recovery rate of 9.6% and a specific activity of 52372.52 U/mg. Its optimal temperature and pH were 50°C and 8.6, respectively. The purified enzyme showed strong thermo-stability and good alkali resistance. In addition, the activity of alkaline pectinase was improved in the presence of Mg²⁺. Cu²⁺, Mn²⁺, and Co²⁺ significantly inhibited its activity. This study provides an important basis for the future development and use of a heat-tolerant alkaline pectinase from B. subtilis ZGL14.