Overexpression, purification and characterization of a recombinant secretary catalase from Bacillus subtilis

Catalase immobilization: Current knowledge, key insights, applications, and future prospects - A review

Catalase (CAT), a ubiquitous enzyme in all oxygen-exposed organisms, effectively decomposes hydrogen peroxide (H2O2), a harmful by-product, into water and oxygen, mitigating oxidative stress and cellular damage, safeguarding cellular organelles and tissues. Therefore, CAT plays a crucial role in maintaining cellular homeostasis and function. Owing to its pivotal role, CAT has garnered considerable interest. However, many challenges arise when used, especially in multiple practical processes. "Immobilization", a widely-used technique, can help improve enzyme properties. CAT immobilization offers numerous advantages, including enhanced stability, reusability, and facilitated downstream processing. This review presents a comprehensive overview of CAT immobilization. It starts with discussing various immobilization mechanisms, support materials, advantages, drawbacks, and factors influencing the performance of immobilized CAT. Moreover, the review explores the application of the immobilized CAT in various industries and its prospects, highlighting its essential role in diverse fields and stimulating further research and investigation. Furthermore, the review highlights some of the world's leading companies in the field of the CAT industry and their substantial potential for economic contribution. This review aims to serve as a discerning, source of information for researchers seeking a comprehensive cutting-edge overview of this rapidly evolving field and have been overwhelmed by the size of publications.

Expression and biochemical characterization of a Bacillus subtilis catalase in Pichia pastoris X-33

Catalase, which catalyzes the decomposition of H₂O₂ to H₂O and O₂, is widely used to reduce H₂O₂ in industrial applications, such as in food processing, textile dyeing and wastewater treatment. In this study, the catalase (KatA) from Bacillus subtilis was cloned and expressed in the yeast Pichia pastoris X-33. The effect of the promoter in the expression plasmid on the activity level of the secreted KatA protein was also studied. First, the gene encoding KatA was cloned and inserted into a plasmid containing an inducible alcohol oxidase 1 promoter (pAOX1) or a constitutive glyceraldehyde-3-phosphate dehydrogenase promoter (pGAP). The recombinant plasmids were validated by colony PCR and sequencing and then linearized and transformed into the yeast P. pastoris X-33 for expression. With the promoter pAOX1, the maximum yield of KatA in the culture medium reached 338.8 ± 9.6 U/mL in 2 days of shake flask cultivation, which was approximately 2.1-fold greater than the maximum yield obtained with the promoter pGAP. The expressed KatA was then purified from the culture medium by anion exchange chromatography, and its specific activity was determined to be 14826.58 U/mg. Finally, the purified KatA exhibited optimum activity at 25 °C and pH 11.0. Its K_m for hydrogen peroxide was 10.9 ± 0.5 mM, and its k_cat/K_m was 5788.1 ± 25.6 s^-1 mM^-1. Through the work presented in this article, we have therefore demonstrated efficient expression and purification of KatA in P. pastoris, which might be advantageous for scaling up the production of KatA for use in a variety of biotechnological applications.

Cloning and expression of the catalase gene (KatA) from Pseudomonas aeruginosa and the degradation of AFB1 by recombinant catalase

BACKGROUND

Aflatoxin B₁ (AFB₁ ) poses a severe threat to human and animal health. Countries worldwide have invested considerable manpower and material resources in degrading aflatoxins. Enzyme degradation is the most efficient and environmentally friendly approach for modifying aflatoxin into less toxic molecules. Catalase is commonly used as a detoxification agent to decrease the contamination levels of aflatoxins in animal feeds. This study aimed to obtain recombinant catalase via gene engineering and determined whether a recombinant catalase could degrade AFB₁ .

RESULTS

The catalase gene (KatA) from Pseudomonas aeruginosa was cloned and expressed in Escherichia coli, and the expression conditions of this recombinant catalase were optimized. The recombinant catalase was isolated and purified using Ni-chelating affinity chromatography, and its ability to degrade AFB₁ was evaluated. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the expressed of catalase was approximately 55.6 kDa, which was subsequently purified using Ni-chelating affinity chromatography. The degradation rate of AFB₁ by recombinant catalase in the presence of syringaldehyde was 38.79%.

CONCLUSION

The degradation of AFB₁ by a recombinant catalase has been reported for the first time. This study provides a new paradigm for the use of recombinant catalases in degrading AFB₁ in food and feed. © 2022 Society of Chemical Industry.

Physiological roles of catalases Cat1 and Cat2 in Myxococcus xanthus

Catalases are key antioxidant enzymes in aerobic organisms. Myxococcus xanthus expresses two monofunctional catalases, small-subunit Cat1 and large-subunit Cat2. The K_m of H₂O₂ for recombinant Cat1 and Cat2 were 14.0 and 9.0 mM, respectively, and the catalytic efficiency of Cat2 (k_cat/K_m = 500 sec^-1 mM^-1) was 4-fold higher than that of Cat1. The activity ratio of Cat1 to Cat2 in the exponential growth phase of M. xanthus was 1 to 3-4. A Cat1-deficient strain was constructed, whereas a Cat2-deficient strain could not be produced In H₂O₂-supplemented medium, the cat1 mutant exhibited marked growth retardation and a longer generation time than the wild-type (wt) strain. After 2 h of incubation in 0.5 mM H₂O₂-supplemented medium, the catalase activity of the wt strain significantly increased (by 64-fold), but that of the cat1 mutant strain did not. Under starvation-induced developmental conditions, catalase activity was induced by approximately 200-fold in both wt and cat1 strains, although in the mutant the activity increase as well as spore formation occurred one day later, indicating that the induction of catalase activity during starvation was due to Cat2. In wt starved cells, catalase activity was not induced by H₂O₂. These results suggest that Cat2 is the primary housekeeping catalase during M. xanthus growth and starvation-induced development, whereas Cat1 may have a complementary role, being responsible for the rapid degradation of H₂O₂ in proliferating vegetative cells subjected to oxidative stress.

Engineering Bacillus subtilis ATCC 6051a for the production of recombinant catalases

Catalases are a large group of enzymes that decompose hydrogen peroxide to oxygen and hydrogen, and have been applied widely in numerous areas. Bacillus subtilis ATCC 6051a is a well-known host strain for high level secretion of heterologous peptides. However, the application of 6051a was seriously hampered by insufficient transformation efficiency. In this study, D-xylose inducible comK was integrated into the genome of B. subtilis ATCC 6051a, generating 164S, a mutant owns a transformation efficiency of 1 000-fold higher than its parent strain, thus allowing gene replacement by double crossover recombination using linear dsDNAs. The efficiency of the flanking arms for homologous recombination was then analyzed. We found that 400 bp was the minimal length of homologous fragments required to initiate efficient recombination in the 164S strain. In addition, DNA cassettes encoding two mesophilic catalases (Orf 2-62 and Orf 2-63) from B. licheniformis were integrated onto 164S. The catalytic properties of recombinant Orf 2-62 and Orf 2-63 were analyzed, and were found to be predominantly secreted into the fermentation broth, although they obviously lack any known secretory signal peptide. This work demonstrated that B. subtilis 164S is an excellent cell tool, not only for its superior secretion capacity, but also for its convenience in genetic modification.

Self-Driven "Microfiltration" Enabled by Porous Superabsorbent Polymer (PSAP) Beads for Biofluid Specimen Processing and Storage

A remote collection of biofluid specimens such as blood and urine remains a great challenge due to the requirement of continuous refrigeration. Without proper temperature regulation, the rapid degradation of analytical targets in the specimen may compromise the accuracy and reliability of the testing results. In this study, we develop porous superabsorbent polymer (PSAP) beads for fast and self-driven "microfiltration" of biofluid samples. This treatment effectively separates small analytical targets (e.g., glucose, catalase, and bacteriophage) and large undesired components (e.g., bacteria and blood cells) in the biofluids by capturing the former inside and excluding the latter outside the PSAP beads. We have successfully demonstrated that this treatment can reduce sample volume, self-aliquot the liquid sample, avoid microbial contamination, separate plasma from blood cells, stabilize target species inside the beads, and enable long-term storage at room temperature. Potential practical applications of this technology can provide an alternative sample collection and storage approach for medically underserved areas.

High production, purification, biochemical characterization and gene analysis of a novel catalase from the thermophilic bacterium Ureibacillus thermosphaericus FZSF03

A catalase-producing thermophilic bacterium, Ureibacillus thermosphaericus FZSF03, was isolated from high-temperature compost. Catalase production in this strain increased 31 times and reached 57,630U/mL after optimization in a shake flask, which might represent the highest catalase activity level among reported wild strains. This catalase was further purified and identified. The purified enzyme showed a specific activity of 219,360U/mg, higher than many other catalases. The molecular weight of this enzyme is 52kDa according to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and the enzyme was identified as a monofunctional haeme catalase of Ureibacillus thermosphaericus by liquid chromatography-mass spectrometry (LC-MS)/MS. The optimal reaction temperature for this catalase was found to be 60°C. Stability was observed at 60°C and at a pH of 10.0, indicating the superiority of this enzyme at a high temperature and under alkaline conditions. Therefore, this catalase is a prospective candidate for industrial production and applications. The gene encoding this catalase is 1503bp. As the amino acid sequence shows low similarity with other catalases, we suggest that this is a novel monofunctional haeme catalase.

Catalase purification from rat liver with iron-chelated poly(hydroxyethyl methacrylate-N-methacryloyl-(l)-glutamic acid) cryogel discs

In this study, iron-chelated poly(hydroxyethyl methacrylate-N-methacryloyl-(l)-glutamic acid) (PHEMAGA/Fe(3+)) cryogel discs were prepared. The PHEMAGA/Fe(3+) cryogel discs were characterized by elemental analysis, scanning electron microscopy, Fourier transform infrared spectroscopy, swelling tests, and surface area measurements. The PHEMAGA/Fe(3+) cryogel discs had large pores ranging from 10 to 100 µm with a swelling degree of 9.36 g H2O/g cryogel. Effects of pH, temperature, initial catalase concentration, and flow rate on adsorption capacity of the PHEMAGA/Fe(3+) cryogel discs were investigated. Maximum catalase adsorption capacity (62.6 mg/g) was obtained at pH 7.0, 25°C, and 3 mg/ml initial catalase concentration. The PHEMAGA/Fe(3+) cryogel discs were also tested for the purification of catalase from rat liver. After tissue homogenization, purification of catalase was performed using the PHEMAGA/Fe(3+) cryogel discs and catalase was obtained with a yield of 54.34 and 16.67 purification fold.

Cloning, Expression, and Characterization of a Novel Thermophilic Monofunctional Catalase from Geobacillus sp. CHB1

Catalases are widely used in many scientific areas. A catalase gene (Kat) from Geobacillus sp. CHB1 encoding a monofunctional catalase was cloned and recombinant expressed in Escherichia coli (E. coli), which was the first time to clone and express this type of catalase of genus Geobacillus strains as far as we know. This Kat gene was 1,467 bp in length and encoded a catalase with 488 amino acid residuals, which is only 81% similar to the previously studied Bacillus sp. catalase in terms of amino acid sequence. Recombinant catalase was highly soluble in E. coli and made up 30% of the total E. coli protein. Fermentation broth of the recombinant E. coli showed a high catalase activity level up to 35,831 U/mL which was only lower than recombinant Bacillus sp. WSHDZ-01 among the reported catalase production strains. The purified recombinant catalase had a specific activity of 40,526 U/mg and K m of 51.1 mM. The optimal reaction temperature of this recombinant enzyme was 60°C to 70°C, and it exhibited high activity over a wide range of reaction temperatures, ranging from 10°C to 90°C. The enzyme retained 94.7% of its residual activity after incubation at 60°C for 1 hour. High yield and excellent thermophilic properties are valuable features for this catalase in industrial applications.

Heterologous expression and characterization of a new heme-catalase in Bacillus subtilis 168

Reactive oxygen species (ROS) is an inherent consequence to all aerobically living organisms that might lead to the cells being lethal and susceptible to oxidative stress. Bacillus pumilus is characterized by high-resistance oxidative stress that stimulated our interest to investigate the heterologous expression and characterization of heme-catalase as potential biocatalyst. Results indicated that recombinant enzyme significantly exhibited the high catalytic activity of 55,784 U/mg expressed in Bacillus subtilis 168 and 98.097 µmol/min/mg peroxidatic activity, the apparent K  m of catalytic activity was 59.6 ± 13 mM with higher turnover rate (K  cat = 322.651 × 103 s−1). The pH dependence of catalatic and peroxidatic activity was pH 7.0 and pH 4.5 respectively with temperature dependence of 40 °C and the recombinant heme-catalase exhibited a strong Fe2+ preference. It was further revealed that catalase KatX2 improved the resistance oxidative stress of B. subtilis. These findings suggest that this B. pumilus heme-catalase can be considered among the industrially relevant biocatalysts due to its exceptional catalytic rate and high stability and it can be a potential candidate for the improvement of oxidative resistance of industrially produced strains.

Enzymatic exploration of catalase from a nanoparticle producing and biodecolorizing algae Shewanella xiamenensis BC01

Shewanella xiamenensis (SXM) was found to produce nanoparticles (NPs) under aerobic condition. The oxidoreductase enzymatic activities including of catalase, manganese peroxidase, laccase, NADH dehydrogenase, flavin reductase, azoreductase and Fe reductase are first investigated. Catalase showed the greatest enzymatic activity among all oxidoreductases in SXM, which with strong activities in multiple substrates of ABTS, guaiacol and 2,6-DMP. The optimum temperature, pH, concentrations of H2O2 and 2,6-DMP for this enzyme were found to be 65 °C, pH 4.0, 128.7 mM and 10 mM, respectively. Finally, from the kinetic parameters and structure simulation of catalase, implied that SXM would potentially apply in bioremediation, microbe fuel cells (MFCs) and nano-biotechnology based on its distinguished enzymatic system.

New bacteria Bacillus nitroreducens PLC9 with hydrogen peroxide-degrading activity with high survival rate in hydrogen peroxide

Bacteria were isolated from wastewater containing highly concentrated hydrogen peroxide that had been used to clean the pure water delivery system in a semiconductor plant. One bacterium was selected for its high hydrogen peroxide degradation activity. In the presence of 1% hydrogen peroxide, it degraded 72.5% in 5 min. It showed 100% viability after 6 h at 1% hydrogen peroxide. Even at 3% hydrogen peroxide, it survived for more than 6 h. This bacterium was named as Bacillus nitroreducens PLC9 since its 16S rRNA showed 100% similarity with the recently reported new species B. nitroreducens. Purified catalase from B. nitroreducens PLC9 was characterized as a thermo-alkali-stable hydroperoxidase type II catalase, and it is suggested as a new type of catalase based on following: (1) it is stable over a broad pH range (pH 4-11); (2) it is consisted of homodimers with a molecular weight of 66 kDa (total molecular weight, 134 kDa); (3) its activity was not inhibited by 3-amino-1,2,4-triazole; and (4) its N-terminal sequence has never been reported before. Both B. nitroreducens PLC9 and the isolated catalase can be used for efficient degradation of hydrogen peroxide at high concentrations.

Enzymatic synthesis of glycosylated puerarin using maltogenic amylase from Bacillus stearothermophilus expressed in Bacillus subtilis

BACKGROUND

The maltogenic amylase from Bacillus stearothermophilus (BSMA) is a valuable biocatalyst that has been used to transglycosylate natural glycosides to improve solubility. To ensure safety, BSMA was produced in Bacillus subtilis, using new shuttle vector-based expression vectors. The transglycosylation of puerarin was also conducted with crude BSMA and analyzed.

RESULTS

Two expression systems, each containing one of the promoters from the genes encoding Bacillus licheniformis maltogenic amylase (BLMA) and an alpha-amylase from B. subtilis NA64 (amyR2), were constructed. The amyR2 promoter system was chosen as the best system; it yielded 107 mg of pure BSMA from a 2 L culture. In the transglycosylation reactions of puerarin using crude BSMA, relative amounts for maltosyl-alpha-(1 --> 6)-puerarin, glucosyl-alpha-(1 --> 6)-puerarin, glucosyl-alpha-(1 --> 3)-puerarin, and puerarin were determined as 26:18:7:49. A two-step purification process, including gel permeation chromatography, yielded 1.7 g of the transfer products from 3 g of puerarin.

CONCLUSION

The crude BSMA produced from a host generally recognized as safe (B. subtilis) can be used to transglycosylate various functional compounds. The expression system developed in this study will be helpful for the production of other food-grade enzymes by B. subtilis.

Retracted Article: On the enzymatic activity of catalase: an iron L-edge X-ray absorption study of the active centre

Fe L_2,3-edge X-ray absorption spectra of a catalase active centre in a physiological solution reveals a partial ferryl character, which stems from the proximal tyrosine residue.