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11 pages, 1844 KiB

Open AccessArticle

Characterization of a Robust and pH-Stable Tannase from Mangrove-Derived Yeast Rhodosporidium diobovatum Q95

by Jie Pan, Ni-Na Wang, Xue-Jing Yin, Xiao-Ling Liang and Zhi-Peng Wang

Mar. Drugs 2020, 18(11), 546; https://doi.org/10.3390/md18110546 - 30 Oct 2020

Cited by 16 | Viewed by 3003

Abstract

Tannase plays a crucial role in many fields, such as the pharmaceutical industry, beverage processing, and brewing. Although many tannases derived from bacteria and fungi have been thoroughly studied, those with good pH stabilities are still less reported. In this work, a mangrove-derived [...] Read more.

Tannase plays a crucial role in many fields, such as the pharmaceutical industry, beverage processing, and brewing. Although many tannases derived from bacteria and fungi have been thoroughly studied, those with good pH stabilities are still less reported. In this work, a mangrove-derived yeast strain Rhodosporidium diobovatum Q95, capable of efficiently degrading tannin, was screened to induce tannase, which exhibited an activity of up to 26.4 U/mL after 48 h cultivation in the presence of 15 g/L tannic acid. The tannase coding gene TANRD was cloned and expressed in Yarrowia lipolytica. The activity of recombinant tannase (named TanRd) was as high as 27.3 U/mL. TanRd was purified by chromatography and analysed by SDS-PAGE, showing a molecular weight of 75.1 kDa. The specific activity of TanRd towards tannic acid was 676.4 U/mg. Its highest activity was obtained at 40 °C, with more than 70% of the activity observed at 25–60 °C. Furthermore, it possessed at least 60% of the activity in a broad pH range of 2.5–6.5. Notably, TanRd was excellently stable at a pH range from 3.0 to 8.0; over 65% of its maximum activity remained after incubation. Besides, the broad substrate specificity of TanRd to esters of gallic acid has attracted wide attention. In view of the above, tannase resources were developed from mangrove-derived yeasts for the first time in this study. This tannase can become a promising material in tannin biodegradation and gallic acid production. Full article

(This article belongs to the Special Issue Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology – II)

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26 pages, 38038 KiB

Open AccessArticle

Enzyme Bioprospection of Marine-Derived Actinobacteria from the Chilean Coast and New Insight in the Mechanism of Keratin Degradation in Streptomyces sp. G11C

by Valentina González, María José Vargas-Straube, Walter O. Beys-da-Silva, Lucélia Santi, Pedro Valencia, Fabrizio Beltrametti and Beatriz Cámara

Mar. Drugs 2020, 18(11), 537; https://doi.org/10.3390/md18110537 - 28 Oct 2020

Cited by 18 | Viewed by 4826

Abstract

Marine actinobacteria are viewed as a promising source of enzymes with potential technological applications. They contribute to the turnover of complex biopolymers, such as pectin, lignocellulose, chitin, and keratin, being able to secrete a wide variety of extracellular enzymes. Among these, keratinases are [...] Read more.

Marine actinobacteria are viewed as a promising source of enzymes with potential technological applications. They contribute to the turnover of complex biopolymers, such as pectin, lignocellulose, chitin, and keratin, being able to secrete a wide variety of extracellular enzymes. Among these, keratinases are a valuable alternative for recycling keratin-rich waste, which is generated in large quantities by the poultry industry. In this work, we explored the biocatalytic potential of 75 marine-derived actinobacterial strains, focusing mainly on the search for keratinases. A major part of the strains secreted industrially important enzymes, such as proteases, lipases, cellulases, amylases, and keratinases. Among these, we identified two streptomycete strains that presented great potential for recycling keratin wastes—Streptomyces sp. CHA1 and Streptomyces sp. G11C. Substrate concentration, incubation temperature, and, to a lesser extent, inoculum size were found to be important parameters that influenced the production of keratinolytic enzymes in both strains. In addition, proteomic analysis of culture broths from Streptomyces sp. G11C on turkey feathers showed a high abundance and diversity of peptidases, belonging mainly to the serine and metallo-superfamilies. Two proteases from families S08 and M06 were highly expressed. These results contributed to elucidate the mechanism of keratin degradation mediated by streptomycetes. Full article

(This article belongs to the Special Issue Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology – II)

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12 pages, 3778 KiB

Open AccessArticle

Characterization of a New Intracellular Alginate Lyase with Metal Ions-Tolerant and pH-Stable Properties

by Yan Ma, Jie Li, Xin-Yue Zhang, Hao-Dong Ni, Feng-Biao Wang, Hai-Ying Wang and Zhi-Peng Wang

Mar. Drugs 2020, 18(8), 416; https://doi.org/10.3390/md18080416 - 9 Aug 2020

Cited by 19 | Viewed by 3211

Abstract

Alginate lyases play an important role in alginate oligosaccharides (AOS) preparation and brown seaweed processing. Many extracellular alginate lyases have been characterized to develop efficient degradation tools needed for industrial applications. However, few studies focusing on intracellular alginate lyases have been conducted. In [...] Read more.

Alginate lyases play an important role in alginate oligosaccharides (AOS) preparation and brown seaweed processing. Many extracellular alginate lyases have been characterized to develop efficient degradation tools needed for industrial applications. However, few studies focusing on intracellular alginate lyases have been conducted. In this work, a novel intracellular alkaline alginate lyase Alyw202 from Vibrio sp. W2 was cloned, expressed and characterized. Secretory expression was performed in a food-grade host, Yarrowia lipolytica. Recombinant Alyw202 with a molecular weight of approximately 38.3 kDa exhibited the highest activity at 45 °C and more than 60% of the activity in a broad pH range of 3.0 to 10.0. Furthermore, Alyw202 showed remarkable metal ion-tolerance, NaCl independence and the capacity of degrading alginate into oligosaccharides of DP2-DP4. Due to the unique pH-stable and high salt-tolerant properties, Alyw202 has potential applications in the food and pharmaceutical industries. Full article

(This article belongs to the Special Issue Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology – II)

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19 pages, 3030 KiB

Open AccessArticle

Characterization of a New Bifunctional and Cold-Adapted Polysaccharide Lyase (PL) Family 7 Alginate Lyase from Flavobacterium sp.

by Hai-Xiang Zhou, Shan-Shan Xu, Xue-Jing Yin, Feng-Long Wang and Yang Li

Mar. Drugs 2020, 18(8), 388; https://doi.org/10.3390/md18080388 - 26 Jul 2020

Cited by 25 | Viewed by 3308

Abstract

Alginate oligosaccharides produced by enzymatic degradation show versatile physiological functions and biological activities. In this study, a new alginate lyase encoding gene alyS02 from Flavobacterium sp. S02 was recombinantly expressed at a high level in Yarrowia lipolytica, with the highest extracellular activity [...] Read more.

Alginate oligosaccharides produced by enzymatic degradation show versatile physiological functions and biological activities. In this study, a new alginate lyase encoding gene alyS02 from Flavobacterium sp. S02 was recombinantly expressed at a high level in Yarrowia lipolytica, with the highest extracellular activity in the supernatant reaching 36.8 ± 2.1 U/mL. AlyS02 was classified in the polysaccharide lyase (PL) family 7. The optimal reaction temperature and pH of this enzyme were 30 °C and 7.6, respectively, indicating that AlyS02 is a cold-adapted enzyme. Interestingly, AlyS02 contained more than 90% enzyme activity at 25 °C, higher than other cold-adapted enzymes. Moreover, AlyS02 is a bifunctional alginate lyase that degrades both polyG and polyM, producing di- and trisaccharides from alginate. These findings suggest that AlyS02 would be a potent tool for the industrial applications. Full article

(This article belongs to the Special Issue Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology – II)

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13 pages, 3862 KiB

Open AccessArticle

Isolation and Characterization of a Novel Cold-Active, Halotolerant Endoxylanase from Echinicola rosea Sp. Nov. JL3085^T

by Jianlong He, Le Liu, Xiaoyan Liu and Kai Tang

Mar. Drugs 2020, 18(5), 245; https://doi.org/10.3390/md18050245 - 6 May 2020

Cited by 9 | Viewed by 3043

Abstract

We cloned a xylanase gene (xynT) from marine bacterium Echinicola rosea sp. nov. JL3085^T and recombinantly expressed it in Escherichia coli BL21. This gene encoded a polypeptide with 379 amino acid residues and a molecular weight of ~43 kDa. Its [...] Read more.

We cloned a xylanase gene (xynT) from marine bacterium Echinicola rosea sp. nov. JL3085^T and recombinantly expressed it in Escherichia coli BL21. This gene encoded a polypeptide with 379 amino acid residues and a molecular weight of ~43 kDa. Its amino acid sequence shared 45.3% similarity with an endoxylanase from Cellvibrio mixtus that belongs to glycoside hydrolases family 10 (GH10). The XynT showed maximum activity at 40 °C and pH 7.0, and a maximum velocity of 62 μmoL min⁻¹ mg⁻¹. The XynT retained its maximum activity by more than 69%, 51%, and 26% at 10 °C, 5 °C, and 0 °C, respectively. It also exhibited the highest activity of 135% in the presence of 4 M NaCl and retained 76% of its activity after 24 h incubation with 4 M NaCl. This novel xylanase, XynT, is a cold-active and halotolerant enzyme that may have promising applications in drug, food, feed, and bioremediation industries. Full article

(This article belongs to the Special Issue Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology – II)

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12 pages, 4078 KiB

Open AccessArticle

Cloning, Secretory Expression and Characterization of a Unique pH-Stable and Cold-Adapted Alginate Lyase

by Zhi-Peng Wang, Min Cao, Bing Li, Xiao-Feng Ji, Xin-Yue Zhang, Yue-Qi Zhang and Hai-Ying Wang

Mar. Drugs 2020, 18(4), 189; https://doi.org/10.3390/md18040189 - 1 Apr 2020

Cited by 38 | Viewed by 3288

Abstract

Cold-adapted alginate lyases have unique advantages for alginate oligosaccharide (AOS) preparation and brown seaweed processing. Robust and cold-adapted alginate lyases are urgently needed for industrial applications. In this study, a cold-adapted alginate lyase-producing strain Vibrio sp. W2 was screened. Then, the gene ALYW201 [...] Read more.

Cold-adapted alginate lyases have unique advantages for alginate oligosaccharide (AOS) preparation and brown seaweed processing. Robust and cold-adapted alginate lyases are urgently needed for industrial applications. In this study, a cold-adapted alginate lyase-producing strain Vibrio sp. W2 was screened. Then, the gene ALYW201 was cloned from Vibrio sp. W2 and expressed in a food-grade host, Yarrowia lipolytica. The secreted Alyw201 showed the activity of 64.2 U/mL, with a molecular weight of approximate 38.0 kDa, and a specific activity of 876.4 U/mg. Alyw201 performed the highest activity at 30 °C, and more than 80% activity at 25–40 °C. Furthermore, more than 70% of the activity was obtained in a broad pH range of 5.0–10.0. Alyw201 was also NaCl-independent and salt-tolerant. The degraded product was that of the oligosaccharides of DP (Degree of polymerization) 2–6. Due to its robustness and its unique pH-stable property, Alyw201 can be an efficient tool for industrial production. Full article

(This article belongs to the Special Issue Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology – II)

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12 pages, 1819 KiB

Open AccessArticle

Two New Alginate Lyases of PL7 and PL6 Families from Polysaccharide-Degrading Bacterium Formosa algae KMM 3553^T: Structure, Properties, and Products Analysis

by Alexey Belik, Artem Silchenko, Olesya Malyarenko, Anton Rasin, Marina Kiseleva, Mikhail Kusaykin and Svetlana Ermakova

Mar. Drugs 2020, 18(2), 130; https://doi.org/10.3390/md18020130 - 24 Feb 2020

Cited by 38 | Viewed by 4111

Abstract

A bifunctional alginate lyase (ALFA3) and mannuronate-specific alginate lyase (ALFA4) genes were found in the genome of polysaccharide-degrading marine bacterium Formosa algae KMM 3553^T. They were classified to PL7 and PL6 polysaccharide lyases families and expressed in E. coli. The [...] Read more.

A bifunctional alginate lyase (ALFA3) and mannuronate-specific alginate lyase (ALFA4) genes were found in the genome of polysaccharide-degrading marine bacterium Formosa algae KMM 3553^T. They were classified to PL7 and PL6 polysaccharide lyases families and expressed in E. coli. The recombinant ALFA3 appeared to be active both on mannuronate- and guluronate-enriched alginates, as well as pure sodium mannuronate. For all substrates, optimum conditions were pH 6.0 and 35 °C; Km was 0.12 ± 0.01 mg/mL, and half-inactivation time was 30 min at 42 °C. Recombinant ALFA4 was active predominately on pure sodium mannuronate, with optimum pH 8.0 and temperature 30 °C, Km was 3.01 ± 0.05 mg/mL. It was stable up to 30 °C; half-inactivation time was 1 h 40 min at 37 °C. ¹H NMR analysis showed that ALFA3 degraded mannuronate and mannuronate-guluronate blocks, while ALFA4 degraded only mannuronate blocks, producing mainly disaccharides. Products of digestion of pure sodium mannuronate by ALFA3 at 200 µg/mL inhibited anchorage-independent colony formation of human melanoma cells SK-MEL-5, SK-MEL-28, and RPMI-7951 up to 17% stronger compared to native polymannuronate. This fact supports previous data and suggests that mannuronate oligosaccharides may be useful for synergic tumor therapy. Full article

(This article belongs to the Special Issue Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology – II)

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13 pages, 2654 KiB

Open AccessArticle

Characterization of a New Chitosanase from a Marine Bacillus sp. and the Anti-Oxidant Activity of Its Hydrolysate

by Chunrui Ma, Xiao Li, Kun Yang and Shangyong Li

Mar. Drugs 2020, 18(2), 126; https://doi.org/10.3390/md18020126 - 19 Feb 2020

Cited by 28 | Viewed by 3521

Abstract

Chitooligosaccharide (COS) has been recognized to exhibit efficient anti-oxidant activity. Enzymatic hydrolysis using chitosanases can retain all the amino and hydroxyl groups of chitosan, which are necessary for its activity. In this study, a new chitosanase encoding gene, csnQ, was cloned from [...] Read more.

Chitooligosaccharide (COS) has been recognized to exhibit efficient anti-oxidant activity. Enzymatic hydrolysis using chitosanases can retain all the amino and hydroxyl groups of chitosan, which are necessary for its activity. In this study, a new chitosanase encoding gene, csnQ, was cloned from the marine Bacillus sp. Q1098 and expressed in Escherichia coli. The recombinant chitosanase, CsnQ, showed maximal activity at pH 5.31 and 60 °C. Determination of CsnQ pH-stability showed that CsnQ could retain more than 50% of its activity over a wide pH, from 3.60 to 9.80. CsnQ is an endo-type chitosanase, yielding chitodisaccharide as the main product. Additionally, in vitro and in vivo analyses indicated that chitodisaccharide possesses much more effective anti-oxidant activity than glucosamine and low molecular weight chitosan (LMW-CS) (~5 kDa). Notably, to our knowledge, this is the first evidence that chitodisaccharide is the minimal COS fragment required for free radical scavenging. Full article

(This article belongs to the Special Issue Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology – II)

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12 pages, 3735 KiB

Open AccessArticle

Elucidation of a Unique Pattern and the Role of Carbohydrate Binding Module of an Alginate Lyase

by Fu Hu, Benwei Zhu, Qian Li, Heng Yin, Yun Sun, Zhong Yao and Dengming Ming

Mar. Drugs 2020, 18(1), 32; https://doi.org/10.3390/md18010032 - 30 Dec 2019

Cited by 27 | Viewed by 3357

Abstract

Alginate oligosaccharides with different degrees of polymerization (DPs) possess diverse physiological activities. Therefore, in recent years, increasing attention has been drawn to the use of enzymes for the preparation of alginate oligosaccharides for food and industrial applications. Previously, we identified and characterized a [...] Read more.

Alginate oligosaccharides with different degrees of polymerization (DPs) possess diverse physiological activities. Therefore, in recent years, increasing attention has been drawn to the use of enzymes for the preparation of alginate oligosaccharides for food and industrial applications. Previously, we identified and characterized a novel bifunctional alginate lyase Aly7A, which can specifically release trisaccharide from three different substrate types with a unique degradation pattern. Herein, we investigated its degradation pattern by modular truncation and molecular docking. The results suggested that Aly7A adopted a unique action mode towards different substrates with the substrate chain sliding into the binding pocket of the catalytic domain to position the next trisaccharide for cleavage. Deletion of the Aly7A carbohydrate binding module (CBM) domain resulted in a complex distribution of degradation products and no preference for trisaccharide formation, indicating that the CBM may act as a “controller” during the trisaccharide release process. This study further testifies CBM as a regulator of product distribution and provides new insights into well-defined generation of alginate oligosaccharides with associated CBMs. Full article

(This article belongs to the Special Issue Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology – II)

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10 pages, 1083 KiB

Open AccessArticle

Functional Characterization of Carbohydrate-Binding Modules in a New Alginate Lyase, TsAly7B, from Thalassomonas sp. LD5

by Zhelun Zhang, Luyao Tang, Mengmeng Bao, Zhigang Liu, Wengong Yu and Feng Han

Mar. Drugs 2020, 18(1), 25; https://doi.org/10.3390/md18010025 - 26 Dec 2019

Cited by 34 | Viewed by 3166

Abstract

Alginate lyases degrade alginate into oligosaccharides, of which the biological activities have vital roles in various fields. Some alginate lyases contain one or more carbohydrate-binding modules (CBMs), which assist the function of the catalytic modules. However, the precise function of CBMs in alginate [...] Read more.

Alginate lyases degrade alginate into oligosaccharides, of which the biological activities have vital roles in various fields. Some alginate lyases contain one or more carbohydrate-binding modules (CBMs), which assist the function of the catalytic modules. However, the precise function of CBMs in alginate lyases has yet to be fully elucidated. We have identified a new multi-domain alginate lyase, TsAly7B, in the marine bacterium Thalassomonas sp. LD5. This novel lyase contains an N-terminal CBM9, an internal CBM32, and a C-terminal polysaccharide lyase family 7 (PL7) catalytic module. To investigate the specific function of each of these CBMs, we expressed and characterized the full-length TsAly7B and three truncated mutants: TM1 (CBM32-PL7), TM2 (CBM9-PL7), and TM3 (PL7 catalytic module). CBM9 and CBM32 could enhance the degradation of alginate. Notably, the specific activity of TM2 was 7.6-fold higher than that of TM3. CBM32 enhanced the resistance of the catalytic module to high temperatures. In addition, a combination of CBM9 and CBM32 showed enhanced thermostability when incubated at 80 °C for 1 h. This is the first report that finds CBM9 can significantly improve the ability of enzyme degradation. Our findings provide new insight into the interrelationships of tandem CBMs and alginate lyases and other polysaccharide-degrading enzymes, which may inspire CBM fusion strategies. Full article

(This article belongs to the Special Issue Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology – II)

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15 pages, 11350 KiB

Open AccessArticle

A New β-Galactosidase from the Antarctic Bacterium Alteromonas sp. ANT48 and Its Potential in Formation of Prebiotic Galacto-Oligosaccharides

by Shangyong Li, Xiangjie Zhu and Mengxin Xing

Mar. Drugs 2019, 17(11), 599; https://doi.org/10.3390/md17110599 - 23 Oct 2019

Cited by 26 | Viewed by 4290

Abstract

As an important medical enzyme, β-galactosidases catalyze transgalactosylation to form prebiotic Galacto-Oligosaccharides (GOS) that assist in improving the effect of intestinal flora on human health. In this study, a new glycoside hydrolase family 2 (GH2) β-galactosidase-encoding gene, galA, was cloned from the [...] Read more.

As an important medical enzyme, β-galactosidases catalyze transgalactosylation to form prebiotic Galacto-Oligosaccharides (GOS) that assist in improving the effect of intestinal flora on human health. In this study, a new glycoside hydrolase family 2 (GH2) β-galactosidase-encoding gene, galA, was cloned from the Antarctic bacterium Alteromonas sp. ANT48 and expressed in Escherichia coli. The recombinant β-galactosidase GalA was optimal at pH 7.0 and stable at pH 6.6–7.0, which are conditions suitable for the dairy environment. Meanwhile, GalA showed most activity at 50 °C and retained more than 80% of its initial activity below 40 °C, which makes this enzyme stable in normal conditions. Molecular docking with lactose suggested that GalA could efficiently recognize and catalyze lactose substrates. Furthermore, GalA efficiently catalyzed lactose degradation and transgalactosylation of GOS in milk. A total of 90.6% of the lactose in milk could be hydrolyzed within 15 min at 40 °C, and the GOS yield reached 30.9%. These properties make GalA a good candidate for further applications. Full article

(This article belongs to the Special Issue Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology – II)

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11 pages, 646 KiB

Open AccessArticle

Unraveling the Detoxification Mechanism of 2,4-Dichlorophenol by Marine-Derived Mesophotic Symbiotic Fungi Isolated from Marine Invertebrates

by Efstratios Nikolaivits, Andreas Agrafiotis, Aikaterini Termentzi, Kyriaki Machera, Géraldine Le Goff, Pedro Álvarez, Suchana Chavanich, Yehuda Benayahu, Jamal Ouazzani, Nikolas Fokialakis and Evangelos Topakas

Mar. Drugs 2019, 17(10), 564; https://doi.org/10.3390/md17100564 - 30 Sep 2019

Cited by 14 | Viewed by 3543

Abstract

Chlorophenols (CPs) are environmental pollutants that are produced through various anthropogenic activities and introduced in the environment. Living organisms, including humans, are exposed to these toxic xenobiotics and suffer from adverse health effects. More specifically, 2,4-dichlorophenol (2,4-DCP) is released in high amounts in [...] Read more.

Chlorophenols (CPs) are environmental pollutants that are produced through various anthropogenic activities and introduced in the environment. Living organisms, including humans, are exposed to these toxic xenobiotics and suffer from adverse health effects. More specifically, 2,4-dichlorophenol (2,4-DCP) is released in high amounts in the environment and has been listed as a priority pollutant by the US Environmental Protection Agency. Bioremediation has been proposed as a sustainable alternative to conventional remediation methods for the detoxification of phenolic compounds. In this work, we studied the potential of fungal strains isolated as symbionts of marine invertebrates from the underexplored mesophotic coral ecosystems. Hence, the unspecific metabolic pathways of these fungal strains are being explored in the present study, using the powerful analytical capabilities of a UHPLC-HRMS/MS. The newly identified 2,4-DCP metabolites add significantly to the knowledge of the transformation of such pollutants by fungi, since such reports are scarce. Full article

(This article belongs to the Special Issue Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology – II)

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13 pages, 4178 KiB

Open AccessArticle

The Characterization and Modification of a Novel Bifunctional and Robust Alginate Lyase Derived from Marinimicrobium sp. H1

by Junjun Yan, Peng Chen, Yan Zeng, Yan Men, Shicheng Mu, Yueming Zhu, Yefu Chen and Yuanxia Sun

Mar. Drugs 2019, 17(10), 545; https://doi.org/10.3390/md17100545 - 23 Sep 2019

Cited by 48 | Viewed by 4574

Abstract

Alginase lyase is an important enzyme for the preparation of alginate oligosaccharides (AOS), that possess special biological activities and is widely used in various fields, such as medicine, food, and chemical industry. In this study, a novel bifunctional alginate lyase (AlgH) belonging to [...] Read more.

Alginase lyase is an important enzyme for the preparation of alginate oligosaccharides (AOS), that possess special biological activities and is widely used in various fields, such as medicine, food, and chemical industry. In this study, a novel bifunctional alginate lyase (AlgH) belonging to the PL7 family was screened and characterized. The AlgH exhibited the highest activity at 45 °C and pH 10.0, and was an alkaline enzyme that was stable at pH 6.0–10.0. The enzyme showed no significant dependence on metal ions, and exhibited unchanged activity at high concentration of NaCl. To determine the function of non-catalytic domains in the multi-domain enzyme, the recombinant AlgH-I containing only the catalysis domain and AlgH-II containing the catalysis domain and the carbohydrate binding module (CBM) domain were constructed and characterized. The results showed that the activity and thermostability of the reconstructed enzymes were significantly improved by deletion of the F5/8 type C domain. On the other hand, the substrate specificity and the mode of action of the reconstructed enzymes showed no change. Alginate could be completely degraded by the full-length and modified enzymes, and the main end-products were alginate disaccharide, trisaccharide, and tetrasaccharide. Due to the thermo and pH-stability, salt-tolerance, and bifunctionality, the modified alginate lyase was a robust enzyme which could be applied in industrial production of AOS. Full article

(This article belongs to the Special Issue Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology – II)

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Review

Jump to: Research

22 pages, 1221 KiB

Open AccessReview

Application-Oriented Marine Isomerases in Biocatalysis

by Antonio Trincone

Mar. Drugs 2020, 18(11), 580; https://doi.org/10.3390/md18110580 - 21 Nov 2020

Cited by 5 | Viewed by 3374

Abstract

The class EC 5.xx, a group of enzymes that interconvert optical, geometric, or positional isomers are interesting biocatalysts for the synthesis of pharmaceuticals and pharmaceutical intermediates. This class, named “isomerases,” can transform cheap biomolecules into expensive isomers with suitable stereochemistry useful in synthetic [...] Read more.

The class EC 5.xx, a group of enzymes that interconvert optical, geometric, or positional isomers are interesting biocatalysts for the synthesis of pharmaceuticals and pharmaceutical intermediates. This class, named “isomerases,” can transform cheap biomolecules into expensive isomers with suitable stereochemistry useful in synthetic medicinal chemistry, and interesting cases of production of l-ribose, d-psicose, lactulose, and d-phenylalanine are known. However, in two published reports about potential biocatalysts of marine origin, isomerases are hardly mentioned. Therefore, it is of interest to deepen the knowledge of these biocatalysts from the marine environment with this specialized in-depth analysis conducted using a literature search without time limit constraints. In this review, the focus is dedicated mainly to example applications in biocatalysis that are not numerous confirming the general view previously reported. However, from this overall literature analysis, curiosity-driven scientific interest for marine isomerases seems to have been long-standing. However, the major fields in which application examples are framed are placed at the cutting edge of current biotechnological development. Since these enzymes can offer properties of industrial interest, this will act as a promoter for future studies of marine-originating isomerases in applied biocatalysis. Full article

(This article belongs to the Special Issue Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology – II)

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