E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Special Issue "Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology"

A special issue of Marine Drugs (ISSN 1660-3397).

Deadline for manuscript submissions: 30 June 2019

Special Issue Editor

Guest Editor
Dr. Antonio Trincone

Istituto di Chimica Biomolecolare, Consiglio Nazionale delle Ricerche, Comprensorio Olivetti, Edificio 70, Via Campi Flegrei 34, I-80078 Pozzuoli, Napoli, Italy
Website | E-Mail
Fax: +39 081 8041770
Interests: biocatalysis; marine enzymes; marine glycosidases; marine biotechnology; oligosaccharides

Special Issue Information

Dear Colleagues,

The interdisciplinary study of the complexity of marine habitats has increased knowledge of marine forms of life. Marine-originating biocatalysts are attractive to biocatalysis practitioners for novel biochemical and stereochemical features. An in-depth knowledge of the precise biological functions of genes, proteins and enzymes within the marine ecosystem is still considered one of the least developed fields of research; even though in recent years marine habitat has been recognized as an untapped source of novel enzymes and metabolites. Expanding the range of enzymes from marine organisms is one of the key points in future marine biotechnology roadmaps. In particular, the importance of marine biocatalysts is recognized when addressing the exploration of chemical and biological diversity for novel materials and products, and for biomass production and processing, both used in foresight analyses for future research in this field. Convincing examples, such as the specific diversity of molecular assets of biocatalysis using marine enzymes with respect to terrestrial counterparts, are increasingly reported in the literature regarding all marine sources (not only microorganisms and fungi, plants and animals, but also extremophiles and symbiotic microorganisms). Indeed the plasticity of biological adaptations of marine organisms to the wide range of environmental events in specific environments (temperature, salinity, tides, pressure, radiation, light, etc.) provides an enormous reservoir of interesting subjects for basic and applicative studies.

Processes using marine enzymes and marine biomasses are central in different biotechnological fields of applications: (i) in a biorefinery value-chain with marine enzymes for biochemical processes; (ii) in food industries for enzymatic procedures in seafood processing; (iii) in fields of fine chemicals—in pharmaceutical, cosmetics, agriculture and environmental sectors—enzymatic treatments are a tool to improve efficiency and selectivity for extraction/manipulation of structurally complex marine molecules to gain access to bioactive compounds and to provide complex core blocks for hemisynthesis; (iv) the field of marine biomarkers and applications in pollution monitoring (biosensor) and bioremediation could also be of high significance for the appreciation of marine sources for enzymes.

Preeminent conclusions by many scientists in the field of marine biotechnology emphasize that due to marine biological diversity and the specificity of biological metabolisms, the study of marine biocatalysts on a global scale is just starting and possesses huge potential for development and applications with industrial benefits.

In this Special Issue, along with contributions regarding the potential of marine enzymes as useful tools in biocatalysis, results of enzymatic bioprospecting in gross marine environments will also be acknowledged. In addition, studies about structural characterizations, biological functions and aspects related to the complexity of marine enzyme-based bioprocesses will be hosted.

Dr. Antonio Trincone
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Marine Drugs is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (13 papers)

View options order results:
result details:
Displaying articles 1-13
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle A Novel Cold-Adapted Leucine Dehydrogenase from Antarctic Sea-Ice Bacterium Pseudoalteromonas sp. ANT178
Mar. Drugs 2018, 16(10), 359; https://doi.org/10.3390/md16100359
Received: 13 September 2018 / Revised: 27 September 2018 / Accepted: 27 September 2018 / Published: 1 October 2018
PDF Full-text (4499 KB) | HTML Full-text | XML Full-text
Abstract
l-tert-leucine and its derivatives are useful as pharmaceutical active ingredients, in which leucine dehydrogenase (LeuDH) is the key enzyme in their enzymatic conversions. In the present study, a novel cold-adapted LeuDH, psleudh, was cloned from psychrotrophic bacteria Pseudoalteromonas sp.
[...] Read more.
l-tert-leucine and its derivatives are useful as pharmaceutical active ingredients, in which leucine dehydrogenase (LeuDH) is the key enzyme in their enzymatic conversions. In the present study, a novel cold-adapted LeuDH, psleudh, was cloned from psychrotrophic bacteria Pseudoalteromonas sp. ANT178, which was isolated from Antarctic sea-ice. Bioinformatics analysis of the gene psleudh showed that the gene was 1209 bp in length and coded for a 42.6 kDa protein containing 402 amino acids. PsLeuDH had conserved Phe binding site and NAD+ binding site, and belonged to a member of the Glu/Leu/Phe/Val dehydrogenase family. Homology modeling analysis results suggested that PsLeuDH exhibited more glycine residues, reduced proline residues, and arginine residues, which might be responsible for its catalytic efficiency at low temperature. The recombinant PsLeuDH (rPsLeuDH) was purified a major band with the high specific activity of 275.13 U/mg using a Ni-NTA affinity chromatography. The optimum temperature and pH for rPsLeuDH activity were 30 °C and pH 9.0, respectively. Importantly, rPsLeuDH retained at least 40% of its maximum activity even at 0 °C. Moreover, the activity of rPsLeuDH was the highest in the presence of 2.0 M NaCl. Substrate specificity and kinetic studies of rPsLeuDH demonstrated that l-leucine was the most suitable substrate, and the catalytic activity at low temperatures was ensured by maintaining a high kcat value. The results of the current study would provide insight into Antarctic sea-ice bacterium LeuDH, and the unique properties of rPsLeuDH make it a promising candidate as a biocatalyst in medical and pharmaceutical industries. Full article
Figures

Figure 1

Open AccessArticle Characterization of Properties and Transglycosylation Abilities of Recombinant α-Galactosidase from Cold-Adapted Marine Bacterium Pseudoalteromonas KMM 701 and Its C494N and D451A Mutants
Mar. Drugs 2018, 16(10), 349; https://doi.org/10.3390/md16100349
Received: 16 August 2018 / Revised: 20 September 2018 / Accepted: 21 September 2018 / Published: 24 September 2018
PDF Full-text (2797 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A novel wild-type recombinant cold-active α-d-galactosidase (α-PsGal) from the cold-adapted marine bacterium Pseudoalteromonas sp. KMM 701, and its mutants D451A and C494N, were studied in terms of their structural, physicochemical, and catalytic properties. Homology models of the three-dimensional α-PsGal structure, its
[...] Read more.
A novel wild-type recombinant cold-active α-d-galactosidase (α-PsGal) from the cold-adapted marine bacterium Pseudoalteromonas sp. KMM 701, and its mutants D451A and C494N, were studied in terms of their structural, physicochemical, and catalytic properties. Homology models of the three-dimensional α-PsGal structure, its active center, and complexes with D-galactose were constructed for identification of functionally important amino acid residues in the active site of the enzyme, using the crystal structure of the α-galactosidase from Lactobacillus acidophilus as a template. The circular dichroism spectra of the wild α-PsGal and mutant C494N were approximately identical. The C494N mutation decreased the efficiency of retaining the affinity of the enzyme to standard p-nitrophenyl-α-galactopiranoside (pNP-α-Gal). Thin-layer chromatography, matrix-assisted laser desorption/ionization mass spectrometry, and nuclear magnetic resonance spectroscopy methods were used to identify transglycosylation products in reaction mixtures. α-PsGal possessed a narrow acceptor specificity. Fructose, xylose, fucose, and glucose were inactive as acceptors in the transglycosylation reaction. α-PsGal synthesized -α(1→6)- and -α(1→4)-linked galactobiosides from melibiose as well as -α(1→6)- and -α(1→3)-linked p-nitrophenyl-digalactosides (Gal2-pNP) from pNP-α-Gal. The D451A mutation in the active center completely inactivated the enzyme. However, the substitution of C494N discontinued the Gal-α(1→3)-Gal-pNP synthesis and increased the Gal-α(1→4)-Gal yield compared to Gal-α(1→6)-Gal-pNP. Full article
Figures

Figure 1

Open AccessArticle Biochemical Characterization and Degradation Pattern of a Novel Endo-Type Bifunctional Alginate Lyase AlyA from Marine Bacterium Isoptericola halotolerans
Mar. Drugs 2018, 16(8), 258; https://doi.org/10.3390/md16080258
Received: 28 June 2018 / Revised: 21 July 2018 / Accepted: 27 July 2018 / Published: 31 July 2018
PDF Full-text (3918 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Alginate lyases are important tools to prepare oligosaccharides with various physiological activities by degrading alginate. Particularly, the bifunctional alginate lyase can efficiently hydrolyze the polysaccharide into oligosaccharides. Herein, we cloned and identified a novel bifunctional alginate lyase, AlyA, with a high activity and
[...] Read more.
Alginate lyases are important tools to prepare oligosaccharides with various physiological activities by degrading alginate. Particularly, the bifunctional alginate lyase can efficiently hydrolyze the polysaccharide into oligosaccharides. Herein, we cloned and identified a novel bifunctional alginate lyase, AlyA, with a high activity and broad substrate specificity from bacterium Isoptericola halotolerans NJ-05 for oligosaccharides preparation. For further applications in industry, the enzyme has been characterized and its action mode has been also elucidated. It exhibited the highest activity (7984.82 U/mg) at pH 7.5 and 55 °C. Additionally, it possessed a broad substrate specificity, showing high activities towards not only polyM (polyβ-d-mannuronate) (7658.63 U/mg), but also polyG (poly α-l-guluronate) (8643.29 U/mg). Furthermore, the Km value of AlyA towards polyG (3.2 mM) was lower than that towards sodium alginate (5.6 mM) and polyM (6.7 mM). TLC (Thin Layer Chromatography) and ESI-MS (Electrospray Ionization Mass Spectrometry) were used to study the action mode of the enzyme, showing that it can hydrolyze the substrates in an endolytic manner to release a series of oligosaccharides such as disaccharide, trisaccharide, and tetrasaccharide. This study provided extended insights into the substrate recognition and degrading pattern of the alginate lyases, with a broad substrate specificity. Full article
Figures

Figure 1

Open AccessArticle Biochemical Characterization and Degradation Pattern of a Unique pH-Stable PolyM-Specific Alginate Lyase from Newly Isolated Serratia marcescens NJ-07
Mar. Drugs 2018, 16(4), 129; https://doi.org/10.3390/md16040129
Received: 28 March 2018 / Revised: 11 April 2018 / Accepted: 12 April 2018 / Published: 15 April 2018
Cited by 2 | PDF Full-text (18465 KB) | HTML Full-text | XML Full-text
Abstract
Enzymatic preparation of alginate oligosaccharides with versatile bioactivities by alginate lyases has attracted increasing attention due to its featured characteristics, such as wild condition and specific products. In this study, AlgNJ-07, a novel polyM-specific alginate lyase with high specific activity and pH stability,
[...] Read more.
Enzymatic preparation of alginate oligosaccharides with versatile bioactivities by alginate lyases has attracted increasing attention due to its featured characteristics, such as wild condition and specific products. In this study, AlgNJ-07, a novel polyM-specific alginate lyase with high specific activity and pH stability, has been purified from the newly isolated marine bacterium Serratia marcescens NJ-07. It has a molecular weight of approximately 25 kDa and exhibits the maximal activity of 2742.5 U/mg towards sodium alginate under 40 °C at pH 9.0. Additionally, AlgNJ-07 could retain more than 95% of its activity at pH range of 8.0–10.0, indicating it possesses excellent pH-stability. Moreover, it shows high activity and affinity towards polyM block and no activity to polyG block, which suggests that it is a strict polyM-specific alginate lyase. The degradation pattern of AlgNJ-07 has also been explored. The activity of AlgNJ-07 could be activated by NaCl with a low concentration (100–300 mM). It can be observed that AlgNJ-07 can recognize the trisaccharide as the minimal substrate and hydrolyze the trisaccharide into monosaccharide and disaccharide. The TLC and ESI-MS analysis indicate that it can hydrolyze substrates in a unique endolytic manner, producing not only oligosaccharides with Dp of 2–5 but also a large fraction of monosaccharide. Therefore, it may be a potent tool to produce alginate oligosaccharides with lower Dps (degree of polymerization). Full article
Figures

Figure 1

Open AccessArticle AlgM4: A New Salt-Activated Alginate Lyase of the PL7 Family with Endolytic Activity
Mar. Drugs 2018, 16(4), 120; https://doi.org/10.3390/md16040120
Received: 6 March 2018 / Revised: 3 April 2018 / Accepted: 3 April 2018 / Published: 6 April 2018
Cited by 1 | PDF Full-text (4685 KB) | HTML Full-text | XML Full-text
Abstract
Alginate lyases are a group of enzymes that catalyze the depolymerization of alginates into oligosaccharides or monosaccharides. These enzymes have been widely used for a variety of purposes, such as producing bioactive oligosaccharides, controlling the rheological properties of polysaccharides, and performing structural analyses
[...] Read more.
Alginate lyases are a group of enzymes that catalyze the depolymerization of alginates into oligosaccharides or monosaccharides. These enzymes have been widely used for a variety of purposes, such as producing bioactive oligosaccharides, controlling the rheological properties of polysaccharides, and performing structural analyses of polysaccharides. The algM4 gene of the marine bacterium Vibrio weizhoudaoensis M0101 encodes an alginate lyase that belongs to the polysaccharide lyase family 7 (PL7). In this study, the kinetic constants Vmax (maximum reaction rate) and Km (Michaelis constant) of AlgM4 activity were determined as 2.75 nmol/s and 2.72 mg/mL, respectively. The optimum temperature for AlgM4 activity was 30 °C, and at 70 °C, AlgM4 activity dropped to 11% of the maximum observed activity. The optimum pH for AlgM4 activity was 8.5, and AlgM4 was completely inactive at pH 11. The addition of 1 mol/L NaCl resulted in a more than sevenfold increase in the relative activity of AlgM4. The secondary structure of AlgM4 was altered in the presence of NaCl, which caused the α-helical content to decrease from 12.4 to 10.8% and the β-sheet content to decrease by 1.7%. In addition, NaCl enhanced the thermal stability of AlgM4 and increased the midpoint of thermal denaturation (Tm) by 4.9 °C. AlgM4 exhibited an ability to degrade sodium alginate, poly-mannuronic acid (polyM), and poly-guluronic acid (polyG), resulting in the production of oligosaccharides with a degree of polymerization (DP) of 2–9. AlgM4 possessed broader substrate, indicating that it is a bifunctional alginate lyase. Thus, AlgM4 is a novel salt-activated and bifunctional alginate lyase of the PL7 family with endolytic activity. Full article
Figures

Figure 1

Open AccessArticle Purification and Characterization of a Novel Alginate Lyase from the Marine Bacterium Bacillus sp. Alg07
Mar. Drugs 2018, 16(3), 86; https://doi.org/10.3390/md16030086
Received: 9 February 2018 / Revised: 28 February 2018 / Accepted: 5 March 2018 / Published: 9 March 2018
Cited by 3 | PDF Full-text (1968 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Alginate oligosaccharides with different bioactivities can be prepared through the specific degradation of alginate by alginate lyases. Therefore, alginate lyases that can be used to degrade alginate under mild conditions have recently attracted public attention. Although various types of alginate lyases have been
[...] Read more.
Alginate oligosaccharides with different bioactivities can be prepared through the specific degradation of alginate by alginate lyases. Therefore, alginate lyases that can be used to degrade alginate under mild conditions have recently attracted public attention. Although various types of alginate lyases have been discovered and characterized, few can be used in industrial production. In this study, AlgA, a novel alginate lyase with high specific activity, was purified from the marine bacterium Bacillus sp. Alg07. AlgA had a molecular weight of approximately 60 kDa, an optimal temperature of 40 °C, and an optimal pH of 7.5. The activity of AlgA was dependent on sodium chloride and could be considerably enhanced by Mg2+ or Ca2+. Under optimal conditions, the activity of AlgA reached up to 8306.7 U/mg, which is the highest activity recorded for alginate lyases. Moreover, the enzyme was stable over a broad pH range (5.0–10.0), and its activity negligibly changed after 24 h of incubation at 40 °C. AlgA exhibited high activity and affinity toward poly-β-d-mannuronate (polyM). These characteristics suggested that AlgA is an endolytic polyM-specific alginate lyase (EC 4.2.2.3). The products of alginate and polyM degradation by AlgA were purified and identified through fast protein liquid chromatography and electrospray ionization mass spectrometry, which revealed that AlgA mainly produced disaccharides, trisaccharides, and tetrasaccharide from alginate and disaccharides and trisaccharides from polyM. Therefore, the novel lysate AlgA has potential applications in the production of mannuronic oligosaccharides and poly-α-l-guluronate blocks from alginate. Full article
Figures

Figure 1

Open AccessArticle A Comparative Study on Asymmetric Reduction of Ketones Using the Growing and Resting Cells of Marine-Derived Fungi
Mar. Drugs 2018, 16(2), 62; https://doi.org/10.3390/md16020062
Received: 16 January 2018 / Revised: 1 February 2018 / Accepted: 3 February 2018 / Published: 14 February 2018
Cited by 2 | PDF Full-text (1084 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Whole-cell biocatalysts offer a highly enantioselective, minimally polluting route to optically active alcohols. Currently, most of the whole-cell catalytic performance involves resting cells rather than growing cell biotransformation, which is one-step process that benefits from the simultaneous growth and biotransformation, eliminating the need
[...] Read more.
Whole-cell biocatalysts offer a highly enantioselective, minimally polluting route to optically active alcohols. Currently, most of the whole-cell catalytic performance involves resting cells rather than growing cell biotransformation, which is one-step process that benefits from the simultaneous growth and biotransformation, eliminating the need for catalysts preparation. In this paper, asymmetric reduction of 14 aromatic ketones to the corresponding enantiomerically pure alcohols was successfully conducted using the growing and resting cells of marine-derived fungi under optimized conditions. Good yields and excellent enantioselectivities were achieved with both methods. Although substrate inhibition might be a limiting factor for growing cell biotransformation, the selected strain can still completely convert 10-mM substrates into the desired products. The resting cell biotransformation showed a capacity to be recycled nine times without a significant decrease in the activity. This is the first study to perform asymmetric reduction of ketones by one-step growing cell biotransformation. Full article
Figures

Figure 1

Open AccessArticle Purification and Characterization of a Biofilm-Degradable Dextranase from a Marine Bacterium
Mar. Drugs 2018, 16(2), 51; https://doi.org/10.3390/md16020051
Received: 18 November 2017 / Revised: 27 January 2018 / Accepted: 31 January 2018 / Published: 7 February 2018
PDF Full-text (7623 KB) | HTML Full-text | XML Full-text
Abstract
This study evaluated the ability of a dextranase from a marine bacterium Catenovulum sp. (Cadex) to impede formation of Streptococcus mutans biofilms, a primary pathogen of dental caries, one of the most common human infectious diseases. Cadex was purified 29.6-fold and had a
[...] Read more.
This study evaluated the ability of a dextranase from a marine bacterium Catenovulum sp. (Cadex) to impede formation of Streptococcus mutans biofilms, a primary pathogen of dental caries, one of the most common human infectious diseases. Cadex was purified 29.6-fold and had a specific activity of 2309 U/mg protein and molecular weight of 75 kDa. Cadex showed maximum activity at pH 8.0 and 40 °C and was stable at temperatures under 30 °C and at pH ranging from 5.0 to 11.0. A metal ion and chemical dependency study showed that Mn2+ and Sr2+ exerted positive effects on Cadex, whereas Cu2+, Fe3+, Zn2+, Cd2+, Ni2+, and Co2+ functioned as inhibitors. Several teeth rinsing product reagents, including carboxybenzene, ethanol, sodium fluoride, and xylitol were found to have no effects on Cadex activity. A substrate specificity study showed that Cadex specifically cleaved the α-1,6 glycosidic bond. Thin layer chromatogram and high-performance liquid chromatography indicated that the main hydrolysis products were isomaltoogligosaccharides. Crystal violet staining and scanning electron microscopy showed that Cadex impeded the formation of S. mutans biofilm to some extent. In conclusion, Cadex from a marine bacterium was shown to be an alkaline and cold-adapted endo-type dextranase suitable for development of a novel marine agent for the treatment of dental caries. Full article
Figures

Graphical abstract

Open AccessArticle Microbial Degradation of Amino Acid-Containing Compounds Using the Microcystin-Degrading Bacterial Strain B-9
Mar. Drugs 2018, 16(2), 50; https://doi.org/10.3390/md16020050
Received: 25 November 2017 / Revised: 25 January 2018 / Accepted: 30 January 2018 / Published: 6 February 2018
Cited by 2 | PDF Full-text (2745 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Strain B-9, which has a 99% similarity to Sphingosinicella microcystinivorans strain Y2, is a Gram-negative bacterium with potential for use in the degradation of microcystin-related compounds and nodularin. We attempted to extend the application area of strain B-9 and applied it to mycotoxins
[...] Read more.
Strain B-9, which has a 99% similarity to Sphingosinicella microcystinivorans strain Y2, is a Gram-negative bacterium with potential for use in the degradation of microcystin-related compounds and nodularin. We attempted to extend the application area of strain B-9 and applied it to mycotoxins produced by fungi. Among the tested mycotoxins, only ochratoxin A was completely hydrolyzed to provide the constituents ochratoxin α and l-phenylalanine, and levels of fumonisin B1 gradually decreased after 96 h. However, although drugs including antibiotics released into the aquatic environment were applied for microbial degradation using strain B-9, no degradation occurred. These results suggest that strain B-9 can only degrade amino acid-containing compounds. As expected, the tested compounds with amide and ester bonds, such as 3,4-dimethyl hippuric acid and 4-benzyl aspartate, were readily hydrolyzed by strain B-9, although the sulfonamides remained unchanged. The ester compounds were characteristically and rapidly hydrolyzed as soon as they came into contact with strain B-9. Furthermore, the degradation of amide and ester compounds with amino acids was not inhibited by the addition of ethylenediaminetetraacetic acid (EDTA), indicating that the responsible enzyme was not MlrC. These results suggest that strain B-9 possesses an additional hydrolytic enzyme that should be designated as MlrE, as well as an esterase. Full article
Figures

Figure 1

Open AccessArticle Optimization of Collagenase Production by Pseudoalteromonas sp. SJN2 and Application of Collagenases in the Preparation of Antioxidative Hydrolysates
Mar. Drugs 2017, 15(12), 377; https://doi.org/10.3390/md15120377
Received: 18 October 2017 / Revised: 6 November 2017 / Accepted: 29 November 2017 / Published: 4 December 2017
Cited by 1 | PDF Full-text (2049 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Collagenases are the most important group of commercially-produced enzymes. However, even though biological resources are abundant in the sea, very few of these commercially popular enzymes are from marine sources, especially from marine bacteria. We optimized the production of marine collagenases by Pseudoalteromonas
[...] Read more.
Collagenases are the most important group of commercially-produced enzymes. However, even though biological resources are abundant in the sea, very few of these commercially popular enzymes are from marine sources, especially from marine bacteria. We optimized the production of marine collagenases by Pseudoalteromonas sp. SJN2 and investigated the antioxidant activities of the hydrolysates. Media components and culture conditions associated with marine collagenase production by Pseudoalteromonas sp. SJN2 were optimized by statistical methods, namely Plackett–Burman design and response surface methodology (RSM). Furthermore, the marine collagenases produced by Pseudoalteromonas sp. SJN2 were seen to efficiently hydrolyze marine collagens extracted from fish by-products, and remarkable antioxidant capacities of the enzymatic hydrolysates were shown by DPPH radical scavenging and oxygen radical absorbance capacity (ORAC) tests. The final optimized fermentation conditions were as follows: soybean powder, 34.23 g·L−1; culture time, 3.72 d; and temperature, 17.32 °C. Under the optimal fermentation conditions, the experimental collagenase yield obtained was 322.58 ± 9.61 U·mL−1, which was in agreement with the predicted yield of 306.68 U·mL−1. Collagen from Spanish mackerel bone, seabream scale and octopus flesh also showed higher DPPH radical scavenging rates and ORAC values after hydrolysis by the collagenase. This study may have implications for the development and use of marine collagenases. Moreover, seafood waste containing beneficial collagen could be used to produce antioxidant peptides by proteolysis. Full article
Figures

Figure 1

Open AccessArticle Identification of 2-keto-3-deoxy-d-Gluconate Kinase and 2-keto-3-deoxy-d-Phosphogluconate Aldolase in an Alginate-Assimilating Bacterium, Flavobacterium sp. Strain UMI-01
Mar. Drugs 2017, 15(2), 37; https://doi.org/10.3390/md15020037
Received: 28 October 2016 / Revised: 26 January 2017 / Accepted: 8 February 2017 / Published: 14 February 2017
Cited by 3 | PDF Full-text (6545 KB) | HTML Full-text | XML Full-text
Abstract
Recently, we identified an alginate-assimilating gene cluster in the genome of Flavobacterium sp. strain UMI-01, a member of Bacteroidetes. Alginate lyase genes and a 4-deoxy-l-erythro-5-hexoseulose uronic acid (DEH) reductase gene in the cluster have already been characterized; however, 2-keto-3-deoxy-d
[...] Read more.
Recently, we identified an alginate-assimilating gene cluster in the genome of Flavobacterium sp. strain UMI-01, a member of Bacteroidetes. Alginate lyase genes and a 4-deoxy-l-erythro-5-hexoseulose uronic acid (DEH) reductase gene in the cluster have already been characterized; however, 2-keto-3-deoxy-d-gluconate (KDG) kinase and 2-keto-3-deoxy-6-phosphogluconate (KDPG) aldolase genes, i.e., flkin and flald, still remained uncharacterized. The amino acid sequences deduced from flkin and flald showed low identities with those of corresponding enzymes of Saccharophagus degradans 2-40T, a member of Proteobacteria (Kim et al., Process Biochem., 2016). This led us to consider that the DEH-assimilating enzymes of Bacteroidetes species are somewhat deviated from those of Proteobacteria species. Thus, in the present study, we first assessed the characteristics in the primary structures of KDG kinase and KDG aldolase of the strain UMI-01, and then investigated the enzymatic properties of recombinant enzymes, recFlKin and recFlAld, expressed by an Escherichia coli expression system. Multiple-sequence alignment among KDG kinases and KDG aldolases from several Proteobacteria and Bacteroidetes species indicated that the strain UMI-01 enzymes showed considerably low sequence identities (15%–25%) with the Proteobacteria enzymes, while they showed relatively high identities (47%–68%) with the Bacteroidetes enzymes. Phylogenetic analyses for these enzymes indicated the distant relationship between the Proteobacteria enzymes and the Bacteroidetes enzymes, i.e., they formed distinct clusters in the phylogenetic tree. recFlKin and recFlAld produced with the genes flkin and flald, respectively, were confirmed to show KDG kinase and KDPG aldolase activities. Namely, recFlKin produced 1.7 mM KDPG in a reaction mixture containing 2.5 mM KDG and 2.5 mM ATP in a 90-min reaction, while recFlAld produced 1.2 mM pyruvate in the reaction mixture containing 5 mM KDPG at the equilibrium state. An in vitro alginate-metabolizing system constructed from recFlKin, recFlAld, and previously reported alginate lyases and DEH reductase of the strain UMI-01 could convert alginate to pyruvate and glyceraldehyde-3-phosphate with an efficiency of 38%. Full article
Figures

Figure 1

Open AccessArticle Structure-Based Design and Synthesis of a New Phenylboronic-Modified Affinity Medium for Metalloprotease Purification
Mar. Drugs 2017, 15(1), 5; https://doi.org/10.3390/md15010005
Received: 17 November 2016 / Revised: 19 December 2016 / Accepted: 21 December 2016 / Published: 27 December 2016
PDF Full-text (1877 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Metalloproteases are emerging as useful agents in the treatment of many diseases including arthritis, cancer, cardiovascular diseases, and fibrosis. Studies that could shed light on the metalloprotease pharmaceutical applications require the pure enzyme. Here, we reported the structure-based design and synthesis of the
[...] Read more.
Metalloproteases are emerging as useful agents in the treatment of many diseases including arthritis, cancer, cardiovascular diseases, and fibrosis. Studies that could shed light on the metalloprotease pharmaceutical applications require the pure enzyme. Here, we reported the structure-based design and synthesis of the affinity medium for the efficient purification of metalloprotease using the 4-aminophenylboronic acid (4-APBA) as affinity ligand, which was coupled with Sepharose 6B via cyanuric chloride as spacer. The molecular docking analysis showed that the boron atom was interacting with the hydroxyl group of Ser176 residue, whereas the hydroxyl group of the boronic moiety is oriented toward Leu175 and His177 residues. In addition to the covalent bond between the boron atom and hydroxyl group of Ser176, the spacer between boronic acid derivatives and medium beads contributes to the formation of an enzyme-medium complex. With this synthesized medium, we developed and optimized a one-step purification procedure and applied it for the affinity purification of metalloproteases from three commercial enzyme products. The native metalloproteases were purified to high homogeneity with more than 95% purity. The novel purification method developed in this work provides new opportunities for scientific, industrial and pharmaceutical projects. Full article
Figures

Figure 1

Review

Jump to: Research

Open AccessFeature PaperReview Enzymatic Processes in Marine Biotechnology
Mar. Drugs 2017, 15(4), 93; https://doi.org/10.3390/md15040093
Received: 17 February 2017 / Revised: 16 March 2017 / Accepted: 20 March 2017 / Published: 25 March 2017
Cited by 7 | PDF Full-text (605 KB) | HTML Full-text | XML Full-text
Abstract
In previous review articles the attention of the biocatalytically oriented scientific community towards the marine environment as a source of biocatalysts focused on the habitat-related properties of marine enzymes. Updates have already appeared in the literature, including marine examples of oxidoreductases, hydrolases, transferases,
[...] Read more.
In previous review articles the attention of the biocatalytically oriented scientific community towards the marine environment as a source of biocatalysts focused on the habitat-related properties of marine enzymes. Updates have already appeared in the literature, including marine examples of oxidoreductases, hydrolases, transferases, isomerases, ligases, and lyases ready for food and pharmaceutical applications. Here a new approach for searching the literature and presenting a more refined analysis is adopted with respect to previous surveys, centering the attention on the enzymatic process rather than on a single novel activity. Fields of applications are easily individuated: (i) the biorefinery value-chain, where the provision of biomass is one of the most important aspects, with aquaculture as the prominent sector; (ii) the food industry, where the interest in the marine domain is similarly developed to deal with the enzymatic procedures adopted in food manipulation; (iii) the selective and easy extraction/modification of structurally complex marine molecules, where enzymatic treatments are a recognized tool to improve efficiency and selectivity; and (iv) marine biomarkers and derived applications (bioremediation) in pollution monitoring are also included in that these studies could be of high significance for the appreciation of marine bioprocesses. Full article
Figures

Graphical abstract

Back to Top