Fibrinolytic enzymes in Asian traditional fermented foods

Fibrin and Fibrinolytic Enzyme Cascade in Thrombosis: Unravelling the Role

Blood clot formation in blood vessels (thrombosis) is a major cause of life-threatening cardiovascular diseases. These clots are formed by αA-, βB-, and ϒ-peptide chains of fibrinogen joined together by isopeptide bonds with the help of blood coagulation factor XIIIa. These clot structures are altered by various factors such as thrombin, platelets, transglutaminase, DNA, histones, and red blood cells. Various factors are used to dissolve the blood clot, such as anticoagulant agents, antiplatelets drugs, fibrinolytic enzymes, and surgical operations. Fibrinolytic enzymes are produced by microorganisms (bacteria, fungi, etc.): streptokinase of Streptococcus hemolyticus, nattokinase of Bacillus subtilis YF 38, bafibrinase of Bacillus sp. AS-S20-I, longolytin of Arthrobotrys longa, versiase of Aspergillus versicolor ZLH-1, etc. They act as a thrombolytic agent by either enhancing the production of plasminogen activators (tissue or urokinase types), which convert inactive plasminogen to active plasmin, or acting as plasmin-like proteins themselves, forming fibrin degradation products which cause normal blood flow again in blood vessels. Fibrinolytic enzymes may be classified in two groups, as serine proteases and metalloproteases, based on their catalytic properties, consisting of a catalytic triad responsible for their fibrinolytic activity having different physiochemical properties (such as molecular weight, pH, and temperature). The analysis of fibrinolysis helps to detect hyperfibrinolysis (menorrhagia, renal failure, etc.) and hypofibrinolysis (diabetes, obesity, etc.) with the help of various fibrinolytic assays such as a fibrin plate assay, fibrin microplate assay, the viscoelastic method, etc. These fibrinolytic activities serve as a key aspect in the recognition of numerous cardiovascular diseases and can be easily produced on a large scale with a short generation time by microbes and are less expensive.

Production, purification, and functional properties of microbial fibrinolytic enzymes produced by microorganism obtained from soy-based fermented foods: developments and challenges

According to the World Health Organization, cardiovascular disease (CVD) has become a major cause of chronic illness around the globe. It has been reported that soy-based fermented food (SFF) is very effective in preventing thrombus (one of the most important contributing factors to CVD), which are mainly attributed to the bioactive substances, especially the fibrinolytic enzymes (FE) generated by microorganisms during the fermentation process of soybean food. This paper therefore mainly reviewed the microbial fibrinolytic enzymes (MFE) from SFF. We first discuss the use of microbial fermentation to produce FE, with an emphasis on the strains involved. The production, purification, physicochemical properties, structure-functional attributes, functional properties and possible application of MFE from SFF are then discussed. Finally, current limitations and future perspectives for the production, purification, and the practical application of MFE are discussed. MFE from SFF pose multiple health benefits, including thrombolysis, antihypertension, anti-inflammatory, anti-hyperlipidemia, anticancer, neuroprotective, antiviral and other activities. Therefore, they exhibit great potential for functional foods and nutraceutical applications, especially foods with CVDs prevention potential.

Recent Advances in Nattokinase-Enriched Fermented Soybean Foods: A Review

With the dramatic increase in mortality of cardiovascular diseases (CVDs) caused by thrombus, this has sparked an interest in seeking more effective thrombolytic drugs or dietary nutriments. The dietary consumption of natto, a traditional Bacillus-fermented food (BFF), can reduce the risk of CVDs. Nattokinase (NK), a natural, safe, efficient and cost-effective thrombolytic enzyme, is the most bioactive ingredient in natto. NK has progressively been considered to have potentially beneficial cardiovascular effects. Microbial synthesis is a cost-effective method of producing NK. Bacillus spp. are the main production strains. While microbial synthesis of NK has been thoroughly explored, NK yield, activity and stability are the critical restrictions. Multiple optimization strategies are an attempt to tackle the current problems to meet commercial demands. We focus on the recent advances in NK, including fermented soybean foods, production strains, optimization strategies, extraction and purification, activity maintenance, biological functions, and safety assessment of NK. In addition, this review systematically discussed the challenges and prospects of NK in actual application. Due to the continuous exploration and rapid progress of NK, NK is expected to be a natural future alternative to CVDs.

Engineered Biofilm: Innovative Nextgen Strategy for Quality Enhancement of Fermented Foods

Microbial communities within fermented food (beers, wines, distillates, meats, fishes, cheeses, breads) products remain within biofilm and are embedded in a complex extracellular polymeric matrix that provides favorable growth conditions to the indwelling species. Biofilm acts as the best ecological niche for the residing microbes by providing food ingredients that interact with the fermenting microorganisms' metabolites to boost their growth. This leads to the alterations in the biochemical and nutritional quality of the fermented food ingredients compared to the initial ingredients in terms of antioxidants, peptides, organoleptic and probiotic properties, and antimicrobial activity. Microbes within the biofilm have altered genetic expression that may lead to novel biochemical pathways influencing their chemical and organoleptic properties related to consumer acceptability. Although microbial biofilms have always been linked to pathogenicity owing to its enhanced antimicrobial resistance, biofilm could be favorable for the production of amino acids like l-proline and L-threonine by engineered bacteria. The unique characteristics of many traditional fermented foods are attributed by the biofilm formed by lactic acid bacteria and yeast and often, multispecies biofilm can be successfully used for repeated-batch fermentation. The present review will shed light on current research related to the role of biofilm in the fermentation process with special reference to the recent applications of NGS/WGS/omics for the improved biofilm forming ability of the genetically engineered and biotechnologically modified microorganisms to bring about the amelioration of the quality of fermented food.

Marine Microbial Fibrinolytic Enzymes: An Overview of Source, Production, Biochemical Properties and Thrombolytic Activity

Cardiovascular diseases (CVDs) have emerged as a major threat to global health resulting in a decrease in life expectancy with respect to humans. Thrombosis is one of the foremost causes of CVDs, and it is characterized by the unwanted formation of fibrin clots. Recently, microbial fibrinolytic enzymes due to their specific features have gained much more attention than conventional thrombolytic agents for the treatment of thrombosis. Marine microorganisms including bacteria and microalgae have the significant ability to produce fibrinolytic enzymes with improved pharmacological properties and lesser side effects and, hence, are considered as prospective candidates for large scale production of these enzymes. There are no studies that have evaluated the fibrinolytic potential of marine fungal-derived enzymes. The current review presents an outline regarding isolation sources, production, features, and thrombolytic potential of fibrinolytic biocatalysts from marine microorganisms identified so far.

Microbial Fibrinolytic Enzymes as Anti-Thrombotics: Production, Characterisation and Prodigious Biopharmaceutical Applications

Cardiac disorders such as acute myocardial infarction, embolism and stroke are primarily attributed to excessive fibrin accumulation in the blood vessels, usually consequential in thrombosis. Numerous methodologies including the use of anti-coagulants, anti-platelet drugs, surgical operations and fibrinolytic enzymes are employed for the dissolution of fibrin clots and hence ameliorate thrombosis. Microbial fibrinolytic enzymes have attracted much more attention in the management of cardiovascular disorders than typical anti-thrombotic strategies because of the undesirable after-effects and high expense of the latter. Fibrinolytic enzymes such as plasminogen activators and plasmin-like proteins hydrolyse thrombi with high efficacy with no significant after-effects and can be cost effectively produced on a large scale with a short generation time. However, the hunt for novel fibrinolytic enzymes necessitates complex purification stages, physiochemical and structural-functional attributes, which provide an insight into their mechanism of action. Besides, strain improvement and molecular technologies such as cloning, overexpression and the construction of genetically modified strains for the enhanced production of fibrinolytic enzymes significantly improve their thrombolytic potential. In addition, the unconventional applicability of some fibrinolytic enzymes paves their way for protein hydrolysis in addition to fibrin/thrombi, blood pressure regulation, anti-microbials, detergent additives for blood stain removal, preventing dental caries, anti-inflammatory and mucolytic expectorant agents. Therefore, this review article encompasses the production, biochemical/structure-function properties, thrombolytic potential and other surplus applications of microbial fibrinolytic enzymes.

Biosynthesis and Characterization of a Novel Fibrinolytic Alkaline Serine Protease from Newly Isolated Bacillus flexus BF12 for Biomedical Applications

BACKGROUND

Cardiovascular Diseases (CVDs) such as stroke, high blood pressure, peripheral vascular disease, ischemic heart disease and acute myocardial infarction are some of the leading causes of death. To treat CVDs, commercially available thrombolytic agents are widely used. However, these thrombolytic agents have various side effects. Alternatively, fibrinolytic enzymes from bacterial sources are highly safe and have direct blood clot lytic activity.

METHODS

A fibrinolytic enzyme producing bacterial strain, Bacillus flexus BF12, was isolated from a solar saltpan in Kanyakumari District, Tamilnadu, India. Enzyme production was improved by optimizing physical factors and nutritional factors.

RESULTS

A novel fibrinolytic enzyme was isolated from a strain of the studied B. flexus BF12. Enzyme production was enhanced significantly by optimizing process parameters. The critical physical factors (pH and salinity) and influencing nutritional factors (carbon, nitrogen and ions) were optimized by one variable at a time approach, followed by the statistical method. The strain BF12 was highly active at alkaline pH (>7.0) and between 4 and 6% NaCl concentration. The nutrients such as fructose (carbon source), beef extract (nitrogen source) and CaCl₂ significantly influenced enzyme production. Central composite design and response surface methodology improved 3.2-fold enzyme yield than unoptimized culture medium. Fibrinolytic protease was purified by ammonium sulphate precipitation, dialysis and gel filtration chromatography.

DISCUSSION

The molecular weight of an enzyme was found to be 23 kDa. It was active at a broad temperature (40-60 °C) and pH (7.0-9.0) ranges. Enzyme activity was enhanced by Ca²⁺ and Co²⁺ ions. The purified protease retained 100% enzyme activity in the presence of ethanol and acetone. Acetonitrile, butanol, DMSO, methanol and chloroform showed enzyme activity of 63%, 92.5%, 94.7%, 92.3% and 90.4%, respectively. The purified enzyme degraded 100% of human blood clot.

CONCLUSION

The Bacillus flexus BF12 fibrinolytic enzyme shows promising potentials in nutraceutical and food fortification applications. The application of fibrinolytic enzymes could prevent CVDs.

Role of Fibrinolytic Enzymes in Anti-Thrombosis Therapy

Thrombosis, a major cause of deaths in this modern era responsible for 31% of all global deaths reported by WHO in 2017, is due to the aggregation of fibrin in blood vessels which leads to myocardial infarction or other cardiovascular diseases (CVDs). Classical agents such as anti-platelet, anti-coagulant drugs or other enzymes used for thrombosis treatment at present could leads to unwanted side effects including bleeding complication, hemorrhage and allergy. Furthermore, their high cost is a burden for patients, especially for those from low and middle-income countries. Hence, there is an urgent need to develop novel and low-cost drugs for thrombosis treatment. Fibrinolytic enzymes, including plasmin like proteins such as proteases, nattokinase, and lumbrokinase, as well as plasminogen activators such as urokinase plasminogen activator, and tissue-type plasminogen activator, could eliminate thrombi with high efficacy rate and do not have significant drawbacks by directly degrading the fibrin. Furthermore, they could be produced with high-yield and in a cost-effective manner from microorganisms as well as other sources. Hence, they have been considered as potential compounds for thrombosis therapy. Herein, we will discuss about natural mechanism of fibrinolysis and thrombus formation, the production of fibrinolytic enzymes from different sources and their application as drugs for thrombosis therapy.

In vitro fibrinolytic activity of an enzyme purified from Bacillus amyloliquefaciens strain KJ10 isolated from soybean paste

A fibrinolytic protease secreting producing Bacillus amyloliquefaciens strain KJ10 was initially screened from the fermented soybean. Maximum productivity was obtained in the culture medium after 40 h incubation, 34 °C incubation temperature at pH 8.0. Fibrinolytic protease production was enhanced in the culture medium with 1% sucrose (3712 ± 52 U/mL), 1% (w/v) yeast extract (3940 ± 28 U/mL) and 0.1% MgSO₄ (3687 ± 38 U/mL). Enzyme was purified up to 22.9-fold with 26%recovery after Q-Sepharose HP column chromatography. After three steps purification, enzyme activity was 1606U/mg and SDS-PAGE analysis revealed 29 kDa protein and enzyme band was detected by zymograpy. Enzyme was highly active at pH 8.0, at wide temperature ranges (40 °C − 55 °C) and was activated by Mn²⁺ (102 ± 3.1%) and Mg²⁺ (101.4 ± 2.9%) ions. The purified fibrinolytic enzyme was highly specific against N-Suc-Ala-Ala-Pro-Phe-pNA (189 mmol/min/mL) and clot lytic activity reached 28 ± 1.8% within 60 minin vitro. The purified fibrinolytic enzyme showed least erythrocytic lysis activity confirmed safety to prevent various health risks, including hemolytic anemia. Based on this study, administration of fibrinolytic enzyme from B. amyloliquefaciens strain KJ10 is safe for clinical applications.

Isolation of Bacillus spp. with High Fibrinolytic Activity and Performance Evaluation in Fermented Douchi

ABSTRACT

Fibrinolytic enzymes are effective and highly safe in treating cardiovascular and cerebrovascular diseases. Therefore, screening fibrinolytic enzyme-producing microbial strains with excellent fermentation performance is of great value to industrial applications. The fibrin plate method was used in screening strains with high yields of fibrinolytic enzymes from different fermented food products, and the screened strains were preliminarily identified using molecular biology. Then, the strains were used for solid-state fermentation of soybeans. Moreover, the fermentation product douchi was subjected to fibrinolytic activity measurement, sensory evaluation, and biogenic amine content determination. The fermentation performance of each strain was comprehensively evaluated through principal component analysis. Finally, the target strain was identified based on strain morphology, physiological and biochemical characteristics, 16S rDNA sequence, and phylogenetic analysis results. A total of 15 Bacillus species with high fibrinolysin activity were selected. Their fibrinolytic enzyme-producing activity levels were higher than 5,500 IU/g. Through molecular biology analysis, we found 4 strains of Bacillus subtilis, 10 strains of Bacillus amyloliquefaciens, and 1 strain of Bacillus velezensis. The principal component analysis results showed that SN-14 had the best fermentation performance and reduced the accumulation of histamine and total amine, the fibrinolytic activity of fermented douchi reached 5,920.5 ± 107.7 IU/g, and the sensory score was 4.6 ± 0.3 (out of 5 points). Finally, the combined results of physiological and biochemical analyses showed SN-14 was Bacillus velezensis. The high-yield fibrinolytic and excellent fermentation performance strain Bacillus velezensis SN-14 has potential industrial application.

HIGHLIGHTS

Purification and Characterization of a Thrombolytic Enzyme Produced by a New Strain of Bacillus subtil

Fibrinolytic enzymes with a direct mechanism of action and safer properties are currently requested for thrombolytic therapy. This paper reports on a new enzyme capable of degrading blood clots directly without impairing blood coagulation. This enzyme is also non-cytotoxic and constitutes an alternative to other thrombolytic enzymes known to cause undesired side effects. Twenty-four Bacillus isolates were screened for production of fibrinolytic enzymes using a fibrin agar plate. Based on produced activity, isolate S127e was selected and identified as B. subtilis using the 16S rDNA gene sequence. This strain is of biotechnological interest for producing high fibrinolytic yield and consequently has potential in the industrial field. The purified fibrinolytic enzyme has a molecular mass of 27.3 kDa, a predicted pI of 6.6, and a maximal affinity for Ala-Ala-Pro-Phe. This enzyme was almost completely inhibited by chymostatin with optimal activity at 48°C and pH 7. Specific subtilisin features were found in the gene sequence, indicating that this enzyme belongs to the BPN group of the S8 subtilisin family and was assigned as AprE127. This subtilisin increased thromboplastin time by 3.7% (37.6 to 39 s) and prothrombin time by 3.2% (12.6 to 13 s), both within normal ranges. In a whole blood euglobulin assay, this enzyme did not impair coagulation but reduced lysis time significantly. Moreover, in an in vitro assay, AprE127 completely dissolved a thrombus of about 1 cc within 50 min and, in vivo, reduced a thrombus prompted in a rat tail by 11.4% in 24 h compared to non-treated animals.

A novel serine protease with anticoagulant and fibrinolytic activities from the fruiting bodies of mushroom Agrocybe aegerita

A novel fibrinolytic enzyme, ACase was isolated from fruiting bodies of a mushroom, Agrocybe aegerita. ACase was purified by using ammonium sulfate precipitation, gel filtration, ion exchange and hydrophobic chromatographies to 237.12 fold with a specific activity of 1716.77 U/mg. ACase was found to be a heterodimer with molecular mass of 31.4 and 21.2 kDa by SDS-PAGE and appeared as a single band on Native-PAGE and fibrin-zymogram. The N-terminal sequence of the two subunits of ACase was AIVTQTNAPWGL (subunit 1) and SNADGNGHGTHV (subunit 2). ACase had maximal activity at 47 °C and pH 7.6. It's activity was improved by Cu²⁺, Na⁺, Fe³⁺, Zn²⁺, Ba²⁺, K⁺ and Mn²⁺, but inhibited by Fe²⁺, Mg²⁺ and Ca²⁺. PMSF, SBTI, aprotinine and Lys inhibited the enzyme activity, which suggested that ACase was a serine protease. ACase could degrade all three chains (α, β and γ) of fibrinogen. Moreover, the enzyme acted as both, a plasmin-like fibrinolytic enzyme and a plasminogen activator. It could hydrolyze human thrombin slightly, which indicated that the ACase could inhibit the activity of thrombin and acted as an anticoagulant to prevent thrombosis. Based on these results, ACase might act as a therapeutic agent for treating thrombosis, or as a functional food. Further investigation of the enzyme is underway.

Purification, physicochemical properties, and statistical optimization of fibrinolytic enzymes especially from fermented foods: A comprehensive review

Fibrinolytic enzymes are proteases responsible for cleavage of fibrin mesh in thrombus clots, which are the primary causative agents in cardiovascular diseases. Developing safe, effective and cheap thrombolytic agents are important for prevention and cure of thrombosis. Although a wide variety of sources have been discovered for fibrinolytic enzymes, only few of them have been employed in clinical and therapeutic applications due to the drawbacks such as high cost of production, low stability of enzyme or therapeutic side effects. However, the discovery of new fibrinolytic enzymes requires complex purification stages and characterization, which gives an insight into their diverse modes of action. Post-discovery, approaches such as a) statistical optimization for fermentative bioprocessing and b) genetic engineering are advantageous in providing economic viability by finding simple and cost-effective medium, strain development with sufficient nutrient supplements for stable and high-level production of recombinant enzyme. This review provides a comprehensive understanding of different sources, purification techniques, production through genetic engineering approaches and statistical optimization of fermentation parameters as proteases have a wide variety of industrial and biotechnological applications making 60% of total enzyme market worldwide. New strategies targeting increased enzyme yields, non-denaturing environments, improved stability, enzyme activity and strain improvement have been discussed.

Microbial Fermentation and Its Role in Quality Improvement of Fermented Foods

Fermentation processes in foods often lead to changes in nutritional and biochemical quality relative to the starting ingredients. Fermented foods comprise very complex ecosystems consisting of enzymes from raw ingredients that interact with the fermenting microorganisms’ metabolic activities. Fermenting microorganisms provide a unique approach towards food stability via physical and biochemical changes in fermented foods. These fermented foods can benefit consumers compared to simple foods in terms of antioxidants, production of peptides, organoleptic and probiotic properties, and antimicrobial activity. It also helps in the levels of anti-nutrients and toxins level. The quality and quantity of microbial communities in fermented foods vary based on the manufacturing process and storage conditions/durability. This review contributes to current research on biochemical changes during the fermentation of foods. The focus will be on the changes in the biochemical compounds that determine the characteristics of final fermented food products from original food resources.

Genome sequencing, purification, and biochemical characterization of a strongly fibrinolytic enzyme from Bacillus amyloliquefaciens Jxnuwx-1 isolated from Chinese traditional douchi

A strongly fibrinolytic enzyme was purified from Bacillus amyloliquefaciens Jxnuwx-1, found in Chinese traditional fermented black soya bean (douchi). The molecular mass of the enzyme, estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), was 29 kDa. The optimal pH and temperature for the enzyme were 7.6 and 41°C, respectively. The enzyme was inhibited by phenylmethylsulfonyl fluoride, soybean trypsin inhibitor, ethylenediaminetetraacetic acid, Fe3+, and Fe2+. The highest affinity exhibited by the enzyme was towards N-Succinyl-Ala-Ala-Pro-Phe-pNA. These results indicated that it is a subtilisin-like serine metalloprotease. The enzyme degraded both fibrinogen and fibrin, displaying its highest degrading activity towards the Aα-chains followed by Bβ chains and Cγ chains. The enzyme was also activated by plasminogen, indicating its ability to degrade fibrinogen and fibrin in two ways: (a) by activating plasminogen conversion into plasmin, or (b) by direct hydrolysis. It degraded thrombin, suggesting that it may act as an anticoagulant to prevent thrombosis. Taken together, our results indicate the potential of this enzyme in controlling cardiovascular disease.

Metagenomic Insights Into the Taxonomic and Functional Features of Kinema, a Traditional Fermented Soybean Product of Sikkim Himalaya

Kinema is an ethnic, naturally fermented soybean product consumed in the Sikkim Himalayan region of India. In the present study, the whole metagenome sequencing approach was adopted to examine the microbial diversity and related functional potential of Kinema, consumed in different seasons. Firmicutes was the abundant phylum in Kinema, ranging from 82.31 to 93.99% in different seasons, followed by Actinobacteria and Proteobacteria. At the species level, the prevalent microorganisms were Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis, Corynebacterium glutamicum, Bacillus pumilus, and Lactococcus lactis. The abundance of microbial species varied significantly in different seasons. Further, the genomic presence of some undesirable microbes like Bacillus cereus, Proteus mirabilis, Staphylococcus aureus, Proteus penneri, Enterococcus faecalis, and Staphylococcus saprophyticus, were also detected in the specific season. The metagenomic analysis also revealed the existence of bacteriophages belonging to the family Siphoviridae, Myoviridae, and Podoviridae. Examination of the metabolic potential of the Kinema metagenome depicted information about the biocatalysts, presumably involved in the transformation of protein and carbohydrate polymers into bioactive molecules of health-beneficial effects. The genomic resource of several desirable enzymes was identified, such as β-galactosidase, β-glucosidase, β-xylosidase, and glutamate decarboxylase, etc. The catalytic function of a novel glutamate decarboxylase gene was validated for the biosynthesis of γ-aminobutyric acid (GABA). The results of the present study highlight the microbial and genomic resources associated with Kinema, and its importance in functional food industry.

Bioprospecting endophytic fungi from Fusarium genus as sources of bioactive metabolites

Endophytic fungi became an attractive source for the discovery of new leads, because of the complexity and the structural diversity of their secondary metabolites. The genus Fusarium comprising about 70 species is extremely variable in terms of genetics, biology, ecology, and consequently, secondary metabolism and have been isolated from countless plants genera from diverse habitats. These endophytic microbes may provide protection and survival strategies in their host plants with production of a repertoire of chemically diverse and structurally unprecedented secondary metabolites reported to exhibit an incredible array of biological activities including antimicrobial, anticancer, antiviral, antioxidants, antiparasitics, immunosuppressants, immunomodulatory, antithrombotic, and biocontrol ability against plants pathogens and nematodes. This review comprehensively highlights over the period 1981-2019, the bioactive potential of metabolites produced by endophytes from Fusarium genus. Abbreviations: AIDS: Acquired immune deficiency syndrome; BAPT: C-13 phenylpropanoid side chain-CoA acyltransferase; CaBr2: Calcium bromide; DBAT: 10-deacetylbaccatin III-10-O-acetyl transferase; DNA: Deoxyribonucleic acid; EI-MS: Electron ionization mass spectrometer; EN: Enniatin; ERK: Extracellular regulated protein kinase; EtOAc: Ethyl acetate; FDA: Food and Drug Administration; GAE/g: Gallic acid equivalent per gram; GC-MS: Gas chromatography-mass spectrometry; HA: Hyperactivation; HCV: Hepatitis C Virus; HCVPR: Hepatitis C Virus protease; HeLa: Human cervical cancer cell line; HIV: Human immunodeficiency viruses; HPLC: High Performance Liquid Chromatography; IAA: Indole-3-acetic acid; IARC: International Agency for Research on Cancer; IC50: Half maximal inhibitory concentration; LC50: Concentration of the compound that is lethal for 50% of exposed population; LC-MS: Liquid chromatography-mass spectrometry; MCF-7: Human breast cancer cell line; MDR: Multidrug-resistant; MDRSA: Multidrug-resistant S. aureus; MFC: Minimum fungicidal concentration; MIC: Minimum inhibitory concentration; MRSA: Multidrug-resistant S. aureus; MTCC: Microbial type culture collection; PBMCs: Peripheral blood mononuclear cells; PCR: Polymerase chain reaction; TB: Tuberculosis; TLC: Thin layer chromatography; TNF: Tumor necrosis factor; WHO: World Health Organization http://www.zoobank.org/urn:lsid:zoobank.org:pub:D0A7B2D8-5952-436D-85C8-C79EAAD1013C.

Purification and characterization of a novel, highly potent fibrinolytic enzyme from Bacillus subtilis DC27 screened from Douchi, a traditional Chinese fermented soybean food

The highly fibrinolytic enzyme-producing bacterium was identified as Bacillus subtilis DC27 and isolated from Douchi, a traditional fermented soybean food. The DFE27 enzyme was purified from the fermentation broth of B. subtilis DC27 by using UNOsphere Q column chromatography, Sephadex G-75 gel filtration, and high-performance liquid chromatography. It was 29 kDa in molecular mass and showed the optimal reaction temperature and pH value of 45 °C and 7.0, respectively, with a stable fibrinolytic activity below 50 °C and within the pH range of 6.0 to 10.0. DFE27 was identified as a serine protease due to its complete inhibition by phenylmethysulfony fluoride. The first 24 amino acid residues of the N-terminal sequence of the enzyme were AQSVPYGVSQIKAPALHSQGFTGS. The enzyme displayed the highest specificity toward the substrate D-Val-Leu-Lys-pNA for plasmin and it could not only directly degrade but also hydrolyze fibrin by activating plasminogen into plasmin. Overall, the DFE27 enzyme was obviously different from other known fibrinolytic enzymes in the optimum substrate specificity or fibrinolytic action mode, suggesting that it is a novel fibrinolytic enzyme and may have potential applications in the treatment and prevention of thrombosis.

Properties of a fibrinolytic enzyme secreted by Bacillus subtilis JS2 isolated from saeu (small shrimp) jeotgal

Bacillus species were screened to be used as starters for jeotgals, salted and fermented Korean sea foods. A strain, JS2, showing strong fibrinolytic activity was isolated from saeu (small shrimp) jeotgal, and identified as Bacillus subtilis. Bacillus subtilis JS2 grew well at 20% (w/v) NaCl concentration. SDS-PAGE of culture supernatant from JS2 showed 3 major bands of 27, 29, and 60 kDa in size. Fibrin zymography showed that the 27 kDa band was the major fibrinolytic protein. The gene, aprEJS2, was cloned and introduced into B. subtilis WB600 using pHY300PLK. A B. subtilis transformant harboring pHYJS2 showed higher fibrinolytic activity than B. subtilis JS2. aprEJS2 was overexpressed in Escherichia coli BL21 (DE3). The optimum pH and temperature for AprEJS2 were pH 8.0 and 40 °C, respectively. Km and Vmax values were determined. AprEJS2 has strong α-fibrinogenase activity and moderate β-fibrinogenase activity.

The N-terminal-truncated recombinant fibrin(ogen)olytic serine protease improves its functional property, demonstrates in vivo anticoagulant and plasma defibrinogenation activity as well as pre-clinical safety in rodent model

An N-terminal truncated fibrino(geno)lytic serine protease gene encoding a ~42kDa protein from Bacillus cereus strain AB01 was produced by error prone PCR, cloned into pET19b vector, and expressed in E5 coli BL21 DE3 cells. The deletion of 24 amino acid residues from N-terminal of wild-type Bacifrinase improves the catalytic activity of [Bacifrinase (ΔN24)]. The anticoagulant potency of [Bacifrinase (ΔN24)] was comparable to Nattokinase and Warfarin and results showed that its anticoagulant action is contributed by progressive defibrinogenation and antiplatelet activities. Nonetheless, at the tested concentration of 2.0μM [Bacifrinase (ΔN24)] did not show in vitro cytotoxicity or chromosomal aberrations on human embryonic kidney cells-293 (HEK-293) and human peripheral blood lymphocytes (HPBL) cells. [Bacifrinase (ΔN24)], at a dose of 2mg/kg, did not show toxicity, adverse pharmacological effects, tissue necrosis or hemorrhagic effect after 72h of its administration in Swiss albino mice. However, at the tested doses of 0.125 to 0.5mg/kg, it demonstrated significant in anticoagulant effect as well as defibrinogenation after 6h of administration in mice. We propose that [Bacifrinase (ΔN24)] may serve as prototype for the development of potent drug to prevent hyperfibrinogenemia related disorders.

Evaluation of bioactivities and phenolic contents of wild edible mushrooms from northeastern Thailand

Twenty-five wild edible mushrooms from Northeastern Thailand were analyzed for their antioxidant activities, proteins, sugars, β-glucan, and phenolic profiles. Results showed that T. clypeatus and V. volvacea exhibited the greatest scavenging activity (83.07 and 86.60%) and reductive power (9.79 and 8.42 g Fe(II)/kg, respectively). T. clypeatus recorded the highest content of (+)-catechin and naringenin (13.40 and 0.74 g/kg dw), with V. volvacea the highest amount of quercetin and quercetin-3-O-rutinoside (1.82 and 1.16 g/kg dw, respectively). Both T. clypeatus and V. volvacea also exhibited the greatest amounts of β-glucan (125.23 and 344.43 g/kg dw) and protein (343.30 and 452.20 g/kg dw, respectively) among the mushroom species evaluated. Results suggested that both T. clypeatus and V. volvacea were a good source of healthy compounds, namely β-glucan and flavonoids, and could be used to mitigate diseases involving free radicals.

Bioactive peptides derived from traditional Chinese medicine and traditional Chinese food: A review

There is an urgent treat of numerous chronic diseases including heart disease, stroke, cancer, chronic respiratory diseases and diabetes, which have a significant influence on the health of people worldwide. In addition to numerous preventive and therapeutic drug treatments, important advances have been achieved in the identification of bioactive peptides that may contribute to long-term health. Although bioactive peptides with various biological activities received unprecedented attention, as a new source of bioactive peptides, the significant role of bioactive peptides from traditional Chinese medicine and traditional Chinese food has not fully appreciated compared to other bioactive components. Hence, identification and bioactivity assessment of these peptides could benefit the pharmaceutical and food industry. Furthermore, the functional properties of bioactive peptides help to demystify drug properties and health benefits of traditional Chinese medicine and traditional Chinese food. This paper reviews the generation and biofunctional properties of various bioactive peptides derived from traditional Chinese medicine and traditional Chinese food. Mechanisms of digestion, bioavailability of bioactive peptides and interactions between traditional Chinese medicine and traditional Chinese food are also summarized in this review.

Expression of nattokinase in Escherichia coli and renaturation of its inclusion body

Nattokinase is an important fibrinolytic enzyme with therapeutic applications for cardiovascular diseases. The full-length and mature nattokinase genes were cloned from Bacillus subtilis var. natto and expressed in pQE30 vector in Escherichia coli. The full-length gene expressed low nattokinase activity in the intracellular soluble and the medium fractions. The mature gene expressed low soluble nattokinase activity and large amount insoluble protein in inclusion bodies without enzyme activity. Large amount of refolding solutions (RSs) at different pH values were screening and RS-10 and RS-11 at pH 9 were selected to refold nattokinase inclusion bodies. The recombinant cells were lysed with 0.1mg/mL lysozyme and ultrasonic treatment. After centrifugation, the pellete was washed twice with 20mM Tris-HCl buffer (pH 7.5) containing 1% Triton X-100 to purify the inclusion bodies. The inclusion bodies were dissolved in water at pH 12.0 and refolded with RS-10. The refolded proteins showed 42.8IU/mg and 79.3IU/mg fibrinolytic activity by the traditional dilution method (20-fold dilution into RS-10) and the directly mixing the protein solution with equal volume RS-10, respectively, compared to the 52.0IU/mg of total water-soluble proteins from B. subtilis var. natto. This work demonstrated that the inclusion body of recombinant nattokinase expressed in E. coli could be simply refolded to the natural enzyme activity level by directly mixing the protein solution with equal volume refolding solution.

Functional Properties of Microorganisms in Fermented Foods

Fermented foods have unique functional properties imparting some health benefits to consumers due to presence of functional microorganisms, which possess probiotics properties, antimicrobial, antioxidant, peptide production, etc. Health benefits of some global fermented foods are synthesis of nutrients, prevention of cardiovascular disease, prevention of cancer, gastrointestinal disorders, allergic reactions, diabetes, among others. The present paper is aimed to review the information on some functional properties of the microorganisms associated with fermented foods and beverages, and their health-promoting benefits to consumers.

Cow Dung Is a Novel Feedstock for Fibrinolytic Enzyme Production from Newly Isolated Bacillus sp. IND7 and Its Application in In Vitro Clot Lysis

Bacterial fibrinolytic enzymes find great applications to treat and prevent cardiovascular diseases. The novel fibrinolytic enzymes from food grade organisms are useful for thrombolytic therapy. This study reports fibrinolytic enzyme production by Bacillus sp. IND7 in solid-state fermentation (SSF). In this study, cow dung was used as the cheap substrate for the production of fibrinolytic enzyme. Enzyme production was primarily improved by optimizing the nutrient and physical factors by one-variable-at-a-time approach. A statistical method (two-level full factorial design) was applied to investigate the significant variables. Of the different variables, pH, starch, and beef extract significantly influenced on the production of fibrinolytic enzyme (p < 0.05). The optimum levels of these significant factors were further investigated using response surface methodology. The optimum conditions for enhanced fibrinolytic enzyme production were 1.23% (w/w) starch and 0.3% (w/w) beef extract with initial medium pH 9.0. Under the optimized conditions, cow dung substrate yielded 8,345 U/g substrate, and an overall 2.5-fold improvement in fibrinolytic enzyme production was achieved due to its optimization. This is the first report of fibrinolytic enzyme production using cow dung substrate from Bacillus sp. in SSF. The crude enzyme displayed potent activity on zymography and digested goat blood clot completely in in vitro condition.

A low cost fermentation medium for potential fibrinolytic enzyme production by a newly isolated marine bacterium, Shewanella sp. IND20

Agro-residues were used as the substrate for the production of fibrinolytic enzyme in solid state fermentation. In this study, two-level full factorial design (2⁵) and response surface methodology were applied to optimize a fermentation medium for the production of fibrinolytic enzyme from the marine isolate Shewanella sp. IND20. The 2⁵ factorial design demonstrated that the physical factors (pH and moisture) and nutrient factors (trehalose, casein, and sodium dihydrogen phosphate) had significant effect on fibrinolytic enzyme production. Central composite design was employed to search for the optimal concentration of the three factors, namely moisture, pH, and trehalose, and the experimental results were fitted with a second-order polynomial model at 99% level (p < 0.0001). The optimized medium showed 2751 U/mL of fibrinolytic activity, which was 2.5-fold higher than unoptimized medium. The molecular weight of fibrinolytic enzyme was found to be 55.5 kDa. The optimum pH and temperature were 8.0 and 50 °C, respectively.

Purification and biochemical characterization of a novel fibrinolytic enzyme, PSLTro01, from a medicinal animal Porcellio scaber Latreille

A novel protease, named PSLTro01, with fibrinolytic and anticoagulant activity was isolated from Porcellio scaber Latreille and was purified by a combination of hollow fibre membrane molecular weight cut-off (MWCO), ammonium sulfate fractionation, gel filtration and ion-exchange chromatography. PSLTro01 is a single-chain protein with a molecular mass of 38,497 Da as estimated by non-reduced SDS-PAGE and MALDI-TOF MS spectrometry, and its N-terminal 15 amino acid sequence was determined as DINGGGATLPQPLYQ. PSLTro01 is stable in the range of 20-40 °C and pH 6.0-10.0, with a maximum fibrinolytic activity at 40 °C and pH 7.0. The PSLTro01-induced fibrinolytic activity was not influenced by K(+) or Na(+) but was slightly increased by Mg(2+) and completely inhibited by aprotinin and pepstatin A. Fibrin plate assays revealed that PSLTro01 could not directly degrade fibrin but was a plasminogen activator. PSLTro01 exhibited high specificity for the substrate S-2251 for plasmin, followed by S-2238 for thrombin and S-2444 for urokinase. Moreover, the fibrinogenolysis pattern of PSLTro01 was Aα-chains>Bβ-chains>γ-chain. Tail-thrombus of the enzyme treated group was significantly shorter than the physiological saline treated group and the thrombus decrement was correlated with the enzyme dose. PSLTro01 prolongs both thrombin time (TT) and activated partial thromboplastin time (APTT). These results indicate that PSLTro01 may have potential applications in the prevention and treatment of thrombosis.

Antiplatelet and antithrombotic activity of a fibrin(ogen)olytic protease from Bacillus cereus strain FF01

Fibrin(ogen)olytic enzymes offer great promise for the treatment of thrombosis associated disorders. The present study describes the characterization of an extracellular fibrin(ogen)olytic serine protease (named Bacethrombase) purified from the Bacillus cereus strain FF01. The molecular mass of the Bacethrombase was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis and matrix assisted laser desorption/ionization-time-of-flight-mass spectroscopy analyses at 39.5 kDa and 38,450.51 Da, respectively. The peptide mass fingerprinting and analyses of the composition of the amino acids revealed the similarity of the Bacethrombase to the bacterial serine proteases. The secondary structure of the Bacethrombase was composed of 14% helix, 6.6% beta-sheet, and 79.4% random coil. Bacethrombase was found to contain 48% sialic acid and it preferentially degraded the Aα-chain of fibrinogen, as well as fibrin. The anticoagulant potency of the Bacethrombase was comparable with that of warfarin and heparin, and was corroborated by its fibrinogenolytic activity rather than the inhibition of thrombin, prothrombin or FXa. Bacethrombase demonstrated antiplatelet activity, and dose-dependently inhibited the ADP-induced platelet aggregation. Bacethrombase (10 mg/kg) did not show toxicity after i.v. administration in Wistar rats; however, it revealed an in vivo anticoagulant effect and significantly inhibited the carrageenan-induced in vivo thrombus formation in rats.

Purification and biochemical characterization of a novel fibrinolytic enzyme from culture supernatant of Cordyceps militaris

A novel fibrinolytic enzyme from Cordyceps militaris was produced by submerged culture fermentation, purified, and biochemically characterized. The enzyme was purified to homogeneity, with an overall yield of 4.0% and a specific activity of 1682 U/mg. The molecular weight and pI of the enzyme were 32 kDa and 9.3 ± 0.2, respectively. The optimal pH and temperature of the enzyme were 7.4 and 37 °C, respectively. The enzyme activity was inhibited by Fe(2+), phenylmethane sulfonyl fluoride (PMSF), aprotinin, and pepstatin but not by N-tosyl-L-phenylalanine chloromethyl ketone (TPCK) and ethylenediamine tetracetic acid (EDTA). Three internal peptides of the enzyme, APQALTVAAVGATWAR, EKNVGSTVNLLSYDGNK, and TDATSVLLDGYNVSAVNDLVAK, were obtained. The enzyme could hydrolyze fibrin(ogen) directly and cleave the α-chains more efficiently than β- and γ-chains, suggesting that it is a plasmin like protein. It degraded thrombin, which indicated that it can act as an anticoagulant and prevent thrombosis. Intravascular thrombosis is one of the major reasons of cardiovascular diseases. On the basis of these results, the purified enzyme can be developed as a natural agent for oral fibrinolytic therapy or prevention of thrombosis.

Fibrinolytic activity and dose-dependent effect of incubating human blood clots in caffeic acid phenethyl ester: in vitro assays

Background. Caffeic acid phenethyl ester (CAPE) has been reported to possess time-dependent fibrinolytic activity by in vitro assay. This study is aimed at investigating fibrinolytic dose-dependent activity of CAPE using in vitro assays. Methods. Standardized human whole blood (WB) clots were incubated in either blank controls or different concentrations of CAPE (3.75, 7.50, 15.00, 22.50, and 30.00 mM). After 3 hours, D-dimer (DD) levels and WB clot weights were measured for each concentration. Thromboelastography (TEG) parameters were recorded following CAPE incubation, and fibrin morphology was examined under a confocal microscope. Results. Overall, mean DD (μg/mL) levels were significantly different across samples incubated with different CAPE concentrations, and the median pre- and postincubation WB clot weights (grams) were significantly decreased for each CAPE concentration. Fibrin removal was observed microscopically and indicated dose-dependent effects. Based on the TEG test, the Ly30 fibrinolytic parameter was significantly different between samples incubated with two different CAPE concentrations (15.0 and 22.50 mM). The 50% effective dose (ED50) of CAPE (based on DD) was 1.99 mg/mL. Conclusions. This study suggests that CAPE possesses fibrinolytic activity following in vitro incubation and that it has dose-dependent activities. Therefore, further investigation into CAPE as a potential alternative thrombolytic agent should be conducted.

Effects of a novel marine natural product: pyrano indolone alkaloid fibrinolytic compound on thrombolysis and hemorrhagic activities in vitro and in vivo

Fungi fibrinolytic compound 1 (FGFC1) is a novel marine natural product as a low-weight fibrinolytic pyranoindole molecule, whose thrombolytic effects were evaluated on FITC-fibrin (Fluorescein isothiocyanate, FITC) degradation methods in vitro and on acute pulmonary thromboembolism animal model in vivo. We determined the FGFC1 induced thrombolysis that stems from its fibrin(ogen)olytic activities as measured by fibrin(ogen) degradation products (FDPs) experiment, acute pulmonary thromboembolism animal model experiment, and euglobulin lysis assay. In vitro, measurement of FITC-fibrin degradation revealed that fibrin hydrolysis occurred in a concentration-dependent manner of FGFC1 from 5 to 25 μ mol/L. In vivo test of a classical acute pulmonary thromboembolism model in rat showed that when the injected dose was 5 mg/kg or above, FGFC1 was effective in dissolution of extrinsic FITC-fibrin induced blood clots. Euglobulin lysis time (ELT) in FGFC1-treated rats was shortened 30 s compared with rats in the positive control group, which were injected with clopidogrel sulfate and single-chain urokinase-type plasminogen activator. As compared to the control, FGFC1 (5-25 mg/kg) did not significantly alter the formation of fibrinogen and FDPs in vivo. Our research indicates that FGFC1 presents pharmacodynamic action in both the thrombolysis and the hemolytic procedure, which can be characterized by fibrinogenolysis in blood and FDPs in plasma. In vivo, increasing fibrinolytic doses of FGFC1 from 5 to 25 mg/kg did not induce fibrinogenolysis when compared with control group, this result corresponds to that FGFC1 did not induce the increasing of FDPs (compared with the saline-treated control). It indicates that the FGFC1 may act as a novel thrombolytic agent and represent an effective approach to the treatment of thrombus without significant risk of hemorrhagic activity.

Statistical optimization of fibrinolytic enzyme production using agroresidues by Bacillus cereus IND1 and its thrombolytic activity in vitro

A potent fibrinolytic enzyme-producing Bacillus cereus IND1 was isolated from the Indian food, rice. Solid-state fermentation was carried out using agroresidues for the production of fibrinolytic enzyme. Among the substrates, wheat bran supported more enzyme production and has been used for the optimized enzyme production by statistical approach. Two-level full-factorial design demonstrated that moisture, supplementation of beef extract, and sodium dihydrogen phosphate have significantly influenced enzyme production (P < 0.05). A central composite design resulted in the production of 3699 U/mL of enzyme in the presence of 0.3% (w/w) beef extract and 0.05% (w/w) sodium dihydrogen phosphate, at 100% (v/w) moisture after 72 h of fermentation. The enzyme production increased fourfold compared to the original medium. This enzyme was purified to homogeneity by ammonium sulfate precipitation, diethylaminoethyl-cellulose ion-exchange chromatography, Sephadex G-75 gel filtration chromatography, and casein-agarose affinity chromatography and had an apparent molecular mass of 29.5 kDa. The optimum pH and temperature for the activity of fibrinolytic enzyme were found to be 8.0 and 60°C, respectively. This enzyme was highly stable at wide pH range (7.0–9.0) and showed 27% ± 6% enzyme activity after initial denaturation at 60°C for 1 h. In vitro assays revealed that the enzyme could activate plasminogen and significantly degraded the fibrin net of blood clot, which suggests its potential as an effective thrombolytic agent.

Statistical optimization of fibrinolytic enzyme production by Pseudoalteromonas sp. IND11 using cow dung substrate by response surface methodology

Fibrinolytic enzymes are agents that dissolve fibrin clots. These fibrinolytic agents have potential use to treat cardiovascular diseases, such as heart attack and stroke. In the present article, a fibrinolytic enzyme producing Pseudoalteromonas sp. IND11 was isolated from the fish scales and optimized for enzyme production. Cow dung was used as a substrate for the production of fibrinolytic enzyme in solid-state culture. A two-level full factorial design was used for the screening of key ingredients while further optimization was carried out using the central composite design. Statistical analysis revealed that the second-order model is significant with model F-value of 6.88 and R² value of 0.860. Enzyme production was found to be high at pH 7.0, and the supplementation of 1% (w/w) maltose and 0.1% (w/w) sodium dihydrogen phosphate enhanced fibrinolytic enzyme production. The optimization of process parameters using response surface methodology resulted in a three-fold increase in the yield of fibrinolytic enzyme. This is the first report on production of fibrinolytic enzyme using cow dung substrate in solid-state fermentation.

Medium optimization for the production of fibrinolytic enzyme by Paenibacillus sp. IND8 using response surface methodology

Production of fibrinolytic enzyme by a newly isolated Paenibacillus sp. IND8 was optimized using wheat bran in solid state fermentation. A 2(5) full factorial design (first-order model) was applied to elucidate the key factors as moisture, pH, sucrose, yeast extract, and sodium dihydrogen phosphate. Statistical analysis of the results has shown that moisture, sucrose, and sodium dihydrogen phosphate have the most significant effects on fibrinolytic enzymes production (P < 0.05). Central composite design (CCD) was used to determine the optimal concentrations of these three components and the experimental results were fitted with a second-order polynomial model at 95% level (P < 0.05). Overall, 4.5-fold increase in fibrinolytic enzyme production was achieved in the optimized medium as compared with the unoptimized medium.