Fibrinolysis and anticoagulant potential of a metallo protease produced by Bacillus subtilis K42

Heterologous expression and characterization of Bacillus velezensis SW5 serine protease involved in the hydrolysis of anchovy protein

BACKGROUND

Bacillus velezensis SW5, with good enzyme production ability, was isolated and identified in our laboratory from fermented fish sauce. Its galactosidase has been expressed in Escherichia coli, which could hydrolyze lactose in milk. The present study aims to express a novel serine protease gene (SPr-SW5) of this strain by Bacillus subtilis WB800N, and applies the expressed enzyme in hydrolysis of anchovy to prepare antioxidant substances, aiming to alleviate the waste of low-value fish resources.

RESULTS

SPr-SW5 with the open reading frame of 1353 bp encodes a serine protease (SPr-SW5) with 450 amino acids. The theoretical molecular weight and isoelectric point are 47.2 kDa and 5.22, respectively. The successful expression of SPr-SW5 in B. subtilis WB800N was confirmed by a skim milk plate test. Its optimal temperature and pH were 50 °C and 8.0, respectively. SPr-SW5 activity was increased by Ca²⁺ and Zn²⁺ , but inhibited by Fe³⁺ . Furthermore, SPr-SW5 was tolerant to 1% Tween-40 and Tween-80; however, its activity was strongly inhibited by 10 mm phenylmethylsulfonyl fluoride. Additionally, SPr-SW5 could be capable of hydrolyzing anchovy, the hydrolysate (AHP) at 10 g L^-1 , with 2,2-diphenyl-1-picrylhydrazyl and hydroxyl (·OH) scavenging rates of 73.21% and 79.71%, displaying good antioxidant activity.

CONCLUSION

The novel SPr-SW5 was successfully expressed in B. subtilis WB800N. It exhibited excellent temperature stability and good tolerance to several metal ions. In addition, the anchovy hydrolyzed by expressed SPr-SW5 has good antioxidant ability. Overall, this research lays a good foundation for SPr-SW5 with respect to exploration and application in the food industry as enzyme preparation. © 2023 Society of Chemical Industry.

A survey of elastase-producing bacteria and characteristics of the most potent producer, Priestia megaterium gasm32

Ninety-one elastase-producing bacterial isolates were recovered from different localities of the Eastern Province of Saudi Arabia. Elastase from the best isolate Priestia megaterium gasm32, from luncheon samples was purified to electrophoretic homogeneity using DEAE-Sepharose CL-6B and Sephadex G-100 chromatographic techniques. The recovery was 17.7%, the purification fold was 11.7x, and the molecular mass was 30 kDa. Enzymatic activity was highly repressed by Ba2+ and almost completely lost by EDTA, but it was greatly stimulated by Cu2+ ions, suggesting a metalloprotease type. The enzyme was stable at 45°C and pH 6.0-10.0 for 2 hours. Ca2+ ions considerably enhanced the stability of the heat-treated enzyme. The Vmax and Km against the synthetic substrate elastin-Congo red were 6.03 mg/mL, and 8.82 U/mg, respectively. Interestingly, the enzyme showed potent antibacterial activity against many bacterial pathogens. Under SEM, most bacterial cells showed loss of integrity, damage, and perforation. SEM micrographs also showed a time-dependent gradual breakdown of elastin fibers exposed to elastase. After 3 hours, intact elastin fibers disappeared, leaving irregular pieces. Given these good features, this elastase may be a promising candidate for treating damaged skin fibers with the inhibition of contaminating bacteria.

Thrombolytic Enzymes of Microbial Origin: A Review

Enzyme therapies are attracting significant attention as thrombolytic drugs during the current scenario owing to their great affinity, specificity, catalytic activity, and stability. Among various sources, the application of microbial-derived thrombolytic and fibrinolytic enzymes to prevent and treat vascular occlusion is promising due to their advantageous cost-benefit ratio and large-scale production. Thrombotic complications such as stroke, myocardial infarction, pulmonary embolism, deep venous thrombosis, and peripheral occlusive diseases resulting from blood vessel blockage are the major cause of poor prognosis and mortality. Given the ability of microbial thrombolytic enzymes to dissolve blood clots and prevent any adverse effects, their use as a potential thrombolytic therapy has attracted great interest. A better understanding of the hemostasis and fibrinolytic system may aid in improving the efficacy and safety of this treatment approach over classical thrombolytic agents. Here, we concisely discuss the physiological mechanism of thrombus formation, thrombo-, and fibrinolysis, thrombolytic and fibrinolytic agents isolated from bacteria, fungi, and algae along with their mode of action and the potential application of microbial enzymes in thrombosis therapy.

Histological Studies on a Newly Isolated Bacillus subtilis D10 Protease in the Debridement of Burn Wound Eschars Using Mouse Model

Background: Proteases are among the most important industrial enzymes, playing a critical role in the physiological, biochemical, and regulatory processes of all living organisms. This study evaluated the histological effects of a Bacillus subtilis D10 protease in combination with the antibacterial ointment silver sulfadiazine (SSD) on the burned skin of mice. Materials and Methods: The bacterial proteolytic enzyme was produced and purified through DEAE-Sepharose CL-6B and Sephadex G-100 FF. The in vitro protease specificity was then determined. The dorsal skin of albino mice was burned with 80% HCl solution, then treated under three conditions: cold cream, SSD, and SSD combined with the tested protease. After 15 days of daily treatment, the mice were sacrificed and skin tissue samples were histopathologically examined using hematoxylin eosin, and Masson trichrome staining. Results: The D10 protease hydrolyzed the proteinaceous components of eschars (fibrin, normal collagen, and denatured collagen) in vitro. Mice skins treated with protease and SSD mixture showed promising results, with more rapid healing than the other treatments. This group regenerated epidermis and dermis with newly formed granulated follicles, fibroblasts and blood capillaries in the dermis, and collagen fibers in the hypodermis. Conclusions: These results suggest that the serine protease produced by B. subtilis D10 promotes wound healing of mice skin burnt with HCl and restores the normal architectural pattern in a shorter time than the standard treatments.

The Practical Potential of Bacilli and Their Enzymes for Industrial Production

Bacillus spp. are an affordable source of enzymes due to their wide distribution, safety in work, ease of cultivation, and susceptibility to genetic transformations. Researchers are particularly interested in proteolytic enzymes, which constitute one of the most diverse groups of microbial proteins in terms of properties. Despite the long history of their research, this group of enzymes continue to show great potential for practical application in the biomedical industry, as well as in the agricultural industry. Thus, the unique properties of bacillary proteinases, such as stability in a wide range of temperatures and pH, high specificity, biodegradability of a wide range of substrates, and the high potential of sequenced Bacillus genomes are a powerful foundation for the development of new biotechnologies. The current review aims to discuss recent studies on various enzymes in particular, proteinases produced by bacteria of the genus Bacillus, along with their prospective practical applications. This article also presents an interpretive summary of the recent developments on the usage of probiotic Bacillus strains as potential feed additives.

Thrombolytic Potential of Novel Thiol-Dependent Fibrinolytic Protease from Bacillus cereus RSA1

The present study demonstrates the production and thrombolytic potential of a novel thermostable thiol-dependent fibrinolytic protease by Bacillus cereus RSA1. Statistical optimization of different parameters was accomplished with Plackett-Burman design and validated further by central composite design with 30.75 U/mL protease production. Precipitation and chromatographic approaches resulted in 33.11% recovery with 2.32-fold purification. The molecular weight of fibrinolytic protease was 40 KDa and it exhibited a broad temperature and pH stability range of 20-80 °C and pH 5-10 with utmost activity at 50 °C and pH 8, respectively. The protease retained its fibrinolytic activity in organic solvents and enhanced the activity in solutions with divalent cations (Mn2+, Zn2+, and Cu2+). The enzyme kinetics revealed Km and Vmax values of 1.093 mg/mL and 52.39 µg/mL/min, respectively, indicating higher affinity of fibrinolytic activity towards fibrin. Also, complete inhibition of fibrinolytic activity with DFP and a 2-fold increase with DTT and β-mercaptoethanol indicates its thiol-dependent serine protease nature. MALDI-TOF analysis showed 56% amino acid sequence homology with Subtilisin NAT OS = Bacillus subtilis subsp. natto. The fibrinolysis activity was compared with a commercial thrombolytic agent for its therapeutic applicability, and fibrinolytic protease was found highly significant with absolute blood clot dissolution within 4 h in in vitro conditions. The isolated fibrinolytic protease of Bacillus cereus RSA1 is novel and different from other known fibrinolytic proteases with high stability and efficacy, which might have wide medicinal and industrial application as a thrombolytic agent and in blood stain removal, respectively.

Production, purification and characterization of fibrinolytic enzyme from Serratia sp. KG-2-1 using optimized media

Intravascular thrombosis is one of the major causes of variety of cardiovascular disorders leading to high mortality worldwide. Fibrinolytic enzymes from microbial sources possess ability to dissolve these clots and help to circumvent these problems in more efficient and safer way. In the present study, fibrinolytic protease with higher fibrinolytic activity than plasmin was obtained from Serratia sp. KG-2-1 isolated from garbage dump soil. Response surface methodology was used to study the interactive effect of concentration of maltose, yeast extract + peptone (1:1), incubation time, and pH on enzyme production and biomass. Maximum enzyme production was achieved at 33 °C after 24 h at neutral pH in media containing 1.5% Maltose, 4.0% yeast extract + peptone and other trace elements resulting in 1.82 folds increased production. The enzyme was purified from crude extract using ammonium sulfate precipitation and DEAE-Sephadex chromatography resulting in 12.9 fold purification with 14.9% yield. The purified enzyme belongs to metalloprotease class and had optimal activity in conditions similar to physiological environment with temperature optima of 40 °C and pH optima of 8. The enzyme was found to be stable in various solvents and its activity was enhanced in presence of Na⁺, K⁺, Ba²⁺, Cu²⁺, Mn²⁺, Hg²⁺ but inhibited by Ca²⁺ and Fe³⁺. Hence, the obtained enzyme may be used as potential therapeutic agent in combating various thrombolytic disorders.

Extremozymes from Marine Actinobacteria

Marine microorganisms that have the possibility to survive in diverse conditions such as extreme temperature, pH, pressure, and salinity are known as extremophiles. They produce biocatalysts so named as extremozymes that are active and stable at extreme conditions. These enzymes have numerous industrial applications due to its distinct properties. Till now, only a fraction of microorganisms on Earth have been exploited for screening of extremozymes. Novel techniques used for the cultivation and production of extremophiles, as well as cloning and overexpression of their genes in various expression systems, will pave the way to use these enzymes for chemical, food, pharmaceutical, and other industrial applications.

MALDI-TOF MS and CD spectral analysis for identification and structure prediction of a purified, novel, organic solvent stable, fibrinolytic metalloprotease from Bacillus cereus B80

The ability to predict protein function from structure is becoming increasingly important; hence, elucidation and determination of protein structure become the major steps in proteomics. The present study was undertaken for identification of metalloprotease produced by Bacillus cereus B80 and recognition of characteristics that can be industrially exploited. The enzyme was purified in three steps combining precipitation and chromatographic methods resulting in 33.5% recovery with 13.1-fold purification of enzyme which was detected as a single band with a molecular mass of 26 kDa approximately in SDS-PAGE and zymogram. The MALDI-TOF MS showed that the enzyme exhibited 70-93% similarity with zinc metalloproteases from various strains Bacillus sp. specifically from Bacillus cereus group. The sequence alignment revealed the presence of zinc-binding region VVVHEMCHMV in the most conserved C terminus region. Secondary structure of the enzyme was obtained by CD spectra and I-TASSER. The enzyme kinetics revealed a Michaelis constant (Km) of 0.140 μmol/ml and Vmax of 2.11 μmol/min. The application studies showed that the enzyme was able to hydrolyze various proteins with highest affinity towards casein followed by BSA and gelatin. The enzyme exhibited strong fibrinolytic, collagenolytic, and gelatinolytic properties and stability in various organic solvents.

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.

Production, optimization and characterization of fibrinolytic enzyme by Bacillus subtilis RJAS19

The present study aimed at the production, purification and characterization of fibrinolytic nattokinase enzyme from the bacteria isolated from natto food. For the purpose, a fibrinolytic bacterium was isolated and identified as Bacillus subtilis based on 16S rDNA sequence analysis. The strain was employed for the production and optimization of fibrinolytic enzyme. The strain showed better enzyme production during 72nd h of incubation time with 50 degrees C at the pH 9. The lactose and peptone were found to be increasing the enzyme production rate. The enzyme produced was purified and also characterized with the help of SDS-PAGE analysis. The activity and stability profile of the purified enzyme was tested against different temperature and pH. The observations suggesting that the potential of fibrinolytic enzyme produced by Bacillus subtilis RJAS 19 for its applications in preventive medicines.

Purification and partial characterization of a chymotrypsin-like serine fibrinolytic enzyme from Bacillus amyloliquefaciens FCF-11 using corn husk as a novel substrate

A non-toxic, direct-acting fibrinolytic enzyme, FCF-11, from a newly isolated Bacillus amyloliquefaciens FCF-11 was purified, characterized and assayed both in vitro and in vivo for its thrombolytic potential. Corn husk was used as for the first time as the sole carbon/nitrogen source for enzyme production. The molecular weight of the purified enzyme was 18.2 kDa and purification increased its specific activity 443.5-fold with a recovery of 17 %. Maximal activity was attained at a temperature of 40 °C and pH of 8.0. Additionally the isoelectric point of this protein was 10 ± 0.2. Tosyl lysine chloromethyl ketone, phenylmethylsulphonyl fluoride, soybean trypsin inhibitor, and aprotinin highly repressed this activity. The presence of ethylenediaminetetraacetic acid, and two metalloprotease inhibitors, 2,2'-bipyridine and o-phenanthroline, didn't affect the enzymatic activity. Furthermore, it was found to exhibit a higher specificity for the chromogenic substrate S-2586 for chymotrypsin, indicating that the enzyme is a chymotrypsin-like serine protease. Its apparent K(m) and V(max) for the synthetic substrate N-Suc-Phe-pNA were 0.45 mM and 8.26 μmoles/mg/min, respectively. FCF-11 showed direct action upon blood clots in vitro and prolonged the blood clotting time to 4.1-fold, suggesting this enzyme be a beneficial thrombolytic agent especially, with regard with low molecular weight and non specificity to other plasma proteins. FCF-11 could not degrade collagen and was non-cytotoxic to HT29 cells or mammalian erythrocytes. Further, enzyme at a dose of 2 mg/kg was devoid of toxicity as well as hemorrhagic activity on BALB/c mouse model, supporting its suitability for the development of a better and safer thrombolytic drug.

Protease production by Staphylococcus epidermidis and its effect on Staphylococcus aureus biofilms

Due to the resistance of Staphylococcus aureus to several antibiotics, treatment of S. aureus infections is often difficult. As an alternative to conventional antibiotics, the field of bacterial interference is investigated. Staphylococcus epidermidis produces a serine protease (Esp) which inhibits S. aureus biofilm formation and which degrades S. aureus biofilms. In this study, we investigated the protease production of 114 S. epidermidis isolates, obtained from biofilms on endotracheal tubes (ET). Most of the S. epidermidis isolates secreted a mixture of serine, cysteine and metalloproteases. We found a link between high protease production by S. epidermidis and the absence of S. aureus in ET biofilms obtained from the same patient. Treating S. aureus biofilms with the supernatant (SN) of the most active protease producing S. epidermidis isolates resulted in a significant biomass decrease compared to untreated controls, while the number of metabolically active cells was not affected. The effect on the biofilm biomass was mainly due to serine proteases. Staphylococcus aureus biofilms treated with the SN of protease producing S. epidermidis were thinner with almost no extracellular matrix. An increased survival of Caenorhabditis elegans, infected with S. aureus Mu50, was observed when the SN of protease positive S. epidermidis was added.

Activity assessment of microbial fibrinolytic enzymes

Conversion of fibrinogen to fibrin inside blood vessels results in thrombosis, leading to myocardial infarction and other cardiovascular diseases. In general, there are four therapy options: surgical operation, intake of antiplatelets, anticoagulants, or fibrinolytic enzymes. Microbial fibrinolytic enzymes have attracted much more attention than typical thrombolytic agents because of the expensive prices and the side effects of the latter. The fibrinolytic enzymes were successively discovered from different microorganisms, the most important among which is the genus Bacillus. Microbial fibrinolytic enzymes, especially those from food-grade microorganisms, have the potential to be developed as functional food additives and drugs to prevent or cure thrombosis and other related diseases. There are several assay methods for these enzymes; this may due to the insolubility of substrate, fibrin. Existing assay methods can be divided into three major groups. The first group consists of assay of fibrinolytic activity with natural proteins as substrates, e.g., fibrin plate methods. The second and third groups of assays are suitable for kinetic studies and are based on the determination of hydrolysis of synthetic peptide esters. This review will deal primarily with the microorganisms that have been reported in literature to produce fibrinolytic enzymes and the first review discussing the methods used to assay the fibrinolytic activity.