Extracellular collagenase isolated from Streptomyces antibioticus UFPEDA 3421: purification and biochemical characterization.

Collagenases are proteases able to degrade native and denatured collagen, with broad applications such as leather, food, and pharmaceutical industries. The aim of this research was to purify and characterize a collagenase from Streptomyces antibioticus. In the present work, the coffee ground substrate provided conditions to obtaining high collagenase activity (377.5 U/mL) using anion-exchange DEAE-Sephadex G50 chromatographic protocol. SDS-PAGE revealed the metallo-collagenase with a single band of 41.28 kDa and was able to hydrolyzed type I and type V collagen producing bioactive peptides that delayed the coagulation time. The enzyme activity showed stability across a range of pH (6.0-11) and temperature (30-55 °C) with optima at pH 7.0 and 60 °C, respectively. Activators include Mg+2, Ca+2, Na+, K+, while full inhibition was given by other tested metalloproteinase inhibitors. Kinetic parameters (Km of 27.14 mg/mol, Vmax of 714.29 mg/mol/min, Kcat of 79.9 s-1 and Kcat/Km of 2.95 mL/mg/s) and thermodynamic parameters (Ea of 65.224 kJ/mol, ΔH of 62.75 kJ/mol, ΔS of 1.96 J/mol, ΔG of 62.16 kJ/mol, ΔGE-S of 8.18 kJ/mol and ΔGE-T of -2.64 kJ/mol) were also defined. Coffee grounds showed to be an interesting source to obtaining a collagenase able to produce bioactive peptides with anticoagulant activity.

Reutilization of residual glycerin for the produce ß-carotene by Rhodotorula minuta.

This study aimed to evaluate the production of carotenoid pigments by Rhodotorula spp. in submerged fermentation, using residual glycerin from biodiesel production as a carbon source. Chromatographic analysis by HPLC showed that the residual glycerin used as substrate was 57.88% composed of glycerol. The best growth conditions were found in the fermentation medium composed of residual glycerin at a concentration of 30 g/L and pH 9. From all the Rhodotorula strains tested, R. minuta URM6693 was selected because of their performance and adaptation in all culture media assayed. The maximum volumetric production of carotenoids was found at 48 h (equivalent to 17.20 mg/L, for the R. minuta). The production of ß-carotene since the first 24 h of fermentation reach a final concentration of 1.021 mg/L. The yeast Rhodotorula minuta proved its capability to efficiently convert the substrate (mainly at the concentration of 50 g/L), obtaining products of biotechnological interest.

In vitro thrombolytic activity of a purified fibrinolytic enzyme from Chlorella vulgaris.

A fibrinolytic enzyme was produced by microalga Chlorella vulgaris cultivated in autotrophic and mixotrophic conditions added corn steep liquor, purified by a single chromatographic step, then biochemical characterization and in vitro thrombolytic activity was performed. Maximum cell concentration (1637.45 ±â€¯15 mg L-1) and productivity (181.93 mg L-1 day-1) was obtained in mixotrophic culture using 1% corn steep liquor. Enzyme-extracted microalgal biomass was purified by acetone precipitation and DEAE Sephadex anion exchange chromatography up to 2 fold with recovery of 4.0%. After purification, fibrinolytic activity was 1834.6 U mg-1 and 226.86 mm2 by spectrophotometry and fibrin plate assays, respectively. SDS-PAGE results exhibited a protein band of about 45 kDa and fibrinolytic band was detected by fibrin zymography. Enzyme activity was enhanced in the presence of Fe2+ and inhibited by phenylmethane sulfonyl fluoride (PMSF) and ethylenediamine tetracetic acid (EDTA), which suggest it to be a metal-dependent serine protease. The extract also showed a red blood cell lysis <4% and in vitro thrombolytic activity of 25.6% in 90 min of reaction. These results indicate that the fibrinolytic enzyme from C. vulgaris may have potential applications in the prevention and treatment of thrombosis.

Probiotics as a preventive strategy for surgical infection in colorectal cancer patients: a systematic review and meta-analysis of randomized trials.

BACKGROUND: Infection following abdominal surgery remains a major factor in morbidity among colorectal cancer (CRC) patients. Probiotic therapy has been suggested to improve the clinical and laboratory outcome of patients undergoing gastrointestinal surgery. The aim of this study was to investigate the efficacy of probiotic lactic acid bacteria in patients with CRC in the pre- and postoperative phases. METHODS: Systematic database searches identified 1,080 related articles. However, only seven articles were selected according to the eligibility criteria for qualitative and quantitative evaluation. RESULTS: Most of the reviewed articles presented satisfactory results related to the prevention of surgical inflammation in patients undergoing resection of CRC when using strains of Lactobacillus genus, predominantly. CONCLUSIONS: Probiotics are suggested to prevent surgical inflammation of CRC, at the same time that the combination of particular microorganisms administered is beneficial to the treatment and surgical recovery.

Can γ-radiation modulate hemagglutinating and anticoagulant activities of PpyLL, a lectin from Phthirusa pyrifolia?

Blood coagulation and platelet-dependent primary homeostasis are important defense mechanisms against bleeding and novel inhibitors have been researched to obtain pharmacological and clinical applications. In this work, the PpyLL, a lectin obtained from Phthirusa pyrifolia, was characterized in terms of its molecular structure and biological functions (anticoagulant, antiplatelet agreggation and hemagglutinating activities) in presence or absence of Gamma radiation exposure. Results revealed a lectin with secondary-structure content by approximately 49% of ß-sheet, 20% of ß-turn and 31% of disordered structure. Irradiation effect demonstrated possible different sites of function by lectin on anticoagulant and hemagglutinating activities, once a decrease about 80% was observed when compared the activities under 0.5kGy of exposition to gamma radiation. An emphatic discussion about the use of gamma radiation as a possible modulator of the lectin activity was made, and once the ionizing radiation affected differently the anticoagulation and hemagglutinating activities, we speculated that the results are determined by selective molecular damages in different binding sites. PpyLL biological activities and gamma radiation modulation could be considered for future researches in biomedical field aiming possible medical applications.

Saccharomyces cerevisiae from Brazilian kefir-fermented milk: An in vitro evaluation of probiotic properties.

The therapeutic use of probiotics for supporting the antibiotic action against gastrointestinal disorders is a current trend and emerging applications have gained popularity because of their support for various microbiological activities in digestive processes. Microorganisms isolated from kefir with great probiotic properties, in addition to high resistance to harsh environmental conditions, have been widely researched. Administration of probiotic yeasts offers a number of advantages, when compared to bacteria, because of particular characteristics as their larger cell size. In the present study, 28 strains of Saccharomyces cerevisiae were isolated, after in vitro digestion of kefir-fermented milk, and identified by molecular based approaches. A screening was performed to determine important quality requirements for probiotics including: antagonistic and antioxidant activities, ß-galactosidase synthesis, autoaggregation, surface hydrophobicity and adhesion to epithelial cells. The results showed strains: with antagonistic activity against microbial pathogens such as Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis; able to produce ß-galactosidase; with antioxidant activity levels higher than 90%; with hydrophobicity activity and autoaggregation ability (evaluated by adhesion test, where all the strains presented adhesion to mice ileal epithelial cells). These findings are relevant and the strains are recommended for further in vivo studies as well as for potential therapeutic applications.

Collagenase produced from Aspergillus sp. (UCP 1276) using chicken feather industrial residue.

An extracellular collagenolytic serine protease was purified from Aspergillus sp., isolated from the Caatinga biome in northeast Brazil by a two-step chromatographic procedure, using an anion-exchanger and gel filtration. The enzyme was produced by submerged fermentation of feather residue as a substrate. The purified collagenase showed a 2.09-fold increase in specific activity and 22.85% yield. The enzyme was a monomeric protein with a molecular mass of 28.7 kDa, estimated by an SDS-PAGE and AKTA system. The optimum temperature and pH for enzyme activity were around 40°C and pH 8.0, respectively. The enzyme was strongly inhibited by phenyl-methylsulfonyl fluoride, a serine protease inhibitor, and was thermostable until 65°C for 1 h. We then evaluated the enzyme's potential for degradation of Type I and Type V collagens for producing peptides with antifungal activity. Our results revealed that the cleavage of Type V collagen yielded more effective peptides than Type I, inhibiting growth of Aspergillus terreus, Aspergillus japonicus and Aspergillus parasiticus. Both groups of peptides (Type I and Type V) were identified by SDS-PAGE. To conclude, the thermostable collagenase we purified in this study has various potentially useful applications in the fields of biochemistry, biotechnology and biomedical sciences.

Evidences of the static magnetic field influence on cellular systems.

Efforts to elucidate the doubtful character of the static magnetic field (SMF) influence on living cells have been made, although the topic still faces controversies because confusing reports in the scientific literature. This study intended to collect the most relevant issues separated by different topics (relating the SMF to its action on cellular systems) and analyze how the many field intensities, cell types and exposure time would affect the cell or intracellular structures. The analysis was based in the search in online databases aiming to give a general view of how the data can show conformity. It is proposed that scientists have been searching for linearity in what is actually a well characterized nonlinear system and two outputs are considered: the high sensitivity of parameters in which specific cell responses are generated and also the complexity and particularity of each cellular system. It is possible to trigger effects from a SMF, however in a stochastic way and depending on the cell system.