Keila Aparecida Moreira

Application of protease from Nocardiopsis sp. as a laundry detergent additive

The application of protease as a laundry detergent additive from a newly isolated Nocardiopsis sp., isolated from a soil sample collected in Northeast Brazil is reported. The optimal pH and temperature for protease activity were pH 10.5 and 50 °C, respectively. The enzyme was stable in a long-term incubation, showed 73.5% of initial activity at pH 10.5 and 61.7% at pH 12.0 for 120 min. Approximately 60% of initial activity remained after 120 min at 50 °C or after 30 min at 80 °C. Almost 87% of enzyme activity was retained in the presence of 10% (v/v) of peroxide at 40 °C, after 1 h. The protease also was stable in the presence of oxidants and surfactants such as SDS, saponin, Tween 20 and Tween 80 after 30 min. In the presence of Omo®, the enzyme retained 64% of its activity at 40 °C for 1 h. An increase in the proteolytic activity (6–17%) was observed with K+, Na+, and Mg++ ions. At pH 8.0, the protease hydrolysed casein maximally (50 U/mg).

New alkaline protease from Nocardiopsis sp.: partial purification and characterization

Abstract A new alkaline protease from Nocardiopsis sp., isolated from a soil sample collected from the Northeast of Brazil is reported. The crude extract (CE) was designate as partially purified extract (PPE) after purification with ammonium sulphate (0–20%). Optimal pH and temperature for detection of protease activity were obtaining at pH 10.5 and 8.0, for CE and PPE, respectively, at 50xa0°C for both extracts. The enzyme was stable at alkaline pH and more than 75% activity was retained even after incubation for 120 min at pHs between 8.0 and 10.5, for both extracts. The use of specific inhibitors, made it possible to show that the enzyme belongs to the group of serine protease. Maximum protease activity was achieved at pH 8.0 (50 U/mg) for CE and at pH 10.0 for PPE (1260 U/mg). The CE was partial purified with Sephadex G-75 obtained 26-purification fold and 34% yield.

Cellulase Production by Aspergillus japonicus URM5620 Using Waste from Castor Bean (Ricinus communis L.) Under Solid-State Fermentation

The activity of β-glucosidase (βG), total cellulase (FPase) and endoglucanase (CMCase), produced by Aspergillus japonicus URM5620, was studied on solid-state fermentation using castor bean meal as substrate. The effect of the substrate amount, initial moisture, pH, and temperature on cellulase production was studied using a full factorial design (24). The maximum βG, FPase, and CMCase activity was 88.3, 953.4, and 191.6xa0U/g dry substrate, respectively. The best enzyme activities for all three enzymes were obtained at the same conditions with 5.0xa0g of substrate, initial moisture 15% at 25xa0°C and pHxa06.0 with 120xa0h of fermentation. The optimum activity for FPase and CMCase was found at pHxa03.0 at an optimum temperature of 50xa0°C for FPase and of 55xa0°C for CMCase. The cellulases were stable in the range of pHxa03.0–10.0 at 50xa0°C temperature. The enzyme production optimization demonstrated clearly the impact of the process parameters on the yield of the cellulolytic enzymes.

Quantification, Antioxidant and Antimicrobial Activity of Phenolics Isolated from Different Extracts of Capsicum frutescens (Pimenta Malagueta)

This paper presents the quantification, antioxidant and antimicrobial activity of capsaicin, dihydrocapsaicin and the flavonoid chrysoeriol isolated from different extracts (hexane and acetonitrile extracts from whole fruit, peel and seed) of Capsicum frutescens (pimenta malagueta). The acetonitrile extract of the seeds, peel and whole fruits contained capsaicin as a major component, followed in abundance by dihydrocapsaicin and chrysoeriol. The antimicrobial activity of the isolated compounds against seven microorganisms showed chrysoeriol was the most active compound. In the antioxidant test, the acetonitrile extract from the whole fruit showed the highest activity. The antioxidant activity of pimenta malagueta may be correlated with its phenolic content, principally with the most active compound, capsaicin.

Extraction of amylase from fermentation broth in poly (Ethylene Glycol) salt aqueous two-phase system

Studies were carried out on the partition of amylase from Bacillus subtilis in a minimal medium at 37 oC and 110 rpm. Enzyme recovery was carried out in aqueous two-phase system PEG-Phosphate salt were carried out. The best purification factor (5.4) was obtained in system PEG 1000 (16.7% w/w) with potassium phosphate (14.8% w/w), at pH 6.0, resulting in a recovery of 45.2% activity enzymatic in the salt-rich phase.

Jacaratia corumbensis O. Kuntze a new vegetable source for milk-clotting enzymes

The partial characterization and purification of milk clotting enzyme obtained from the (root latex) of Jacaratia corumbensis O. kuntze was studied, by fractional precipitation with ammonium sulphate and ion exchange chromatography. The ammonium sulphate precipitate showed five fractions (AS1- 0-20%; AS2 - 20-40%; AS3 - 40-60%; AS4 - 60-80%; AS5 - 80-100%) and among the fractions obtained, the 40-60% fraction (AS3) showed the highest milk clotting activity with a purification factor of 1.2 fold in relation to the crude extract. This fraction when applied on Mono Q column yielded two protein peaks (p1 and p2), but p1 pool showed the best milk-clotting activity. The optimal pH for the crude and partially purified extract was 6.5 and 7.0, respectively. The maximum milk-clotting activity was at 55oC for the both crude and partially purified extracts. The enzyme was inhibited by iodoacetic acid which suggested that this enzyme was a cysteine protease, with molecular weight of 33 kDa.

Production of Polygalacturonases by Aspergillus section Nigri Strains in a Fixed Bed Reactor

Polygalacturonases (PG) are pectinolytic enzymes that have technological, functional and biological applications in food processing, fruit ripening and plant-fungus interactions, respectively. In the present, a microtitre plate methodology was used for rapid screening of 61 isolates of fungi from Aspergillus section Nigri to assess production of endo- and exo-PG. Studies of scale-up were carried out in a fixed bed reactor operated under different parameters using the best producer strain immobilised in orange peels. Four experiments were conducted under the following conditions: the immobilised cells without aeration; immobilised cells with aeration; immobilised cells with aeration and added pectin; and free cells with aeration. The fermentation was performed for 168 h with removal of sample every 24 h. Aspergillus niger strain URM 5162 showed the highest PG production. The results obtained indicated that the maximum endo- and exo-PG activities (1.18 U·mL−1 and 4.11 U·mL−1, respectively) were obtained when the reactor was operating without aeration. The microtitre plate method is a simple way to screen fungal isolates for PG activity detection. The fixed bed reactor with orange peel support and using A. niger URM 5162 is a promising process for PG production at the industrial level.

Recovery of ascorbic oxidoreductase from crude extract with an aqueous two-phase system in a perforated rotating disc contactor

A continuous perforated rotating disc contactor was used to extract the enzyme ascorbic oxidoreductase (E.C.1.10.3.3) from crude extract of Curcubita maxima with an aqueous two-phase system of poly (ethylene glycol) and phosphate salts. The effect of dispersed phase velocity on either protein mass transfer coefficients or separation efficiency at 1, 2 and 3 mL/min was studied. An increase of the mass transfer coefficients was observed with the dispersed phase velocity, while the separation efficiency showed a small decrease with the increase of this parameter. The experimental results obtained during continuous extraction showed that the ascorbic oxidoreductase activity was partitioned preferentially into the salt-rich phase in all conditions studied. The best recovery of enzyme activity was 236%, with a purification factor of 34 in flow rates of 1 mL/min for dispersed phase.

Aspergillus niveus Blochwitz 4128URM: new source for inulinase production

Aspergillus niveus Blochwitz 4128 URM isolated from sunflower rhizosphere demonstrated a new source of inulinase. The enzyme was produced in culture medium containing inulin as substrate in the concentrations: 10, 15 and 20g L-1. Maximum enzyme activity was obtained in medium containing 20g L-1 inulin. The enzyme was partially purified using ammonium sulphate precipitation, followed by ion charge (DE-32) and molecular exclusion (Sephadex) chromatography. The results showed the optimal pH and temperature of inulinase from crude extract were 4.0 and 4.8 and 45oC, respectively. The enzyme was purified 34.65 fold with yield of 53.63%. A. niveus 4128URM can be used in the inulinase production with use in the food industries.

PARTIAL CHARACTERIZATION OF PROTEASES FROM STREPTOMYCES CLAVULIGERUS USING AN INEXPENSIVE MEDIUM

The partial characterization of extracellular proteases from Streptomyces clavuligerus NRRL 3585 and 644 mutant was investigated. The enzyme production was carried out in batch fermentation using soy bean filtrate as nitrogen source. Maximum activity was obtained after 96h of fermentation with an initial pH of 7.0. The enzyme was partially purified by ammonium sulphate precipitation. Enzymes from the two strains retained 37% of their initial activities at pH 8.0 after 2 h incubation at 25oC. Enzyme half-life at pH 8.0 and 60oC was 40.30 and 53.32 min, respectively for both strains (partially purified extract). The optimum pH was obtained at pH 7.0-8.0 and 8.4 for enzymes produced for 3585 and 644 strains (crude extract), respectively, and 8.4 and 8.0 for enzymes from the partially purified extract 3585 and 644 strains, respectively. The optimum temperature for the crude extract was 21oC for both strains. However, for the partially preparation the optimum temperature was 50oC and 40°C for S. clavuligerus NRRL 3585 and 644 strains respectively.