A polysaccharide fraction extracted from Pleurotus ostreatus mycelial biomass inhibit Sarcoma 180 tumor.

Fungi of Pleurotus genus have attracted a great interest due to their medicinal properties such as anti-inflammatory, antimicrobial and antitumor. These properties are attributed mainly to polysaccharides synthesized by Pleurotus. This work aimed to study the mycelial growth of P. ostreatus in submerged culture, evaluating the influence of the initial concentration of substrate (20 and 40 g/L of glucose) and the pH (4 and 6) on kinetic parameters of production of biomass. The effectiveness of different doses (10, 30 and 50 mg/kg) of a mycelium polysaccharide fraction extracted from P. ostreatus in reducing Sarcoma 180 development in mice was also verified. In the range of this study, maximum concentration of mycelial biomass (about 12.8 g/L) was obtained using 40.0 g/L of glucose, at pH 4.0. The total biomass productivity (Px) was not significantly affected by substrate concentration and pH, reaching values of 0.034 g/L.h. Sarcoma 180 tumor weight was reduced in 74.1, 75.5 and 53.7% when 10, 30 and 50 mg/kg were administered, respectively. These results show the high antitumor potential of intracellular polysaccharide fraction of mycelial biomass of P. ostreatus, particularly at lower doses of 10 and 30 mg/kg.

Evaluation of different methods for immobilization of Candida antarctica lipase B (CalB lipase) in polyurethane foam and its application in the production of geranyl propionate.

With the aim of studying the best method for the interaction of polyurethane (PU) foam and Candida antarctica lipase B, different methods of CalB immobilization were studied: adsorption (PU-ADS), bond (using polyethyleneimine) (PU-PEI), ionic adsorption by PEI with cross-linking with glutaraldehyde (PU-PEI-GA) and entrapment (PU). The characterization of immobilized enzyme derivatives was performed by apparent density and Fourier transform infrared spectroscopy. The free enzyme and enzyme preparations were evaluated at different pH values and temperatures. The highest enzyme activity was obtained using the PU method (5.52 U/g). The methods that stood out to compare the stabilities and kinetic parameters were the PU and PU-ADS. Conversions of 83.5 and 95.9 % for PU and PU-ADS derivatives were obtained, in 24 h reaction, using citronella oil and propionic acid as substrates.

A review on lipase-catalyzed reactions in ultrasound-assisted systems.

The named "green chemistry" has been receiving increasing prominence due to its environmentally friendly characteristics. The use of enzymes as catalysts in processes of synthesis to replace the traditional use of chemical catalysts present as main advantage the fact of following the principles of the green chemistry. However, processes of enzymatic nature generally provide lower yields when compared to the conventional chemical processes. Therefore, in the last years, the ultrasound has been extensively used in enzymatic processes, such as the production of esters with desirable characteristics for the pharmaceutical, cosmetics, and food industry, for the hydrolysis and glycerolysis of vegetable oils, production of biodiesel, etc. Several works found in the open literature suggest that the energy released by the ultrasound during the cavitation phenomena can be used to enhance mass transfer (substrate/enzyme), hence increasing the rate of products formation, and also contributing to enhance the enzyme catalytic activity. Furthermore, the ultrasound is considered a "green" technology due to its high efficiency, low instrumental requirement and significant reduction of the processing time in comparison to other techniques. The main goal of this review was to summarize studies available to date regarding the application of ultrasound in enzyme-catalyzed esterification, hydrolysis, glycerolysis and transesterification reactions.

Effect of the support size on the properties of ß-galactosidase immobilized on chitosan: advantages and disadvantages of macro and nanoparticles.

The effect of the support size on the properties of enzyme immobilization was investigated by using chitosan macroparticles and nanoparticles. They were prepared by precipitation and ionotropic gelation, respectively, and were characterized by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), transmission electron microscopy (TEM), light scattering analysis (LSA), and N(2) adsorption-desorption isotherms. ß-Galactosidase was used as a model enzyme. It was found that the different sizes and porosities of the particles modify the enzymatic load, activity, and thermal stability of the immobilized biocatalysts. The highest activity was shown by the enzyme immobilized on nanoparticles when 204.2 mg protein·(g dry support)(-1) were attached. On the other hand, the same biocatalysts presented lower thermal stability than macroparticles. ß-Galactosidase immobilized on chitosan macro and nanoparticles exhibited excellent operational stability at 37 °C, because it was still able to hydrolyze 83.2 and 75.93% of lactose, respectively, after 50 cycles of reuse.

Production of new nanobiocatalysts via immobilization of lipase B from C. antarctica on polyurethane nanosupports for application on food and pharmaceutical industries.

Nanobiocatalysts were produced via immobilization of CalB lipase on polyurethane (PU) based nanoparticles and their application on the synthesis of important industrial products was evaluated. Nanoparticles of polyurethane functionalized with poly(ethylene glycol) (PU-PEG) were synthetized through miniemulsion polymerization and the addition of crosslinking agents were evaluated. The nanoparticles were employed as support for CalB and the kinetic parameters were reported. The performance of new biocatalysts was evaluated on the hydrolysis reaction of p-NPB and on the enantioselective hydrolysis of (R,S)-mandelic acid. The esterification reaction was evaluated on the production of ethyl esters of Omega-3. The effect of poly(ethylene glycol) molar mass (400, 4000 or 6000 Da)on the biocatalyst activity was also analyzed. The PU-PEG6000-CalB showed the highest value of the kinetic parameters, highlighting the high reaction rate. The addition of trehalose as crosslinking agent improved the thermal stability of the biocatalysts. PU-PEG400-CalB was the most active nanobiocatalyst, exhibiting a ethyl esters production of 43.72 and 16.83 mM.U -1 using EPA and DHA, respectively. The nanobiocatalyst was also applied in enantiomeric resolution of mandelic acid, showing promising enantiomeric ratios. The results obtained in this work present alternative and sustainable routes for the synthesis of important compounds used on food and pharmaceutical industries.

Production of fungal chitosan in liquid cultivation using apple pomace as substrate.

In this work, we propose the reuse of apple pomace as a substrate for fungal chitosan production by liquid cultivation of Gongronella butleri CCT4274. Different concentrations of reducing sugars and sodium nitrate were added to the aqueous extract of apple pomace and the best result was obtained with 40 g/L of reducing sugars and 2.5 g/L of sodium nitrate. The results indicate the possibility of producing 1.19 g/L of chitosan per liter of culture medium after 72.5 hours of cultivation, representing around 21% of the biomass content.

Chitosan crosslinked with genipin as support matrix for application in food process: Support characterization and ß-D-galactosidase immobilization.

In order to develop safer processes for the food industry, we prepared a chitosan support with the naturally occurring crosslinking reagent, genipin, for enzyme. As application model, it was tested for the immobilization of ß-D-galactosidase from Aspergillus oryzae. Chitosan particles were obtained by precipitation followed by adsorption of the enzyme and crosslinking with genipin. The particles were characterized by Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). The immobilization of the enzyme by crosslinking with genipin provided biocatalysts with satisfactory activity retention and thermal stability, comparable with the ones obtained with the traditional methodology of immobilization using glutaraldehyde. ß-D-Galactosidase-chitosan-genipin particles were applied to galactooligosaccharides synthesis, evaluating the initial lactose concentration, pH and temperature, and yields of 30% were achieved. Moreover, excellent operational stability was obtained, since the immobilized enzyme maintained 100% of its initial activity after 25 batches of lactose hydrolysis. Thus, the food grade chitosan-genipin particles seem to be a good alternative for application in food process.

Kinetic study of Candida antarctica lipase B immobilization using poly(methyl methacrylate) nanoparticles obtained by miniemulsion polymerization as support.

With the objective to obtain immobilized Candida antarctica lipase B (CalB) with good activity and improved utilization rate, this study evaluated the influence of enzyme and crodamol concentrations and initiator type on the CalB enzyme immobilization in nanoparticles consisting of poly(methyl methacrylate) (PMMA) obtained by miniemulsion polymerization. The kinetic study of immobilized CalB enzyme in PMMA nanoparticles was evaluated in terms of monomer conversion, particle size, zeta potential, and relative activity. The optimum immobilization condition for CalB was compared with free enzyme in the p-NPL hydrolysis activity measurement. Results showed a higher CalB enzyme stability after 20 hydrolysis cycles compared with free CalB enzyme; in particular, the relative immobilized enzyme activity was maintained up to 40%. In conclusion, PMMA nanoparticles proved to be a good support for the CalB enzyme immobilization and may be used as a feasible alternative catalyst in industrial processes.

Lipozyme TL IM as Catalyst for the Synthesis of Eugenyl Acetate in Solvent-Free Acetylation.

The ability of commercial immobilized lipase from Thermomyces lanuginosus (Lipozyme TL IM) to catalyze the acetylation of essential clove oil with acetic anhydride in a solvent-free system was studied, and the antimicrobial activity of the ester formed was evaluated as well. Experimental design based on two variables (eugenol to acetic anhydride molar ratio and temperature) was employed to evaluate the experimental conditions of eugenyl acetate ester production. The maximum conversion yield (92.86 %) was obtained using Lipozyme TL IM (5 wt%, based on the total amount of substrates), with eugenol to acetic anhydride molar ratio of 1:5 at 70 °C. The chemical structure of the eugenyl acetate ester obtained at the optimized condition, and purified, was confirmed by the proton nuclear magnetic resonance ((1)H-NMR) analysis. The antimicrobial activity of eugenyl acetate ester was proven effective on Gram-positive and Gram-negative bacteria, with means of 16.62 and 17.55 mm of inhibition halo.

High stability of immobilized ß-D-galactosidase for lactose hydrolysis and galactooligosaccharides synthesis.

ß-D-Galactosidase from Kluyveromyces lactis was immobilized on glutaraldehyde-activated chitosan and used in a packed-bed reactor for the continuous hydrolysis of lactose and the synthesis of galactooligosaccharides (GOS). The biocatalyst was tested for its optima pH and temperature, thermal stability in the presence of substrate and products, and operational stability. Immobilization increased the range of operational pH and temperature, and the enzyme thermal stability was sharply increased in the presence of lactose. Almost complete lactose hydrolysis was achieved for both milk whey and lactose solution at 37 °C at flow rates up to 2.6 mL min(-1). Maximal GOS concentration of 26 g L(-1) was obtained at a flow rate of 3.1 mL min(-1), with a productivity of 186 g L(-1) h(-1). Steady-state operation for 15 days showed the reactor stability concerning lactose hydrolysis.

A polysaccharide fraction extracted from Pleurotus ostreatus mycelial biomass inhibit Sarcoma 180 tumor

ABSTRACT Fungi of Pleurotus genus have attracted a great interest due to their medicinal properties such as anti-inflammatory, antimicrobial and antitumor. These properties are attributed mainly to polysaccharides synthesized by Pleurotus. This work aimed to study the mycelial growth of P. ostreatus in submerged culture, evaluating the influence of the initial concentration of substrate (20 and 40 g/L of glucose) and the pH (4 and 6) on kinetic parameters of production of biomass. The effectiveness of different doses (10, 30 and 50 mg/kg) of a mycelium polysaccharide fraction extracted from P. ostreatus in reducing Sarcoma 180 development in mice was also verified. In the range of this study, maximum concentration of mycelial biomass (about 12.8 g/L) was obtained using 40.0 g/L of glucose, at pH 4.0. The total biomass productivity (Px) was not significantly affected by substrate concentration and pH, reaching values of 0.034 g/L.h. Sarcoma 180 tumor weight was reduced in 74.1, 75.5 and 53.7% when 10, 30 and 50 mg/kg were administered, respectively. These results show the high antitumor potential of intracellular polysaccharide fraction of mycelial biomass of P. ostreatus, particularly at lower doses of 10 and 30 mg/kg.

Esterification activity of novel fungal and yeast lipases.

The main objective of this work was the isolation and screening of microorganisms with potential for producing lipases for the synthesis of fatty esters as well as evaluating the specificity of the enzymes produced, using different alcohols (methanol, ethanol, n-propanol, and butanol) and fatty acids (oleic and lauric acids) as substrates. Promising biocatalysts for organic synthesis were obtained in this work. The isolated strains 69F and 161Y showed ability to efficiently catalyze the reaction for production of n-propyl oleate. Other strains can also be considered of potential interest, as 74F, 111Y, and 186Y. The future development of production using different substrates could result in cheap crude lipase of high importance to industrial applicability.

Apple pomace: a versatile substrate for biotechnological applications.

Apple pomace is the processing waste generated after apple juice manufacturing and represents up to 30% of the original fruit. This solid residue consists of a complex mixture of peel, core, seed, calyx, stem, and soft tissue. This residual material is a poor animal feed supplement because of its extremely low protein content and high amount of sugar. The application of agroindustrial by-products in bioprocesses offers a wide range of alternative substrates, thus helping solve pollution problems related to their disposal. Attempts have been made to use apple pomace to generate several value-added products, such as enzymes, single cell protein, aroma compounds, ethanol, organic acids, polysaccharides, and mushrooms. This article reviews recent developments regarding processes and products that employed apple pomace as a substrate for biotechnological applications.

Lipase-catalyzed synthesis of monoacylglycerol in a homogeneous system.

The 1,3-regiospecifique lipase, Lipozyme IM, catalyzed the esterification of lauric acid and glycerol in a homogeneous system. To overcome the drawback of the insolubility of glycerol in hexane, which is extensively used in enzymatic synthesis, a mixture of n-hexane/tert-butanol (1:1, v/v) was used leading to a monophasic system. The conversion of lauric acid into monolaurin was 65% in 8 h, when a molar ratio of glycerol to fatty acid (5:1) was used with the fatty acid at 0.1 M, and the phenomenon of acyl migration was minimized.

Production of fungal chitosan in liquid cultivation using apple pomace as substrate / Produção de quitosana fungica em cultivo liquido utilisando bagaço de maçã como substrato

In this work, we propose the reuse of apple pomace as a substrate for fungal chitosan production by liquid cultivation of Gongronella butleri CCT4274. Different concentrations of reducing sugars and sodium nitrate were added to the aqueous extract of apple pomace and the best result was obtained with 40 g/L of reducing sugars and 2.5 g/L of sodium nitrate. The results indicate the possibility of producing 1.19 g/L of chitosan per liter of culture medium after 72.5 hours of cultivation, representing around 21% of the biomass content.

Este trabalho propõe o reuso do bagaço de maçã como substrato para a produção de quitosana fúngica em cultivo liquido do fungo Gongronella butleri CCT4274. Diferentes concentrações de açúcares redutores e nitrato de sódio foram adicionadas ao extrato aquoso do bagaço de maçã. O melhor resultado foi obtido para concentrações de 40 g/L e 2,5 g/L de açúcares redutores e nitrato de sódio, respectivamente. Os resultados indicam a possibilidade de produzir 1,19 g/L de quitosana após 72,5 horas de cultivo, representando 21% da composição da biomassa.