Gabriela Alves Macedo

Seed lipases: sources, applications and properties - a review

This paper provides an overview regarding the main aspects of seed lipases, such as the reactions catalyzed, physiological functions, specificities, sources and applications. Lipases are ubiquitous in nature and are produced by several plants, animals and microorganisms. These enzymes exhibit several very interesting features, such as low cost and easy purification, which make their commercial exploitation as industrial enzymes a potentially attractive alternative. The applications of lipases in food, detergents, oils and fats, medicines and fine chemistry, effluent treatment, biodiesel production and in the cellulose pulp industry, as well as the main sources of oilseed and cereal seed lipases, are reviewed.

Lipases de látex vegetais: propriedades e aplicações industriais

Biocatalysts have innumerous advantages with respect to classical chemical processes, such as high specificity. Lipases (EC 3.1.1.3) are biocatalysts with large application in synthesis and hydrolysis reactions of triacylglycerols. The search for new sources of lipases has been intensified in the last years due to the high cost of microbial and animal lipases, wich restricts their use on an industrial scale. Lipases obtained from the latex of Carica papaya, Carica pentagona, Euphorbia characias, E. wulfenii, known for their proteolytic properties, are a good alternative source. In this review, we describe the well-known sources of vegetal lipases extracted from the latex and present some of their industrial applications.

Potencial de biocatálise enantiosseletiva de lipases microbianas

Microbial lipases have a great potential for commercial applications due to their stability, selectivity and broad substrate specificity because many non-natural acids, alcohols or amines can be used as the substrate. Three microbial lipases isolated from Brazilian soil samples (Aspergillus niger; Geotrichum candidum; Penicillium solitum) were compared in terms of their stability and as biocatalysts in the enantioselective esterification using racemic substrates in organic medium. The lipase from Aspergillus niger showed the highest activity (18.2 U/mL) and was highly thermostable, retaining 90% and 60% activity at 50 oC and 60 oC after 1 hour, respectively. In organic medium, this lipase provided the best results in terms of enantiomeric excess of the (S)-active acid (ee = 6.1%) and conversion value (c = 20%) in the esterification of (R,S)-ibuprofen with 1-propanol in isooctane. The esterification reaction of the racemic mixture of (R,S)-2-octanol with decanoic acid proceeded with high enantioselectivity when lipase from Aspergillus niger (E = 13.2) and commercial lipase from Candida antarctica (E = 20) were employed.

Detoxification of castor bean residues and the simultaneous production of tannase and phytase by solid-state fermentation using Paecilomyces variotii.

In this work, we introduce a biological detoxification method that converts toxic waste from castor beans into animal feed material. This method simultaneously induces the production of tannase and phytase by Paecilomyces variotii; both enzymes have high levels of activity and have the potential to be used in feedstuffs because they decrease overall anti-nutritional factors. The maximum tannase and phytase activities obtained were 2600 and 260 U/g after 48 and 72 h, respectively. SDS-PAGE electrophoresis of the fermented castor cake extracts revealed a reduction in ricin bands during fermentation, and the bands were no longer visible after 48 h. The cytotoxicity of the extracts was evaluated by MTT testing on RAW cells, and a progressive increase in cellular viability was obtained, reaching almost 100% after 72 h of fermentation.

Effects of temperature, pH and additives on the activity of tannase produced by Paecilomyces variotii

A biochemical characterization of the tannase from a Paecilomyces variotii strain isolated in Sao Paulo, Brazil was carried out. Paecilomyces variotii is a strain obtained from the screening of five hundred fungi that were tested for their production of tannase. The enzyme produced was partially purified using ammonium sulfate precipitation followed by ion exchange chromatography, diethylaminoethyl (DEAE)-Sepharose. Effects of temperature and pH on the activity of crude tannase crude and purified tannase was studied. K m was found to be 0.61 µmol and V max = 0.55 U/mL. Temperature of 40 to 65oC and pH 4.5 to 6.5 were optimum for tannase activity and stability; it could find potential use in the food-processing industry. The effects of different inhibitors, surfactants and chelators on the enzyme activity were also studied.

Enzymatic synthesis of short chain citronellyl esters by a new lipase from Rhizopus sp

Short chain citronellyl esters were synthesized by a new microbial lipase from Rhizopus sp strain isolated and lipase produced at UNICAMP, Brazil. Direct esterification and transesterification reactions have been performed to produce citronellyl acetate and butyrate in a free-solvent system and with n-hexane in reaction medium. Reaction mixture for direct esterification and transesterification was carried out at 45oC in equimolar concentration of substrates: acid or ester and alcohol. Only citronellyl butyrate was synthesized by direct esterification with yields from 95 to 100% after 24 hrs. of reaction time, with or without n-hexane. Citronellyl acetate was synthesized by transesterification with ethyl acetate and cytronellol, with yield of 58% after 48 hrs. and 48% of conversion for reaction butyl acetate and cytronellol. The results suggest that the size of the aliphatic chain from acyl donor was importance to conversion rate. Acids with more than two carbons showed to be better substrate for Rhizopus sp lipase. Transesterification reaction showed different behaviour, ester substrate with four carbons was better than six carbon for citronellyl acetate synthesis. Esters of short chain fatty acids and alcohols are known as flavour and fragrance compounds. Used in the food, beverage, cosmetic and pharmaceutical industries. Currently, most of the flavour compounds are

Simultaneous extraction of oil and antioxidant compounds from oil palm fruit (Elaeis guineensis) by an aqueous enzymatic process

Oil palm (Elaeis guineensis) fruit was treated with enzymes to facilitate simultaneous recovery of oil and bioactive compounds. Tannase from Paecilomyces variotii, cellulase and pectinase were evaluated for their influence on oil recovery and antioxidant capacity (DPPH), oxidative stability (Rancimat), fatty acid profile, total phenols, total carotenoids and tocols of the oil. Maximum oil recovery (90-93% total oil) was obtained with central composite design using 4% of enzyme preparation (w/w) as 80 U of tannase, 240 U of cellulase and 178 U of pectinase, pH 4, ratio of solution to pulp of 2:1 and 30 min of incubation at 50 °C. Tannase improved the phenolic compounds extraction by 51% and pectinase plus cellulase improved carotene extraction by 153%. Samples treated with tannase showed a 27% and 53% higher antioxidant capacity for the lipophilic and hydrophilic fractions.

A rapid screening method for cutinase producing microorganisms

Both cutinase and lipase belong to the esterase group of enzymes (EC 3.1.1.X), which are capable of catalyzing the hydrolysis of ester bonds. Cutinase catalyzes the hydrolysis of cutin, an insoluble biopolyester which is the structural component of plant cuticles. As cutinase is an efficient catalyst in watery or organic media, it is potentially appropriate for the detergent, food and cosmetic industries. The objective of this work was to isolate microorganisms from plants and perform a pre-selection of molds showing esterase producing ability. The selected strains were then submitted to fermentation in media containing cutin. The lipolytic and cutinolytic activities of the supernatant were determined in order to differentiate lipase producers from cutinase-producing strains. The mold strain selected as the best cutinase producer was identified as being Fusarium oxysporium.

Chemopreventive potential of the tannase-mediated biotransformation of green tea

Green tea (Camellia sinensis) is one of the most widely consumed beverages in the world. The cancer chemopreventive qualities of green tea have been well documented. Epigallocatechin gallate (EGCG) is often described as the most potently chemopreventive green tea catechin; however, the low bioavailability of EGCG is a limiting factor for its biological effect. Thus, the aim of this work was to test the chemopreventive potential of green tea extract and EGCG after tannase-mediated hydrolysis. The results showed that the biotransformed compounds retained most of the beneficial properties of the original compounds, and some beneficial properties were improved in the biotransformed compounds. Biotransformation of EGCG decreased its toxicity without affecting its antiproliferative effects. Furthermore, human cells gene expression profiling showed that the biotransformed compounds modulated the expression of several genes related to carcinogenesis. These results demonstrate the benefits of the biotechnological modification of natural food molecules, allowing the improvement of the nutraceutical potential of a beverage as green tea.

Purification and Biochemical Characterization of Tannase from a Newly Isolated Strain of Paecilomyces Variotii

An extracellular tannase was isolated from Paecilomyces variotii and partially purified using ammonium sulphate precipitation followed by DEAE-Sepharose ion exchange chromatography. Paecilomyces variotii is a newly isolated strain obtained in São Paulo, Brazil, from the screening of 500 fungi evaluated for their production of tannase. The tannase was separated into two peaks. SDS-PAGE analysis indicated that the purified enzyme migrated as a single protein band corresponding to molecular mass of 87.3 kDa (major peak) and 71.5 kDa (minor peak). The peaks eluted very close together between 150 and 250 mM NaCl. DEAE-Sepharose column chromatography led to an overall purification of 19.3 fold. The Km was found to be 0.61 μmol and the Vmax = 0.55 U.mL−1. Temperatures from 40 to 65°C and pH values from 4.5 to 6.5 were optimum for tannase activity and stability. This tannase could find potential use in the food-processing industry.