Hélia Harumi Sato

Recent progress of propolis for its biological and chemical compositions and its botanical origin.

Propolis is the generic name given to the product obtained from resinous substances, which is gummy and balsamic and which is collected by bees from flowers, buds, and exudates of plants. It is a popular folk medicine possessing a broad spectrum of biological activities. These biological properties are related to its chemical composition and more specifically to the phenolic compounds that vary in their structure and concentration depending on the region of production, availability of sources to collect plant resins, genetic variability of the queen bee, the technique used for production, and the season in which propolis is produced. Many scientific articles are published every year in different international journal, and several groups of researchers have focused their attention on the chemical compounds and biological activity of propolis. This paper presents a review on the publications on propolis and patents of applications and biological constituents of propolis.

Biologically active peptides: Processes for their generation, purification and identification and applications as natural additives in the food and pharmaceutical industries

Recent technological advances have created great interest in the use of biologically active peptides. Bioactive peptides can be defined as specific portions of proteins with 2 to 20 amino acids that have desirable biological activities, including antioxidant, anti-hypertensive, antithrombotic, anti-adipogenic, antimicrobial and anti-inflammatory effects. Specific characteristics, including low toxicity and high specificity, make these molecules of particular interest to the food and pharmaceutical industries. This review focuses on the production of bioactive peptides, with special emphasis on fermentation and enzymatic hydrolysis. The combination of different technologies and the use of auxiliary processes are also addressed. A survey of isolation, purification and peptide characterization methods was conducted to identify the major techniques used to determine the structures of bioactive peptides. Finally, the antioxidant, antimicrobial, anti-hypertensive, anti-adipogenic activities and probiotic-bacterial growth-promoting aspects of various peptides are discussed.

Production of cyclodextrin from starch by cyclodextrin glycosyltransferase from Bacillus firmus and characterization of purified enzyme

During screening for cyclodextrin-forming microorganisms, an alkalophilic Bacillus sp, which produced high activity of cyclodextrin glycosyltransferase, was isolated and identified as Bacillus firmus. The crude enzyme transformed starch to mainly β-and γ-cyclodextrin. The purified enzyme had an optimum pH of 7.5–8.5 and its optimum temperature was 65°C, which is the highest optimum temperature as compared to other cyclodextrin glycosyltransferases except that produced by Bacillus amyloliquefaciens.

Paenibacillus campinasensis sp. nov., a cyclodextrin-producing bacterium isolated in Brazil.

An alkaliphilic, endospore-forming bacterium isolated from Brazilian soil was taxonomically studied and is proposed as a new Paenibacillus species. This organism (strain 324T) was particularly distinguishable from other Paenibacillus species by its ability to grow optimally at pH 10 and 40 degrees C. The DNA G+C content was 5.0 mol%. The diamine acid of the cell-wall peptidoglycan was meso-diaminopimelic acid. MK-7 was the predominant menaquinone and anteiso-C15:0 was the major fatty acid. Levels of 16S rDNA similarity between strain 324T and other Paenibacillus species were 90.6-95.9%. Phylogenetically, strain 324T formed an evolutionary lineage distinct from other species within the evolutionary radiation encompassing the genus Paenibacillus. Based on phenotyic and chemotaxonomic properties, and phylogenetic inference, it is proposed that strain 324T should be placed in the genus Paenibacillus as a new species is strain 324T should be placed in the genus Paenibacilus as a new species, Paenibacillus campinasensis. This type strain of the new species is strain 325T (= KCTC 0364BP).

Optimization of medium composition for transglutaminase production by a Brazilian soil Streptomyces sp

Finding a new microbial source of transglutaminase (MTGase) and the study of the medium composition for MTGase production were the goals of this work. A total of 200 actinomycete-like strains were isolated from Brazilian soil samples and two of them named T10b and P20 were selected based on their ability to produce 0.15 U.mL -1 and 0.25 U.mL -1 of MTGase, respectively. Strain P20 was chosen to continue the study and was identified as Streptomyces sp. In order to optimize the MTGase activity, modifications of the usual media composition described for enzyme production were tested. The strategy adopted was: (1) screening experiment for the best carbon and nitrogen sources; (2) fractional factorial design (FFD) to elucidate the key ingredients in the media (the results indicated that the soybean flour, peptone, KH 2 PO 4 and MgSO 4 .7H 2 O had a significant effect on MTGase) production and (3) central composite design (CCD) to optimize the concentration of the key components. The experimental results were fitted to a second-order polynomial model at the 95% level of significance (P -1 , very closely matching the experimental activity of 1.4 U.mL -1 .

Potential Applications of Carbohydrases Immobilization in the Food Industry

Carbohydrases find a wide application in industrial processes and products, mainly in the food industry. With these enzymes, it is possible to obtain different types of sugar syrups (viz. glucose, fructose and inverted sugar syrups), prebiotics (viz. galactooligossacharides and fructooligossacharides) and isomaltulose, which is an interesting sweetener substitute for sucrose to improve the sensory properties of juices and wines and to reduce lactose in milk. The most important carbohydrases to accomplish these goals are of microbial origin and include amylases (α-amylases and glucoamylases), invertases, inulinases, galactosidases, glucosidases, fructosyltransferases, pectinases and glucosyltransferases. Yet, for all these processes to be cost-effective for industrial application, a very efficient, simple and cheap immobilization technique is required. Immobilization techniques can involve adsorption, entrapment or covalent bonding of the enzyme into an insoluble support, or carrier-free methods, usually based on the formation of cross-linked enzyme aggregates (CLEAs). They include a broad variety of supports, such as magnetic materials, gums, gels, synthetic polymers and ionic resins. All these techniques present advantages and disadvantages and several parameters must be considered. In this work, the most recent and important studies on the immobilization of carbohydrases with potential application in the food industry are reviewed.

Screening of Supports for the Immobilization of β-Glucosidase

A set of supports were screened for the immobilization of a partially purified extract of β-glucosidase from Aspergillus sp. These supports, namely, Eupergit, Amberlite, alginate, gelatin, polyvinyl alcohol- (PVA-) based matrices (Lentikats), and sol-gel, have proved effective for the implementation of some other enzyme-based processes. The initial criterion for selection of promising supports prior to further characterization relied on the retention of the catalytic activity following immobilization. Based on such criterion, where immobilization in sol-gel and in Lentikats outmatched the remaining approaches, those two systems were further characterized. Immobilization did not alter the pH/activity profile, whereas the temperature/activity profile was improved when sol-gel support was assayed. Both thermal and pH stability were improved as a result of immobilization. An increase in the apparent K M (Michaelis constant) was observed following immobilization, suggesting diffusion limitations.

Production of fruity aroma by newly isolated yeast

SummaryOne strain of yeast (Geotrichum sp) which was isolated from papaya fruit produced 22 volatile compounds and 8 of these were chemically identified. Ethyl isovalerate and ethyl hexanoate showed as fruity flavor, whereas ethyl propionate and ethyl butyrate showed weak fruitiness. Production of two fruity compounds was further studied by using various culture media.

Production, purification and application of extracellular chitinase from Cellulosimicrobium cellulans 191.

This study concerned the production, purification and application of extracellular chitinase from Cellulosimicrobium cellulans strain 191. In shaken flasks the maximum yield of chitinase was 6.9 U/mL after 72 h of cultivation at 25oC and 200 rpm. In a 5 L fermenter with 1.5 vvm aeration, the highest yield obtained was 4.19 U/mL after 168 h of fermentation at 25oC and 200 rpm, and using 3 vvm, it was 4.38 U/mL after 144 h of fermentation. The chitinase (61 KDa) was purified about 6.65 times by Sepharose CL 4B 200 gel filtration with a yield of 46.61%. The purified enzyme was able to lyse the cell walls of some fungi and to form protoplasts.

Produção de isomaltulose a partir da transformação enzimática da sacarose, utilizando-se Erwinia sp D12 imobilizada com alginato de cálcio

The glucosyltransferase of Erwinia sp D12 is able to convert sucrose into isomaltulose (6-0-a-D-glucopyranosyl-D-fructofuranose), an alternative sugar which presents low cariogenic potential, and can be used to produce chocolate, chewing gum and candy. The isomaltulose is also used to produce isomalt, a mixture of alcohol-sugar with a low caloric value and low cariogenicity power. In the study of the influence of the components of the culture medium in the glucosyltransferase production in flasks under shaking conditions, the highest activity (12.8 units of activity /mL of culture medium) was obtained in culture medium A, containing molasses 12% (p/v) of the total soluble solid, peptone 4% (p/v) and meat extract 0,4% (p/v). In the study of the effects of time and temperature on the fermentation of Erwinia sp D12 in a 3L New Brunswick fermentor containing culture medium A. the highest glucosyltransferase activity (15.6 units of activity /mL of culture medium) was obtained during the exponential growth phase after 8 hours of fermentation at 30oC. In the production of isomaltulose from enzymatic transformation of sucrose by Erwinia sp D12 cells immobilized in calcium alginate, the effects of the temperature (25-35oC) and substrate concentration (12,5-60%) were evaluated, the yield of isomaltulose was approximately 50%, from sucrose solutions ranging from 20 to 30% at 35oC. Excess of sucrose affected the activity of the immobilized cell, decreasing conversion of sucrose into isomaltulose. The syrup obtained was purified through Ion Exchange Chromatography, and the crystallization of eluent by the decreasing temperature. The obtained crystals presented 91,39% of isomaltulose.SUMMARY PRODUCTION OF ISOMALTULOSE FROM ENZYMATIC TRANSFORMATION OF SUCROSE, USING Erwinia sp D12 IMMOBILIZED WITH CALCIUM ALGINATE. The glucosyltransferase of Erwinia sp D12 is able to convert sucrose into isomaltulose (6-0-α-D-glucopyranosyl-Dfructofuranose), an alternative sugar which presents low cariogenic potential, and can be used to produce chocolate, chewing gum and candy. The isomaltulose is also used to produce isomalt, a mixture of alcohol-sugar with a low caloric value and low cariogenicity power. In the study of the influence of the components of the culture medium in the glucosyltransferase production in flasks under shaking conditions, the highest activity (12.8 units of activity /mL of culture medium) was obtained in culture medium A, containing molasses 12% (p/v) of the total soluble solid, peptone 4% (p/v) and meat extract 0,4% (p/v). In the study of the effects of time and temperature on the fermentation of Erwinia sp D12 in a 3L New Brunswick fermentor containing culture medium A. the highest glucosyltransferase activity (15.6 units of activity /mL of culture medium) was obtained during the exponential growth phase after 8 hours of fermentation at 30oC. In the production of isomaltulose from enzymatic transformation of sucrose by Erwinia sp D12 cells immobilized in calcium alginate, the effects of the temperature (25–35oC) and substrate concentration (12,5–60%) were evaluated, the yield of isomaltulose was approximately 50%, from sucrose solutions ranging from 20 to 30% at 35oC. Excess of sucrose affected the activity of the immobilized cell, decreasing conversion of sucrose into isomaltulose. The syrup obtained was purified through Ion Exchange Chromatography, and the crystallization of eluent by the decreasing temperature. The obtained crystals presented 91,39% of isomaltulose.