Purification of Hollow Sporopollenin Microcapsules from Sunflower and Chamomile Pollen Grains.

Pollen grains are natural microcapsules comprised of the biopolymer sporopollenin. The uniformity and special tridimensional architecture of these sporopollenin structures confer them attractive properties such as high resistance and improved bioadhesion. However, natural pollen can be a source of allergens, hindering its biomedical applicability.

The Benzyl Ester Group of Amino Acid Monomers Enhances Substrate Affinity and Broadens the Substrate Specificity of the Enzyme Catalyst in Chemoenzymatic Copolymerization.

The chemoenzymatic polymerization of amino acid monomers by proteases involves a two-step reaction: the formation of a covalent acyl-intermediate complex between the protease and the carboxyl ester group of the monomer and the subsequent deacylation of the complex by aminolysis to form a peptide bond. Although the initiation with the ester group of the monomer is an important step, the influence of the ester group on the polymerization has not been studied in detail. Herein, we studied the effect of the ester groups (methyl, ethyl, benzyl, and tert-butyl esters) of alanine and glycine on the synthesis of peptides using papain as the catalyst.

Chemo-Enzymatic Synthesis of Linear and Branched Cationic Peptides: Evaluation as Gene Carriers.

Cationic peptides such as poly(l-lysine) and poly(l-arginine) are important tools for gene delivery since they can efficiently condense DNA. It is difficult to produce cationic peptides by recombinant bacterial expression, and its chemical synthesis requires several steps of protection/deprotection and toxic agents. Chemo-enzymatic synthesis of peptides is a clean chemistry technique that allows fast production under mild conditions.

Atypical yeasts identified as Saccharomyces cerevisiae by MALDI-TOF MS and gene sequencing are the main responsible of fermentation of chicha, a traditional beverage from Peru.

Chicha is a drink prepared in several Andean countries from Inca's times by maize fermentation. Currently this fermentation is carried out in familiar artesanal "chicherías" that make one of the most known types of chicha, the "chicha de jora". In this study we isolate and identify the yeasts mainly responsible of the fermentation process in this type of chicha in 10 traditional "chicherías" in Cusco region in Peru.

Proteinase K-catalyzed synthesis of linear and star oligo(L-phenylalanine) conjugates.

Chemoenzymatic synthesis of peptides is a green and clean chemical reaction that offers high yields without using organic synthesis and serves as an alternative to traditional peptide synthesis methods. This report describes the chemoenzymatic synthesis of oligo(L-phenylalanine) mediated by proteinase K from Tritirachium album, which is one of the most widely used proteases in molecular biological studies. The synthesized linear oligo-phenylalanine showed a unique self-assembly in aqueous solutions.

A novel Kluyveromyces marxianus strain with an inducible flocculation phenotype.

Flocculation is a very useful phenotype for industrial yeast strains, since it facilitates cell harvest and represents an easy way of cell immobilization in continuous fermentation processes. The present work represents the first time that an inducible flocculation phenotype has been generated in a non flocculent strain of Kluyveromyces marxianus. This was accomplished by expressing Saccharomyces cerevisiae FLO5 gene in K.

In vitro Ca(2+)-dependent maturation of milk-clotting recombinant Epr: minor extracellular protease: from Bacillus licheniformis.

The minor extracellular protease (Epr) is secreted into the culture medium during Bacillus licheniformis, strain USC13, stationary phase of growth. Whereas, B. subtilis Epr has been reported to be involved in swarming; the B.

Construction of a novel Pichia pastoris strain for production of xanthophylls.

In this study, we used the yeast carotenogenic producer Pichia pastoris Pp-EBIL strain, which has been metabolically engineered, by heterologously expressing β-carotene-pathway enzymes to produce β-carotene, as a vessel for recombinant astaxanthin expression. For this purpose, we designed new P. pastoris recombinant-strains harboring astaxanthin-encoding genes from carotenogenic microorganism, and thus capable of producing xanthophyllic compounds.

Influence of nutritional and environmental factors on ethanol and endopolygalacturonase co-production by Kluyveromyces marxianus CCEBI 2011.

Ethanol and endopolygalacturonase (endoPG) are simultaneously produced by the yeast Kluyveromyces marxianus CCEBI 2011. The aim of this study was to determine the optimal combination of seven environmental and nutritional variables, as well as the influence of each one, with respect to the fermentation process in yeast cultures in which sugarcane juice was the substrate. Simplex sequential optimization showed that after 15 runs the optimal conditions were: pH, 4.

Oily yeasts as oleaginous cell factories.

Oily yeasts have been described to be able to accumulate lipids up to 20% of their cellular dry weight. These yeasts represent a minor proportion of the total yeast population, and only 5% of them have been reported as able to accumulate more than 25% of lipids. The oily yeast genera include Yarrowia, Candida, Rhodotorula, Rhodosporidium, Cryptococcus, Trichosporon, and Lipomyces.

Cloning and expression of buffalo active chymosin in Pichia pastoris.

To date, only recombinant chymosin has been obtained in its active form from supernatants of filamentous fungi, which are not as good candidates as yeasts for large-scale fermentations. Since Bos taurus chymosin was cloned and expressed, the world demand for this protease has increased to such an extent that the cheesemaking industry has been looking for novel sources of chymosin. In this sense because buffalo chymosin has properties that are more stable than those of B.

Enzybiotics: a look to the future, recalling the past.

The discovery and development of antibiotics was one of the greatest successes of Medicine in the 20th century and allowed the control of many diseases caused by microorganisms. Nevertheless, it is necessary to search constantly for new therapeutic tools in the continuing fight against disease-causing microorganisms and this probably leads us to today's concept of enzybiotics. Although microorganism-degrading enzymes have been known since the beginning of the last century, their use was soon forgotten because of the widespread use of antibiotics.