Biochemical characterization of extracellular fructosyltransferase from Aspergillus oryzae IPT-301 immobilized on silica gel for the production of fructooligosaccharides.

Objective: Extracellular fructosyltransferase (FTase, E.C.2.

Effect of agitation speed and aeration rate on fructosyltransferase production of Aspergillus oryzae IPT-301 in stirred tank bioreactor.

Objective: Fructooligosaccharides (FOS) are prebiotic substances that have been extensively incorporated in different products of food industry mostly for their bifidogenic properties and economic value. The main commercial FOS production comes from the biotransformation of sucrose and intracellular and extracellular microbial enzymes-fructosyltransferases (FTase). Aspergillus oryzae IPT-301 produces FTase.

Application of microbial fuel cell technology for vinasse treatment and bioelectricity generation.

Objective: Our study evaluated the performance of different two-chambered microbial fuel cell (MFC) prototypes, operated with variable distance between electrodes and Nafion membrane and specific inoculum concentration, applied for vinasse treatment.

Results: The performance of the developed MFC resulted in a maximum current density of 1200 mA m and power density of 800 mW m in a period of 61 days. MFC performed a chemical oxygen demand removal at a rate ranging from 51 to 60%.

Screening of filamentous fungi for antimicrobial silver nanoparticles synthesis.

The present work had the goal of screening a batch of 20 fungal strains, isolated from sugar cane plantation soil, in order to identify those capable of biosynthesis of silver nanoparticles. These nanoparticles are known to have a large and effective application in clinical microbiology. Four strains were found to be capable of biosynthesis of silver nanoparticles.

Mutagenesis of Aspergillus Oryzae IPT-301 to improve the production of β-Fructofuranosidase.

Aspergillus oryzae IPT-301, previously reported as a β-fructofuranosidase producing microorganism, was successfully mutated using UV irradiation at 253.7 nm followed by the screening of survivors resistant to certain stress conditions. Strains were first subjected to the β-fructofuranosidase activity assay using a portion from the colony grown in Petri dish as the enzyme source.

Microbial production of fructosyltransferases for synthesis of pre-biotics.

Fructooligosaccharides (FOS) are prebiotic substances found in several vegetable or natural foods. The main commercial production of FOS comes from enzymatic transformation of sucrose by the microbial enzyme fructosyltransferase. The development of more efficient enzymes, with high activity and stability, is required and this has attracted the interest of biotechnologists and microbiologists with production by several microorganisms being studied.

Screening of beta-fructofuranosidase-producing microorganisms and effect of pH and temperature on enzymatic rate.

Seventeen different strains of filamentous fungi were grown in batch cultures to compare their abilities for the production of beta-fructofuranosidase. Three of them, Aspergillus oryzae IPT-301, Aspergillus niger ATCC 20611 and strain IPT-615, showed high production with total fructosyltransferase activity higher than 12,500 units l(-1). In addition, the beta-fructofuranosidases of those strains have a high fructosyltransferase activity-to-hydrolytic activity ratio.

Enzymatic recovery and purification of polyhydroxybutyrate produced by Ralstonia eutropha.

Polyhydroxybutyrate (PHB) is the most studied among a wide variety of polyhydroxyalkanoates, bacterial biodegradable polymers known as potential substitutes for conventional plastics. This work aimed at evaluating the use of enzymes to recover and purify the PHB produced by Ralstonia eutropha DSM545. Screening experiments allowed the selection of trypsin, bromelain and lysozyme among six enzymes, based on their efficiency in lysing cells of a non-PHB producing R.

Influence of carbon, nitrogen and phosphorous sources on glucoamylase production by Aspergillus awamori in solid state fermentation.

It was the objective of the present study to increase the production of glucoamylase by Aspergillus awamori through solid state fermentation, using wheat bran as the main carbon source and (NH4)2SO4, urea, KH2PO4, glucose, maltose and starch as additional nitrogen, phosphorus, and carbon sources. The production of glucoamylase is strongly influenced by N and C sources. A 100% increase was observed when the (NH4)2SO4 was replaced by urea, with C/N = 4.