Nelson Torto

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The catalytic domain of a xylanase from Rhodothermus marinus was produced in Escherichia coli. The catalytic domain belongs to glycosyl hydrolase family 10. The produced protein has a 22-amino acid leader peptide followed by a 411-amino acid truncated xylanase. The molecular mass was 48 kDa and the recombinant xylanase had a pI of 4.9. The pH and(More)
A beta-mannosidase was purified to homogeneity from the culture filtrate of Aspergillus niger. A specific activity of 500 nkat mg-1 and a 53-fold purification was achieved using ammonium sulfate precipitation, anion-exchange chromatography, and gel filtration. The isolated enzyme has an isoelectric point of 5.0 and appears to be a dimer composed of two(More)
Sorption properties of baker's yeast cells, characterised as Saccharomyces cerevisiae were evaluated for trace enrichment of metal ions: Cd(2+), Cr(3+), Cr(6+), Cu(2+), Pb(2+) and Zn(2+) from aqueous environments. Metal concentration was determined by flame atomic absorption spectrometry (FAAS). Parameters affecting metal uptake such as solution pH,(More)
Sorption properties of six yeast strains were evaluated for trace enrichment of metal ions; Cd(2+), Cr(3+), Cr(6+), Cu(2+), Pb(2+), and Zn(2+) from aqueous environments. Metal concentration was determined by flame atomic absorption spectrometry (FAAS). The results showed that trace enrichment of the metals under study with yeast, was dependent on the pH and(More)
An on-line system based on microdialysis sampling (MD), micro-high performance anion exchange chromatography (micro-HPAEC), integrated pulsed electrochemical detection (IPED), and electrospray ionization mass spectrometry (MS) for the monitoring of on-line desalted enzymatic hydrolysates is presented. Continuous monitoring of the enzymatic degradation of(More)
An assay based on enzymatic hydrolysisand microdialysis sampling, micro-high-performance anion-exchange chromatography (micro-HPAEC) with electrospray ionisation mass spectrometry (ESI-MS) for the characterisation of legumes is presented. Characterisation of two bean varieties; Phaseolus mungo and P. acutifilous was based upon enzymatic hydrolysis using an(More)
An analytical methodology based on microdialysis sampling, high-performance anion-exchange chromatography and integrated pulsed electrochemical detection for the monitoring of oligosaccharides in bioprocesses is presented. Amylopectin and model maltooligosaccharide standards; glucose, maltose, maltotriose, maltotetraose, maltopentaose, maltohexaose and(More)
Challenges associated with analyte and matrix complexities and the ever increasing pressure from all sectors of industry for alternative analytical devices, have necessitated the development and application of new materials in analytical chemistry. To date, nanomaterials have emerged as having excellent properties for analytical chemistry applications(More)
Electrospinning has emerged as the most versatile technique for nanofiber fabrication. Owing to their large surface area to volume ratio, electrospun nanofibers have the potential to serve as a good sorbent material for solid phase extraction (SPE) based techniques. The ability to incorporate a variety of functionalities prior or post-electrospinning(More)
In this study, samples from a sewage treatment lagoon and those from a receiving stream were analyzed for their phthalate esters content. Knowledge of the distribution of ubiquitous phthalate esters in the sewage lagoon and the receiving stream was necessary because of the reports of their subtle toxicity to aquatic biota and humans. Liquid-liquid(More)