Publications by authors named "Adalberto P Junior"

L-asparaginase has been used in the remission of malignant neoplasms such as acute lymphoblastic leukemia. The search for new sources of this enzyme has become attractive for therapeutics. Traditional methods for biomolecule purification involve several steps.

View Article and Find Full Text PDF

L-Asparaginase (ASNase) is a vital component of the first line treatment of acute lymphoblastic leukemia (ALL), an aggressive type of blood cancer expected to afflict over 53,000 people worldwide by 2020. More recently, ASNase has also been shown to have potential for preventing metastasis from solid tumors. The ASNase treatment is, however, characterized by a plethora of potential side effects, ranging from immune reactions to severe toxicity.

View Article and Find Full Text PDF

An acidic thermostable protease was extracellularly produced either in shake flask or in stirred tank bioreactor by an Aspergillus foetidus strain isolated from the Brazilian savanna soil using different nitrogen sources. Its maximum activity (63.7 U mL) was obtained in a medium containing 2% (w/v) peptone.

View Article and Find Full Text PDF

Antibodies and antibody fragments are nowadays among the most important biotechnological products, and Pichia pastoris is one of the most important vectors to produce them as well as other recombinant proteins. The conditions to effectively cultivate a P. pastoris strain previously genetically modified to produce the single-chain variable fragment anti low density lipoprotein (-) under the control of the alcohol oxidase promoter have been investigated in this study.

View Article and Find Full Text PDF

The kinetics of a thermostable extracellular acid protease produced by an Aspergillus foetidus strain was investigated at different pH, temperatures and substrate concentrations. The enzyme exhibited maximal activity at pH 5.0 and 55°C, and its irreversible deactivation was well described by first-order kinetics.

View Article and Find Full Text PDF
Article Synopsis
  • This study explored the partitioning of protease produced by Penicillium fellutanum using an affordable aqueous two-phase system (ATPS) made from PEG, NaPA, and salt.
  • The research examined how variations in the molar mass and concentration of PEG and NaPA, as well as sodium sulfate (Na2SO4) levels, affected the efficiency of protease separation and recovery.
  • Findings showed a wide range in the partition coefficient, demonstrating the method's effectiveness for isolating proteases, with successful reextraction achieved through the addition of Na2SO4, highlighting its potential for practical applications in enzyme purification.
View Article and Find Full Text PDF

Upstream improvements have led to significant advances in the productivity of biomolecules and bioparticles. Today, downstream processes are the bottleneck in the production of some biopharmaceuticals, a change from previous years. Current purification platforms will reach their physical limits at some point, indicating the need for new approaches.

View Article and Find Full Text PDF

Most of the metals released from industrial activity, among them are cadmium (Cd) and nickel (Ni), inhibit the productivity of cultures and affect microbial metabolism. In this context, the aim of this work was to investigate the capacity of sugar cane vinasse to mitigate the adverse effects of Cd and Ni on cell growth, viability, budding rate and trehalose content of Saccharomyces cerevisiae, likely because of adsorption and chelating action. For this purpose, the yeast was grown batch-wise in YED medium supplemented with selected amounts of vinasse and Cd or Ni.

View Article and Find Full Text PDF

The thermal stability of the recombinant green fluorescent protein (GFPuv) expressed by Escherichia coli cells and isolated by three-phase partitioning extraction with hydrophobic interaction chromatography was studied. The GFPuv (3.5-9.

View Article and Find Full Text PDF

To determine the influence of various culture conditions, transformed cells of Escherichia coli expressing recombinant green fluorescent protein (GFPuv) were grown in nine cultures with four variable conditions (storage of inoculated broth at 4 degrees C prior to incubation, agitation speed, isopropyl-beta-D-thiogalactopyranoside [IPTG] concentration, and induction time). The pelleted cells were resuspended in extraction buffer and subjected to the three-phase partitioning (TPP) extraction method. To determine the most appropriate purification resin, protein extracts were eluted through one of four types of HiTrap hydrophobic interaction chromatography (HIC) columns prepacked with methyl, butyl, octyl, or phenyl resins and analyzed further on a 12% sodium dodecylsulfate polyacrylamide gel.

View Article and Find Full Text PDF

Transformed cells of Escherichia coli expressing recombinant green fluorescent protein (GFPuv) were subjected to two methods of extraction: (1) freezing/thawing/sonication (FTS) cycles prior to the three-phase partitioning (TPP) method, or (2) directly to TPP extraction. The amount of GFPuv released by the FTS plus TPP method varied: 374 microg/mL (first cycle), 93-442 microg/mL (second cycle), 32-359 microg/mL (third cycle), 18-115 microg/mL (fourth cycle). The GFPuv yields by the second method (TPP only) were, 23-54 microg/mL for the first extract and 33-91 microg/mL for the second.

View Article and Find Full Text PDF