Poly(lactic-co-glycolic acid) matrix incorporated with nisin as a novel antimicrobial biomaterial.

The use of poly(lactic-co-glycolic acid) (PLGA) matrix as a biomolecule carrier has been receiving great attention due to its potential therapeutic application. In this context, we investigated the PLGA matrix capacity to incorporate nisin, an antimicrobial peptide capable of inhibiting the growth of Gram-positive bacteria and bacterial spores germination. Nisin-incorporated PLGA matrices were evaluated based on the inhibitory effect against the nisin-bioindicator Lactobacillus sakei.

Response of Saccharomyces cerevisiae to cadmium and nickel stress: the use of the sugar cane vinasse as a potential mitigator.

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.

Citrate and phosphate influence on green fluorescent protein thermal stability.

Protein structure and function can be regulated by no specific interactions, such as ionic interactions in the presence of salts. Green fluorescent protein (GFP) shows remarkable structural stability and high fluorescence; its stability can be directly related to its fluorescence output, among other characteristics. GFP is stable under increasing temperatures, and its thermal denaturation is highly reproducible.

Influence of Pluronic® F68 on ceftazidime biological activity in parenteral solutions.

β-Lactam antimicrobials are known to have a low concentration/therapeutic response. However, extending the period in which β-lactam are free in the plasma does directly influence therapeutic outcomes. The objective of this study was to evaluate the influence of Pluronic® F68 on the antimicrobial activity of ceftazidime when admixed with aminophylline in parenteral solutions by the evaluation of its minimal inhibitory concentration (MIC) within 24 h.

LPS removal from an E. coli fermentation broth using aqueous two-phase micellar system.

In biotechnology, endotoxin (LPS) removal from recombinant proteins is a critical and challenging step in the preparation of injectable therapeutics, as endotoxin is a natural component of bacterial expression systems widely used to manufacture therapeutic proteins. The viability of large-scale industrial production of recombinant biomolecules of pharmaceutical interest significantly depends on the separation and purification techniques used. The aim of this work was to evaluate the use of aqueous two-phase micellar system (ATPMS) for endotoxin removal from preparations containing recombinant proteins of pharmaceutical interest, such as green fluorescent protein (GFPuv).

Effect of polyethylene glycol on the thermal stability of green fluorescent protein.

Green fluorescent protein (GFP) shows remarkable structural stability and high fluorescence; its stability can be directly related to its fluorescence output, among other characteristics. GFP is stable under increasing temperatures, and its thermal denaturation is highly reproducible. Some polymers, such as polyethylene glycol, are often used as modifiers of characteristics of biological macromolecules, to improve the biochemical activity and stability of proteins or drug bioavailability.

Evaluation of the sterilization efficacy of domestic electric drills used in orthopaedic surgeries.

It is estimated that electric drills (ED) have been used in orthopaedic surgeries for bone drilling for more than 50 years in Brazilian hospitals. It is an electric, thermosensitive equipment, not indicated for surgical use, which has not been previously evaluated regarding the sterilization efficacy, being suspect of infection risk. This study evaluated the efficacy of sterilization by ethylene oxide (EtO) of new drills that were intentionally contaminated with Bacillus atrophaeus spores.

Sterilization of medical devices by ethylene oxide, determination of the dissipation of residues, and use of Green Fluorescent Protein as an indicator of process control.

Ethylene oxide (EO) is used to sterilize Oxygenator and Tubing applied to heart surgery. Residual levels of EO and its derivatives, ethylene chlorohydrin (ECH) and ethylene glycol (EG), may be hazardous to the patients. Therefore, it must be removed by the aeration process.

Evaluation of the pH- and thermal stability of the recombinant green fluorescent protein (GFP) in the presence of sodium chloride.

The thermal stability of recombinant green fluorescent protein (GFP) in sodium chloride (NaCl) solutions at different concentrations, pH, and temperatures was evaluated by assaying the loss of fluorescence intensity as a measure of denaturation. GFP, extracted from Escherichia coli cells by the three-phase partitioning method and purified through a butyl hydrophobic interaction chromatography (HIC) column, was diluted in water for injection (WFI) (pH 6.0-7.

Biosurfactant production by cultivation of Bacillus atrophaeus ATCC 9372 in semidefined glucose/casein-based media.

Biosurfactants are proteins with detergent, emulsifier, and antimicrobial actions that have potential application in environmental applications such as the treatment of organic pollutants and oil recovery. Bacillus atrophaeus strains are nonpathogenic and are suitable source of biosurfactants, among which is surfactin. The aim of this work is to establish a culture medium composition able to stimulate biosurfactants production by B.

Nisin production utilizing skimmed milk aiming to reduce process cost.

Nisin is a natural additive for conservation of food, pharmaceutical, and dental products and can be used as a therapeutic agent. Nisin inhibits the outgrowth of spores, the growth of a variety of gram-positive and gram-negative bacteria. This study was performed to optimize large-scale nisin production in skimmed milk and subproducts aiming at low-costs process and stimulating its utilization.

Methods of endotoxin removal from biological preparations: a review.

Purpose: Endotoxins, also called lipopolysaccharides (LPS), are major contaminants found in commercially available proteins or biologically active substances, which often complicate study of the biological effects of the main ingredient. The presence of small amounts of endotoxin in recombinant protein preparations can cause side effects in host organism such as endotoxin shock, tissue injury, and even death. Due to these reactions, it is essential to remove endotoxins from drugs, injectables, and other biological and pharmaceutical products.

Preliminary study on the potential utility of GFP as a biosensor for drug stability in parenteral solutions.

In the health care setting, drugs added to large volume parenteral solutions (LVPS) are routinely administered to improve therapeutic effects and provide a faster clinical response. The development of analytical techniques that permit the detection of incompatibilities between drugs and parenteral solutions is necessary to guarantee their correct association with minimum adverse effects. Green fluorescent protein (GFP) has been used as a biological indicator of sterilization and disinfection processes because it exhibits a high thermal stability and is easily detected using UV light and spectrofluorometry.

Study on the thermal stability of green fluorescent protein (GFP) in glucose parenteral formulations.

Large volume parenteral solutions (LVPS) that are widely used in the healthcare system must be processed by moist-heat treatment to an assured sterility level in which the efficacy is measured by a bioindicator (BI) that provides fast, accurate and reliable results. This study evaluated the thermal stability of green fluorescent protein (GFP) into glucose-based LVPS (1.5-50%) solutions to determine its utility as a BI for thermal processes.

Stability of green fluorescent protein (GFP) in chlorine solutions of varying pH.

Green fluorescent protein (GFP) is an excellent biosensor as a result of its ability to be easily monitored in a wide variety of applications. Enzymes and proteins have been used as biological indicators to evaluate the immediate efficacy of industrial procedures, such as blanching, pasteurization, and disinfection treatments, as well as to monitor the satisfactory preservation of a product subjected to disinfection or sterilization. The purpose of this work was to study GFP stability in chlorinated water for injection (WFI) and chlorinated buffered solutions at various pH ranges, with and without agitation, to evaluate the exposure time required for chlorine to decrease 90% of its fluorescence intensity (decimal reduction time, D-value, min, 25 degrees C).

Detection of nisin expression by Lactococcus lactis using two susceptible bacteria to associate the effects of nisin with EDTA.

Nisin, a bacteriocin produced during the exponential growth phase of Lactococcus lactis ATCC 11454, inhibits the growth of a broad range of Gram-positive bacteria. Gram-negative bacteria can also be inhibited by nisin with EDTA. In this study, nisin production was assayed by the agar diffusion method using Lactobacillus sake ATCC 15521 and a recombinant Escherichia coli DH5-alpha expressing the recombinant green fluorescent protein as the nisin-susceptible test organisms.

Biofiltration methods for the removal of phenolic residues.

Industrial effluents from the pharmaceutical industry often contain high concentrations of phenolic compounds. The presence of "anthropogenic" organic compounds in the environment is a serious problem for human health; therefore, it merits special attention by the competent public agencies. Different methods have been proposed in the last two decades for the treatment of this kind of industrial residues, the most important of which are those utilizing absorption columns, vaporization and extraction, and biotechnological methods.

Chemical resistance of the gram-negative bacteria to different sanitizers in a water purification system.

Background: Purified water for pharmaceutical purposes must be free of microbial contamination and pyrogens. Even with the additional sanitary and disinfecting treatments applied to the system (sequential operational stages), Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas alcaligenes, Pseudomonas picketti, Flavobacterium aureum, Acinetobacter lowffi and Pseudomonas diminuta were isolated and identified from a thirteen-stage purification system. To evaluate the efficacy of the chemical agents used in the disinfecting process along with those used to adjust chemical characteristics of the system, over the identified bacteria, the kinetic parameter of killing time (D-value) necessary to inactivate 90% of the initial bioburden (decimal reduction time) was experimentally determined.

Affinity-tagged green fluorescent protein (GFP) extraction from a clarified E. coli cell lysate using a two-phase aqueous micellar system.

Green fluorescent protein (GFP) has been proposed as an ideal choice for a protein-based biological indicator for use in the validation of decontamination or disinfection treatments. In this article, we present a potentially scalable and cost-effective way to purify recombinant GFP, produced by fermentation in Escherichia coli, by affinity-enhanced extraction in a two-phase aqueous micellar system. Affinity-enhanced partitioning, which improves the specificity and yield of the target protein by specific bioaffinity interactions, has been demonstrated.

Production of nisin by Lactococcus lactis in media with skimmed milk.

Nisin is a bacteriocin that inhibits the germination and growth of Gram-positive bacteria. With nisin expression related to growth conditions of Lactococcus lactis subsp. lactis, the effects of growth parameters, media components, and incubation time were studied to optimize expression.

Stability of recombinant green fluorescent protein (GFPuv) in glucose solutions at different concentrations and pH values.

The stability at room temperature (25 degrees C) of recombinant green fluorescent protein (GFPuv), expressed by Escherichia coli cells and isolated by three-phase partitioning extraction with hydrophobic interaction column, was studied. The GFPuv was diluted in buffered (each 10 mM: Tris-HCl, pH 8.0; phosphate, pH 6.

Perspectives on bioenergy and biotechnology in Brazil.

Brazil is one of the world's largest producers of alcohol from biomass at low cost and is responsible for more than 1 million direct jobs. In 1973, the Brazilian Program of Alcohol (Proalcool) stimulated the creation of a bioethanol industry that has led to large economic, social, and scientific improvements. In the year 1984, 94.

Thermal stability of recombinant green fluorescent protein (GFPuv) at various pH values.

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.

Evaluation of recombinant green fluorescent protein, under various culture conditions and purification with HiTrap hydrophobic interaction chromatography resins.

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.

Determination of decimal reduction time (D value) of chemical agents used in hospitals for disinfection purposes.

Background: Prior to the selection of disinfectants for low, intermediate and high (sterilizing) levels, the decimal reduction time, D-value, for the most common and persistent bacteria identified at a health care facility should be determined.

Methods: The D-value was determined by inoculating 100 mL of disinfecting solution with 1 mL of a bacterial suspension (10(4)-10(5) CFU/mL for vegetative and spore forms). At regular intervals, 1 mL aliquots of this mixture were transferred to 8 mL of growth media containing a neutralizing agent, and incubated at optimal conditions for the microorganism.