Given the importance of protease’s worldwide market, the determination of optimum conditions and the development of a standard protocol are critical during selection of a reliable method to determine its bioactivity. This paper uses quality control theory to validate a modified version of a method proposed by Charney and Tomarelli in 1947. The results obtained showed that using azocasein substrate bromelain had its optimum at 45°C and pH 9 (Glycine-NaOH 100 mM). We also quantified the limit of detection (LoD) and limit of quantification (LoQ) in the above-mentioned optimum (0.072 and 0.494 mg·mL⁻¹of azocasein, resp.) and a calibration curve that correlates optical density with the amount of substrate digested. In all analysed samples, we observed a significant decrease in response after storage (around 17%), which suggests its use must be immediately after preparation. Thus, the protocol presented in this paper offers a significant improvement, given that subjective definitions are commonly used in the literature and this simple mathematical approach makes it clear and concise.

Characterized as one of the most potent biosurfactants, surfactin is a cyclic lipopeptide synthesized by several strains of Bacillus genus. The aim of this review was to present the physicochemical and structural properties of surfactin and to demonstrate advances and applications of this biosurfactant for health and environmental biotechnology. Further, this review also focused on toxicological effects of surfactin on in vivo and in in vitro systems. The hydrophobic nature of surfactin enables interaction with membrane-bound phospholipids and indicates the ability of the molecule to act as a new weapon with respect to therapeutic and environmental properties. Seeking to avoid environmental contamination produced by widespread use of synthetic surfactants, surfactin emerges as a biological control agent against pathogen species owing to its antibacterial and antiviral properties. In addition, the mosquitocidal activity of surfactin was suggested as new strategy to control disease vectors. The current findings warrant future research to assess the toxicity of surfactin to enable an optimizing anticancer therapy and to seek refined methodologies, including nanotechnology techniques, to allow for an improved delivery of the biogenic molecule on target cells.

The aim of this work was to isolate and purify bromelain extracted from the pineapple peel by ammonium sulfate precipitation (40-80%), followed by desalting and freeze-drying with a 75% activity recovery and 2.2 fold increased specific activity. Ion exchange chromatography on DEAE-Sepharose was able to separate the polysaccharides from the enzyme, which was recovered in the elution step, maintaining its enzymatic activity. The batch adsorption of bromelain was evaluated in terms of total protein and enzymatic activity using Langmuir and Langmuir-Freundlich models. Results showed that the process could be suitable for the recovery and purification of the enzyme, maintaining its specific activity.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Estadual de Campinas Faculdade de Engenharia QuímicaUniversidade Federal de São Paulo (UNIFESP) Departamento de Ciências Exatas e da TerraUniversidade Federal de Uberlândia Instituto de Genética e BioquímicaUniversidade Estadual de Campinas Faculdade de Ciências MédicasUNIFESP, Depto. de Ciências Exatas e da TerraSciEL