Comparison of kinetic characteristics of xylanases from Aspergillus niger and Trichoderma sp. with pH and temperature baking process parameters

Arabinoxylans are the predominant non-starch polysaccharides of the cell walls of wheat grain, and can contribute up to 3% of the total polysaccharide content of the flour. Endo-(1-4)-β-xylanase is able to hydrolyze the glycosidic bonds between two xylose units in the xylan backbone during baking process. The use of xylanases in the baking process leads to changes in the rheology of the dough. The aim of this work was to establish the best enzymatic hydrolysis conditions. The results suggest that the pure xylanase from Aspergillus niger needs less substrate to achieve maximum velocity (Vmax). However the xylanase from Trichoderma sp. has a higher Vmax apparent which means that it needs less time to convert the substrate into products. The xylanase from A. niger presented 50°C as its optimum temperature, 40% residual activity at 25°C and 80% at 36°C. The xylanase from Trichoderma sp. presented 50°C as its optimum temperature, 20% residual activity at 25°C and 60% at 36°C, which could be evidence that this enzyme is less active than the xylanase from A. niger. Moreover, the xylanase from Trichoderma sp. presented 90% residual activity in the baking process pH range, indicating that this enzyme can be more effective in the dough making process. The catalytic reactions of both enzymes are endothermic due to positive enthalpy and they are favourable process because the both Gibbs free energy were negative.Keywords: Xylanase, baking, enzyme, Trichoderma sp., Aspergillus nige

Methods of endotoxin removal from biological preparations : a review

ABSTRACTPURPOSE: 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. An overview of this subject is provided by this article. METHODS: An extensive review of literature with regard to methods for removal of endotoxin from biotechnological preparations was carried out. RESULTS: A short history of endotoxin is presented first. This is followed by a review of chemical and physical properties of endotoxin and its pathophysiological effects when the body is exposed to LPS excessively or systemically. The techniques of endotoxin determination and interaction of endotoxin with proteins is also presented, taking into consideration the established techniques as well as the state of the art technology in this field. A review of techniques of endotoxin mentioned with relatively high protein recoveries; however, special attention is given to two-phase aqueous micellar systems, which are valuable tools for endotoxin removal from pharmaceutical proteins on a small scale because they provide a mild environment for biological materials. CONCLUSIONS: Efficient and cost-effective removal of endotoxins from pharmaceutical and biotechnology preparations is challenging. Despite development of novel methods, such as the two- phase aqueous micellar systems, in recent years, more research is needed in this field

Production of extracellular L-asparaginase : from bioprospecting to the engineering of an antileukemic biopharmaceutical

The L-asparaginase (L-asparagine amino hydrolase, E.C.3.5.1.1) catalyzes the hydrolysis of L-aspargine into L-aspartic acid and ammonia. The effective depletion of L-asparine results in cytotoxicity for leukemic cell. Therefore the enzyme has been a clinically acceptable anti-tumour agent for the effective treatment of acute lymphoblastic leukemia (ALL) and lymphosarcoma. L-asparaginase production using microbial system had attracted considerable attention, owing to the cost effective and eco friendly nature. A wide range of microorganisms such as filamentous fungi, yeasts and bacteria have proved to be the good sources of the enzyme L-asparaginase. Thus, in this review mainly focuses on the biochemical aspects of L-asparaginase production, aiming to comprehend the physiochemical characteristics, such as stability, bioavailability, toxicity, allergenic aspects, application, and enzyme properties and kinetics of recombinant enzyme production by fermentation. Processes central to these biochemical aspects, including fermentation of L-asparaginase producing organisms and downstream processing of the enzyme are also discussed

Glucose-6-phosphate dehydrogenase purification by two-phase aqueous micellar systems with affinity ligands

O presente trabalho teve como objetivo a purificação da enzima glicose-6-fosfato desidrogenase pela tecnologia de extração líquido-líquido em Sistemas Micelares de Duas Fases Aquosas (SMDFA). Estes sistemas são constituídos por soluções de tensoativos contendo micelas e oferecem ambientes hidrofóbico e hidrofílico, o que possibilita seletividade na partição da enzima de acordo com sua hidrofobicidade e proporciona um ambiente ameno às biomoléculas. Foram estudados alguns dos fatores que influenciam a partição da G6PD, como: tipo e concentração de diferentes agentes tensoativos não-iônicos (C10E4 e Triton X-114), temperatura e adição de ligantes de afinidade (cibacron blue e procion red) e o efeito da adição dos sais sulfato de amônio ((NH4)2SO4) e sulfato de sódio (Na2SO4). Estudou-se ainda a síntese do tensoativo de afinidade TX-114-Blue. Em todos os ensaios a enzima foi recuperada preferencialmente na fase diluída, pobre em micelas, tanto em sistema Triton X-114/tampão como para C10E4/tampão, no qual existe maior volume disponível, resultando em valores de KG6PD inferiores a 1. A utilização dos ligantes de afinidade na partição da G6PD nos sistemas descritos proporcionou um pequeno aumento nos valores de KG6PD da enzima, porém com valores inferiores a 1. Os sistemas Triton X-114/Sal não influenciaram a partição da enzima para a fase micelar, apesar da existência da diferença de potencial eletrostático entre as fases destes sistemas. O efeito desempenhado pelo volume de exclusão foi dominante em todos os sistemas estudados e, portanto, a enzima foi predominantemente excluída para a fase aquosa, pobre em micelas. A tecnologia por SMDFA para a purificação do homogeneizado celular de Saccharomyces cerevisiae demonstrou ser eficiente em recuperar a biomolécula alvo na fase aquosa, pobre em micelas, permitindo separar da presença de biomoléculas ou mesmo de contaminantes com caráter hidrofóbico. Dessa forma, o SMDFA pode ser empregado como uma possível etapa de purificação num processo biotecnológico.In this work, the use of two-phase micellar system was studied aiming at the purification of the enzyme glucose-6-phosphate dehydrogenase. Usually, these systems are constituted of micellar surfactants solutions and offer both hydrophobic and hydrophilic environments, providing selectivity to the enzyme partitioning according to its hydrophobicity. Some of the factors influencing the G6PD partition in micellar systems were studied, such as: type and concentration of nonionic surfactant agents (C10E4 and Triton X-114), temperature, addition of affinity ligands (Cibacron Blue and Procion Red) and the addition of the salts ammonium sulfate ((NH4)2SO4) and sodium sulfate (Na2SO4). The synthesis of the affinity surfactant TX-114-Blue was also studied. In all the assays the experiments, G6PD partitioned preferentialy to dilute, micelle-poor phase, in which there is a higher volume available for the enzyme to be, resulting in KG6PD values lower than 1. The use of affinity ligands in G6PD partitioning in both C10E4 and Triton X-114 systems provided some increase in the KG6PD, however with values still lower than 1. Employing a methodology previously described in the literature with some alterations, it was not possible to obtain the affinity surfactant TX-114-Blue. The systems Triton X-114/salt have not shown a significant influence on the enzyme partition to the micelle-rich phase, in spite of the existence of an electrostatic potential difference between the phases of the systems. The excluded-volume effect was dominant in all the systems studied and, therefore, the enzyme predominantly excluded to the dilute, micelle-poor phase. The use of Triton X-114 two-phase aqueous micellar systems to the purification of the Saccharomyces cerevisiae cell homogenate was found to be efficient in the recovery of G6PD in the dilute, micelle-poor phase, partially separating this target molecule from other proteins and contaminants of hydrophobic character. Therefore, aqueous two-phase micellar systems can be considered useful as a possible purification stage in a biotechnology process

Endotoxin removal from fermentation broth containing biomolecules using two-phase micellar system

Foi investigada a utilização de Sistema Micelar de Duas Fases Aquosas (SMDFA) para remoção de lipolissacarídeos (LPS) de preparações contendo proteínas recombinantes de interesse farmacêutico, como a proteína verde fluorescente (GFPuv). Os SMDFA são constituídos por soluções de tensoativos contendo micelas e oferecem ambientes hidrofóbico e hidrofílico, que possibilitam seletividade na partição de biomoléculas de acordo com sua hidrofobicidade, permitindo a remoção de LPS contaminante. Neste trabalho, foi realizada a implementação do método para a quantificação de LPS em amostras contaminadas e a obtenção de LPS e GFPuv puros a partir de cultivo de E. coli recombinante. Além disso, foi estudada a influência do Triton X-114 na metodologia de quantificação de LPS, e a adição de MgSO4, CaCl2, KI e (NH4)2SO4 na partição de GFPuv e LPS puros em SMDFA. E ainda, realizou-se um planejamento experimental (22) para avaliar os maiores KGFPuv e %RECGFPuv. O homogeneizado celular de E. coli foi testado nas melhores condições obtidas com o planejamento experimental. E finalmente, o processo por cromatografia de afinidade por íons metálicos (IMAC) foi empregado para investigar a adsorção de LPS em matriz IDA-Ca2+. Conforme os resultados obtidos, o TX-114 causou elevada interferência no método cinético cromogênico, em função da similaridade desta molécula com os LPS. Os LPS apresentaram partição preferencial para a fase concentrada em micelas, com altos valores de remoção, %REMLPS>98,0%. Ao contrário, a GFPuv foi recuperada preferencialmente na fase diluída, na qual existe maior volume disponível, resultando em valores de KGFPuv>1. A adição de sais ocasionou diminuição nos valores KGFPuv, provavelmente por causa da carga negativa que GFPuv adquiriu nas condições avaliadas. Os resultados do planejamento experimental mostraram que a melhor condição de partição obtida foi na região do ponto central, 4,0% (p/p) a 60,0°C, com KGFPuv>10. O processo por IMAC apresentou as maiores capacidades de adsorção de LPS-IDA-Ca+2 nas condições de menor pH e maior força iônica 4,0 e 1,0 mol/L, respectivamente. O processo de purificação por SMDFA empregado para a remoção de LPS contaminante presente em meio fermentado contendo GFPuv, demonstrou ser eficiente em recuperar a biomolécula-alvo na fase diluída e separar o principal contaminante na fase rica em micelas. Portanto, pode ser empregado como primeira etapa para a remoção de altas concentrações de LPS na purificação de proteínas hidrofílicas como a GFPuv.The Aqueous Two-Phase Micellar System (ATPMS) was investigated for endotoxin (LPS) removal from preparations containing recombinant proteins of pharmaceutical interest, such as the green fluorescent protein (GFPuv). These systems usually consist of micellar surfactants solutions and offer both hydrophobic and hydrophilic environments, providing selectivity to the biomolecules partitioning according to its hydrophobicity. In this work, the implementation of the method for LPS quantification in contaminated samples was accomplished, as well as the obtaining of pure LPS and GFPuv from recombinant E. coli. Furthermore, the influence of Triton X-114 in the methodology for LPS quantification was studied, as the addition of MgSO4, CaCl2, KI, and (NH4)2SO4 into the partition of pure GFPuv and LPS in ATPMS. In addition, a statistical design (22) was carried out to evaluate the highest KGFPuv and %RECGFPuv. The E. coli cell lysate was tested under optimum conditions obtained with the statistical design. And, finally, the process by ionmetal affinity chromatography (IMAC) was used to investigate the adsorption of LPS in IDA-Ca2+ matrix. The results showed that the TX-114 caused high interference in the kinetic chromogenic method, according to the similarity of this molecule to LPS. The LPS showed preferential partitioning to the micellerich phase, with high values of removal, %REMLPS>98.0%. In the other hand, the GFPuv was preferentially recovered in the micelle-poor phase, in which there is greater volume available resulting in values of KGFPuv>1. The addition of salts caused a reduction in the values KGFPuv, probably because of the negative charge that the GFPuv acquired at the conditions evaluated. The results of the statistical design showed that the best partitioning condition obtained was in the central point region, 4.0% (wt/wt) at 60.0°C, with KGFPuv>10. The process by IMAC showed the highest adsorption of LPS-IDA-Ca+2 capacities at the conditions of lower pH and higher ionic strength 4.0 and 1.0 mol/L, respectively. The purification process for the LPS contaminant removal from E. coli fermentation containing GFPuv by ATPMS proved to be efficient in the recovering of target biomolecule in the micelle-poor phase, and separating the main contaminant in the micelle-rich phase. Furthermore, this system can be exploited as the first step for removal of higher LPS concentrations from hydrophilics protein purification

Radiolabeled Human Serum Albumin Nanoparticles Co-Loaded with Methotrexate and Decorated with Trastuzumab for Breast Cancer Diagnosis

Breast cancer is a leading cause of cancer-related mortality among women worldwide, with millions of new cases diagnosed yearly. Addressing the burden of breast cancer mortality requires a comprehensive approach involving early detection, accurate diagnosis, effective treatment, and equitable access to healthcare services. In this direction, nano-radiopharmaceuticals have shown potential for enhancing breast cancer diagnosis by combining the benefits of nanoparticles and radiopharmaceutical agents. These nanoscale formulations can provide improved imaging capabilities, increased targeting specificity, and enhanced sensitivity for detecting breast cancer lesions. In this study, we developed and evaluated a novel nano-radio radiopharmaceutical, technetium-99m ([99mTc]Tc)-labeled trastuzumab (TRZ)-decorated methotrexate (MTX)-loaded human serum albumin (HSA) nanoparticles ([99mTc]-TRZ-MTX-HSA), for the diagnosis of breast cancer. In this context, HSA and MTX-HSA nanoparticles were prepared. Conjugation of MTX-HSA nanoparticles with TRZ was performed using adsorption and covalent bonding methods. The prepared formulations were evaluated for particle size, PDI value, zeta (ζ) potential, scanning electron microscopy analysis, encapsulation efficiency, and loading capacity and cytotoxicity on MCF-7, 4T1, and MCF-10A cells. Finally, the nanoparticles were radiolabeled with [99mTc]Tc using the direct radiolabeling method, and cellular uptake was performed with the nano-radiopharmaceutical. The results showed the formation of spherical nanoparticles, with a particle size of 224.1 ± 2.46 nm, a PDI value of 0.09 ± 0.07, and a ζ potential value of −16.4 ± 0.53 mV. The encapsulation efficiency of MTX was found to be 32.46 ± 1.12%, and the amount of TRZ was 80.26 ± 1.96%. The labeling with [99mTc]Tc showed a high labeling efficiency (>99%). The cytotoxicity studies showed no effect, and the cellular uptake studies showed 97.54 ± 2.16% uptake in MCF-7 cells at the 120th min and were found to have a 3-fold higher uptake in cancer cells than in healthy cells. In conclusion, [99mTc]Tc-TRZ-MTX-HSA nanoparticles are promising for diagnosing breast cancer and evaluating the response to treatment in breast cancer patients

Liquid–liquid extraction of lipase produced by psychrotrophic yeast leucosporidium scottii L117 using aqueous two-phase systems

Aqueous two-phase systems (ATPS) have been used in biomolecules separation and as an efficient alternative to traditional purification systems for lipases extraction. Here, we investigated the partitioning and recovery of lipase derived from Leucosporidium scottii L117 using ATPS and aqueous two-phase micellar systems (ATPMS). Thus, we evaluated three ATPS: (i) polyethylene glycol (PEG)/phosphate salts and (ii) PEG/polyacrylic acid (NaPA) in different molecular weights (1500, 4000 and 8000 g/mol). (iii) Triton X-114 (TX-114)/McIlvaine buffer pH 7.0 in different conditions (2.0% (w/w) of TX-114 at 25.0 and 28.0 °C). The PEG/phosphate and PEG/NaPA systems resulted in a great loss of enzymatic activity; thus these systems do not represent viable alternatives for these lipase extraction. The micellar systems yielded the best results for lipase extraction with enzyme activity balances ranging between 84.7% and 113.05%. After optimizing the micellar system by experimental design of the partition coefficient of lipase increased by 10.3-fold (0.75–7.76). Lipase preferentially partitioned into the micelle-rich phase with KLip = 7.76, %RECBot = 93.85% and PF = 1.2 at 25.03 °C, 5.1 pH and 10.38% TX-114 and KLip = 4.77, %RECBot = 73.53% and PF = 1.97 at 28.00 °C, 4.5 pH and 8.0% TX-114, indicating that the ATPMS represents an alternative to purification/extraction of lipase L. scottii L117. A crude lipase extract was also evaluated to define the optimum pH and temperature. Lipase reached optimal activity at 40 °C, and remained stable in pH values ranging from pH 3.0 to 8.0 and temperatures from 20.0 to 45.0 °C, with relative residual lipase activity above 80% after 30 min of incubation156Part 2215225CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPnão temnão tem2010/08352-5; 2010/17033-0; 2013/19486-

Stability, purification, and applications of bromelain: a review

Bromelain is a cysteine protease found in pineapple tissue. Due to its anti-inflammatory and anti-cancer activities, as well as its ability to induce apoptotic cell death, bromelain has proved useful in several therapeutic areas. The market for this protease is growing, and several studies exploring various properties of this molecule have been reported. This review aims to compile this data, and summarize the main findings on bromelain in the literature to date. The physicochemical properties and stability of bromelain under different conditions are discussed. Several studies on the purification of bromelain from crude extracts using a wide range of techniques such as liquid-liquid extractions by aqueous two-phase system, ultrafiltration, precipitation, and chromatography, have been reported. Finally, the various applications of bromelain are presented. This review therefore covers the main properties of bromelain, aiming to provide an up-to-date compilation of the data reported on this enzyme

Microbial Colorants Production in Stirred-Tank Bioreactor and Their Incorporation in an Alternative Food Packaging Biomaterial

Natural colorants from microbial fermentation have gained significant attention in the market to replace the synthetic ones. Talaromyces spp. produce yellow-orange-red colorants, appearing as a potential microorganism to be used for this purpose. In this work, the production of natural colorants by T. amestolkiae in a stirred-tank bioreactor is studied, followed by its application as additives in bio-based films. The effect of the pH-shift control strategy from 4.5 to 8.0 after 96 h of cultivation is evaluated at 500 rpm, resulting in an improvement of natural colorant production, with this increase being more significant for the orange and red ones, both close to 4-fold. Next, the fermented broth containing the colorants is applied to the preparation of cassava starch-based films in order to incorporate functional activity in biodegradable films for food packaging. The presence of fermented broth did not affect the water activity and total solids of biodegradable films as compared with the standard one. In the end, the films are used to pack butter samples (for 45 days) showing excellent results regarding antioxidant activity. It is demonstrated that the presence of natural colorants is obtained by a biotechnology process, which can provide protection against oxidative action, as well as be a functional food additive in food packing biomaterials