High concentrations of dried sorghum stalks as a biomass feedstock for single cell oil production by Rhodosporidium toruloides

Environmental crisis and concerns for energy security have made the research for renewable fuels that will substitute the usage of fossil fuels an important priority. Biodiesel is a potential substitute for petroleum, but its feasibility is hindered by the utilization of edible vegetable oil as raw material, which is responsible for a large fraction of the production cost and fosters the food versus fuel competition. Microbial oils are an interesting alternative as they do not compete with food production, and low cost renewable materials could serve as raw materials during cultivation of microorganisms. Sweet sorghum is an excellent candidate as substrate for microbial oil production, as it possesses high photosynthetic activity yielding high amounts of soluble and insoluble carbohydrates, and does not require high fertilization and irrigation rates8FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informaçã

Immobilized metal-ion affinity chromatography (IMAC) of biomolecules: fundamental aspects and technological applications

Immobilized Metal Ion Affinity Cromatography - IMAC - is a group-specific based adsorption applied to the purification and structure-function studies of proteins and nucleic acids. The adsorption is based on coordination between a metal ion chelated on the surface of a solid matrix and electron donor groups at the surface of the biomolecule. IMAC is a highly selective, low cost, and easily scaled-up technique being used in research and commercial operations. A separation process can be designed for a specific molecule by just selecting an appropriate metal ion, chelating agent, and operational conditions such as pH, ionic strength, and buffer type.1288129

C/N ratio and carbon source-dependent lipid production profiling in Rhodotorula toruloides

Microbial oils are lipids produced by oleaginous microorganisms, which can be used as a potential feedstock for oleochemical production. The oleaginous yeast Rhodotorula toruloides can co-produce microbial oils and high-value compounds from low-cost substrates, such as xylose and acetic acid (from hemicellulosic hydrolysates) and raw glycerol (a byproduct of biodiesel production). One step towards economic viability is identifying the best conditions for lipid production, primarily the most suitable carbon-to-nitrogen ratio (C/N). Here, we aimed to identify the best conditions and cultivation mode for lipid production by R. toruloides using various low-cost substrates and a range of C/N ratios (60, 80, 100, and 120). Turbidostat mode was used to achieve a steady state at the maximal specific growth rate and to avoid continuously changing environmental conditions (i.e., C/N ratio) that inherently occur in batch mode. Regardless of the carbon source, higher C/N ratios increased lipid yields (up to 60% on xylose at a C/N of 120) but decreased the specific growth rate. Growth on glycerol resulted in the highest specific growth and lipid production (0.085\ua0g lipids/gDW*h) rates at C/Ns between 60 and 100. We went on to study lipid production using glycerol in both batch and fed-batch modes, which resulted in lower specific lipid production rates compared with turbisdostat, however, fed batch is superior in terms of biomass production and lipid titers. By combining the data we obtained in these experiments with a genome-scale metabolic model of R. toruloides, we identified targets for improvements in lipid production that could be carried out either by metabolic engineering or process optimization

Processo De Produção De Gel De Hidróxido De Alumìnio Por Eletrocoagulação,gel Contendo Hidróxido De Alumìnio, Uso Do Mesmo Para Remoção De Compostos De Interesse De Amostras Multicomponentes E Processo De Remoção De Compostos Por Adsorção Na Superfìcie Do Gel Produzido

PROCESSO DE PRODUÇÃO DE GEL DE HIDRÓXIDO DE ALUMÍNIO POR ELETROCOAGULAÇÃO, GEL CONTENDO HIDRÓXIDO DE ALUMÍNIO, USO DO MESMO PARA REMOÇÃO DE COMPOSTOS DE INTERESSE DE AMOSTRAS MULTICOMPONENTES E PROCESSO DE REMOÇÃO DE COMPOSTOS POR ADSORÇÃO NA SUPERFÍCIE DO GEL PRODUZIDO. A presente invenção refere-se a um processo de produção do gel de hidróxido de alumínio, o produto obtido um gel contendo hidróxido de alumínio, uso do dito gel para remoção de compostos de interesse de amostras multicomponentes e a um processo de remoção de compostos desejados por adsorção na superfície do dito gel. A essência do invento é a remoção de compostos biológicos como pigmentos, polifenóis, proteínas, carboidratos e alcalóides, como também os compostos sintéticos por adsorção em gel de hidróxido de alumínio produzido por um processo de eletrocoagulação. Sua principal aplicação está em processos de obtenção de proteínas recombinantes das plantas transgênicas, especialmente de folhas de plantas. O presente processo também pode ser usado para remoção de clorofila e/ou polifenóis de amostras como, por exemplo, remoção dos mesmos de extratos vegetais usados na produção de produtos naturais ou produtos contendo produtos naturais. Outros tipos de substancias também podem ser removidos pelo processo proposto como, por exemplo: óleos, essências, carboidratos, polímeros sintéticos, entre outros.BRPI0906819 (A2)C01F7/02BR2009PI06819C01F7/0

Study of the polyribosyl-ribitol-phosphate precipitation mechanism by salts and organic solvents

Precipitation has been widely applied to purification and fractionation of biological macromolecules. Several physical-chemical factors contribute to the destabilization of those solutions, such as the nature of solvent employed, presence of salts, temperature, and concentration of the macromolecule. In the case of charged biopolymers, electrostatic forces are the major contributors to their stability in solution. However, the role of each variable and the exact mechanism of precipitation are not completely understood yet. The aim of this work was to study the precipitation of polyribosyl-ribitol-phosphate (PRP, a linear homogeneous anionic biopolymer) in presence of salts and non-solvents, in order to contribute to the elucidation of its precipitation mechanism. The solvents tested (acetone, ethanol, and isopropanol) presented distinct dielectric constants. The salts used (NH4Cl, NaCl, KCl, MgCl2, and CaCl2) differ by their cations. For each salt concentration, the solvent fraction that induces precipitation was identified and the dielectric constant of the bulk solution was calculated. Precipitation always occurred at well-defined combinations of solvents and salts. At low concentration of monovalent salts, there was a linear correlation between the logarithm of the salt concentration and the inverse of the medium dielectric constant at a defined precipitation point. This is a strong indication that the stability of the solution depends almost exclusively on the balance of electrostatic forces. This behavior is compatible with the DLVO modeling of colloidal systems. When divalent salts were used, low concentrations of the counterion were sufficient to induce precipitation, due to a phenomenon called ionic condensation. Apparently, PRP precipitates when around 90% of its charges are neutralized, value that is similar to charge neutralization for DNA precipitation140102108COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESsem informaçãoWe gratefully acknowledge the financial support provided by Fundação Butantan, BNDES (grant number 11.2.0322.1/2012) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-CAPES, Brazil (Finance Code 001

Cromatografia de afinidade por íons metálicos imobilizados (IMAC) de biomoléculas: aspectos fundamentais e aplicações tecnológicas

Immobilized Metal Ion Affinity Cromatography - IMAC - is a group-specific based adsorption applied to the purification and structure-function studies of proteins and nucleic acids. The adsorption is based on coordination between a metal ion chelated on the surface of a solid matrix and electron donor groups at the surface of the biomolecule. IMAC is a highly selective, low cost, and easily scaled-up technique being used in research and commercial operations. A separation process can be designed for a specific molecule by just selecting an appropriate metal ion, chelating agent, and operational conditions such as pH, ionic strength, and buffer type

Microbial oil production in sugarcane bagasse hemicellulosic hydrolysate without nutrient supplementation by a Rhodosporidium toruloides adapted strain

Sugarcane bagasse hemicellulosic hydrolysate (SCBH) is a low-cost substrate for single-cell oil (SCO) production. However, this hydrolysate has an undesirable low carbon/nitrogen (C/N) ratio and contains inhibitors. Yeast adaptation is a simple strategy to overcome the presence of inhibitors, while the concentration of the hydrolysate and glycerol supplementation are alternatives to solve the low C/N limitation. This work aimed to investigate the adaptation of the yeast Rhodosporidium toruloides in undetoxified SCBH and its use in SCO production. The adapted strain produced more lipids than the parental strain: the concentration of SCBH or the addition of glycerol increased the lipid content, concentration, and productivity to at least 108%, 175%, and 118%, respectively. Lipid production in SCBH was done without salts or nitrogen supplementation. Transcriptomic study showed that hydrolysate-tolerance- and lipid accumulation-related genes were strongly induced. These genes can be targets for metabolic engineering571625CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informaçãosem informação2013/03103-

Evaluation of the effect of ammonium carbamate on the stability of proteins

The use of the volatile salt ammonium carbamate in protein downstream processing has recently been proposed. The main advantage of using volatile salts is that they can be removed from precipitates and liquid effluents through pressure reduction or temperature increase. Although previous studies showed that ammonium carbamate is efficient as a precipitant agent, there was evidence of denaturation in some enzymes. In this work, the effect of ammonium carbamate on the stability of five enzymes was evaluated. RESULTS: Activity assays showed that α‐amylase (1,4‐α–D‐glucan glucanohydrolase, EC 3.2.1.1), lysozyme (1,4‐β‐N‐acetylmuramoylhydrolase, EC 3.2.1.17) and lipase (triacyl glycerol acyl hydrolase, EC 3.1.1.3) did not undergo activity loss in ammonium carbamate solutions with concentrations from 1.0 to 5.0 mol kg−1, whereas cellulase complex (1,4‐(1,3:14)‐β‐D‐glucan 4‐glucano‐hydrolase, EC 3.2.1.4) and peroxidase (hydrogen peroxide oxidoreductase, EC 1.11.1.7) showed an average activity loss of 55% and 44%, respectively. Precipitation assays did not show enzyme denaturation or phase separation for α‐amylase and lipase, while celullase and peroxidase precipitated with some activity reduction. Analysis of similar experiments with ammonium and sodium sulfate did not affect the activity of enzymes. CONCLUSION: Celullase and peroxidase were denatured by ammonium carbamate. While more systematic studies are not available, care must be taken in designing a protein precipitation with this salt. The results suggest that the generally accepted idea that salts that denature proteins tend to solubilize them does not hold for ammonium carbamate857962967CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informaçã

Negative chromatography on agarose-TREN as a technique for purification of protein spiked in soybean seeds extract

Alkyl amines and polyamines have been used as ligands for protein purification by mixed-mode chromatography. the adsorption of proteins onto these ligands seems to be governed by multiple effects such as electrostatic, hydrophobic, and affinity interactions. in this work we investigated the adsorption of proteins extracted from soybean onto the adsorbent agarose-Tris(2-aminoethyl)amine (TREN). the effects of flow rate, buffer system, and extract concentration on the capture of proteins extracted from soybean were evaluated. Experiments using Mes at pH 6.5 as adsorption buffer allowed the adsorption of almost the totality of native soybean protein with a dynamic adsorption capacity of 13.50 mg mL(-1) adsorbent. Experiments with human IgG (pl in the range of 5.8-9.0) and human serum albumin (HSA, pl of 4.9) spiked into these extracts lead to the conclusion that electrostatic forces play a major role in the interaction between protein and agarose-TREN. Based on this work, negative chromatography with agarose-TREN should be considered as a method for purification of basic recombinant protein produced in transgenic soybean seeds. (C) 2012 Elsevier B.V. All rights reserved.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Estadual Campinas, UNICAMP, Sch Chem Engn, BR-13083970 Campinas, SP, BrazilUniversidade Federal de São Paulo, UNIFESP, Dept Exact & Earth Sci, BR-09913030 Diadema, SP, BrazilUniversidade Federal de São Paulo, UNIFESP, Dept Exact & Earth Sci, BR-09913030 Diadema, SP, BrazilWeb of Scienc