Lidiane Maria de Andrade

Comparative study of different matrix/solvent systems for the analysis of crude lyophilized microalgal preparations using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

RATIONALE Due to increases in greenhouse gas emissions, it is necessary to explore renewable sources of energy. Interesting alternatives are biofuels derived from microalgae. One challenge is the development of a detailed microalgae database compiling species identifications and characterizations that would facilitate microalgae selection for biomass production. Mass spectrometric (MS) analysis using a matrix-assisted laser desorption/ionization (MALDI) source is an advanced technique that enables advancement in this biological area. In this work a MALDI time-of-flight (TOF)MS method for the rapid identification of proteins in whole cells of selected microalgae species was studied. Furthermore, the efficiency of different matrix and solvent systems was tested. MS analyses were performed using an UltrafleXtreme MALDI-TOF mass spectrometer operating in linear positive ion mode. METHODS Mass spectra were acquired in a mass range from 4000 to 20,000 Da with ions generated from Smartbeam laser irradiation using a frequency of 2000 Hz, a PIE 100 ns and a lens 7 kV. The voltage was 25 kV for the first ion source and 23 kV for the second. Each spectrum was generated by averaging of 10,000 laser shots and the laser irradiance was set at 95-100%. RESULTS Similar mass spectra were obtained for all matrices (SA, HCCA, DHB and sDHB); however, the use of the sDHB matrix resulted in spectrum profiles with a greater amount number of proteins, a better signal/noise (S/N) ratio and higher intensities for the majority of microalgae analyzed. Trifluoroacetic acid (TFA) content was also studied and the best results in terms of S/N ratio, number of proteins and signal intensities were obtained with 0.1% TFA in the matrix solvent. The addition of isopropanol did not produce improvement in the quality of spectrum profiles. CONCLUSIONS Therefore, the optimal matrix for the analysis of protein from intact microalgae cells is sDHB with TA50 as the matrix solvent and without isopropanol. These conditions allow the acquisition of high quality spectrum profiles.

Lipid and protein fingerprinting for Fusarium oxysporum f. sp. cubense strain-level classification

AbstractBanana is one of the most popular fruits in the world but has been substantially impaired by Panama disease in the last years. Fusarium oxysporum f. sp. cubense (Foc) is the causal agent and colonizes banana cultivars from many subgroups with different aggressiveness levels, often leading to plant death while compromising new crops in infested areas. This study has evaluated the ability of MALDI-MS protein and lipid fingerprinting to provide intraspecies classification of Foc isolates and to screen biomolecules related to host-pathogen relationship. The MS data, when inspected via partial least square discriminant analysis (PLS-DA), distinguished the isolates by aggressiveness as well as by specific location and host. Although both lipids and proteins show discriminating tendencies, these differences were more clearly perceived via the protein profiles. Considering that Cavendish cultivar is the more resistant option to endure Foc presence in the field, the lipids and proteins related to this subgroup might have an important role in pathogen adaptation. This study reports a new application of MALDI-MS for the analysis of a banana pathogen with intraspecies classification ability. Graphical abstractMALDI-MS classified Foc isolates by aggressiveness level on banana revealing the additional influence of location and host cultivar on the expression of lipids and proteins.

DIAGNÓSTICO DA GESTÃO DO PROCESSO DE DESENVOLVIMENTO DE PRODUTOS: UM ESTUDO DE CASO NO SETOR DE EQUIPAMENTOS E PRÓTESES MÉDICAS

O processo de desenvolvimento de produtos e uma fonte importante de vantagem competitiva para as empresas. A melhor forma de gerencia-lo e por meio da abordagem de processos de negocio. Uma das barreiras para a aplicacao desta abordagem e a dificuldade de se realizar o diagnostico da situacao do processo, visando a identificacao e priorizacao das acoes de melhoria. Avalia-se um caso de aplicacao do modelo de maturidade de gestao de desenvolvimento de produtos que faz parte do Modelo Unificado de PDP, proposto por Rozenfeld et al em 2006. Apresenta-se os componentes deste modelo e, em seguida, descreve-se uma experiencia de aplicacao pratica do modelo em um fabricante de equipamentos e proteses medicas. Justifica-se pela inexistencia de verificacoes deste modelo, publicado recentemente. O metodo principal e o estudo de caso unico, do tipo holistico, e os instrumentos de coleta sao entrevista com questionario semi-aberto, observacoes nao-participantes e analise de documentos da empresa. Como resultado, tem-se uma avaliacao da aplicabilidade do modelo para a verificacao do nivel de maturidade do processo de desenvolvimento de produto e sua adequacao na industria de equipamentos e proteses medicas.