Outer membrane vesicles (OMV) production of Neisseria meningitidis serogroup B in batch process

AbstractSerogroup B outer membrane vesicles (OMV) with iron regulated proteins (IRP) from Neisseria meningitidis constitute the antigen for the vaccine against the disease caused by this bacterium. Aiming to enhance final OMV concentration, seven batch experiments were carried out under four different conditions: (i) with original Catlin medium; (ii) with original Catlin medium and lactate and amino acids pulse at the 6th cultivation hour; (iii) with Catlin medium with double initial concentrations of lactate and amino acids and (iv) Catlin medium without glycerol and with double initial concentrations of lactate and amino acids. The cultivation experiments were carried out in a 7-L bioreactor under the following conditions: 36°C, 0.5atm, overlay air 1L/min, agitation: 250–850rpm, and O2 control at 10%, 20h. After lactate and amino acids exhaustion, cell growth reached stationary phase and a significant release increase of OMV was observed. According to the Luedeking & Piret model, OMV liberation is non-growth associated. Glycerol was not consumed during cultivation. The maximum OMV concentration value attained was 162mg/L with correspondent productivity of 8.1mg/(Lh) employing Catlin medium with double initial concentrations of lactate and amino acids. The obtained OMV satisfied constitution and protein pattern criteria and were suitable for vaccine production

Avaliação da Contaminação Ambiental por Arsênio e Estudo Epidemiológico da Exposição Humana em Paracatu-MG - Brasil

We present an interdisciplinary study where environmental, social and health conditions are integrated to evaluate the risk of exposure to arsenic in the population of Paracatu, due to the exploitation of the largest open pit gold mine in Brazil. The study had three phases: evaluation of environmental contamination; assessment of human environmental exposure; investigation of factors associated with behavior to reduce the risk of exposure. Water for human consumption in the urban area is not contaminated with arsenic. The levels of arsenic in urine indicate higher exposure in neighborhoods near the mine, in agreement with data on atmospheric particulate matter. The cancer mortality rate was not higher than the controls. Social networks and gender relations are key in the adoption of preventive behaviors. It is recommended the establishment of an Arsenic Exposure Surveillance Program, with the involvement of the Brazilian Universal Health Care System, “SUS”, at the municipal, state and federal levels.Apresentamos um estudo interdisciplinar onde condições ambientais, sociais e de saúde são integradas para avaliar o risco de exposição ao arsênio na população de Paracatu, devido à exploração da maior mina de ouro a céu aberto do Brasil. O estudo possui três fases: avaliação da contaminação ambiental; estudo epidemiológico de exposição ambiental humana; exame dos fatores associados aos comportamentos para reduzir o risco de exposição. As águas de consumo humano na área urbana não estão contaminadas com arsênio. Os teores de arsênio em urina indicam exposição mais alta em bairros próximos à mina, em concordância com os dados sobre material particulado atmosférico. A taxa de mortalidade por câncer não se mostrou superior aos controles. As redes sociais e relações de gênero são chave na adoção de comportamentos preventivos. Recomenda-se o estabelecimento de um Programa de Vigilância da exposição ao arsênio, com envolvimento do SUS, ao nível municipal, estadual e federal

Proteolytic activity characterization of the Mycobacterium leprae hsp65

O presente trabalho relata, pela primeira vez, que a hsp65 recombinante de Mycobacterium leprae (chaperonina 2) apresenta atividade proteolitica. A atividade proteolitica da hsp65 de M. leprae mostrou uma especificidade semelhante a tripsina perante peptideos de fluorescencia apagada derivados da dinorfina. Quando outros substratos peptidicos foram utilizados b-endorfina, neurotensina e angiotensina I) a clivagem da ligacao peptidica predominante tambem envolveu aminoacidos basicos em P1 embora, em menor extensao, tambem foi observada a hidrolise envolvendo aminoacidos neutros e hidrofobicos (G e F). O alinhamento da sequencia de aminoacidos da hsp65 de M. leprae com a protease HSIW de Escherichia coli sugere dois grupos cataliticos putativos de treonina, um no dominio-N (T136, K168 e Y264) e o outro no dominio-C (T375, K4º9 e S$º2). Estudos de mutagenese mostraram que a substituicao de K409 por A causou uma perda completa da atividade proteolitica, ao passo que a mutacao de K168 para A resultou em uma perda de 25 por cento. Estes resultados sugerem fortemente que os residuos de aminoacidos T3'5, K 4o9 e S'º' no dominio-C formem o grupo catalitico responsavel pela atividade proteolitica da hsp65 de M. leprae. As possiveis implicacoes patofisiologicas da atividade proteolitica da hsp65 de M. leprae estao agora sob ampla investigacao em nosso laboratorioBV UNIFESP: Teses e dissertaçõe

Culture medium of diluted skimmed milk for the production of nisin in batch cultivations

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Nisin is a promising alternative to chemical preservatives for use as a natural biopreservative in foods. This bacteriocin has also potential biomedical applications. Lactic acid bacteria are commonly cultivated in expensive standard complex media. We have evaluated the cell growth and nisin production of Lactococcus lactis in a low-cost natural medium consisting of diluted skimmed milk in a 2-L bioreactor. The assays were performed at 30 degrees C for 56 h, at varying agitation speeds and airflow rates: (1) 200 rpm (no airflow, and airflow at 0.5, 1.0 and 2.0 L/min); (2) 100 rpm (no airflow, and airflow at 0.5 L/min). Nisin activity was evaluated using agar diffusion assays. The highest nisin concentration, 49.88 mg/L (3.3 log AU/mL or 1,995.29 AU/mL), was obtained at 16 h of culture, 200 rpm and no airflow (k(L)a = 5.29 x 10(-3)). These results show that a cultivation medium composed of diluted skimmed milk supports cell growth to facilitate nisin biosynthesis.621419426Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Nisin expression production from Lactococcus lactis in milk whey medium

BACKGROUND: Nisin is a commercially available bacteriocin produced by Lactococcus lactis ATCC 11454 and used as a natural agent in the biopreservation of food. In the current investigation, milk whey, a byproduct from dairy industries was used as a fermentation substrate for the production of nisin. Lactococcus lactis ATCC 11454 was developed in a rotary shaker (30 degrees C/36 h/100 rpm) using two different media with milk whey (i) without filtration, pH 6.8, adjusted with NaOH 2 mol L-1 and without pH adjustment, both autoclaved at 121 degrees C for 30 min, and (ii) filtrated (1.20 mu m and 0.22 mu m membrane filter). These cultures were transferred five times using 5 mL aliquots of broth culture for every new volume of the respective media. RESULTS: The results showed that culture media composed of milk whey without filtration supplied L. lactis its adaptation needs better than filtrated milk whey. Nisin titers, in milk whey without filtration (pH adjusted), was 11120.13 mg L-1 in the second transfer, and up to 1628-fold higher than the filtrated milk whey, 6.83 mg.L-1 obtained in the first(t) transfer. CONCLUSIONS: Biological processing of milk byproducts (milk whey) can be considered a profitable alternative, generating high-value bioproducts and contributing to decreasing river disposals by dairy industries. (C) 2008 Society of Chemical Industry