Influence of NaCl on "Brachiaria humidicola" inoculated or not with "Glomus etunicatum"

An experiment was carried out to investigate the effects of different levels of NaCl on the growth of the grass Brachiaria humidicola inoculated or not with the arbuscular mycorrhizal fungus (AMF) Glomus etunicatum. The concentrations of NaCl utilized were 0, 0.22, 1.09, 1.96 and 2.84 g kg-1 of soil; corresponding to electrical conductivities of 2.22, 4.00, 8.13, 12.53 and 16.50 dS m-1. The salinity ratio of the soil reduced the dry matter in different parts of the plant when the electrical conductivity was above 8 dS m-1. Leaf area ratio and succulence increased at high salinity levels of the soil. The percentage of root colonization and the number of AMF spores in the rhizosphere were not affected by the increasing doses of NaCl added to the soi

Efetividade da inoculação com rizóbio e fungos micorrízicos arbusculares em mudas de sabia submetidas a diferentes níveis de fósforo.

Visando otimizar a produção de mudas de sabiá (Mimosa caesalpiniifolia Benth), foi conduzido um experimento para avaliar a efetividade da dupla inoculaçãocom fungos micorrízicos arbusculares (FMA) e rizóbio. Os tratamentos, arrumados em esquema fatorial consistiram de presença e ausência de Rhizobium sp. e de FMA (Glomus etunicatum, Acaulospora morrowae e A. longula), e de três níveis de P (0, 20 e 40 kg/ha de P2O5, na forma de superfosfato triplo). A aplicação de P na ausência e na presença dos fungos não favoreceu o desenvolvimento das plantas. As mudas com a dupla inoculação apresentaram valores significativos no crescimento, área foliar, altura das plantas, atividade da enzima nitrogenase, porcentagem de colonização radicular e outros parâmetros analisados, independentemente do nível de P usado. A nodulação do sabiá foi favorecida pela micorrização, uma vez que as mudas inoculadas apenas com Rhizobium apresentaram nodulação significativamente menor. Houve aumento da colonização micorrízica e diminuição da esporulação na presença de Rhizobium.Título em inglês: Effectiveness of inoculation with arbuscular mycorrhizal fungi and Rhizobium sp. on Mimosa caesalpiniifolia seedlings, under different phosphorus levels

Respuesta a la inoculación de "Bradyrhizobium sp." en caupí ("Vigna unguiculata" L. Walp.) utilizando diferentes sustratos de cultivos alternativos

Con el objetivo de evaluar la eficiencia de la inoculación con una cepa de Bradyrhizobium en el cultivo del caupí (Vigna unguiculata L. Walp.) respecto a los sustratos, a los medios de inoculación y esterilización del suelo, así como verificar los efectos de suplementación de la turba con sustratos de cultivo disponibles en la región, se llevaron a cabo dos experimentos en invernadero utilizando diferentes sustratos alternativos: turba, compost urbano, diatomita, vermiculita y vinaza seca. Los materiales biológicos fueron el cultivar IPA-205 de caupí y la cepa BR-2001 de Bradyrhizobium sp. La preparación de los inoculantes fue 109 células viables g¿1; m ¿0,1MPa. El cultivo del caupí se hizo en suelo Podzólico rojo amarillo. Los resultados muestran que el método de inoculación del suelo fue significativamente superior al método de inoculación de la semilla, sugiriendo que es posible mejorar el desempeño de los inoculantes con el estudio de los métodos de inoculación. La esterilización del suelo también afectó al comportamiento de la nodulación y a la productividad de las plantas. En el estudio delos sustratos, la diatomita produjo una mayor productividad en las plantas de caupí. La suplementación de los sustratos de cultivo con turba al 20 % proporcionó una mejor eficiencia simbiótica

A Clinical Algorithm to Diagnose Invasive Pulmonary Aspergillosis in Critically Ill Patients

Rationale: The clinical relevance of Aspergillus-positive endotracheal aspirates in critically ill patients is difficult to assess. Objectives: We externally validate a clinical algorithm to discriminate Aspergillus colonization from putative invasive pulmonary aspergillosis in this patient group. Methods: We performed a multicenter (n = 30) observational study including critically ill patients with one or more Aspergillus-positive endotracheal aspirate cultures (n = 524). The diagnostic accuracy of this algorithm was evaluated using 115 patients with histopathologic data, considered the gold standard. Subsequently, the diagnostic workout of the algorithm was compared on the total cohort (n=524), with the categorization based on the diagnostic criteria of the European Organization for the Research and Treatment of Cancer/Mycoses Study Group. Measurements and Main Results: Among 115 histopathology-controlled patients, 79 had proven aspergillosis. The algorithm judged 86 of 115 cases to haveputative aspergillosis. This diagnosis was confirmed in 72 and rejected in 14 patients. The algorithm judged 29 patients to have Aspergillus colonization. This was confirmed in 22 and rejected in 7 patients. The algorithm had a specificity of 61% and a sensitivity of 92%. The positive and negative predictive values were 61 and 92%, respectively. In the total cohort (n = 524), 79 patients had proven invasive pulmonary aspergillosis (15.1%). According to the European Organization for the Research and Treatment of Cancer/Mycoses Study Group criteria, 32 patients had probable aspergillosis (6.1%) and 413 patients were not classifiable (78.8%). The algorithm judged 199 patients to have putative aspergillosis (38.0%) and 246 to have Aspergillus colonization (46.9%). Conclusions: The algorithm demonstrated favorable operating characteristics to discriminate Aspergillus respiratory tract colonization from invasive pulmonary aspergillosis in critically ill patients. Copyright © 2012 by the American Thoracic Society

Tuning recombinant protein expression to match secretion capacity

Abstract Background The secretion of recombinant disulfide-bond containing proteins into the periplasm of Gram-negative bacterial hosts, such as E. coli, has many advantages that can facilitate product isolation, quality and activity. However, the secretion machinery of E. coli has a limited capacity and can become overloaded, leading to cytoplasmic retention of product; which can negatively impact cell viability and biomass accumulation. Fine control over recombinant gene expression offers the potential to avoid this overload by matching expression levels to the host secretion capacity. Results Here we report the application of the RiboTite gene expression control system to achieve this by finely controlling cellular expression levels. The level of control afforded by this system allows cell viability to be maintained, permitting production of high-quality, active product with enhanced volumetric titres. Conclusions The methods and systems reported expand the tools available for the production of disulfide-bond containing proteins, including antibody fragments, in bacterial hosts