Characterization of a new coagulase-negative Staphylococcus species (Staphylococcus pettenkoferi) isolated from blood cultures from a hospitalized patient in Porto Alegre, Brazil

INTRODUCTION: Staphylococcus pettenkoferi was originally isolated and described by Trülzsch et al (2002). In this study, we characterized two isolates of this newly described species. METHODS: Blood cultures were initially processed using the BacT/ALERT® device, and the isolates were initially characterized using the Vitek2 identification system. RESULTS: The initial characterization revealed slow-growing Gram-positive cocci that formed opaque colonies on sheep blood agar. Other phenotypic/genotypic tests were performed. CONCLUSIONS: We would like to emphasize that this new staphylococcus species is phenotypically similar to other CoNS, especially S. auricularis. This could potentially lead to misidentification of these uncommon species.

Impact of carbon/nitrogen feeding strategy on polyhydroxyalkanoates production using mixed microbial cultures

Polyhydroxyalkanoates (PHA) production using mixed microbial cultures (MMC) requires a multi-stage process involving the microbial selection of PHA-storing microorganisms, typically operated in sequencing batch reactors (SBR), and an accumulation reactor. Since low-cost renewable feedstocks used as process feedstock are often nitrogen-deficient, nutrient supply in the selection stage is required to allow for microbial growth. In this context, the possibility to uncouple nitrogen supply from carbon feeding within the SBR cycle has been investigated in this study. Moreover, three different COD:N ratios (100:3.79, 100:3.03 and 100:2.43) were tested in three different runs which also allowed the study of COD:N ratio on the SBR performance. For each run, a synthetic mixture of acetic and propionic acids at an overall organic load rate of 8.5 gCOD L-1 d-1 was used as carbon feedstock, whereas ammonium sulfate was the nitrogen source in a lab-scale sequence batch reactor (SBR) with 1 L of working volume. Besides, a sludge retention time (SRT) of 1 d was used as well as a 6 h cycle length. The uncoupled feeding strategy significantly enhanced the selective pressure towards PHA-storing microorganisms, resulting in a two-fold increase in the PHA production (up to about 1.3 gCOD L-1). A high storage response was observed for the two runs with the COD:N ratios (gCOD:gN) of 100:3.79 and 100:3.03, whereas the lowest investigated nitrogen load resulted in very poor performance in terms of polymer production. In fact, strong nitrogen limitation caused fungi to grow and a very poor storage ability by microorganisms that thrived in those conditions. The COD:N ratio also affected the polymer composition, indeed the produced poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) showed a variable HV content (1-20 %, w/w) among the three runs, lessening as the COD:N increased. This clearly suggests the possibility to use the COD:N ratio as a tool for tuning polymer properties regardless the composition of the feedstock.

Polyhydroxyalkanoates production by photosynthetic mixed cultures

Polyhydroxyalkanoates (PHAs) are natural biologically synthesized polymers that have been the subject of much interest in the last decades due to their biodegradability. Thus far, its microbial production is associated with high operational costs, which increases PHA prices and limits its marketability. To address this situation, this thesis’ work proposes the utilization of photosynthetic mixed cultures (PMC) as a new PHA production system that may lead to a reduction in operational costs. In fact, the operational strategies developed in this work led to the selection of PHA accumulating PMCs that, unlike the traditional mixed microbial cultures, do not require aeration, thus permitting savings in this significant operational cost. In particular, the first PHA accumulating PMC tested in this work was selected under non-aerated illuminated conditions in a feast and famine regime, being obtained a consortium of bacteria and algae, where photosynthetic bacteria accumulated PHA during the feast phase and consumed it for growth during the famine phase, using the oxygen produced by algae. In this symbiotic system, a maximum PHA content of 20% cell dry weight (cdw) was reached, proving for the first time, the capacity of a PMC to accumulate PHA. During adaptation to dark/light alternating conditions, the culture decreased its algae content but maintained its viability, achieving a PHA content of 30% cdw. Also, the PMC was found to be able to utilize different volatile fatty acids for PHA production, accumulating up to 20% cdw of a PHA co-polymer composed of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (HV) monomers. Finally, a new selective approach for the enrichment of PMCs in PHA accumulating bacteria was tested. Instead of imposing a feast and famine regime, a permanent feast regime was used, thus selecting a PMC that was capable of simultaneously growing and accumulating PHA, being attained a maximum PHA content of 60% cdw, the highest value reported for a PMC thus far. The results presented in this thesis prospect the utilization of cheap, VFA-rich fermented wastes as substrates for PHA production, which combined with this new photosynthetic technology opens up the possibility for direct sunlight illumination, leading to a more cost-effective and environmentally sustainable PHA production process.

Effects of residues on the degradation of PHA produced from mixed microbial cultures and processed in extrusion

Thermal degradation upon melting is one of the major drawbacks reported for polyhydroxyalkanoates (PHA). However, the role of residues originating from the fermentation and the extraction steps on the thermal stability of this class of biopolymers still needs to be clarified. In the particular case of PHA produced from mixed microbial cultures (MMC), this topic is even less documented in the literature. Here, two polyhydroxy(butyrate-co-valerate) (PHBV) produced from MMC enriched in PHA accumulating organisms and fed with cheese whey were studied. A micro extrusion line is used to produce filaments and assess the processability and the degradation of processed PHBV. The prototype micro extrusion line allows for studying grams of materials. The two PHBV contain 18 mol% HV. PHBV was recovered with 11 wt% residues, and further submitted to a purification procedure resulting in a second biopolyester containing less than 2 wt% impurities. The thermorheological characterization of the two PHBV is first presented, together with their semicrystalline properties. Then the processing windows of the two biopolyesters are presented. Finally, the properties of extruded filaments are reported and the thermomechanical degradation of PHBV is extensively studied. The structure was assessed by wide angle X-ray diffraction, mechanical and rheological properties are reported, thermal properties are studied with differential scanning calorimetry and thermogravimetric analysis, whereas Fourier Transform Infrared spectroscopy was used to assess the impact of the extrusion on PHBV chemical structure. All results obtained with the two PHBV are compared to assess the effects of residues on both PHBV processability and degradation.

Local seismic cultures: the use of timber frame structures in the south of Portugal

Given the fact that using timber frame structures has proven to improve the seismic behavior of vernacular architecture, as has been reported in past earthquakes in many countries, its preservation as a traditional earthquake resistant practice is important. This paper firstly intends to evaluate whether the use of timber frames as a traditional seismic resistant technique for vernacular architecture in the South of Portugal, traditionally a seismic region, is still active. Secondly, the city of Vila Real de Santo António was selected as a case study because it also followed a Pombaline development contemporary to the reconstruction of Lisbon. The plan included the provision of timber frame partition walls for some of the buildings and, thus, an overview of the type of constructions originally conceived is provided. Finally, the alterations done in the original constructions and the current state of the city center are described and the effect of these changes on the seismic vulnerability of the city is discussed.

Effect of fetal bovine serum on Candida glabrata cultures

Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Engenharia Clínica)

Production of secondary metabolites in cell suspension cultures of Ocimum sanctum L.

Dissertação de mestrado em Plant Molecular Biology, Biotechnology and Bioentrepreneurship

Effects of fermentation residues on the melt processability and thermomechanical degradation of PHBV produced from cheese whey using mixed microbial cultures

"Available online 28 March 2016"

Tecnología de igy anti-escherichia coli aplicada mediante nanotubos sobre cultivos de enterocitos porcinos. Anti- escherichia coli igy technology applied through nanotubes on porcine enterocyte cultures.

La diarrea neonatal representa uno de los problemas sanitarios de mayor relevancia en las primeras semanas de vida del cerdo. Provoca importantes pérdidas económicas por morbilidad y mortalidad. El cultivo de enterocitos primarios representa una herramienta valiosa para el estudio de patologías causadas por agentes infecciosos que afectan la integridad del epitelio intestinal. La producción de anticuerpos extraídos a partir de la yema de huevo de gallinas inmunizadas (IgY), es una tecnología innovadora, que ha mostrado ser protectiva contra diarreas causadas por agentes víricos y bacterianos. La nanotecnología permite mejorar la eficiencia en la administración de distintas drogas. Los nanotubos de carbono han ganado una enorme popularidad por sus propiedades y aplicaciones únicas. La investigación sobre los aspectos toxicológicos de estas nanopartículas es escasa. Una vez dentro de la célula, las nanopartículas pueden inducir estrés oxidativo intracelular por perturbar el equilibrio oxidativo. Las hipótesis de trabajo es: La administración de IgY anti-Escherichia coli a través de nanotubos protegerá in vitro e in vivo a los enterocitos de una infección por E. coli previniendo la diarrea neonatal porcina. Los objetivos del trabajo son: Evaluar la protección por un anticuerpo aviario IgY anti-E. coli aplicado mediante nanotubos de carbono a cultivo de enterocitos porcinos primarios sometidos a una post-infección con E. coli; Analizar los efectos secundarios de los nanotubos con IgY anti-E coli en la citotoxicidad, el balance oxidativo y la apoptosis de los enterocitos porcinos cultivados in vitro y Evaluar la acción terapeútica de la IgY anti-E coli aplicada a porcinos y efectos secundarios de la administración con nanotubos. Se implementará un diseño experimental in vitro con diferentes grupos de cultivos con nanotubos, con IgY anti-E. coli e inespecifica y con exposición a E. coli. Se realizará cultivo de enterocitos porcinos primarios con una técnica de disgregación enzimática con colagenasa según protocolo de Bader et al. (2000). Se evaluará la viabilidad por la prueba de azul tripan. Para la obtención del anticuerpo anti-E. coli aviario se aplicarán un total de 3 dosis de E. coli (109 UFC/ml de adyuvante) a gallinas Legorhn en condiciones fisiológicas. Se recolectarán los huevos diariamente. Se purificará la IgY según método de Polson et al. (1985) utilizando PEG 6000. La concentración de IgY se medirá por ELISA de alta sensibilidad. La IgY será incorporada a nanotubos según protocolo de Acevedo et al. 2006. Para analizar los posibles efectos secundarios de los nanotubos se evaluará: 1. Citotoxicidad por técnica de MTT 2. Estrés oxidativo por técnica de TBARS y 3. Apoptosis por técnica de TUNEL.Además, se implementará un diseño experimental in vivo para probar la acción terapeútica de este nutraceútico aplicados a lechones destetados y los efectos secundarios de la administración con nanotubos. Se realizará un cultivo de enterocitos de lechones que previamente fueron tratados con la IgY anti-E. coli administrada mediante nanotubos y efectuarán las técnicas descriptas anteriormente. Los resultados esperados son: Elaboración de un Ac aviario IgY anti-E. coli para prevenir infección de enterocitos, Profundización en el conocimiento acerca de los efectos citotóxicos de los nanotubos de carbono multilamelares, Generación de tratamiento alternativo para enfermedades entéricas porcinas.

Neurodegeneration and neurogenesis in organotypic hippocampal slice cultures after oxygen and glucose deprivation

Organotypic hippocampal slice cultures, neurogenesis, posterior periventricle, oxygen-glucose deprivation, microglia, inflammation

Spatiotemporal metabolic organization during development of brain cell cultures

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2009

The induction of root and shoot morphogenesis in Phaseolus vulgaris tissue cultures

Exogenous concentrations of bean seed extract prepared from seeds pretreated in aerated water, homogenized in Veliky and Martin's 67-V salt solution, filtered, and added to the culture medium at proper concentrations promote callus proliferation, root morphogenesis, and shoot morphogenesis in leaf explains of Phaseolus vulgaris var. Bico de Ouro. The activity of the bean seed factor is dependent upon the period of pretreatment in aerated water.

The human genetic mutant cell repository : list of genetic variants, chromosomal aberrations and normal cell cultures submitted to the repository / Institute for Medical Research, Camden, New Jersey.

4th ed.

Atividade antibacteriana do Aspergillus niger van Tieghem, 1867; pesquisas em 14 amostras da National Collection of Type Cultures (M. R. C.)

1. Pesquisamos a atividade antibacteriana em 14 amostras de Aspergillus niger da National Collection of Type Cultures. 2. Em meio de Raulin e Mosseray, sete amostras apresentaram atividade total, nunca superior a 1:10, contra Staphylococcus aureus nº 553, sendo que as amostras 1.161 e 2.390 permaneceram ativas por mais de 40 dias. 3. A utilização do meio de Czapek-Dox com 5% de "corn-steep" não melhorou os resultados obtidos com o meio de Raulin e Mosseray. 4. No meio de levedo peptonado, todas as amostras apresentaram-se inativas.