Influence of biofilm composition on the resistance to detachment

Bacillus cereus and Pseudomonas fluorescens were used to develop monoculture biofilms in a bioreactor rotating system using a stainless steel cylinder for biofilm formation. The biofilms were allowed to grow for 7 days, exposed continuously to a Reynolds number of agitation (ReA) of 2,400. Afterwards, the biofilms were characterised in terms of respiratory activity, amount of biomass, cellular density, cellular size and total and extracellular proteins and polysaccharides. The biofilm mechanical stability was assessed by sequential submission of the biofilms to increasing ReA, respectively, 4,000, 8,100, 12,100 and 16,100. The results showed that P. fluorescens biofilms were five times more active, had a higher amount of biomass, cellular density, a reduced cellular size and a four-fold higher amount of extracellular proteins and polysaccharides than B. cereus biofilms. The application of shear stress forces higher than the one under which the biofilm was formed (ReA ¼ 2,400) caused biomass removal. The high percentage of removal occurred with the implementation of a ReA of 8,100 for both B. cereus and P. fluorescens biofilms. The total series of ReA did not give rise to total biofilm removal, as only about 76% of P. fluorescens biofilm mass and 53% of B. cereus biofilm mass were detached from the cylinders. This latter result evidences that B. cereus had a higher mechanical stability than P. fluorescens biofilms. The overall results demonstrate that P. fluorescens and B. cereus formed physiologically distinct biofilms, B. cereus biofilms mainly being constituted by cells and P. fluorescens biofilms largely constituted by extracellular proteins and polysaccharides. B. cereus biofilms had a substantially higher mechanical stability than P. fluorescens biofilms.IBQF Portuguese Foundation for Science and Technology

The effects of a biocide and a surfactant on the detachment of Pseudomonas fluorescens from glass surfaces

Application of antimicrobial chemicals is a general procedure in the cleaning and disinfection of food-contacting surfaces. Adhesion to glass surfaces and chemically induced detachment of Pseudomonas fluorescens ATCC 13525T were studied in situ, under flow conditions, in a well-controlled parallel plate flow chamber (PPFC). Ortho-phthalaldehyde (OPA) and cetyltrimethyl ammonium bromide (CTAB) were applied separately, at several concentrations, to attached bacteria and their subsequent detachment was monitored. Following treatments the remaining adhered bacteria were characterized in terms of viability and cell size. Simultaneously, the planktonic cell surface was characterized in order to correlate PPFC results with thermodynamic approaches for adhesion evaluation, and surface free energy of chemically treated cells with adhesion strength. About 2.8 × 106 cells/cm2 adhered to the glass surface after 30 min of bacterial flow, although thermodynamic analyses evidenced unfavourable adhesion. The independent application of OPA and CTAB promoted bacterial detachment to a small extent (16% of total cells). The remaining adhering bacteria were totally non-viable for OPA ≥ 0.75 mM and CTAB ≥ 0.25 mM, showing a lack of correlation between bacterial viability and detachment. The cellular size decreased as attachment proceeded and with chemical treatment. Both chemicals altered the cell surface properties, increasing the cell-glass adhesion strength, and promoting the emergence of polar characteristics. The overall results emphasize that OPA and CTAB were markedly ineffective in removing glass-attached P. fluorescens, demonstrating that bacteria can be non-viable but remain strongly attached to the adhesion surface.Fundação para a Ciência e a Tecnologia (FCT) - Project CHEMBIO – POCI/BIO/61872/2004; SFRH/BD/ 31661/2006; SFRH/BPD/20582/2004

Nutritional and phytochemical composition of Vaccinium padifolium Sm wild berries and radical scavenging activity

Blueberries have a well-deserved reputation as a potential functional food, supported by studies which have identified and quantified various nutrients and bioactive phytochemicals with known benefits for human diet and health. Wild blueberries have attracted particular attention due to the levels and concentrations of those phytonutrients. This study aims to evaluate for the first time the chemical composition of Madeira Island's endemic Vaccinium padifolium Sm wild berry. Results show that this fruit contains high values of total soluble phenolic content (around 4 g GAE kg-1 FW), as well as significant values of total monomeric anthocyanin content (around 3 g eq. cyanidin kg-1 FW) and DPPH scavenging activity (around 86.72%). Additionally, results reveal that this fruit has water content of about 88% as well as low sugar content (17.98 and 29.73 g kg-1 for glucose and fructose, respectively). Results also confirm that this wild blueberry is a good source of dietary fiber, fat and minerals. The high level of terpenoid compounds stands out in the aroma profile analysis.Ana C. Pereira acknowledges Agencia Regional para o Desenvolvimento da Investigação Tecnologia e Inovação (ARDITI) for financial support through her grant, M1420-09-5369-FSE- 000001.info:eu-repo/semantics/publishedVersio

Gastrointestinal parasites in iberian wolf (canis lupus signatus) from the Iberian Peninsula

The Iberian Peninsula is one of the most humanized areas in Europe, yet humans may cohabit with large predators, such as the Iberian wolf (Canis lupus signatus), at the expense of many contributions to its conservation. The limited wolves? territory leads to a close relationship between this wild species, humans, and other animals, which may promote the spillover of pathogens, such as gastrointestinal parasites. This review intends to provide an update concerning gastrointestinal parasite findings performed using coprological methods on fecal samples from Iberian wolves. Studies conducted in Portugal and Spain through coprology presented a prevalence of gastrointestinal parasites of 57.0?100% in Spain and 21.5?68.3% in Portugal. Parasites belonging to Protozoa, Trematoda, Cestoda, and Nematoda were specified, alongside thirteen genera and twenty species of gastrointestinal parasites. In this study, 76.9% (10/13) of genera and 65.0% (13/20) of species of gastrointestinal parasites were identified as having zoonotic potential. These results highlight that further studies are needed to better understand the parasitic agents circulating in the wild in humanized areas, such as the Iberian Peninsula.A91F-E8B8-FA62 | Teresa Susana Letra MateusN/

Automatic simulation models generation of warehouses with milk runs and pickers

To help a company of the Bosch Group to reduce its costs (both in time and space) with its supermarket, a micro simulation model was developed in Simio. Particularly, the tool is able to model pickers riding milk runs to collect containers of products, from a supermarket, to satisfy the needs of the production lines. Practitionaer may benefit from this tool, since it is able to model different supermarket scenario, for instance different storage strategies. Additionally, the supermarket itself is automatically created, through an Add-in of Simio that was developed in C#, which implements the API of Simio. Conclusions and future work are discussed.This work has been co-supported by SI I&DT project in joint-promotion nº 36265/2013 (HMIEXCEL 2013-2015 Project) and by FCT Fundação para a Ciência e Tecnologia in the scope of the project: PEst-OE/EEI/UI0319/2014.info:eu-repo/semantics/publishedVersio

Sodium dodecyl sulfate allows the persistence and recovery of biofilms of Pseudomonas fluorescens formed under different hydrodynamic conditions

The effect of the anionic surfactant sodium dodecyl sulfate (SDS) on Pseudomonas fluorescens biofilms was investigated using flow cell reactors with stainless steel substrata, under turbulent (Re=5200) and laminar (Re=2000) flow. Steady-state biofilms were exposed to SDS in single doses (0.5, 1, 3 and 7 mM) and biofilm respiratory activity and mass measured at 0, 3, 7 and 12 h after the SDS application. The effect of SDS on biofilm mechanical stability was assessed using a rotating bioreactor. Whilst high concentrations (7 mM) of SDS promoted significant biofilm inactivation, it did not significantly reduce biofouling. Turbulent and laminar flow-generated biofilms had comparable susceptibility to SDS application. Following SDS exposure, biofilms rapidly recovered over the following 12 h, achieving higher respiratory activity values than before treatment. This phenomenon of posttreatment recovery was more pronounced for turbulent flow-generated biofilms, with an increase in SDS concentration. The mechanical stability of the biofilms increased with surfactant application, except for SDS concentrations near the critical micellar concentration, as measured by biofilm removal due to an increase in external shear stress forces. The data suggest that although SDS exerts antimicrobial action against P. fluorescens biofilms, even if only partial and reversible, it had only limited antifouling efficacy, increasing biofilm mechanical stability at low concentrations and allowing significant and rapid recovery of turbulent flow-generated biofilms.Fundação para a Ciência e a Tecnologia (FCT

Using simio to automatically create 3d warehouses and compare different storage strategies

This paper focuses on a simulation based approach to reduce warehouse costs. At an early stage, the tool needs to be able to generate different types of warehouses. To accomplish this, a Simio add-in was built in C#, using the Simio API, where the user only needs to insert the layout data on an excel spreadsheet. Afterwards, the created warehouse is capable of modelling different storage strategies and compare them. The obtained results indicate that the proposed strategy is able to reduce the picking time in about 15% and the number of stops per milk run in 50%. Moreover, it was found that the strategy currently in use needs 35% more space than the proposed one.This work has been co-supported by SI I&DT project in joint-promotion nº 36265/2013 (HMIEXCEL - 2013-2015 Project) and by FCT – Fundação para a Ciência e Tecnologia in the scope of the project: PEstOE/EEI/UI0319/2014.info:eu-repo/semantics/publishedVersio

Simulation model generation for warehouse management: Case study to test different storage strategies

A simulation model generator was developed to help a company of the Bosch Group to reduce costs in time and space with its warehouse. The simulation models are automatically created in Simio and can simulate pickers riding milk runs to collect containers from the warehouse, to satisfy the needs of production lines, assisting warehouse management by testing different storage strategies. Thus, the purpose of this paper is to present the developed generator and to use it in a case study, to test different storage policies for the company. The generator was validated, as was the simulation model automatically created. With this tool, some suggestions could be made to the company in question. Namely, it was shown that it would not be possible to maintain the FIFO rule and, at the same time, eliminate the upper floor of all racks for ergonomic reasons. To allow this, the rate of replacing containers should be synchronised with the needs of production lines. Alternatively, it was also shown that the performance of the warehouse would improve by dividing it into zones allocated to each milk run.This work has been supported by QREN: FCT – Fundação para a Ciência e Tecnologia within the Project Scope: PDE/BDE/114566/2016 – AESI: Advanced Engineering Systems for Industry doctoral programme

Using simulation to model the logistic operations of a company of the cement industry

This paper presents a discrete-event simulation model to study the logistics operations involved in a plant of the cement industry, aligned with a real project developed in partnership between Cachapuz (a company that provides international weighing solutions) and the University of Minho. The purpose of this work consists in using simulation to model several activities, involving weighing, loading and unloading of raw materials, regardless of the type of industry, e.g. cement, tomato, cereals. Thus, this paper documents the work conducted to apply the developed simulation model in a case study of the cement industry. After validating the model, a set of simulation experiments were conducted, which allowed to estimate the maximum capacity of the plant and the impact in the performance of the plant, of the arrival of a cargo vessel. In this regard, it was found that in the case study in question, it is not possible to unload all the cargo from the vessel in a working day - around 3 working days would be required. Further conclusions and future work are discussed in the last section.- (undefined