Figueiredo, Hugo

Fonseca, Bruna

Quintelas, C.

Rocha, Zélia

Silva, Bruna Andreia Nogueira Airosa

Tavares, M. T.

Universidade do Minho: RepositoriUM

 76 Proceedings of Biofilms III Conference [P60] BIOFILMS FORMED ON THE SURFACE OF PA/PE LAMINATES PACKAGING Izabela Steinka  Gdynia Maritime University, Department of Commodity and Cargo Science 81-225 Gdynia, Morska 81-87 isteinka@wp.pl Adhesion of micro-organisms to the basis (adherence) is dependent on type of the basis, conditions occurring in given environment and hydrophobic character of the structures contained in cellular wall of micro-organisms. Assessment of character of interactions occurring between these bacteria and the packaging is important due to the influence of these interactions on the quality of hermetically-packed food. The aim of research was to assess the ability to form biofilms by facultative anaerobic bacteria on the surface of PA/PE laminates.  The ability to form and size of biofilms were evaluated during 14 days of refrigerating storage of cheese curds in hermetically sealed PA/PE backs. Tested material consisted of PA/PE packaging in the form of bags. Bags were filled with lactic acid curd made by souring 2% pasteurised milk lyophilised with  starter of Rhodia Food Biolacta Company.  The ability to form biofilms by Lactococcus sp. bacteria on the PA/PE surface was observed. Enterococcus bacteria and yeast did not form biofilms. The insignificant growth on laminate surface was observed for filamentous fungi. Growth of bacteria on PA/PE laminates surface showed weak linear correlation with storage time of lactic acid curd in this packaging.  At refrigerating temperature, only Lactococcus sp. bacteria showed the ability to form biofilms on the PA/PE laminate surface. In these conditions of curd hydration, the enterococci, yeast and filamentous fungi were not able to form biofilms on the surface of tested packaging. [P39] BIOSORPTION OF HEAVY METALS FROM AQUEOUS SOLUTIONS BY AN E. COLI BIOFILM SUPPORTED ON ZEOLITE NAY Cristina Quintelas, Zélia Rocha, Bruna Silva, Bruna Fonseca, Hugo Figueiredo and TeresaTavares The increasing concern with the environmental pollution motivates the development of new technologies for the treatment of heavy metals pollution. Several heavy metals can seriously damage the environment with hazardous effects on the human health.  Aiming a solution for this problem, various efforts have been made towards research and implementation of an economic and easily adaptable process for any system for removal of heavy metals. The ability of a biofilm of Escherichia coli supported on zeolite NaY to biosorb Cr(VI), Cd(II), Fe(III) and Ni(II) was investigated in batch studies aiming the treatment of low metal concentration wastewater. The effect of heavy metal initial concentrations was analysed. Adsorption characteristics of a biosorbent can be depicted  77 Proceedings of Biofilms III Conference from an adsorption isotherm. Langmuir, Sips and Toth models are commonly used for the description of adsorption data and were applied to the experimental results described herein. The presence of functional groups in the suspended biomass that may have a role in the biosorption process was confirmed by FTIR. The results show that the biofilm of E. coli supported on NaY zeolite is able to remove Cr (VI), Cd (II), Ni (II) and Fe (III) from aqueous solutions. The isotherms were fitted and the best fit for chromium was obtained with the Toth model isotherm and for cadmium and nickel the best fit was the obtained with the Sips model. In terms of removal percentage, the results showed 100% of removal for iron for the whole range of concentrations tested. For nickel, the removal percentage remains approximately the same for all the initial concentrations tested (between 82.5% and 85.5%) and is higher than the obtained for cadmium and chromium. The analyses by FTIR showed that functional groups on the biomass such as hydroxyl, carboxyl and phosphate groups, would be the main binding sites for biosorption of the studied heavy metals by E. coli. Finally, the metal affinity to the biofilm was found to be in the order of Fe > Ni > Cd > Cr and the preference of a sorbent for a metal may be explained on the basis of the electronegativity of the metal ions and on the basis of the cation/anion oxidation state. [P113] CAN INTRAUTERINE CONTRACEPTIVE DEVICES BE A CANDIDA ALBICANS RESERVOIR? Chassot F, Negri MF, Svidzinski AE, Donatti L, Peralta RM, Svidzinski TI, Consolaro ME. Division of Clinical Cytology, Teaching and Research in Clinical Analysis Laboratory, State University of Maringá, Maringá, 87020-900 Paraná, Brazil. BACKGROUND: The in vitro adherence of Candida albicans isolated from vaginal exudates of patients with vulvovaginal candidiasis (VVC) to intrauterine contraceptive devices (IUDs) and biofilm formation capacity were evaluated. STUDY DESIGN: This research was conducted with two vaginal C. albicans isolates. The adherence on IUD by both radiomarked adhesion assay and scanning electron microscopy, and the biofilm production capacity by spectrophotometric method were determined. RESULTS: The yeasts adhered strongly to different parts of the IUD (covered with copper wire, without copper wire and tail), and there was no significant difference in the rates of adhesion to the different parts (p=.7771). The vaginal yeasts showed a high capacity to produce biofilm. CONCLUSIONS: Two vaginal yeasts evaluated showed a high capacity to produce biofilm on IUD. It was confirmed that all parts of the IUD allow the adherence of yeasts. The adherence of C. albicans to different parts of the IUD and its formation of biofilm seems to be important attributes influencing the occurrence of VVC and recurrent VVC. 

Biosorption of heavy metals from aqueous solutions by an E. coli biofilm supported on zeolite NaY

http://repositorium.sdum.uminho.pt/bitstream/1822/26186/1/Pages%20from%20_Proceedings_biofilms3.pdf

Biosorption of heavy metals from aqueous solutions by an E. coli biofilm supported on zeolite NaY

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