The influence of the nutrient load on the formation of Escherichia coli biofilms

• Type: Chapter or Part of a Book
• Date: 2011

Authors

M. Simões (Author) FEUP; Luís Manuel Ferreira de Melo (Author) FEUP; Filipe Mergulhão (Author) FEUP; Joana Teodósio (Author) FEUP

Book

Title: Advances in Medicine and Biology

Pages: 153-168

ISBN: 978-1-61324-068-7

Publisher: Nova Science Publishers Inc

Scientific classification

FOS: Engineering and technology > Industrial biotechnology

CORDIS: Technological sciences

Other information

Abstract (EN): The attachment of microorganisms to surfaces and the subsequent biofilm development are very complex processes affected by several variables. Among these variables, it has been shown that the nutrient/substrate concentration may influence the structure of biofilms growing in aqueous environments. The goal of this study was to assess the effect of the nutrient load on biofilm formation by Escherichia coli JM109(DE3) by using three substrate feed concentrations (glucose concentrations of 0.55, 0.15 and 0.050 g.L-1) and four dilution rates (0.0042, 0.0126, 0.0800 and 0.1650 h-1) on separate experiments. Biofilms were formed in a flow cell reactor under turbulent conditions, with a Reynolds number of approximately 5000, by using a recirculating system that enables independent control of the dilution rate and flow velocity. Three nutrient load ranges were obtained on the independent experiments and our results show that when high nutrient loads were used, planktonic cell concentration was reduced and glucose consumption was proportional to the nutrient load. Additionally, when moderate nutrient loads were tested, higher planktonic cell concentrations were observed when compared to the high nutrient load conditions. When the nutrient load was further reduced planktonic cell concentration was further increased. Unlike the glucose consumption values obtained for the high nutrient load conditions, glucose consumption for the moderate and low nutrient loads was not dependent on the nutrient load that was used. Furthermore, when the system was fed with the highest nutrient concentration (0.55 g.L-1), glucose consumption was the same even when the dilution rate was increased.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 15