Dataset Information

Cholate-stimulated biofilm formation by Lactococcus lactis cells.

ABSTRACT: Bile acid resistance by Lactococcus lactis depends on the ABC-type multidrug transporter LmrCD. Upon deletion of the lmrCD genes, cells can reacquire bile acid resistance upon prolonged exposure to cholate, yielding the ?lmrCD(r) strain. The resistance mechanism in this strain is non-transporter based. Instead, cells show a high tendency to flocculate, suggesting cell surface alterations. Contact angle measurements demonstrate that the ?lmrCD(r) cells are equipped with an increased cell surface hydrophilicity compared to those of the parental and wild-type strains, while the surface hydrophilicity is reduced in the presence of cholate. ?lmrCD(r) cells are poor in biofilm formation on a hydrophobic polystyrene surface, but in the presence of subinhibitory concentrations of cholate, biofilm formation is strongly stimulated. Biofilm cells show an enhanced extracellular polymeric substance production and are highly resistant to bile acids. These data suggest that non-transporter-based cholate resistance in L. lactis is due to alterations in the cell surface that stimulate cells to form resistant biofilms.

SUBMITTER: Zaidi AH

PROVIDER: S-EPMC3126353 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Cholate-stimulated biofilm formation by Lactococcus lactis cells.

Zaidi Arsalan Haseeb AH Bakkes Patrick J PJ Krom Bastiaan P BP van der Mei Henny C HC Driessen Arnold J M AJ

Applied and environmental microbiology 20110218 8

Bile acid resistance by Lactococcus lactis depends on the ABC-type multidrug transporter LmrCD. Upon deletion of the lmrCD genes, cells can reacquire bile acid resistance upon prolonged exposure to cholate, yielding the ΔlmrCD(r) strain. The resistance mechanism in this strain is non-transporter based. Instead, cells show a high tendency to flocculate, suggesting cell surface alterations. Contact angle measurements demonstrate that the ΔlmrCD(r) cells are equipped with an increased cell surface ...[more]

PMID: 21335382

Similar Datasets

Project description:BackgroundCheese ripening is a complex, time consuming and expensive process, which involves the generation of precursors from carbohydrates, proteins and fats and their subsequent conversion into a wide range of compounds responsible for the flavour and texture of the cheese. This study aims to investigate production of cheese aroma compounds outside the cheese matrix that could be applied for instance as food supplements in dairy or non-dairy products.ResultsIn this study, aroma formation by a dairy Lactococcus lactis was analysed as a function of the growth medium [milk, hydrolysed micellar casein isolate (MCI) and chemically defined medium (CDM)] and the cultivation conditions (batch culture, retentostat culture and a milli-cheese model system). In the retentostat cultures, the nutrient supply was severely restricted resulting in low growth rates (~ 0.001 h-1), thereby mimicking cheese ripening conditions in which nutrients are scarce and bacteria hardly grow. In total 82 volatile organic compounds were produced by the bacteria. Despite the use of a chemically defined medium, retentostat cultures had the biggest qualitative overlap in aroma production with the milli-cheese model system (36 out of 54 compounds). In the retentostat cultures, 52 known cheese compounds were produced and several important cheese aroma compounds and/or compounds with a buttery or cheese-like aroma increased in retentostat cultures compared to batch cultures and milli-cheeses, such as esters, methyl ketones, diketones and unsaturated ketones. In cultures on CDM and MCI, free fatty acids and their corresponding degradation products were underrepresented compared to what was found in the milli-cheeses. Addition of a mixture of free fatty acids to CDM and MCI could help to enhance flavour formation in these media, thereby even better resembling flavour formation in cheese.ConclusionsThis study demonstrates that retentostat cultivation is the preferred method to produce cheese flavours outside the cheese matrix by mimicking the slow growth of bacteria during cheese ripening.

Dataset Information

Cholate-stimulated biofilm formation by Lactococcus lactis cells.

Publications

Cholate-stimulated biofilm formation by Lactococcus lactis cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets