Premium
Characterization of the binding capacity of mercurial species in Lactobacillus strains
Author(s) -
Alcántara Cristina,
JadánPiedra Carlos,
Vélez Dinoraz,
Devesa Vicenta,
Zúñiga Manuel,
Monedero Vicente
Publication year - 2017
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.8388
Subject(s) - lactobacillus casei , chemistry , mercury (programming language) , cell wall , lipoteichoic acid , biosorption , bacteria , lactobacillus , chelation , microbiology and biotechnology , food science , biochemistry , fermentation , biology , adsorption , organic chemistry , sorption , computer science , genetics , programming language , staphylococcus aureus
BACKGROUND Metal sequestration by bacteria has been proposed as a strategy to counteract metal contamination in foodstuffs. Lactobacilli can interact with metals, although studies with important foodborne metals such as inorganic [Hg( II )] or organic ( CH 3 Hg ) mercury are lacking. Lactobacilli were evaluated for their potential to bind these contaminants and the nature of the interaction was assessed by the use of metal competitors, chemical and enzymatical treatments, and mutants affected in the cell wall structure. RESULTS Lactobacillus strains efficiently bound Hg( II ) and CH 3 Hg . Mercury binding by Lactobacillus casei BL23 was independent of cell viability. In BL23 , both forms of mercury were cell wall bound. Their interaction was not inhibited by cations and it was resistant to chelating agents and protein digestion. Lactobacillus casei mutants affected in genes involved in the modulation of the negative charge of the cell wall anionic polymer lipoteichoic acid showed increased mercury biosorption. In these mutants, mercury toxicity was enhanced compared to wild‐type bacteria. These data suggest that lipoteichoic acid itself or the physicochemical characteristics that it confers to the cell wall play a major role in mercury complexation. CONCLUSION This is the first example of the biosorption of Hg( II ) and CH 3 Hg in lactobacilli and it represents a first step towards their possible use as agents for diminishing mercury bioaccessibility from food at the gastrointestinal tract. © 2017 Society of Chemical Industry