title: S-layer production by Lactobacillus acidophilus IBB 801 under environmental stress conditions.
abstract: The ability of microorganisms to synthesize S-layer, the outermost structure of the microbial cell envelope composed of non-covalently bound proteins, has been ascribed to help microorganisms to exert their probiotic properties in the host. In this work, formation of S-layer by the potentially probiotic strain Lactobacillus acidophilus IBB 801 under different stress culture conditions (high incubation temperatures, presence of bile salts or NaCl, and acidic pH) was assayed. A marked S-layer synthesis by L. acidophilus IBB 801 was detected when the strain was grown at 42 °C and in the presence of 0.05 % bile salts or 2.0 % NaCl. The presence of S-layer proteins was further confirmed by transmission electron microscopy and protein identification by MS/MS. The differential expression of the proteome of this strain at 42 °C, when a marked formation of S-layer was detected, revealed the overexpression of six proteins mainly related to general stress and protein biosynthesis and translation, while four proteins detected in lower amounts were involved in DNA repair and energy metabolism. As L. acidophilus IBB 801 produces both a bacteriocin and S-layer proteins, the strain could be of interest to be used in the formulation of functional food products with specific properties.
authors.affiliation: Institute of Biology Bucharest of the Romanian Academy, Splaiul Independentei No. 296, 060031, Bucharest, Romania.
authors.forename: Silvia-Simona
authors.initials: SS
authors.lastname: Grosu-Tudor
authors.affiliation: Centro de Referencia para Lactobacilos (CERELA)-CONICET, Chacabuco 145, 4000, San Miguel de Tucumán, Argentina.
authors.forename: Lucia
authors.initials: L
authors.lastname: Brown
authors.affiliation: Centro de Referencia para Lactobacilos (CERELA)-CONICET, Chacabuco 145, 4000, San Miguel de Tucumán, Argentina.
authors.forename: Elvira M
authors.initials: EM
authors.lastname: Hebert
authors.affiliation: Institute of Biology Bucharest of the Romanian Academy, Splaiul Independentei No. 296, 060031, Bucharest, Romania.
authors.forename: Aurelia
authors.initials: A
authors.lastname: Brezeanu
authors.affiliation: Institute of Biology Bucharest of the Romanian Academy, Splaiul Independentei No. 296, 060031, Bucharest, Romania.
authors.forename: Alexandru
authors.initials: A
authors.lastname: Brinzan
authors.affiliation: Centro de Referencia para Lactobacilos (CERELA)-CONICET, Chacabuco 145, 4000, San Miguel de Tucumán, Argentina.
authors.forename: Silvina
authors.initials: S
authors.lastname: Fadda
authors.affiliation: Centro de Referencia para Lactobacilos (CERELA)-CONICET, Chacabuco 145, 4000, San Miguel de Tucumán, Argentina.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Mozzi
authors.affiliation: Institute of Biology Bucharest of the Romanian Academy, Splaiul Independentei No. 296, 060031, Bucharest, Romania. medana.zamfir@ibiol.ro.
authors.forename: Medana
authors.initials: M
authors.lastname: Zamfir
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis*; D001430:Bacteriocins / Q000096:biosynthesis; D001647:Bile Acids and Salts / Q000737:chemistry; D003470:Culture Media / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology; D007779:Lactobacillus acidophilus / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D040901:Proteomics; D012965:Sodium Chloride / Q000737:chemistry; D013312:Stress, Physiological; D053719:Tandem Mass Spectrometry
chemical_list: D001426:Bacterial Proteins; D001430:Bacteriocins; D001647:Bile Acids and Salts; D003470:Culture Media; D008562:Membrane Glycoproteins; C055764:S-layer proteins; D012965:Sodium Chloride
keywords: Lactobacilli; Proteomics; S-layer proteins; Stress