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Titolo:
The acid-stress response in Lactobacillus sanfranciscensis CB1
Autore:
De Angelis, M; Bini, L; Pallini, V; Cocconcelli, PS; Gobbetti, M;
Indirizzi:
Univ Bari, Dipartimento Protez Piante & Microbiol Applicata, I-70126 Bari,Italy Univ Bari Bari Italy I-70126 e & Microbiol Applicata, I-70126 Bari,Italy Univ Perugia, Dipartimento Sci Alimenti, Sez Microbiol Agroalimentare, I-06126 Perugia, Italy Univ Perugia Perugia Italy I-06126 groalimentare, I-06126 Perugia, Italy Univ Siena, Dipartimento Biol Mol, I-53100 Siena, Italy Univ Siena SienaItaly I-53100 partimento Biol Mol, I-53100 Siena, Italy Univ Cattolica Sacro Cuore, Ist Microbiol, Piacenza, Italy Univ Cattolica Sacro Cuore Piacenza Italy st Microbiol, Piacenza, Italy
Titolo Testata:
MICROBIOLOGY-SGM
, volume: 147, anno: 2001,
parte:, 7
pagine: 1863 - 1873
SICI:
1350-0872(200107)147:<1863:TARILS>2.0.ZU;2-T
Fonte:
ISI
Lingua:
ENG
Soggetto:
IMMOBILIZED PH GRADIENTS; COMPLETE GENOME SEQUENCE; LACTIS SUBSP LACTIS; LACTOCOCCUS-LACTIS; BACILLUS-SUBTILIS; HEAT-SHOCK; LISTERIA-MONOCYTOGENES; POLYACRYLAMIDE GELS; TOLERANCE RESPONSE; PROTEIN;
Keywords:
lactic acid bacteria; acid-tolerant mutant; protein expression; sourdough;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
40
Recensione:
Indirizzi per estratti:
Indirizzo: Gobbetti, M Univ Bari, Dipartimento Protez Piante & Microbiol Applicata, Via G Amendola 165-A, I-70126 Bari, Italy Univ Bari Via G Amendola 165-A Bari Italy I-70126 Bari, Italy
Citazione:
M. De Angelis et al., "The acid-stress response in Lactobacillus sanfranciscensis CB1", MICROBI-SGM, 147, 2001, pp. 1863-1873

Abstract

Lactobacillus sanfranciscensis CB1, an important sourdough lactic acid bacterium, can withstand low ph after initial exposure to sublethal acidic conditions. The sensitivity to low ph varied according to the type of acid used. Treatment of Lb. sanfranciscensis CB1 with chloramphenicol during acid adaptation almost completely eliminated the protective effect, suggesting that induction of protein synthesis was required for the acid-tolerance response. Two constitutively acid-tolerant mutants, CB1-5R and CB1-7R, were isolated using natural selection techniques after sequential exposure to lacticacid (pH 3.2). Two-dimensional gel electrophoresis analysis of protein expression by non-adapted, acid-adapted and acid-tolerant mutant cells of Lk. sanfranciscensis showed changes in the levels of 63 proteins. While some ofthe modifications were common to the acid-adapted and acid-tolerant mutantcells, several differences, especially regarding the induced proteins, were determined. The two mutants showed a very similar level of protein expression. Antibodies were used to identify heat-shock proteins DnaJ, DnaK, GroES and GrpE. Only GrpE showed an increased level of expression in the acid-adapted and acid-tolerant mutants as compared with non-adapted cells. The N-terminal sequence was determined for two proteins, one induced in both the acid-adapted and mutant cells and the other showing the highest induction factor of those proteins specifically induced in the acid-adapted cells. This second protein has 60% identity with the N-terminal portion of YhaH, a transmembrane protein of Bacillus subtilis, which has 54 and 47% homology with stress proteins identified in Listeria monocytogenes and Bacillus halodurans. The constitutively acid-tolerant mutants showed other different phenotypic features compared to the parental strain: (i) the aminopeptidase activity of CB1-5R decreased and that of CB1-7R markedly increased, especially in acid conditions; (ii) the growth in culture medium at 10 degreesC and in the presence of 5% NaCl was greater (the same was found for acid-adapted cells); and (iii) the acidification rate during sourdough fermentation in acid conditions was faster and greater.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 30/11/20 alle ore 16:50:34