Effect of growth at low pH on the cell surface properties of a typical strain of Lactobacillus casei group
Abstract
Background and Objectives: Although members of the Lactobacillus casei group are known to survive under acidic conditions, the underlying mechanisms of growth at acidic condition and the impact of low pH on the relative level of protein expression at the cell surface remain poorly studied.
Material and Methods: After confirming the taxonomy of L. casei strain GCRL 12 which was originally isolated from cheese and confirmed by 16S rRNA sequence analysis, the impact of acidic pH on growth rate was determined.
Results: Late log-phase cells cultured at pH 4.0 showed obvious changes in Gram staining properties while transmission electron microscopy analysis revealed evidence of structural distortions of the cell surface relative to the controls cultured at pH 6.5. When comparing cytosolic or whole cell preparations on SDS-PAGE, few changes in protein profiles were observed under the two growth conditions. However, analysis of surface protein extracted by 5M LiCl demonstrated changes in the proportions of proteins present in the molecular weight range of 10 to 80 kDa, with some proteins more dominant at pH 6.5 and other at pH 4.
Conclusion: These data suggest that surface proteins of this strain are associated with growth and survival at low pH. The function of these proteins is subject to further investigation.
Hussain MA, Knight M, McDonagh M, Britz ML.Proteomics of Lactobacillus casei under starvation adaptation. Food Microbiol 2006 Bologna, Italy, p 82.
Lane DJ (1991). 16S/23S rRNA sequencing. In: Nucleic acid techniques in bacterial systematics. (E. Stackenbrandt and M. Goodfellow ed.), John Wiley and Sons, Chichester, England. pp. 115-176.
Pirt SJ (1975). Principles of microbe and cell cultivation.John Willey and Sons Inc, New York, NY 21.
McKay AL, Peters AC, Wimpenny JWT. Determining specific growth rates in different regions of Salmonella typhimurium colonies. Lett Appl Microbiol 1997; 24 (1):74-76.
Glauert AM, Lewis PR (1998). Biological specimen preparation for transmission electron microscopy. Princeton University Press, Princeton, N.J.
Lortal S, van Heijenoort J, Gruber K and Sleytr UB.S-layer of Lactobacillus helveticus ATCC 12046: Isolation, chemical characterization and re-formation after extraction with lithium chloride. Microbiology 1992; 138 (3): 611-618.
Laemmli UK. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 1970;227 (5259): 680-685.
Wilkins JC, Homer KA, Beighton D. Analysis of Streptococcus mutans proteins modulated by culture under acidic conditions. Appl Environ Microbiol 2002;68 (5): 2382-2390.
Amor BK, Vaughan EE, de Vo WM. Advanced molecular tools for the identification of lactic acid bacteria. J Nutr 2007; 137 (3): 741-747.
10. Felis GE, Dellaglio F. Taxonomy of lactobacilli and bifidobacteria. Curr Issues Intest Microbiol 2007; 8 (2):44-61.
Taranto MP, Perez-Martinez G, X de Valdez GF. Effect of bile acid on the cell membrane functionality of lactic acid bacteria for oral administration. Res Microbiol 2006; 157 (8): 720-725.
Piuri MC, Sanchez-Rivas C, Ruzal SM. Cell wall modifications during osmotic stress in Lactobacillus casei. J Appl Microbiol 2005; 98 (1): 84-95.
13. Prasad JP, McJarrow P, Gopal P. Heat and osmotic stress responses of probiotic Lactobacillus rhamnosus HN 001(DR 20) in relation to viability after drying. Appl Environ Microbiol 2003; 69 (2):917-925.
Turner MS, Hafner LM, Walsh T, Giffard PM.Peptide surface display and secretion using two LPXTG-containing surface proteins from Lactobacillus fermentum BR11. Appl Environ Microbiol 2003; 69 (10): 5855-5863.
Garrote GL, Delfederico L, Bibiloni R, Abraham AG, Fernando Pérez P, Semorile L, De Antoni GL. Lactobacilli isolated from kefir grains: evidence of the presence of S-layer proteins. J Dairy Res 2004;71 (2): 222-230.
Frece JB, Svetec, IK, Zgaga, Z, Mrša V, Suškovic J. Importance of S-layer proteins in probiotic activity of Lactobacillus acidophilus M92. J Appl Microbiol 2005; 98 (2): 285-292.
Morata De Ambrosini V, S. Gonzalez S, Pesce De Ruiz Holgado A, Oliver G. Cell wall sugars from strains used as starters for dairy products. Microbiol Aliment Nutr 1994; 12 (1): 17-21.
Murga MLF, Font de Valdez G, Disalvo AE.Changes in the surface potential of Lactobacillus acidophilus under freeze-thawing stress. Cryobiology 2000; 41 (1): 10-16.
Fozo EM, Kajfasz JK. Low pH-induced membrane fatty acid alterations in oral bacteria. FEMS Microbiol Lett 2004; 238 (2): 291-295.
Wall R, Fitzgerald G, Hussey S, Ryan T, Murphy B, Ross P, Stanton C. Genomic diversity of cultivable Lactobacillus populations residing in the neonatal and adult gastrointestinal tract. FEMS Microbiol Ecol 2007; 59 (1): 127-137.
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Issue | Vol 2 No 3 (2010) | |
Section | Articles | |
Keywords | ||
Lactobacillus casei transmission electron microscopy cell surface acidic condition SDS-PAGE |
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