Comparison of protein patterns ofListeria monocytogenesgrown in biofilm or in planktonic mode by proteomic analysis

Abstract

The proteome of a Listeria monocytogenes strain isolated from a food plant was investigated to study the differential protein pattern expressed by biofilms and planktonic bacteria. The approach used in this study was a combination of two-dimensional electrophoresis, matrix-assisted laser desorption ionization-time of flight and database searches for the protein identification. Thirty-one proteins varied significantly between the two growth conditions. Twenty-two and nine proteins were up- and down-regulated respectively and nine proteins were successfully identified. The variations of the protein patterns indicated that the biofilm development is probably controlled by specific regulation of protein expression involved at various levels of cellular physiology.

The Expression of Superoxide Dismutase (SOD) and a Putative ABC Transporter Permease Is Inversely Correlated during Biofilm Formation in Listeria monocytogenes 4b G

“…The high expression of SOD in Δ 1771 mutant may help biofilm formation because the induction of sod was only present in biofilm cells and not in planktonic cells. Since oxidative stress influences biofilm formation, the denser biofilms in Δ 1771 may produce more oxidative stress than the wild-type, indicating that the up-regulation of the sod gene is needed to cope with oxidative stress, as described by Tremoulet et al [16]. This hypothesis was confirmed by the fact that the Δsod mutant produced more ROS than the wild-type, and thereby exhibited the reduced ability in biofilm formation.…”

“…Total protein of strains were prepared using the procedure of Tremoulet et al [16]. The protein concentration was determined by the Bio-Rad protein estimation kit with bovine serum albumin as the standard (Bio-Rad, Hercules, CA).…”

“…These defense systems include: (i) genes that scavenge reactive oxygen, such as superoxide dismutases ( sod ) and catalases ( kat ), (ii) stress regulators that regulate some antioxidant genes expression, such as perR and sigB , and (iii) DNA repair genes that repair damaged DNA, such as recA . The function of these genes has been studied in L. monocytogenes , and it was found that some genes ( sod , sigB and recA ) were induced in biofilm formation [16], [17], [18].…”

“…There are three sod genes in Escherichia coli , biofilm formation is significantly reduced in a sodC (CuZnSOD)-deleted mutant of E.coli O157:H7 [22]; only one SOD (MnSOD) is present in L. monocytogenes [23]. Proteomic analysis showed that in L. monocytogenes SOD was up-regulated in biofilms versus planktonic cells [16]. Thus, we speculate that SOD plays an important role in the biofilm formation of L. monocytogenes .…”

Susceptibility ofListeria monocytogenesBiofilms and Planktonic Cultures to Hydrogen Peroxide in Food Processing Environments

“…Biofilms were prepared as previously described, with a slight modification. 12) Autoclaved extrathick glass-fiber filters (GFFs) 25 mm in diameter (Pall Life Science, Ann Arbor, MI, USA) were used for culturing the biofilms. A sterile GFF was inoculated with 500 mL of the bacterial suspension (ca.…”