Novel two-component regulatory systems play a role in biofilm formation of Lactobacillus reuteri rodent isolate 100-23

Abstract

This study characterized the two-component regulatory systems encoded by bfrKRT and cemAKR, and assessed their influence on biofilm formation by Lactobacillus reuteri 100-23. A method for deletion of multiple genes was employed to disrupt the genetic loci of two-component systems. The operons bfrKRT and cemAKR showed complementary organization. Genes bfrKRT encode a histidine kinase, a response regulator and an ATP-binding cassette-type transporter with a bacteriocin-processing peptidase domain, respectively. Genes cemAKR code for a signal peptide, a histidine kinase and a response regulator, respectively. Deletion of single or multiple genes in the operons bfrKRT and cemAKR did not affect cell morphology, growth or the sensitivity to various stressors. However, gene disruption affected biofilm formation; this effect was dependent on the carbon source. Deletion of bfrK or cemA increased sucrose-dependent biofilm formation in vitro. Glucose-dependent biofilm formation was particularly increased by deletion of cemK. The expression of cemK and cemR was altered by deletion of bfrK, indicating cross-talk between these two regulatory systems. These results may contribute to our understanding of the genetic factors related to the biofilm formation and competitiveness of L. reuteri in intestinal ecosystems.

Enhanced Probiotic Potential of Lactobacillus reuteri When Delivered as a Biofilm on Dextranomer Microspheres That Contain Beneficial Cargo

“…Indeed, failure of sucrose to affect L. reuteri adherence to CMs (cross-linked glucan with variant glycosidic linkages) supports this notion. Sucrose-dependent biofilm formation has previously been linked to two-component regulatory systems in the rodent strain 100-23 of L. reuteri (Frese et al, 2011; Su and Ganzle, 2014); however, the genes necessary for this phenomenon appear to be absent in the human-derived strain of L. reuteri used in this study (23272/DSM 20016). Since sucrose is a preferred carbon source of the L. reuteri used in this study via its sucrose phophorylase mediated metabolism (Ganzle and Follador, 2012) it was not surprising that sucrose had a positive impact on biofilm formation and increased adherence to DMs and is likely due to the increased doubling time of L. reuteri in the presence of sucrose.…”

Biofilm Forming Lactobacillus: New Challenges for the Development of Probiotics

“…The suppression of bfrK or cemA genes improved in vitro biofilm formation in a saccharose dependent fashion. Glucose dependent biofilm formation was particularly enhanced by cemK suppression [ 71 ].…”

Signaling between two interacting sensor kinases promotes biofilms and colonization by a bacterial symbiont

“…One developmental process in bacteria that is often governed by TCS circuits is the formation of biofilms, or matrix‐encased communities of cells (Hamon and Lazazzera, ; Li et al ., ; Ferrieres and Clarke, ; Irie et al ., ; Zhang et al ., ; Gooderham and Hancock, ; Petrova and Sauer, ; Huang et al ., ; Stipp et al ., ; Su and Ganzle, ). It is believed that environmental signals can activate or deactivate specific TCS pathways to disfavor the independent, planktonic state and favor the assembly of a community (Ventre et al ., ; McLoon et al ., ; Mulcahy and Lewenza, ).…”