Cell wall associated protein TasA provides an initial binding component to extracellular polysaccharides in dual-species biofilm

Danielle Duanis-Assaf, Tal Duanis-Assaf, Guanghong Zeng, Rikke Louise Meyer, Meital Reches, Doron Steinberg, Moshe Shemesh*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


Many bacteria in biofilm surround themselves by an extracellular matrix composed mainly of extracellular polysaccharide (EP), proteins such as amyloid-like fibers (ALF) and nucleic acids. While the importance of EP in attachment and acceleration of biofilm by a number of different bacterial species is well established, the contribution of ALF to attachment in multispecies biofilm remains unknown. The study presented here aimed to investigate the role of TasA, a precursor for ALF, in cell-cell interactions in dual-species biofilms of Bacillus subtilis and Streptococcus mutans. Expression of major B. subtilis matrix operons was significantly up-regulated in the presence of S. mutans during different stages of biofilm formation, suggesting that the two species interacted and modulated gene expression in each other. Wild-type B. subtilis expressing TasA adhered strongly to S. mutans biofilm, while a TasA-deficient mutant was less adhesive and consequently less abundant in the dual-species biofilm. Dextran, a biofilm polysaccharide, induced aggregation of B. subtilis and stimulated adhesion to S. mutans biofilms. This effect was only observed in the wild-type strain, suggesting that interactions between TasA and dextran-associated EP plays an important role in inter-species interactions during initial stages of multispecies biofilm development.

Original languageAmerican English
Article number9350
JournalScientific Reports
Issue number1
StatePublished - 1 Dec 2018

Bibliographical note

Funding Information:
This report forms contribution No. 790/17-E, 2017 Series, from the Agricultural Research Organization, the Volcani Center, Rishon LeZion, Israel. This study forms part of Danielle Duanis-Assaf’s Ph.D. project. This work was partially supported by the COST ACTION FA1202 BacFoodNet. Danielle Duanis-Assaf is a recipient of Scholarship of Excellency for outstanding Ph.D. students from The ARO. We would like to thank Dr. Y. Chai of Northeastern University, Boston, USA for B. subtilis strains. We are also grateful to Dr. Mark Tarshish of the Hebrew University for excellent technical assistance with confocal microscopy.

Publisher Copyright:
© 2018 The Author(s).


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