Kin discrimination drives territorial exclusion during Bacillus subtilis swarming and restrains exploitation of surfactin

Kraigher, Barbara (author), Butolen, Monika (author), Štefanič, Polonca (author), Mandić-Mulec, Ines (author)

Swarming is the collective movement of bacteria across a surface. It requires the production of surfactants (public goods) to overcome surface tension and provides an excellent model to investigate bacterial cooperation. Previously, we correlated swarm interaction phenotypes with kin discrimination between B. subtilis soil isolates, by showing that less related strains form boundaries between swarms and highly related strains merge. However, how kin discrimination affects cooperation and territoriality in swarming bacteria remains little explored. Here we show that the pattern of surface colonization by swarming mixtures is influenced by kin types. Closely related strain mixtures colonize the surface in a mixed swarm, while mixtures of less related strains show competitive exclusion as only one strain colonizes the surface. The outcome of nonkin swarm expansion depends on the initial ratio of the competing strains, indicating positive frequency-dependent competition. We find that addition of surfactin (a public good excreted from cells) can complement the swarming defect of nonkin mutants, whereas close encounters in nonkin mixtures lead to territorial exclusion, which limits the exploitation of surfactin by nonkin nonproducers. The work suggests that kin discrimination driven competitive territorial exclusion may be an important determinant for the success of cooperative surface colonization.

• Language: English
• Keywords: Bacillus subtilis, swaraming, social interactions, surfactin, biofilms, microbial ecology
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2022
• Number of pages: Str. 833–841
• Numbering: Vol. 16, iss. 3
• PID: 20.500.12556/RUL-135330
• UDC: 579.22/.26:579.852.11
• ISSN on article: 1751-7362
• DOI: 10.1038/s41396-021-01124-4
• COBISS.SI-ID: 80968963
• Publication date in RUL: 08.03.2022

Record is a part of a journal

• Title: The ISME journal
• Shortened title: ISME j.
• Publisher: Springer Nature, International Society for Microbial Ecology
• ISSN: 1751-7362
• COBISS.SI-ID: 513948953

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: Bacillus subtilis, rojenje, socialne interakcije, surfaktin