Exopolysaccharides Play a Role in the Swarming of the Benthic Bacterium Pseudoalteromonas sp. SM9913.
Most marine bacteria secrete exopolysaccharide (EPS), which is important for bacterial survival in the marine environment. However, it is still unclear whether the self-secreted EPS is involved in marine bacterial motility. Here we studied the role of EPS in the lateral flagella-driven swarming motility of benthic bacterium Pseudoalteromonas sp. SM9913 (SM9913) by a comparison of wild SM9913 and ΔepsT, an EPS synthesis defective mutant. Reduction of EPS production in ΔepsT did not affect the growth rate or the swimming motility, but significantly decreased the swarming motility on a swarming plate, suggesting that the EPS may play a role in SM9913 swarming. However, the expression and assembly of lateral flagella in ΔepsT were not affected. Instead, ΔepsT had a different swarming behavior from wild SM9913. The swarming of ΔepsT did not have an obvious rapid swarming period, and its rate became much lower than that of wild SM9913 after 35 h incubation. An addition of surfactin or SM9913 EPS on the surface of the swarming plate could rescue the swarming level. These results indicate that the self-secreted EPS is required for the swarming of SM9913. This study widens our understanding of the function of the EPS of benthic bacteria.
Marine and Agricultural Biotechnology Laboratory, State Key Laboratory of Microbial Technology, Shandong UniversityJinan, China; Marine Biotechnology Research CenterJinan, China.
Ang
A
Liu
Marine and Agricultural Biotechnology Laboratory, State Key Laboratory of Microbial Technology, Shandong UniversityJinan, China; Marine Biotechnology Research CenterJinan, China.
Zi-Hao
ZH
Mi
Marine and Agricultural Biotechnology Laboratory, State Key Laboratory of Microbial Technology, Shandong UniversityJinan, China; Marine Biotechnology Research CenterJinan, China.
Xiao-Yu
XY
Zheng
Marine and Agricultural Biotechnology Laboratory, State Key Laboratory of Microbial Technology, Shandong UniversityJinan, China; Marine Biotechnology Research CenterJinan, China.
Yang
Y
Yu
Marine and Agricultural Biotechnology Laboratory, State Key Laboratory of Microbial Technology, Shandong UniversityJinan, China; Marine Biotechnology Research CenterJinan, China.
Hai-Nan
HN
Su
Marine and Agricultural Biotechnology Laboratory, State Key Laboratory of Microbial Technology, Shandong UniversityJinan, China; Marine Biotechnology Research CenterJinan, China.
Xiu-Lan
XL
Chen
Marine and Agricultural Biotechnology Laboratory, State Key Laboratory of Microbial Technology, Shandong UniversityJinan, China; Marine Biotechnology Research CenterJinan, China.
Bin-Bin
BB
Xie
Marine and Agricultural Biotechnology Laboratory, State Key Laboratory of Microbial Technology, Shandong UniversityJinan, China; Marine Biotechnology Research CenterJinan, China.
Bai-Cheng
BC
Zhou
Marine and Agricultural Biotechnology Laboratory, State Key Laboratory of Microbial Technology, Shandong UniversityJinan, China; Marine Biotechnology Research CenterJinan, China.
Yu-Zhong
YZ
Zhang
Marine and Agricultural Biotechnology Laboratory, State Key Laboratory of Microbial Technology, Shandong UniversityJinan, China; Marine Biotechnology Research CenterJinan, China.
Qi-Long
QL
Qin
benthic bacteria; exopolysaccharide; flagella; marine sediment; swarming