Carbon dioxide can inhibit biofilms formation and cellular properties of Shewanella putrefaciens at both 30 °C and 4 °C.

[Display omitted] • The dynamic formation process of S. putrefaciens biofilms was delayed by CO 2. • CO 2 did not damage the cell integrity. • The cellular surface characteristics were inhibited by CO 2. • The cellular metabolic properties were inhibited by CO 2. Shewanella putrefaciens (S. putrefaciens), which is a common specific spoilage organism (SSO) of marine fish, has strong spoilage ability even under low-temperature conditions. Carbon dioxide (CO 2) was widely applied to control microorganisms in aquatic products package. To explore the regulation mechanism of CO 2 on biofilm formation and cell properties of S. putrefaciens , the dynamic formation process of biofilms, cellular surface properties, and cellular metabolic characteristics of S. putrefaciens at both 30 °C and 4 °C in pure CO 2 gas were evaluated. As evidenced by the crystal violet staining method, confocal laser scanning microscopy (CLSM) analysis, and field emission scanning electron microscopy (FESEM) observation, dynamic formation process of S. putrefaciens biofilms was apparently delayed by CO 2 with integral cellular morphology. The number and viability of sessile cells in S. putrefaciens biofilms was significantly lower than those in normal air composition. The changes in cellular surface properties, such as decreased auto-aggregation and hydrophobicity, might be one of the reasons why biofilms were inhibited by CO 2. Inhibition of swimming and swarming motility ability by CO 2 could also be observed with significantly shorter bacterial halo diameter. What's more, cellular metabolism was significantly decreased by CO 2 according to the results of ATP content, ATPase activity and extracellular proteolytic activity. The influence of CO 2 could be both observed whether combined with 30 °C or 4 °C. However, the inhibition produced by CO 2 was more pronounced at the incubation temperature of 4 °C. In summary, it could be concluded that the dynamic formation process of S. putrefaciens biofilms and cellular metabolic properties could be inhibited by CO 2. This research provided a theoretical basis for better application of CO 2 to regulate spoilage microorganisms. [ABSTRACT FROM AUTHOR]