FIG 3.
Effects of SCFA on in vitro growth phenotype of 7D and 8S strains. Cis-complemented csrABb strains lacking the 7 C-terminal residues (7D) or with 8 critical residues of CsrABb replaced with alanines (8S) were propagated with 0, 30, 60, or 90 mM sodium acetate (A), sodium propionate (B), or sodium butyrate (C) at pH 7.6 and 32°C. Motile spirochetes were enumerated every 12 h for a period of 156 h in triplicate by dark microscopy. Statistical significance in growth rates was determined between untreated and treated spirochetes using a two-way ANOVA with α of 95%.