Growth of Autobioluminescent Campylobacter jejuni in Response to Various Environmental Conditions

Abstract

An autobioluminescent Campylobacter jejuni organism generated from the fusion of luxCDABE genes from Xenorhabdus luminescens to the flaA promoter of C. jejuni was used in conjunction with gel-stabilized gradient plates to map the responses of this organism to three environmental factors (pH, NaCl concentration, and temperature) and various concentrations of l-fucose, d-fucose, and sodium desoxycholate. The minimum, optimum, and maximum temperatures for the growth of auto-bioluminescent C. jejuni ATCC 35921 in solid media were found to be 30, 40, and 45°C, respectively. At its optimum growth temperature, C. jejuni ATCC 35921 was able to grow well at pHs of 5.5 to 8.0 and in the presence of up to 1.70 to 1.75% NaCl. At its minimum growth temperature, however, C. jejuni ATCC 35921 could grow only at pHs of 6.5 to 8.0 and in the presence of up to 0.5% NaCl. l-Fucose, d-fucose, and sodium desoxycholate were shown to inhibit the growth of C. jejuni. Autobioluminescent C. jejuni was also used to determine whether the flaA promoter responds to both environmental conditions and chemical stimulants. While sodium desoxycholate was found to down-regulate C. jejuni flaA promoter activity, l-fucose was found to up-regulate its activity. Sodium chloride, pH, and d-fucose were all shown to exert no significant effects on promoter activity. Bacterial bioluminescence in combination with two-dimensional gradient gels is a powerful tool for studying the behavior of bacteria exposed to various environments.