Influence of Temperature of Incubation and Type of Growth Medium on Pigmentation inSerratia marcescens

Abstract

Maximal amounts of prodigiosin were synthesized in either minimal or complete medium after incubation of cultures at 27 C for 7 days. Biosynthesis of prodigiosin began earlier and the range of temperature for formation was greater in complete medium. No prodigiosin was formed in either medium when cultures were incubated at 38 C; however, after a shift to 27 C, pigmentation ensued, provided the period of incubation at 38 C was not longer than 36 hr for minimal medium or 48 hr for complete medium. Washed, nonpigmented cells grown in either medium at 38 C for 72 hr could synthesize prodigiosin when suspended in saline at 27 C when casein hydrolysate was added. These suspensions produced less prodigiosin at a slower rate than did cultures growing in casein hydrolysate at 27 C without prior incubation at 38 C. Optimal concentration of casein hydrolysate for pigment formation by suspensions was 0.4%; optimal temperature was 27 C. Anaerobic incubation, shift back to 38 C, killing cells by heating, or chloramphenicol (25 gg/ml) inhibited pigmentation. Suspensions of washed cells forming pigment reached pH 8.0 to 8.3 rapidly and maintained this pH throughout incubation for 7 days. Measurements of viable count and of protein, plus other data, indicated that cellular multiplication did not occur in suspensions of washed cells during pigment formation. By this procedure utilizing a shift down in temperature, biosynthesis of prodigiosin by washed cells could be separated from multiplication of bacteria.

Towards an understanding of bacterial metabolites prodigiosin and violacein and their potential for use in commercial sunscreens

“…Synthesis of pigments occurs independently of light levels, as well as in the dark [4]. Prodigiosin has lytic activity towards the dinoflagellate Cochlodinium polykrikoides [6] and is also inhibitory to a number of Grampositive bacteria and fungal pathogens [8] Serratia marcescens Soils, water, aerosols, foods, and in association with plants and animals [23] Halotolerant: growth occurs up to 8% (w/v) NaCl, and from 0 to 44°C and pH 5-11 [23][24][25]. The Gram-negative, rod-shaped cells are facultatively anaerobic and motile.…”

The effect of pH on prodigiosin production by non-proliferating cells of Serratia marcescens

“…1983) and localized in vesicles (Matsuyama et al 1986), and the cell envelope seems to be necessary as a physical site for its biosynthesis (Hubert et al 1969). Prodigiosin is a secondary metabolite and many factors have been shown to affect the production of the pigment: medium composition (Kobayashi 1981), incubation temperature (Williams et al 1971a) and oxygen supply (Heinemann ef al. 1970).…”

“…Cultures of Ser. marcescens are unable to synthesize prodigiosin when the incubation temperature is 37°C or higher (Williams et al 1971a). However, if these non-pigmented bacteria are washed and suspended in saline at 27"C, formation of prodigiosin can be induced by the addition of certain aminoacids (Williams et al 1971b).…”

Clinical relevance and virulence factors of pigmented Serratia marcescens

“…All S. marcescens were grown in liquid medium [4] containing 1.0% glycerol, 0.5% ammonium citrate, 0.05% magnesium sulfate, 1.0% potassium phosphate, 0.5% sodium chloride, 0.005% ferric ammonium citrate, 0.1% yeast extract (Difco, Detroit, MI, USA) and 0.2% peptone (Difco). The tubes were incubated at 27³C without shaking and observed for up to 7 days for pigment formation.…”

“…Factors, such as medium composition [2] and oxygen supply [3], a¡ect the production of prodigiosin and the incubation at 37³C may inhibit the pigmentation [4].…”