Carotenoid accumulation in the psychrotrophic bacterium Arthrobacter agilis in response to thermal and salt stress.
A psychrotrophic strain of Arthrobacter agilis, isolated from Antarctic sea ice, grows from 5 degrees C to 40 degrees C and in culture media containing 0-10% (w/v) NaCl. Maximum growth rate occurred at 30-35 degrees C with a drastic decline as the cultivation temperatures diverged. Adaptation to extremes of low temperature may be partially attributed to the production of the C-50 carotenoid bacterioruberin, and its glycosylated derivatives. Lowering of the cultivation temperature resulted in a concomitant increase in carotenoid production, which may contribute to membrane stabilisation at low temperature. Maximum biomass accumulation occurred at 5-30 degrees C with a tenfold reduction at 40 degrees C. Changes in growth rates were minimal in culture media containing 0-2% (w/v) NaCl at 10 degrees C while a gradual decrease in growth rates occurred at higher salinity. Biomass accumulation at different salinity followed a trend similar to that observed with different cultivation temperatures. Maximum biomass accumulation was observed in culture media containing 0-5% (w/v) NaCl with a tenfold reduction at 10% (w/v) NaCl. Carotenoid production also decreased as salinity increased.
Fong
N J
NJ
CRC for Food Industry Innovation, University of New South Wales, Sydney, Australia.
Burgess
M L
ML
Barrow
K D
KD
Glenn
D R
DR
D001173:Arthrobacter / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism* / Q000502:physiology; D018533:Biomass; D002338:Carotenoids / Q000737:chemistry / Q000378:metabolism*; D003080:Cold Temperature; D003470:Culture Media; D012965:Sodium Chloride / Q000494:pharmacology*
D003470:Culture Media; D002338:Carotenoids; D012965:Sodium Chloride