Expression of novel carotenoid biosynthesis genes from Enterococcus gilvus improves the multistress tolerance of Lactococcus lactis

Abstract

Aims: To determine whether the carotenoid production improves stress tolerance of lactic acid bacteria, the cloned enterococcal carotenoid biosynthesis genes were expressed in Lactococcus lactis ssp. cremoris MG1363, and the survival rate of carotenoid-producing engineered MG1363 strain under stress condition was investigated. Methods and Results: We cloned carotenoid biosynthesis genes from yellowpigmented Enterococcus gilvus. The cloned genes consisted of crtN and crtM and its promoter region were inserted into the shuttle vector pRH100, and the resulting plasmid was named pRC. The cloned crtNM was expressed using pRC in noncarotenoid-producing L.

Aerobic condition increases carotenoid production associated with oxidative stress tolerance inEnterococcus gilvus

“…The absorption maxima of purified pigments extracted from E . gilvus grown under aerobic condition for 10 h were at 412, 434.5, and 464 nm; these values are identical to those previously reported for 4,4'‐diaponeurosporene (412, 434.5 and 464 nm) (Hagi et al ., ).…”

“…The yellow pigments of E . gilvus were extracted and purified as previously described (Hagi et al ., ). In brief, the cultures of E .…”

“…H 2 O 2 treatment test was performed as previously reported with some modification (Hagi et al ., ). Enterococcus gilvus cultures (1 mL each; OD 600 nm = c .…”

“…Furthermore, we found that carotenoid production significantly increased the tolerance to oxidative stress in L . lactis MG1363 (Hagi et al ., ). These results indicated that 4,4'‐diaponeurosporene in LAB is related to a stress tolerance mechanism in common with other antioxidants, such as superoxide dismutase and glutathione reductase, implying that carotenoid production may be regulated by stress responses.…”

Tolerance of an Antarctic Bacterium to Multiple Environmental Stressors

“…The possible role of the Htp G protein in tolerance of a cyanobacterial strain to high temperature, low temperature and oxidative stress was demonstrated earlier [7]. The involvement of a C 30 -carotenoid in the tolerance of Lactococcus lactis to low pH, oxidative stress, bile acid and lysozyme was evidenced some time back [6]. These multistress-combatants could be useful for constructing sturdy strains suitable for bioremediation in harsh environments through genetic engineering.…”