화학공학소재연구정보센터
Applied Microbiology and Biotechnology, Vol.77, No.3, 637-643, 2007
Engineering the halophilic bacterium Halomonas elongata to produce beta-carotene
Engineering halophilic bacteria to produce carotenoids is a subject of great scientific and commercial interest, as carotenoids are desirable products used as additives and colorants in the food industry, with beta-carotene the most prominent. With this target, we expressed the beta-carotene biosynthetic genes crtE, crtY, crtI, and crtB from Pantoea agglomerans and the cDNA encoding isopentenyl pyrophosphate isomerase from Haematococcus pluvialis in the halophilic bacterium Halomonas elongata obtaining a strain able to produce practically pure beta-carotene. Reverse transcription-polymerase chain reaction analysis showed crtY, crtI, and crtB heterologous expression in a selected exconjugant of H. elongata. Biosynthesis of beta-carotene was dependent on NaCl concentration in the culture medium, with the highest production ( 560 g per g of dry weight) in 2% NaCl. On the contrary, no beta-carotene was detected in 15% NaCl. Successful construction of the beta-carotene biosynthetic pathway in H. elongata opens the possibility of engineering halophilic bacteria for carotenoid production.