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 microg 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.
Rodríguez-Sáiz
Marta
M
R&D Biology, Antibióticos S. A., Avenida de Antibióticos 59-61, 24009, León, Spain.
Sánchez-Porro
Cristina
C
De La Fuente
Juan Luis
JL
Mellado
Encarnación
E
Barredo
José Luis
JL
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005818:Genetic Engineering; D005822:Genetic Vectors; D020632:Halomonas / Q000235:genetics* / Q000378:metabolism; D019207:beta Carotene / Q000096:biosynthesis* / Q000235:genetics
D001426:Bacterial Proteins; D019207:beta Carotene