Life Science Journal 2013;10(3) http://www.lifesciencesite.com 1904 Cloning, sequencing and expressing of the carotenoid biosynthesis genes of ß-carotene from epiphytic bacteria Erwinia uredovora in non carotenogenic bacteria E. coli. Hany M. Yehia 1 , Alaeldein M. Abudabos 2 , Manal F. Elkhadragy 3 , Ebtesam M. Al- Olayan 3 , Abd-El-Rahman M. Khalaf- Allah 4 and Nagwa M. El-Shimi 4 1 Department of Food Science and Nutrition, College of Food and Agriculture Sciences, King Saud University, P.O. Box 2460, Riyadh, 11451, Kingdom of Saudi Arabia 2 Department of Animal Production, College of Food and Agriculture Sciences, King Saud University, P.O. Box 2460, Riyadh, 11451, Kingdom of Saudi Arabia 3 Department of Zoology, College of Science, King Saud University, P.O. Box 22452, Riyadh 11495, Kingdom of Saudi Arabia 4 Department of Food Science and Technology, Faculty of Agriculture, Cairo University Corresponding author email: hanyehia@ksu.edu.sa , hanyyehuia43@yahoo.de Abstract: Four genes which encode the enzymes of ß-carotene in the epiphytic bacteria Erwinia uredovora have been designated as crtE, crtB, crtI and crtY. These genes were cloned in Eschershia coli BL21 and located on a 4467-bp fragment whose nuclotide sequence was determined. E. coli does not naturally synthesize carotenoids but, by using the carotenogenic genes recombinant strains accumulated ß-carotene where the four genes were expressed as follows: farnesyl diphosphate (FPP) crtE geranylgeranyl diphosphate (GGPP) crtB phytoene crtI lycopene crtY ß-carotene. E. coli BL21 acquired the yellow pigments due to the prescence of ß-carotene after transformed by pGEX-5X-3-crtEBIY. [Hany M. Yehia, Alaeldein M. Abudabos, Manal F. Elkhadragy, Ebtesam M. Al- Olayan, Abd-El-Rahman M. Khalaf- Allah and Nagwa M. El-Shimi. Cloning, sequencing and expressing of the carotenoid biosynthesis genes of ß-carotene from epiphytic bacteria Erwinia uredovora in non carotenogenic bacteria E. coli. Life Sci J 2013; 10(3): 1904-1917] (ISSN: 1097-8135). http://www.lifesciencesite.com . 283 Key Words: Erwinia uredovora, carotenoid genes, Eschershia coli BL21. Introduction: 1. Introduction Recent developments in the molecular biology of carotenoid biosynthetic from organisms that accumulate different carotenoid product have been provided a variety of genes (Sandmann, 1994) that can be employed as a tool for new strategy of heterologous expression in different host organisms. This strategy was used by different researchers to synthesis carotenoid pigments in microorganisms that cannot produce carotenoid naturally such as bacteria (Escherishia coli) and yeasts as (Saccharomyces and Candida). This strategy only works, however, when the substrate specifity of the enzyme is such that does not need to recognize the entire substrate molecule but only certain regions of it that are suitable for conversion. Genes controlling the synthesis of these pigments have been studied in several organisms such as Erwinia species (Misawa et al. 1990), (Perry et al. 1986, and Schnurr et al. 1996), Mycobacterium auraum (Hossaini-Iraqui et al. 1992), Viveiros et al. 2000), Xanthophylomyces drorhous (Verdoes et al. 1999) and Brevibacterium linens (Krubasik and Sandmann, 2000). The aim of metabolic engineering is defined as the purposeful modification networks in living cells to produce desirable chemicals with superior yield and productivity by using recombinant DNA technologies (Bailey, 1991) and (Stephanopoulos, 1994). Its main field should be investigations undertaken to produce chemicals interest efficiently and abundantly by using appropriate microorganisms (Ikeda and Katsumata, 1992). It has traditionally been postulated that microbes naturally synthesizing desirable chemicals should be used as hosts. However, the use of suitable microorganisms which have the ability to produce the precursor for desirable chemicals with superior yield and high levels of productivity is also feasible (Miura et al. 1998). This notion significantly extends the range of microbes used as productive hosts. In order to achieve these objectives, three main research approaches are usually employed (i) introducing exogenous genes which convert the final precursor of host organism to a desirable chemical, at a viable yield; (ii) enhancing the metabolic final precursor (this may, for example, be achieved by amplifying rate limiting reactions or eliminating mechanisms feedback inhibition; and (iii) increasing precursor by minimzing metabolic flow to biosynthetically related products (Shimada et al. 1998). Gene clusters responsible for the synthesis of carotenoids have been isolated from various carotenogenic bacteria including Erwinia species and