Volume 6(5): 286-294 (2014) - 286 J Microb Biochem Technol ISSN: 1948-5948 JMBT, an open access journal Research Article Open Access Hamidi et al., J Microb Biochem Technol 2014, 6:5 http://dx.doi.org/10.4172/1948-5948.1000158 Research Article Open Access Microbial & Biochemical Technology *Corresponding authors: Mohammad Saeid Hejazi, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran, Tel: +98 (411) 337 2256; Fax: +98 (411) 334 4798; E-mail: msaeidhejazi@yahoo.com, saeidhejazi@tbzmed.ac.ir Mohammad Amin Hejazi, West & Northwest Agricultural Biotechnology Research Institute of Iran (ABRII), Tabriz, Iran, Tel: +98 (411) 5156915-598; Fax: +98 (411) 3321615; Email: aminhejazi@yahoo.com Received April 17, 2014; Accepted June 16, 2014; Published June 23, 2014 Citation: Hamidi M, Abdin MZ, Nazemyieh H, Hejazi MA, Hejazi MS (2014) Optimization of Total Carotenoid Production by Halorubrum Sp. TBZ126 Using Response Surface Methodology. J Microb Biochem Technol 6: 286-294. doi:10.4172/1948-5948.1000158 Copyright: © 2014 Hamidi M, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited Abstract Carotenoids are one of the most diverse and broadly distributed classes of pigments in nature with a high number of biotechnological applications. Carotenoids have a broad range of functions, especially in relation to human health and their role as biological antioxidants. The increasing demand for consumption of natural carotenoids has raised interest in their bio-production. The objective of the present study was the analysis of environmental factors (temperature, pH and salinity) through response surface methodology (RSM) on the total carotenoid production of Halorubrum sp. TBZ126. In addition the effect of light was evaluated. Five levels of temperature, pH, and salinity were selected based on central composite design (CCD) and RSM to reach the optimum values for the cell growth and carotenoid production. Bio-production was carried out in an orbital shaker using a 10% (v/v) inoculum, and agitation at 120 rpm for 9 days in a non-illuminated environment. Dry cell weight was determined and total carotenoid was estimated by spectrophotometer. The production of biomass ranged from 0.04 to 0.84 g/l and the total carotenoid from 0.15 to 10.78 mg/l. The optimum conditions for cell growth and total carotenoid production in Halorubrum sp. TBZ126 cultures, were temperature 31ºC and 32ºC, pH 7.51 and 7.94 and NaCl (w/v) 18.33% and 20.55%, respectively. In conclusion, employing RSM design and under the light exposure as an inducing factor, carotenoid production by Halorubrum sp. TBZ126 was elevated by 45%. Additionally, TBZ126 could produce carotenoids at lower concentrations of NaCl (as low as 2.5%), in the absence of sodium acetate without elevating magnesium sulfate concentration. Optimization of Total Carotenoid Production by Halorubrum Sp. TBZ126 Using Response Surface Methodology Masoud Hamidi 1,2 , Malik Zainul Abdin 3 , Hossein Nazemyieh 1 , Mohammad Amin Hejazi 4 * and Mohammad Saeid Hejazi 1,5 * 1 Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran 2 Students’ Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran 3 Centre for Transgenic Plant Development, Department of Biotechnology, Faculty of Science, Jamia Hamdard (Hamdard University), New Delhi, India 4 West and Northwest Agricultural Biotechnology Research Institute of Iran (ABRII), Iran 5 Faculty of Advanced Biomedical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran Keywords: Carotenoid; Halorubrum; Light; Optimization; Salinity; Temperature Introduction Carotenoids are natural pigments synthesized by bacteria, fungi, algae, and plants, and more than 750 diferent carotenoids have been isolated from natural sources [1]. hese pigments are generally hydrophobic compounds which will therefore have a tendency to be associated with lipid or in hydrophobic structure such as membranes. Animals cannot synthesize carotenoids, so their presence is due to dietary intake [2]. Carotenoids are important as nutraceutical compounds and natural lipophilic antioxidants. he antioxidative potential of carotenoids depends on their chemical properties, such as the number of conjugated double bonds, structural end groups, and oxygen-containing substituents [3]. he demand and market for carotenoids is anticipated to change with the discovery that carotenoids exhibit tumor suppressing activity and play an important role in the prevention of chronic diseases. In addition to their antioxidant properties, a number of unexpected biological efects of carotenoids, for example, in junctional communication and gene regulation, have been recently discovered and attributed to their tumor suppressing activity boosting the interest in evaluating the pharmaceutical potential of carotenoids [4]. he commercial demand of carotenoids is mainly met by chemical synthesis and to a minor extent by extraction from natural sources [3]. Food (i.e., plants or food processing wastes) and microorganisms are examples of carotenoids’ natural sources. Unlike microorganisms, the production of carotenoids from food has many disadvantages, such as season luctuation, limited resources, competition with the food industry, and requirement of land beside complicated extraction and puriication process. For instance, the carotenoids produced from plants contain mixtures of carotenoids, fats, oils, waxes, and unsaponiiable compounds. Microbial carotenoids are cell-bound pigments that are produced inside the cells and do not difuse in the agar. Carotenoids give the microbial colonies their distinctive color (i.e., yellow, orange, pink, or red) [5]. Several algae (Dunaliella, Dictyococcus and Haematococcus), bacteria (many species of eubacteria in addition to halobacteria in archaebacteria), some ilamentous fungi (belong to lower fungi and Ascomycetes) and yeasts (Cryptococcus, Phaia, Rhodosporidium, Rhodotorula, Sporidiobolus, and Sporobolomyces) are reported to produce carotenoids [6]. Nevertheless, the microbial production of carotenoids is still awaiting lot of challenges to reduce cost and simultaneously increase productivity possibly by increasing biomass production and/or carotenoid synthesis, for example by selecting a strain that grows fast, accumulates high amount of carotenoids, facilitates the extraction and puriication processes of carotenoids, and has a lower cost production [5].