Carotenoid pigments are the most important and abundant of natural Carotenoids. In this respect, only plants and microorganisms are capable of Carotenoid formation. These compounds because of their staining property and relative stability have widespread use as an antioxidant in industries, especially food manufacturing. Carotenoids are the main precursors of vitamin A in human body and therefore, it is needed to add them foodstuffs. The yeast Rhodotorula is one of the chief Carotenoid-forming microorganisms. The majority of its species can produce Carotenoid compounds to a major extent. Meanwhile, it has a wide distribution in nature and is one of the agents responsible for food decay. Different sources such as decaying lemon are used for its isolation. In this regard the identified strain was Rhodotorula, muciliginosa (rubra). In addition, on the basis of results, the optimized growth conditions were at a velocity of 190 rpm (vibrator), at a temperature of 24°C, and at a pH of 5.8. In average, dried weight for cellular mass was 10.1 g/L of medium and the rate of production was 1617.92/g dried cell mass. Considering the kinetics of Carotenoid synthesis by this yeast, the maximum rate of production is 24 h after the start.

The production of pigments from bacteria is significant due to the low cost, high yield and ease of extract compared with other sources. Carotenoids are one of the most important pigments with antioxidant properties which are the precursor of vitamin A synthesis and have antibody overproduction ability, anti-tumor activity and inhibitory effect on the cardiovascular disease. The present study aimed to isolate and identify Carotenoid-producing bacteria by highperformance liquid chromatography (HPLC) analysis of their Carotenoid pigments. Twenty soil samples were collected from different regions of Tehran. After serial dilution each sample was cultured on BHI agar medium and incubated at 37° C. The pigment-producing bacteria were selected for further identification and their pigments were extracted by methanol. The screening was carried out at two levels: i) selection of the strains by visual color inspection, ii) analysis of the pigment extracts by UV-VIS spectroscopy and HPLC. The isolates were identified by phenotypic methods and their 16S rDNA gene was amplified by PCR method and sequenced. Staphylococcus epidermidis, Micrococcus aloeverae, Citricoccus alkalitolerans, Rhodococcus zopfii, Arthrobacter agilis, Dietzia natronolimnaea and Rhodococcus ruber were identified as Carotenoid-producing strains. The highest rate of absorption was observed using UV-VIS analysis in Staphylococcus epidermidis and Dietzia natronolimnaea. The comparison of HPLC analysis with the standard β-carotene curve showed that the Carotenoids were beta-carotene. Micro-organisms are a potential source in the production of pigments. In this study we introduced two genera of bacteria (Staphylococcus epidermidis and Dietzia natronolimnaea) with Carotenoid-producing ability.

Background: Rhodotorula is characterized by the absence of ballistoconidia, fermentationability, and starch-like compounds. Biology of the species is not well-identified; thereforemolecular identification is required. Sequence analysis of the D1/D2 region can be usedfor the identification of the majority of Basidiomycetous species. Carotenoids which arenatural pigments can be synthesized by some genera of yeasts such as Rhodotorula. Theincrease of demand for Carotenoids obtained from natural sources has promoted majorefforts to recognize potential microbial sources. The aims of this study were to identify astrain isolated from leather wastewater and to investigate its Carotenoid production ability.The effect of 2 different medium (Semi-synthetic medium (MMS) and yeast malt extractmedium (YM)) on biomass and Carotenoid production was studied.Materials and Methods: In this experimental study, sequence analysis of the D1/D2region in addition to morphological and biochemical characterization to identify the strainwas carried out. To isolate the Carotenoid pigment, cells were suspended in acetone andbroken using a homogenizer, followed by centrifugation and supernatant was separated; thus pigments were measured spectrophotometrically at 450 nM using the extinctioncoefficient E1%450=2500.Results: Identification processes represented strain SG006 as a Rhodotorula slooffiae. Thesequence was deposited in the Gene Bank database with accession number JX997835. Theresults showed that SG006 are able to produce Carotenoid and MMS medium promotedCarotenoid production.Conclusion: We found that Rhodotorula slooffiae showed the ability to produceCarotenoid. However, further work is needed to optimize of the amount of product and tocharacterize the Carotenoids.

Producing food colors from natural sources, such as tomatoes, which could be used instead of synthetic colors, is important in relation to health and safety aspects of the consumers. In this research, solvent extracting was carried out by using three non-polar solvents, including petrolium ether (bp=55oC), n-hexane (bp=60oC) and a mixture of n-hexane: ethanol: aceton (1:1:2, bp=50oC). Also, two different temperatures (room temperature and boiling point of the solvent) and three different periods of time (2, 4 and 6 hours) of extraction were tried. Using mixture of the solvents (at boiling point) for six hours showed to be the optimum conditions for extraction and there were significant differences between this treatment and other conditions for extractions. In addition to the above results, the same volumes of the solvent and samples were found to be the best ratio in comparison with the other volumes ratios. It was significant at P £.05.. The yield of color extraction from tomatoes and tomato powder was 0.14 and 0.24% (w/w), respectively. Also, the purity of the extracted color was 82.65% lycopen. The extracted color showed a good stability in sunflower oil for three months at 4oC.