light requirement for the carotenoids production by mucor hiemalis

objective fungi produce many different carotenoids and some are attractive in medical and industrial sources. in this work the ability of mucor hiemalis (ptcc 5292) to produce carotenoids in media with different nitrogenous and carbon sources and incubation with white, yellow, blue and red lights (15w, 220v, e27) against dark-grown were studied. materials and method the microorganism cultivation in sda medium, with or without aeration (120 rpm) at 25 °c. mycelia were collected and dried at 50 °c. the dried mycelia were homogenized in hexane, acetone and h2so4 (0.5 m) solvents.  the carotenoids determined by tlc and hplc methods. results theresults showed that m. hiemalis accumulated astaxanthin (mono-esters, di-esters and free), echinenone and canthaxanthin in the mycelia in different conditions. blue and white lights incubation was the best for production of carotenoid pigments with 1.2 and 1.33 mg/g dried mycelia respectively, but the red light incubation not only did not have an amplifying effect on the production of carotenoid but also slightly reduced this effect. also, the effect of intervention of lactose sugar showed more effectiveness in producing carotenoid than yeast extract and dextrose or in the presence of both of them. conclusion the information reported in this study on the comparative ability of m. hiemalis for producing carotenoids, should be useful for assessing the biotechnological production of carotenoid pigments if it incubates with white or blue lights.