From crude glycerol to carotenoids by using a Rhodotorula glutinis mutant

Abstract

In this work eighteen red yeasts were screened for carotenoids production on glycerol containing medium. Strain C2.5t1 of Rhodotorula glutinis, that showed the highest productivity, was UV mutagenized. Mutant 400A15, that exhibited a 280 % increase in β-carotene production in respect to the parental strain, was selected. A central composite design was applied to 400A15 to optimize carotenoids and biomass productions. Regression analyses of the quadratic polynomial equations obtained (R(2) = 0.87 and 0.94, for carotenoids and biomass, respectively) suggest that the models are reliable and significant (P < 0.0001) in the prediction of carotenoids and biomass productions on the basis of the concentrations of crude glycerol, yeast extract and peptone. Accordingly, total carotenoids production achieved (14.07 ± 1.45 mg l(-1)) under optimized growth conditions was not statistically different from the maximal predicted (14.64 ± 1.57 mg l(-1)) (P < 0.05), and it was about 100 % higher than that obtained under un-optimized conditions. Therefore mutant 400A15 may represent a biocatalyst of choice for the bioconversion of crude glycerol into value-added metabolites, and a tool for the valorization of this by-product of the biodiesel industry.

From Cheese Whey to Carotenes by Blakeslea trispora in a Bubble Column Reactor

“…Mantzouridou et al [14] found that a maximum productivity of carotenes (9.4 and 29.4 mg/g dry biomass/day) was obtained when B. trispora was grown in crude olive pomace oil and crude soybean oil, respectively. The maximum carotene productivity was 0.03-2.9 mg/g dry biomass/day (0.2-16.5 mg/l/day) when several agro-industrial by-products such as whole stillage, corn steep liquor, parboiled rice water, hydrolyzed mung bean waste flour, grape must, fermented radish brine, crude glycerol, wheat straw, grape juice, and molasses were used as substrates for carotene production by Phaffia rhodozyma, Sporobolomyces roseus, Sporidiobolus pararoseus, Cystofilobasidium capitatum, R. glutinis, R. mucilaginosa, recombinant industrial wine yeast, and Arthrobacter globiformis in shake flask culture and stirred tank fermentor [1,5,[15][16][17][18][19][20][33][34][35]. The cited results show that the amounts of carotenes produced from different agro-industrial by-products were very low compared with our results, that is, 55.5 mg/g dry biomass/day (405.0 mg/l/day) using bubble column reactor and deproteinized hydrolyzed whey supplemented with Tween 80, Span 80, and β-ionone.…”

“…However, utilization of a synthetic medium is not economical and the exploitation of a less expensive medium could prove beneficial. Numerous agro-industrial by-products such as crude olive pomace oil, crude soybean oil, whole stillage, grape juice, grude glycerol, wheat straw, parboiled rice water, corn steep liquor, and molasses have been considered as potential carbon sources for biotechnological production of carotenes by different strains of fungi, yeasts, and bacteria [5,[14][15][16][17][18][19].…”

Optimization of the IPP Precursor Supply for the Production of Lycopene, Decaprenoxanthin and Astaxanthin by Corynebacterium glutamicum

“…Furthermore, they are intensively applied for food and beverage coloration (Downham and Collins, 2000; Gassel et al, 2013). Hence, carotenoids have received extensive considerable attention and especially the interest for an efficient and environmental-friendly production by microbial hosts is increasing (Lee and Schmidt-Dannert, 2002; Das et al, 2007; Harada and Misawa, 2009; Cutzu et al, 2013). In order to compete with already existing production processes, such as chemical synthesis or extraction from organic material, the large-scale production in microbial hosts requires process as well as strain optimization.…”

The effects of feeding criteria on the growth of oleaginous yeast—Rhodotorula glutinis in a pilot-scale airlift bioreactor

“…About 10% (w/w) crude glycerol is the main byproduct produced in the biodiesel manufacture process [7]. Since the global production of biodiesel is increasing, the amount of crude glycerol production has also greatly increased, and consequently its market price has reduced leading to crude glycerol being a very promising potential substrate for the cultivation of oleaginous microorganisms [3,8,9]. In addition to the substrate's falling cost, the operating cost for the accumulation of microbial oils is also a major concern for the commercial viability of microbial oils.…”