The identification of carotenoids in B. trispora during pigment production from deproteinized hydrolyzed whey supplemented with plant oils was studied. The carotenoid content in Blakeslea trispora were beta-carotene, gamma-carotene, and lycopene. The composition of carotenoids depends of the amount of oils added to the cheese whey. At the maximum concentration of carotenoids, the proportions of beta-carotene, gamma-carotene, and lycopene (as percent of total carotenoids) was 60.1%, 32.5%, and 7.4%, respectively.

The effect of the aeration rate on carotene production from deproteinized hydrolyzed whey by Blakeslea trispora in a bubble column reactor was investigated. Aeration rate significantly affected carotene concentration and morphology of the fungus. Enhanced aeration caused change of the morphology of B. trispora from pellets with large projected area to pellets with small projected area. This morphological differentiation of the fungus was associated with a significant increase in carotene production. When deproteinized hydrolyzed whey was supplemented with 30 g/l Tween 80, 30 g/l Span 80, and 0.2 % (v/v) β-ionone, the highest carotene productivity (55.5 mg/g dry biomass/day or 405.0 mg/l/day) was obtained at an aeration rate of 4 vvm. This is the highest carotene productivity that has been reported among the agro-industrial by-products up to date. In this case, the carotenes produced consisted of β-carotene (67 %), γ-carotene (15 %), and lycopene (18 %).

The effect of the ratio of (?) and (-) mating type of Blakeslea trispora on carotene production from deproteinized hydrolysed whey in shake flask culture was investigated. Also, the inoculum ratio of the two mating types on the morphology of the microorganism and the relationship between morphological changes of the fungus and product formation were studied. The concentration of carotenes was significantly affected by the ratio of (?) and (-) mating type of B. trispora. A ratio of 1:10 up to 1:100 of (?) and (-) type was found to achieve the highest carotene yields. The optimum ratio of the (?) and (-) mating types for the maximum pigment production (175.0 mg/g dry biomass at 8 days of fermentation) was found to be 1:10. The carotene content in B. trispora consisted of b-carotene, c-carotene, and lycopene. At the maximum concentration of carotenes the proportion of b-carotene, c-carotene, and lycopene (as percent of total carotenes) was 80, 12, and 8%, respectively. B.trispora growing in submerged fermentation is able to develop complex morphologies which have been classified into three major groups: freely dispersed hyphae, clumps and pellets. These parameters are strongly influence the production of carotenes.

No abstract

The phenomenon of autolysis in Blakeslea trispora during carotene production from deproteinized hydrolyzed whey in an airlift reactor was investigated. The process of cellular autolysis was studied by measuring the changes in carotene concentration, dry biomass, residual sugars, pH, intracellular protein, specific activity of the hydrolytic enzymes (proteases, chitinase), and micromorphology of the fungus using a computerized image analysis system. All these parameters were useful indicators of autolysis, but image analysis was found to be the most useful indicator of the onset and progress of autolysis in the culture. Autolysis of B. trispora began early in the growth phase, continued during the stationary phase, and increased significantly in the decline phase. The morphological differentiation of the fungus was a result of the degradation of the cell membrane by hydrolytic enzymes. The biosynthesis of carotenes was carried out in the exponential phase, where the phenomenon of autolysis was not intense.