A new medium for spore production of Blakeslea trispora using response surface methodology

Abstract

Optimization of the medium components which enhance sporulation of the two mating types of the fungus Blakeslea trispora ATCC 14271 and ATCC 14272 (a heterothallic Zygomycota producing carotene) was achieved with the aid of response surface methodology (RSM). Glucose, corn steep liquor, yeast extract, and ammonium sulfate were investigated as carbon and nitrogen sources in a basal medium. RSM was adopted to optimize the medium in order to obtain a good growth of the fungus as a prerequisite for enhanced sporulation. In the second step, the basal medium was supplemented with different trace elements which significantly affect sporulation (i.e. CuSO 4 Á5H 2 O, FeCl 3 Á6H 2 O, Co(NO 3 ) 2 Á6H 2 O, and MnCl 2 Á4H 2 O). Central composite design proved to be valuable in optimizing a chemically defined solid medium for spore production of B. trispora. The composition of the new solid medium to enhance spore production by B. trispora (ATCC 14271) is as follows (per liter): 7.5 g glucose, 3.2 g corn steep liquor, 1.7 g yeast extract, 4.1 g ammonium sulfate, 6 mg CuSO 4 Á5H 2 O, 276 mg FeCl 3 Á6H 2 O, 2 mg Co(NO 3 ) 2 Á6H 2 O, and 20 g agar (pH 6.0). Practical validation of this optimum medium gave spore number of 1.2 9 10 8 spores/dish which is 77% higher than that produced in Potato Dextrose Agar (PDA). In the case of B. trispora (ATCC 14272) the new solid substrate for enhanced sporulation consists of (per l) 6.4 g glucose, 3.3 g corn steep liquor, 1.4 g yeast extract, 4.3 g ammonium sulfate, 264 mg CuSO 4 Á5H 2 O, 485 mg FeCl 3 Á6H 2 O, 223 mg MnCl 2 . 4H 2 O, and 20 g agar (pH 6.0). Spore numbers of 2 9 10 7 spores/dish were obtained on the new medium by B. trispora (ATCC 14272), which is 95% higher than that produced on PDA. The results corroborated the validity and the effectiveness of the models. The new media considerably improved sporulation of both strains of B. trispora compared to the production of spores on PDA, which is the medium usually used for sporulation of the fungus.

A simple method for the measurement of metabolic heat production rates during solid‐state fermentations using β‐carotene production with Blakeslea trispora as a model system

“…Blakeslea trispora plus mating type (ATCC 14059) and B. trispora minus mating type (ATCC 14060) were obtained from Leibnitz Institute DSMZ‐German Collection of Microorganisms and Cell Cultures and precultured as proposed by Roukas et al. .…”