The Effect of pH and Temperature on Arachidonic Acid Production by Glycerol-Grown Mortierella alpina NRRL-A-10995

Abstract

Arachidonic acid (AA) has a wide range of applications in medicine, pharmacology, diet, infant nutrition, and agriculture, due to its unique biological properties. The microbiological processes involved in AA production usually require carbohydrate substrates. In this paper, we propose a method for AA production from glycerol, an inexpensive and renewable carbon substrate that is produced by the fungal strain, Mortierella alpina NRRL-A-10995. Our experimental results showed that the optimum pH values required for fungal growth and the production of lipids and AA were different and depended on the growth phase of the fungus. The AA production was shown to be extremely sensitive to acidic pH values and was completely inhibited at a pH of 3.0. The optimum temperature for AA production was 20-22 • C. Continuous cultivation of M. alpina occurred in a glycerol-containing medium, and growth limitations were implemented through the addition of nitrogen and the selection of optimal conditions (pH 6.0, 20 • C). This ensured that active AA production occurred (25.2% of lipids and 3.1% of biomass), with the product yield from the consumed glycerol being 1.6% by mass and 3.4% by energy.

Lipid production and heavy metals adsorption by an Aspergillus fumigatus GAH1 isolate

“…These results support the importance of pH as a limiting factor for fungal lipid production. These results also agree with the recent findings that pH 6.0 was the most suitable pH for arachidonic acid and biomass production by Mortierella alpine (Mironov et al, 2018).…”

Metal and Phosphate Ions Show Remarkable Influence on the Biomass Production and Lipid Accumulation in Oleaginous Mucor circinelloides

“…Lipid accumulation, as well as biomass formation, can be affected by many different cultivation parameters, such as the nutrient composition of the growth medium, temperature, pH, aeration, or parameter shift during the fermentation (temperature/pH) [ 2 , 21 , 22 ]. Optimization of the nutrient composition of the growth medium is one of the most important aspects in improving fungal lipid production.…”

Physiological Traits of Dihomo-γ-Linolenic Acid Production of the Engineered Aspergillus oryzae by Comparing Mathematical Models

“…Similarly, GLA proportion (25.4 ± 1.3% in TFA) in the engineered A. oryzae culture grown at the optimal CSH medium was higher than that found in the same fungal strain (9.5-16.0% GLA in TFA) (Chutrakul et al, 2016) and the known GLA-producing strains of Zygomycete fungi, such as Mucor rouxii (18.1% GLA in TFA), Cunninghamella sp. (11.9% GLA in TFA), and Mortierella alpina (1.6-6.1% GLA in TFA) (Kavadia et al, 2001;Jeennor et al, 2006;Mironov et al, 2018). Our results revealed that the change in fatty acid phenotypes might be attained by cell acclimatization in the optimal medium apart from the influence of genetic manipulation.…”