Abstract
The effects of combinatorial stress on lipid production in Phanerochaete chrysosporium remain understudied. This species of white-rot fungi was cultivated on solid-state media while under variable levels of known abiotic and biotic stressors to establish the effect upon fungal oil profiles. Environmental stressors induced upon the fungus included the following: temperature, nutrient limitation and interspecies competition to assess impact upon oil profiles. Fatty acid type and its concentration were determined using analytical methods of gas chromatography and mass spectrometry. Growth rate under stress was established using high-performance liquid chromatography with ergosterol as the biomarker. Fungi grown on solid-state agar were able to simultaneously produce short- and long-chain fatty acids which appeared to be influenced by nutritional composition as well as temperature. Addition of nitrogen supplements increased the growth rate, but lipid dynamics remained unchanged. Introducing competition-induced stress had significantly altered the production of certain fatty acids beyond that of the monoculture while under nutrient-limiting conditions. Linoleic acid concentrations, for example, increased from an average of 885ngμl-1 at monoculture towards 13820ngμl-1 at co-culture, following 7days of incubation. Interspecies competition produced the most notable impact on lipid production for solid-state media cultivated fungi while the addition of nitrogen supplementation presented growth and lipid accumulation to be uncorrelated. Combinatorial stress therefore influences the yield of overall lipid production as well as the number of intermediate fatty acids produced, deriving similar oil profiles to the composition of vegetable and fish oils. Fungal secondary metabolism remains highly sensitive following combinatorial stress. The outcome impacts the research towards optimizing fungal oil profiles for biomass and nutrition. Future investigations on fungal stress tolerance mechanisms need to address these environmental factors throughout the experimental design.
Highlights
The white-rot fungus, Phanerochaete chrysosporium, is a species belonging to the Basidiomycota phylum of filamentous fungi (Burdsall and Eslyn 1974; Burdsall 1985) which possesses both ecological and genomic interest within the mycological research community (Kersten and Cullen 2006; Singh and Chen 2008; Liu and QuFatty acid composition analysis of Phanerochaete2019)
We investigated the ability of the fungus to convert saturated fatty acids (SFAs) to polyunsaturated fatty acids (PUFAs) by inducing combinatorial stresses towards P. chrysosporium to mediate stress tolerance secondary metabolism
All five media types were composed of variable nutrient types which each appeared to impact the production of unusual fatty acids, PUFAs
Summary
The white-rot fungus, Phanerochaete chrysosporium, is a species belonging to the Basidiomycota phylum of filamentous fungi (Burdsall and Eslyn 1974; Burdsall 1985) which possesses both ecological and genomic interest within the mycological research community (Kersten and Cullen 2006; Singh and Chen 2008; Liu and QuFatty acid composition analysis of Phanerochaete2019). This species, among other fungi, have been characterized as oleaginous organisms, capable of producing lipids of variable chain lengths throughout growth as microbial oils (Cohen and Ratledge 2010; Athenaki et al 2018) These secondary metabolites are derived from de novo lipid accumulation, a mechanism comprising various enzymes specialized in altering the chain length and double bond number of saturated fatty acids (SFAs) and converting them to monounsaturated fatty acids (MUFAs) or polyunsaturated fatty acids (PUFAs) (Chemler et al 2006; Tang et al 2015; Ochsenreither et al 2016; Athenaki et al 2018). Comparing the growth rate with the oil profiles will further deduce whether the link between fungal biomass and sequential lipid accumulation should be considered for future investigations
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
