IngredientsMortierella alpina Peyronel 1913 (MycoBank MB 170280) is an oleaginous filamentous fungus belonging to the family Mortierellaceae (Mortierellomycota). Its full taxonomic lineage, as recorded in the NCBI Taxonomy database, places it within the kingdom Fungi, phylum Mucoromycota, subphylum Mortierellomycotina, class Mortierellomycetes, order Mortierellales, and family Mortierellaceae.
First described from alpine soils in Italy, this saprotrophic fungus has a cosmopolitan distribution across temperate and cold climatic conditions worldwide, including Europe, North America, Asia, Australasia, and Antarctica, and it inhabits diverse environments ranging from forest litter and agricultural soils to glacier forefields and plant rhizospheres. It belongs to a species complex that also includes Mortierella antarctica and Mortierella globalpina.
Species delimitation within this complex remains challenging because of the high similarity (>99%) in internal transcribed spacer (ITS) sequences, making morphological characters essential for accurate identification. Recent phylogenomic reclassification has restricted Mortierella sensu stricto to a well-supported clade distinct from Linnemannia and Podila.
The fungus is morphologically characterized by a milky-to-cottony appearance during growth and coenocytic (non-septate) mycelial hyphae, which are hallmarks of its zygomycete-related lineage. Molecular identification relies on DNA barcoding of the ITS region, which is considered one of the most suitable methods for molecular fungal identification; the ITS region is preferred over the 18S rDNA because the level of variability in the M. alpina ITS region is higher.
The primary commercial and nutritional significance of M. alpina lies in its exceptional lipid-producing capacity. It has emerged as the leading microbial platform to produce arachidonic acid (ARA, 20:4ω-6), and the fungus can accumulate lipids exceeding 50% of its dry weight, with ARA comprising up to 50% of total fatty acids — representing the highest naturally reported ARA content among characterized fungi.
M. alpina is not consumed as a whole organism but is used exclusively as an industrial fermentation platform, with the refined oil extracted from its biomass serving as the active ingredient in dietary and nutritional products.
The ARA-rich oil derived from M. alpina contains approximately 40% ARA (≥38%) and is a yellow to light-orange colored oil. The application of ARA-rich oil for infant nutrition has led to the development of several commercial production processes, all using Mortierella alpina, which was selected because of its high level of ARA, exceeding 50% of total fatty acids, and because it is an oleaginous fungus able to accumulate high levels of triacylglycerol (TAG) lipids.
The oil appears in commerce in the following principal forms:
Specifications for the ingredient stipulate a minimum of 40% arachidonic acid in the oil. BASF describes M. alpina oil as a light yellow to orange oil with approximately 40% by weight of total fatty acids as ARA.
The fatty acid composition of M. alpina includes palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2), γ-linolenic acid (C18:3), dihomo-γ-linolenic acid (DGLA, C20:3), and a large amount of arachidonic acid (ARA, C20:4). Another notable fatty acid, eicosapentaenoic acid (EPA, C20:5), is usually present in M. alpina in trace amounts below 12°C.
M. alpina has no established history of use in classical herbal medicine traditions. Its relevance is entirely a product of late twentieth-century biotechnology and nutritional science. The fungus itself was first formally described by Peyronel in 1913 from Italian alpine soil samples, but it entered the broader scientific and commercial consciousness only through mid-to-late twentieth-century screening programs aimed at finding microbial sources of long-chain polyunsaturated fatty acids (LC-PUFAs).
One of the pioneers in the commercial development of M. alpina-derived ARA was the Dutch firm DSM (now DSM-Firmenich), which developed a method in the 1990s for fermenting ARA from this filamentous fungus. ARA-rich oil from M. alpina received Generally Recognized As Safe (GRAS) approval from the US FDA in 2001, followed by regulatory approval in the EU, establishing it as the dominant microbial source of dietary ARA used in infant formula worldwide.
The scientific and industrial impetus for its development arose from the established nutritional significance of ARA in human breast milk and the need to replicate this composition in commercial infant formulas for infants who cannot be breastfed. Infants, particularly pre-term infants, may have a limited ability to convert the essential precursor fatty acids (linoleic acid to ARA and linolenic acid to DHA), due to reduced concentrations and activity of desaturase enzymes; supplementation of infant formula with ARA at levels consistent with those in human milk is therefore considered important because these fatty acids have critical roles in membrane structure and as precursors of eicosanoids.
The primary commercially relevant compound produced by M. alpina is arachidonic acid (ARA), a 20-carbon, ω-6 polyunsaturated fatty acid. ARA is an essential component of membrane phospholipids and is abundant in the brain, muscles, and liver. It is an integral constituent of cell structures and is instrumental for the nervous, muscular, and immune systems' functions.
Beyond ARA, M. alpina naturally produces additional biologically relevant PUFAs that appear in the crude oil. Arachidonic acid (AA, 20:4n-6), dihomo-γ-linolenic acid (DGLA, 20:3n-6), and mead acid (MA, 20:3n-9) are among the PUFAs commercially produced using Mortierella fungi. Under specific engineered or cold-growth conditions, the fungus can also accumulate EPA (C20:5n-3).
The fungus can produce lipids accounting for up to 50% of its dry weight in the form of triacylglycerols. The refined oil destined for human use delivers ARA predominantly in triacylglycerol form, which represents the predominant form of dietary fat intake and is well absorbed.
The biosynthetic route for ARA begins with fatty-acid synthase-mediated production of palmitic acid (C16:0), followed by elongation to stearic acid and sequential desaturation steps catalyzed by Δ9-, Δ12-, and Δ6-desaturases. Subsequent elongation produces dihomo-γ-linolenic acid (DGLA), which is converted to ARA through a final Δ5-desaturation step.
More specifically, the primary substrate hexadecanoic acid (16:0) is converted to ARA in sequential steps catalyzed by elongase 1 (MALCE1), Δ9 desaturase, Δ12 desaturase, Δ6 desaturase, elongase 2 (GLELO), and Δ5 desaturase; ARA is biosynthesized through desaturation by Δ9, Δ12, Δ6, and Δ5 desaturases and elongation by MALCE1 and GLELO.
A series of sequential desaturase- and elongase-catalyzed steps are involved in the synthesis of PUFAs from acetyl-CoA precursors, with concomitant NADPH consumption. Oxygen is known to affect the degree of unsaturation of PUFAs, and robustness analysis has determined that an oxygen uptake rate of 2.0 mmol gDW⁻¹ h⁻¹ is optimal for ARA accumulation.
The 38.38 Mb M. alpina genome shows a high degree of gene duplications; approximately 50% of its 12,796 gene models, and 60% of genes in the predicted lipogenesis pathway, belong to multigene families. Notably, M. alpina has 18 lipase genes, of which 11 contain the class 2 lipase domain. Its fatty acid synthase is a single polypeptide containing all of the catalytic domains required for fatty acid synthesis from acetyl-CoA and malonyl-CoA, whereas in many fungi this enzyme is comprised of two polypeptides.
Under culture conditions optimal for large-scale production, the total amount of lipid can reach 500–600 mg/g dry cell weight or 20 g/L of culture broth.
Once consumed in the diet, ARA is incorporated into cell membrane phospholipids throughout the body, where it serves multiple signaling and structural roles.
Eicosanoid precursor function: Esterified ARA on the inner surface of the cell membrane is hydrolyzed to its free form by phospholipase A2 (PLA2), and is in turn further metabolized by cyclooxygenases (COXs) and lipoxygenases (LOXs) and cytochrome P450 (CYP) enzymes to a spectrum of bioactive mediators that includes prostanoids, leukotrienes, epoxyeicosatrienoic acids (EETs), dihydroxyeicosatetraenoic acids (diHETEs), eicosatetraenoic acids (ETEs), and lipoxins.
COX pathway: Both COX-1 and COX-2 catalyze the two-step conversion of arachidonic acid to PGG2 and then to PGH2, which are the immediate precursors of the prostaglandins and thromboxanes that modulate vascular tone, platelet aggregation, and inflammatory responses.
Lipoxygenase pathway: Arachidonic acid is also metabolized by 5-lipoxygenase, resulting in synthesis of leukotrienes; these intracellular messengers play an important role in the regulation of signal transduction implicated in pain and inflammatory responses.
Structural membrane role: PUFAs, specifically ARA (ω-6) and DHA (ω-3), are essential for the development of the nervous system during fetal gestation and lactation, making up a substantial portion of brain fatty acids.
Myogenic signaling: ARA and its metabolites play important physiological roles as local signaling molecules in skeletal muscle, acting through eicosanoid-mediated autocrine and paracrine pathways that modulate muscle cell proliferation and differentiation.
M. alpina is used in an industrial process for the production of ARA for food supplementation, and microbial production of single cell oil (SCO) can be conducted as either submerged fermentation (SmF) or solid-state fermentation (SSF).
Process variables that influence lipid accumulation by Mortierella spp. and the profile of the fatty acids include incubation temperature, time, aeration, growth phase of the mycelium, particle size of the substrate, carbon to nitrogen ratio, initial moisture content and pH, as well as supplementation of the substrate with nitrogen and oil.
Under laboratory conditions, liquid media with glucose and peptone as carbon and nitrogen sources respectively, along with diverse micronutritional factors, can be adjusted for optimal biomass and ARA production; shake flask cultivation at 25°C for 7 days has produced around 0.570 g of ARA per liter of culture.
Both production strains of M. alpina used in GRAS-notified applications are wild-type and non-toxigenic.
This is the most extensively studied and best-supported application of M. alpina-derived ARA oil. The scientific question has been whether supplementing infant formula with ARA (typically alongside DHA) improves neurodevelopmental and visual outcomes compared with unsupplemented formula.
Supplementation of infant formula with ARA and DHA results in fatty acid profiles, neurodevelopmental outcomes, and immune responses in formula-fed infants that are more like those observed in breastfed infants; consequently, ARA and DHA have been historically added together to infant formula.
A 2025 meta-analysis of randomized controlled trials (RCTs) on infant cognitive outcomes aimed to assess the effect of DHA and ARA supplementation on cognitive function in infants from RCTs; the authors systematically searched PubMed, Web of Science, and Embase databases up to July 2024, applying standard methods to assess publication bias, sensitivity analysis, and heterogeneity among nine included RCTs, comprising 1,039 subjects. The meta-analysis showed significantly positive effects of DHA and ARA supplementation on cognitive development in infants (standardized mean difference (SMD): 0.21; 95% CI: 0.03, 0.38).
The DIAMOND trial, a large dose-response study, enrolled infants fed formulas containing 0.32%, 0.64%, or 0.96% total fatty acids as DHA and 0.64% as ARA compared with a formula without DHA and ARA; the trial began in 2003 and was conducted at two sites in the United States, and DHA and ARA supplementation significantly enhanced visual acuity at 12 months of age, confirming earlier studies.
A double-blind RCT in very preterm infants born before 29 weeks gestational age allocated infants to either 100 mg/kg ARA and 50 mg/kg DHA or medium chain triglycerides (control), with the aim of testing whether early enteral supplementation improves white matter microstructure assessed by diffusion-weighted MRI at term equivalent age. From April 2018 to January 2021, 176 infants were checked for eligibility and 121 underwent randomization.
However, although there are many RCTs showing positive effects in visual, cognitive, and immune function, a number of studies have reported no additional benefit. The interventions have predominantly been a combination of DHA and ARA as this reflects the composition of breast milk, and there are only a small number of DHA alone studies; notably there are no published RCTs where the intervention is solely ARA. This makes it difficult to attribute observed effects to ARA alone versus the DHA+ARA combination.
Regarding the ARA:DHA ratio, a clinical study from 2015 concluded that preterm infants fed with an ARA:DHA ratio of 2:1 have better plasma PUFA concentrations and psychomotor development, and non-breastfed infants fed with a 2:1 ARA:DHA ratio achieved neurodevelopmental outcomes similar to breastfed infants.
A longitudinal double-blind controlled trial in toddlers (n=133) aged 13.4 ± 0.9 months randomized participants to receive DHA (200 mg/day) and ARA (200 mg/day) supplement or a corn oil supplement (control) until age 24 months, finding no effect of the supplement on the Bayley Scales of Infant and Toddler Development 3rd Edition cognitive and language composites or the Beery VMI at age 24 months; supplemented toddlers did, however, show higher RBC phosphatidylcholine, phosphatidylethanolamine, and plasma DHA and ARA compared to placebo toddlers at age 24 months.
Evidence strength: Strong for the combined DHA+ARA supplementation improving visual acuity and contributing to neurodevelopmental indices in preterm and formula-fed infants; the effect attributable to ARA alone cannot be fully isolated from the combination, and individual study results remain inconsistent. Regulatory bodies globally have authorized the use of M. alpina oil in infant formula on this basis.
The rationale for ARA supplementation in adult skeletal muscle physiology is based on ARA's role as a precursor to eicosanoids, which act as local signaling molecules mediating muscle repair and growth. ARA is the metabolic precursor to the eicosanoid family of lipid mediators, which have potent pro-inflammatory actions but also act as important autocrine/paracrine signaling molecules in skeletal muscle growth and development.
In a controlled study, resistance-trained men (≥1 year) received dietary supplementation with 1.5 g/day ARA (n=9, 24 ± 1.5 years) or placebo (n=10, 26 ± 1.3 years) for 4 weeks while continuing their normal training regimen; plasma and vastus lateralis muscle biopsies were collected in an overnight fasted state at baseline and week 4. In muscle, ARA supplementation increased mRNA expression of the myogenic regulatory factors MyoD and myogenin, but had no effect on a range of immune cell markers or inflammatory cytokines; these data show that dietary ARA supplementation can rapidly and safely modulate plasma and muscle fatty acid profile and promote myogenic gene expression in resistance-trained men, without a risk of increasing basal systemic or intramuscular inflammation.
A companion study using the same population and design examined exercise-induced inflammatory responses. This study investigated the effect of 4 weeks of dietary supplementation with 1.5 g/day ARA (n=9, 24 ± 1.5 years) or corn-soy oil placebo (n=10, 26 ± 1.3 years) on systemic and intramuscular inflammatory responses to an acute bout of resistance exercise (8 sets each of leg press and extension at 80% one-repetition maximum) in previously trained men.
ARA is necessary for the repair and growth of skeletal muscle tissue, and this role makes ARA an important dietary component in support of muscle anabolic formulations; supplementation of 50–250 mg daily for healthy adults has been cited in the literature.
Evidence strength: Preliminary. The available human studies are small (single-digit participant numbers per group in some trials), short in duration (4 weeks), and focused on biomarker endpoints (gene expression, lipid profiles) rather than definitive performance or hypertrophy outcomes. No large, well-powered RCTs have established a clinically meaningful strength or muscle mass benefit from ARA supplementation in adults.
The efficacy of ARA supplementation has been reported in the fields of cognitive attention and memory, mood states, coronary circulation, and cirrhosis.
A double-blind crossover study in healthy elderly men examined ARA's effects on age-related event-related potentials. Researchers examined the effects of ARA on age-related event-related potential (ERP) changes in 25 healthy elderly men using a double-blind crossover design; subjects were administered 600 mg/day of ARA-enriched triglyceride (SUNTGA40S; containing 240 mg ARA) in capsules or the same amount of olive oil in capsules as an inactive placebo for 1 month. In subjects administered 240 mg/day ARA, P300 latency was significantly shorter and P300 amplitude was significantly higher than in those administered olive oil capsules, and they exhibited a significant increase in ARA content in serum phospholipids; these findings suggest that supplementation of ARA can improve cognitive function in healthy elderly men.
However, the systematic review of ARA RCTs (British Journal of Nutrition, 2019) concluded that supplementation of ARA may reduce age-related decline in cognitive function and learning ability, but this is based upon a single small study and more research is needed in this important area.
Mechanistically, data from several studies have indicated that impairments in long-term potentiation (LTP), the process underlying plasticity in synaptic connections, are associated with a decrease in membrane ARA and DHA in aged rats, and treatment of aged rats with either of these PUFAs reverses age-related decrease in LTP and the decrease in membrane fatty acid concentration.
Evidence strength: Preliminary and based on small human studies. The single available RCT in humans showed electrophysiological signals of benefit in elderly men at 240 mg/day, but the sample size (n=25) is insufficient to support clinical recommendations, and the findings require replication in larger, longer-duration trials.
The conversion of linoleic acid to ARA declines with age, and the importance of ARA supplementation among the elderly has recently gained increased attention; it has been reported that supplementation with ARA among the elderly improves cognitive response and coronary flow velocity reserve.
A published study referenced in the peer-reviewed literature (Oe et al., Heart, 2008) examined ARA and DHA supplementation effects on coronary flow velocity reserve in Japanese elderly individuals, suggesting potential cardiovascular microcirculatory benefit; however, this finding is based on a single study in a specific population.
A randomized, double-blind, placebo-controlled parallel group intervention trial administered ARA-enriched oil (240 or 720 mg ARA per day) or placebo to Japanese healthy men and women aged 55–70 years for 4 weeks followed by a 4-week washout period; these results indicate that ARA supplementation, even at a relatively high dose, does not increase ARA metabolites, and suggest that it does not induce cardiovascular, inflammatory, or allergic diseases in Japanese elderly individuals.
A 2009 review indicated that consumption of 5–10% of food energy from omega-6 fatty acids, including arachidonic acid, may reduce the risk of cardiovascular diseases compared to lower intakes.
Evidence strength: Preliminary. Existing evidence is insufficient to support a specific cardiovascular indication for M. alpina-derived ARA supplementation beyond the general evidence base for omega-6 PUFAs in cardiovascular health maintenance.
Arachidonic acid supplementation has been reported to enhance synthesis of eicosanoids without suppressing immune functions in young healthy men — a finding from a controlled metabolic ward study referenced by Kelley et al. (1998).
In trained men, ARA supplementation reduced circulating platelet and monocyte number, and decreased the mRNA expression of the immune cell surface markers neutrophil elastase/CD66b and interleukin-1β in peripheral blood mononuclear cells.
The 2019 British Journal of Nutrition systematic review concluded that the studies reviewed suggest no adverse effects in adults of increased ARA intake up to at least 1,000–1,500 mg/d on blood lipids, platelet aggregation and blood clotting, immune function, inflammation, or urinary excretion of ARA metabolites; however, in many areas there are insufficient studies to make firm conclusions, and higher intakes of ARA are deserving of further study. Based on the RCTs reviewed, there are not enough data to make any recommendations for specific health effects of ARA intake.
The following dosages are those specifically reported in cited scientific studies and regulatory documents — they are descriptive of study designs, not prescriptive recommendations:
ARA-rich oil from M. alpina received GRAS approval from the US FDA in 2001, followed by regulatory approval in the EU. The safety evaluation considers the composition, intake, nutritional, microbiological, and toxicological properties of M. alpina-derived oil; corroborative safety data are described in multiple GRAS notices (GRNs 730, 41, 80, 94), each of which received "no questions" letters from the US FDA.
The toxicity of ARA-rich oils produced from different strains of Mortierella alpina has been well documented over the last decades; an update of the literature has been conducted and did not reveal any safety concerns.
An ARA-enriched oil derived from Mortierella alpina was subjected to a program of studies to establish its preliminary safety for use in infant nutrition, including gene mutation assays in bacteria and mammalian cells in vitro, chromosome aberration assays both in vitro and in vivo, and acute and subacute (4-week) oral toxicity in the rat. No known mycotoxins were produced by the production strains under the conditions tested; the oil did not show mutagenic or clastogenic activity, and the acute oral toxicity, expressed as the LD₅₀ value, exceeded 20 mL/kg body weight (18.2 g/kg body weight).
Production strains of M. alpina used in GRAS-notified oils are wild-type and non-toxigenic.
A 2019 review of clinical studies investigating the potential health effects of ARA supplementation of up to 1,500 mg per day on human health found there were no clear benefits, but also no adverse effects in adults on several biomarkers of blood chemistry, immune function, and inflammation.
Overall, there seem to be few marked benefits for adults of increasing ARA intake from the typical usual intake of 100–200 mg/d to as much as 1,000 mg/d; the few studies using higher doses (1,500 or 2,000 mg/d) also report little benefit.
A source-documented safety concern relates not to M. alpina itself but to the industrial processing environment. Bacillus cereus contamination is common in food manufacturing environments, and it is possible for the cereulide toxin produced by B. cereus to contaminate ARA oil if the fermentation or subsequent processing steps become contaminated. This is an extrinsic manufacturing risk applicable to all fermentation-derived food ingredients, not a property of M. alpina itself.
Because ARA is the direct substrate for cyclooxygenase (COX) enzymes that are inhibited by non-steroidal anti-inflammatory drugs (NSAIDs), there is a theoretical pharmacodynamic interaction: ARA is metabolized by cyclooxygenase and 5-lipoxygenase, resulting in synthesis of prostaglandins and leukotrienes, which play important roles in the regulation of signal transduction implicated in pain and inflammatory responses. Drugs that block this pathway (e.g., aspirin, ibuprofen) would be expected to attenuate the downstream eicosanoid effects of ARA supplementation, though direct interaction studies specifically using M. alpina-derived ARA oil have not been identified in the published literature.
The FDA GRAS notification process for M. alpina-derived oils includes an allergenicity assessment. GRAS notifications for M. alpina-derived ARA oil include sections addressing safety, absorption, distribution, metabolism, excretion, toxicology studies, clinical studies, and allergenicity. The oil is extensively refined, and no allergenic proteins from the fungal biomass are expected to persist at detectable levels in the final product; however, individuals with mold or fungal hypersensitivity should note the fermentation origin.
Health conditions that Mortierella alpina may help support.
Body systems that Mortierella alpina may help support.
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