Q: What kind of microbes make oil?

Dr. Jeffries: Several types of microbes naturally produce oil, including yeasts, bacteria, and microalgae. These organisms are considered oleaginous because they can store over 20% of their biomass as lipids. In the right conditions, some can reach up to 70% lipid content. These fats typically accumulate when a nutrient like nitrogen or phosphorus becomes limiting, shifting the organism's focus from growth to storage. For formulators, this means access to unique oils that can be optimized for texture, melting behavior, or nutritional profile, depending on the application.

Q: Which oleaginous microbes are used commercially today?

Dr. Jeffries: On the commercial side, a few microbes stand out:

• Bacteria such as Rhodococcus opacus show potential but are not yet widespread.

• Fungi like Mortierella alpina are used for producing arachidonic acid used in infant nutrition

• Yeasts like Yarrowia lipolytica, Cryptococcus curvatus, and Lipomyces starkeyi are leading players, especially in food and cosmetic ingredient innovation.

Each of these can be optimized to produce different lipid profiles, giving formulators flexibility to meet specific texture, stability, or sensory goals in both emulsions and edible products.

Q: What makes Lipomyces starkeyi special?

Dr. Jeffries: It’s a natural and among the most efficient oil producers. Lipomyces starkeyi can store up to 80% of its dry weight as oil and produces a unique blend of saturated and monounsaturated fatty acids, especially palmitic (C16:0) and oleic acid (C18:1).

This makes it highly relevant for creating structured oils and fats used in beauty balms, body butters, and also in plant-based spreads or functional foods requiring specific melting profiles. We’ve built up its genetic toolbox over time and paired that with fermentation optimization to get high yields of solid-at-room-temperature oils. It can also naturally utilize a variety of sugars, making it an excellent platform for producing oil from cellulosic materials, such as corn stover, which will further enhance the sustainability of the oil produced.

Q: Why not just use plant oils?

Dr. Jeffries: While plant oils are widely used, they can vary significantly by geography, season, and growing conditions. That affects not only consistency but also sustainability. Plants require arable land, water, and long supply chains.

For beauty formulators, this may lead to unpredictable texture or absorbency. In food, it can mean shifts in flavor or shelf life. Fermentation-based oils offer reliable performance, greater traceability, and a smaller environmental footprint.

Q: What’s next for microbial oils in beauty?

Dr. Jeffries: Customization. We're entering an era where we can design oils based on what we want them to do, not just what's available in nature. Microbial oils can be engineered for oxidative stability, melt behavior, or compatibility with active ingredients. Imagine designing a lipid for a specific mouthfeel or a balm that melts perfectly on contact—all made sustainably in a fermenter.

Where Xylome Fits In

Whether you're developing a soft-touch balm or a plant-based spread, fats are foundational to product performance. At Xylome, we're building next-gen oils through yeast fermentation—delivering consistent, sustainable, and designer-quality lipids for beauty, food, pharma, and more. Our toolbox starts with Lipomyces starkeyi, but the possibilities go far beyond a single strain.