INFORM October 2025

inform October 2025, Vol. 36 (9) • 29

The increasing demand for liquid fuels that meet the criteria for being both renewable and yielding a carbon footprint that is at least half of its petroleum equivalent has put a lot of pressure on the supply of seed oils, animal fats and used cooking oil. In the case of seed oil, a consequence of additional crush is the increased supply of protein, leading to an oversupply and a decrease in the value of soybean and canola meals. An alternative to the tradi tional supply chain is to utilize biotechnology to enable large scale production of microbial lipids. However, when contemplating the use of biotechnology to meet this demand for lipid feedstock, it is also important to consider both the cost of the feedstock for the microbe as well as the overall carbon footprint of the microbial process. The first article evaluates the use of Wickerhamomyces anomalus , a fungi, that can use spent grains as a carbon source to produce triglycerides. The second article explores the use of Capriavidus necater , a bacteria that can use carbon dioxide as a car bon source to produce triglycerides. The third article investigates the use of an algae-bacterial consortia in wastewater to produce triglycerides. The fourth article uses a hybrid combination of car bon dioxide and sodium bicarbonate to enhance triglyceride pro duction from an algae called Chlamydomonas reinhardtii . The fifth article explores the use of hydrolysate made from olive tree prun ings as the carbon source for Yarrowia lypolytica for the production of triglycerides. Quality control and law exploration of microbial oil production from spent grains fermented by Wickerhamomyces anomalus CY2 Yang, L., et al. , Journal of Environmental Management , 380, 124854, 2025. https://doi.org/10.1016/j.jenvman.2025.124854 Microbial oils are gaining attention as a promising raw material for biodiesel production. However, the high cost of microbial culture media and the elevated cold filter plugging point of the resulting biodiesel hinder their conversion. This study focused on fermenting SGs with added metal ions to regulate microbial oil saturation and enhance biodiesel quality. We investigated the relationship between sugar metabolism and lipid synthesis in the CY2 strain fermentation of SGs, aiming to provide insights into metabolic regulation for the industrial production of microbial oils. The results indicated that the addition of 50 mg/L FeCl 3 •6H 2 O to the lipid-producing medium for the CY2 strain sig nificantly enhanced the content of unsaturated fatty acids without compromising the yield of microbial oils. This modification effectively reduced the cold filter plugging point of biodiesel, thereby improving its anti-freezing performance. In the analy sis of material metabolism during the fermentation of SGs by the CY2 strain, it was observed that amylase and cellulase activities increased from 24 h to 60 h. The sugar content initially decreased, reaching its lowest point at 36 h, before gradually rising again. Within the first 48 h of fermentation, sugar catabolism in the CY2 strain surpassed lipid synthesis metabolism, leading to rapid microbial growth and reproduction. Subsequently, microbial growth plateaued, with excess carbon sources converted into triglycerides. This study produced high-quality biodiesel from

edge gaps remain in understanding protein–polyphenol inter actions, lipid oxidation pathways, and consumer-driven design principles. By synthesizing cutting-edge studies and proposing directions for future work, this review underscores the significance of deploying biochemical, genetic, and engineering perspectives in tandem. It is anticipated that a broader uptake of these strategies will lead to alternative proteins that meet both sustainability goals and consumer expectations for taste and sensory quality. Development of vegetative oil sorghum: From lab-to-field Park, K., et al. , Plant Biotechnology Journal , 23, 2, 660, 2024. https://doi.org/10.1111/pbi.14527 Biomass crops engineered to accumulate energy-dense triacyl glycerols (TAG or ‘vegetable oils’) in their vegetative tissues have emerged as potential feedstocks to meet the growing demand for renewable diesel and sustainable aviation fuel (SAF). Unlike oil palm and oilseed crops, the current commercial sources of TAG, vegetative tissues, such as leaves and stems, only transiently accu mulate TAG. In this report, we used grain (Texas430 or TX430) and sugar-accumulating ‘sweet’ (Ramada) genotypes of sorghum, a high-yielding, environmentally resilient biomass crop, to accu mulate TAG in leaves and stems. We initially tested several gene combinations for a ‘push-pull-protect’ strategy. The top TAG yielding constructs contained five oil transgenes for a sorghum WRINKLED1 transcription factor (‘push’), a Cuphea viscosis sima diacylglycerol acyltransferase (DGAT; ‘pull’), a modified sesame oleosin (‘protect’) and two combinations of specialized Cuphea lysophosphatidic acid acyltransferases and medium-chain acyl-acyl carrier protein thioesterases. Though intended to generate oils with medium-chain fatty acids, engineered lines accumulated oleic acid-rich oil to amounts of up to 2.5% DW in leaves and 2.0% DW in stems in the greenhouse, 36-fold and 49-fold increases rela tive to wild-type (WT) plants, respectively. Under field conditions, the top-performing event accumulated TAG to amount to 5.5% DW in leaves and 3.5% DW in stems, 78-fold and 58-fold increases, respectively, relative to WT TX430. Transcriptomic and fluxomic analyses revealed potential bottlenecks for increased TAG accu mulation. Overall, our studies highlight the utility of a lab-to-field pipeline coupled with systems biology studies to deliver high vege tative oil sorghum for SAF and renewable diesel production.

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Bryan Yeh has over 30+ years of senior leader experience in the agribusiness, biofuels, energy, food, management con sulting, renewable chemicals, synthetic biology, and water industries. He is based in Walnut Creek, California.