Evidence map›Paper›PMID 40394595›Full record

ArticleMicrobial cell factories2025

Enabling malic acid production from corn-stover hydrolysate in Lipomyces starkeyi via metabolic engineering and bioprocess optimization.

Jeffrey J Czajka, Ziyu Dai, Tijana Radivojević, Joonhoon Kim, Shuang Deng, Teresa Lemmon, Marie Swita, Meagan C Burnet, Nathalie Munoz, Yuqian Gao and 6 more

Abstract read
In one paragraph

Article in Microbial cell factories, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

16 authors.

Jeffrey J CzajkaEnergy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
Ziyu DaiEnergy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
Tijana RadivojevićDOE Agile BioFoundry, Emeryville, CA, 94608, USA.
Joonhoon KimEnergy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
Shuang DengEnergy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
Teresa LemmonEnergy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
Marie SwitaEnergy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
Meagan C BurnetDOE Agile BioFoundry, Emeryville, CA, 94608, USA.
Nathalie MunozDOE Agile BioFoundry, Emeryville, CA, 94608, USA.
Yuqian GaoDOE Agile BioFoundry, Emeryville, CA, 94608, USA.
Young-Mo KimDOE Agile BioFoundry, Emeryville, CA, 94608, USA.
Beth HofstadEnergy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
Jon K MagnusonEnergy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
Hector Garcia MartinDOE Agile BioFoundry, Emeryville, CA, 94608, USA.
Kristin E Burnum-JohnsonDOE Agile BioFoundry, Emeryville, CA, 94608, USA.
Kyle R PomraningEnergy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA. kyle.pomraning@pnnl.gov.

Funding

Biological and Environmental Research DE-AC0205CH11231Office of Energy Efficiency and Renewable Energy DE-NL0030038
6 · The paper itself

Abstract

backgroundLipomyces starkeyi is an oleaginous yeast with a native metabolism well-suited for production of lipids and biofuels from complex lignocellulosic and waste feedstocks. Recent advances in genetic engineering tools have facilitated the development of L. starkeyi into a microbial chassis for biofuel and chemical production. However, the feasibility of redirecting L. starkeyi lipid flux away from lipids and towards other products remains relatively unexplored. Here, we engineer the native metabolism to produce malic acid by introducing the reductive TCA pathway and a C4-dicarboxylic acid transporter to the yeast.

resultsHeterogeneous expression of two genes, the Aspergillus oryzae malate transporter and malate dehydrogenase, enabled L. starkeyi malic acid production. Overexpression of a third gene, the native pyruvate carboxylase, allowed titers to reach approximately 10 g/L during shaking flasks cultivations, with production of malic acid inhibited at pH values less than 4. Corn-stover hydrolysates were found to be well-tolerated, and controlled bioreactor fermentations on the real hydrolysate produced 26.5 g/L of malic acid. Proteomic, transcriptomic and metabolomic data from real and mock hydrolysate fermentations indicated increased levels of a S. cerevisiae hsp9/hsp12 homolog (proteinID: 101453), glutathione dependent formaldehyde dehydrogenases (proteinIDs: 2047, 278215), oxidoreductases, and expression of efflux pumps and permeases during growth on the real hydrolysate. Simultaneously, machine learning based medium optimization improved production dynamics by 18% on mock hydrolysate and revealed lower tolerance to boron (a trace element included in the standard cultivation medium) than other yeasts.

conclusionsTogether, this work demonstrated the ability to produce organic acids in L. starkeyi with minimal byproducts. The fermentation characterization and omic analyses provide a rich dataset for understanding L. starkeyi physiology and metabolic response to growth in hydrolysates. Identified upregulated genes and proteins provide potential targets for overexpression for improving growth and tolerance to concentrated hydrolysates, as well as valuable information for future L. starkeyi engineering work.

Indexed as

LipomycesMalatesMetabolic EngineeringZea maysAspergillus oryzaeBioreactorsFermentationHydrolysisMalate DehydrogenasePyruvate CarboxylaseMalate DehydrogenaseMalatesmalic acidPyruvate CarboxylaseLipomyces starkeyiMachine learning medium optimizationMalic acid productionOleaginous yeast

Identifiers

PMID40394595
PMCPMC12093598

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LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.