ArticleMicrobial cell factories2015
L-lactic acid production by Aspergillus brasiliensis overexpressing the heterologous ldha gene from Rhizopus oryzae.
Article in Microbial cell factories, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 9 papers.
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Who cites it
9 citing papers in PubMed, 32 citations in OpenAlex.
- Synergistic Enhancement of Straw Hydrolysis and Lactic Acid Production inJournal of fungi (Basel, Switzerland) · 2026Article
- Lactic acid fermentation using Rhizopus spp.: current insights and future prospects.Bioresources and bioprocessing · 2025Review
- Recent Advances in Lactic Acid Production by Lactic Acid Bacteria.Applied biochemistry and biotechnology · 2021Review
- Blocking utilization of major plant biomass polysaccharides leads Aspergillus niger towards utilization of minor components.Microbial biotechnology · 2021Article
- Exploitation of Ultrasound Technique for Enhancement of Microbial Metabolites Production.Molecules (Basel, Switzerland) · 2020Review
- Lactic acid production - producing microorganisms and substrates sources-state of art.Heliyon · 2020Review
- In silico evolution ofBiotechnology for biofuels · 2020Article
- Biodesulfurization: a model system for microbial physiology research.World journal of microbiology & biotechnology · 2016Review
- Expression of Lactate Dehydrogenase in Aspergillus niger for L-Lactic Acid Production.PloS one · 2015Article
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Authors and funding
8 authors at 3 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundLactic acid is the building block of poly-lactic acid (PLA), a biopolymer that could be set to replace petroleum-based plastics. To make lactic acid production cost-effective, the production process should be carried out at low pH, in low-nutrient media, and with a low-cost carbon source. Yeasts have been engineered to produce high levels of lactic acid at low pH from glucose but not from carbohydrate polymers (e.g. cellulose, hemicellulose, starch). Aspergilli are versatile microbial cell factories able to naturally produce large amounts of organic acids at low pH and to metabolize cheap abundant carbon sources such as plant biomass. However, they have never been used for lactic acid production.
resultsTo investigate the feasibility of lactic acid production with Aspergillus, the NAD-dependent lactate dehydrogenase (LDH) responsible for lactic acid production by Rhizopus oryzae was produced in Aspergillus brasiliensis BRFM103. Among transformants, the best lactic acid producer, A. brasiliensis BRFM1877, integrated 6 ldhA gene copies, and intracellular LDH activity was 9.2 × 10(-2) U/mg. At a final pH of 1.6, lactic acid titer reached 13.1 g/L (conversion yield: 26%, w/w) at 138 h in glucose-ammonium medium. This extreme pH drop was subsequently prevented by switching nitrogen source from ammonium sulfate to Na-nitrate, leading to a final pH of 3 and a lactic acid titer of 17.7 g/L (conversion yield: 47%, w/w) at 90 h of culture. Final titer was further improved to 32.2 g/L of lactic acid (conversion yield: 44%, w/w) by adding 20 g/L glucose to the culture medium at 96 h. This strain was ultimately able to produce lactic acid from xylose, arabinose, starch and xylan.
conclusionWe obtained the first Aspergillus strains able to produce large amounts of lactic acid by inserting recombinant ldhA genes from R. oryzae into a wild-type A. brasiliensis strain. pH regulation failed to significantly increase lactic acid production, but switching nitrogen source and changing culture feed enabled a 1.8-fold increase in conversion yields. The strain produced lactic acid from plant biomass. Our findings make A. brasiliensis a strong contender microorganism for low-pH acid production from various complex substrates, especially hemicellulose.
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