{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Hu M"],"funding":["National Natural Science Foundation of China"],"pagination":["1135484"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC9989019"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["11"],"pubmed_abstract":["Lactate is the precursor for polylactide. In this study, a lactate producer of <i>Z. mobilis</i> was constructed by replacing <i>ZMO0038</i> with <i>LmldhA</i> gene driven by a strong promoter P<i>adhB</i>, replacing <i>ZMO1650</i> with native <i>pdc</i> gene driven by P<i>tet,</i> and replacing native <i>pdc</i> with another copy of <i>LmldhA</i> driven by P<i>adhB</i> to divert carbon from ethanol to D-lactate. The resultant strain ZML-pdc-ldh produced 13.8 ± 0.2 g/L lactate and 16.9 ± 0.3 g/L ethanol using 48 g/L glucose. Lactate production of ZML-pdc-ldh was further investigated after fermentation optimization in pH-controlled fermenters. ZML-pdc-ldh produced 24.2 ± 0.6 g/L lactate and 12.9 ± 0.8 g/L ethanol as well as 36.2 ± 1.0 g/L lactate and 40.3 ± 0.3 g/L ethanol, resulting in total carbon conversion rate of 98.3% ± 2.5% and 96.2% ± 0.1% with final product productivity of 1.9 ± 0.0 g/L/h and 2.2 ± 0.0 g/L/h in RMG5 and RMG12, respectively. Moreover, ZML-pdc-ldh produced 32.9 ± 0.1 g/L D-lactate and 27.7 ± 0.2 g/L ethanol as well as 42.8 ± 0.0 g/L D-lactate and 53.1 ± 0.7 g/L ethanol with 97.1% ± 0.0% and 99.1% ± 0.8% carbon conversion rate using 20% molasses or corncob residue hydrolysate, respectively. Our study thus demonstrated that it is effective for lactate production by fermentation condition optimization and metabolic engineering to strengthen heterologous <i>ldh</i> expression while reducing the native ethanol production pathway. The capability of recombinant lactate-producer of <i>Z. mobilis</i> for efficient waste feedstock conversion makes it a promising biorefinery platform for carbon-neutral biochemical production."],"journal":["Frontiers in bioengineering and biotechnology"],"pubmed_title":["Metabolic engineering of <i>Zymomonas mobilis</i> for co-production of D-lactic acid and ethanol using waste feedstocks of molasses and corncob residue hydrolysate."],"pmcid":["PMC9989019"],"funding_grant_id":["21978071 U1932141"],"pubmed_authors":["Yang X","Xu P","Hu W","Hu M","Bao W","Peng Q","Xiang Y","He Q","Yan X","Yang S","Li M"],"additional_accession":[]},"is_claimable":false,"name":"Metabolic engineering of <i>Zymomonas mobilis</i> for co-production of D-lactic acid and ethanol using waste feedstocks of molasses and corncob residue hydrolysate.","description":"Lactate is the precursor for polylactide. In this study, a lactate producer of <i>Z. mobilis</i> was constructed by replacing <i>ZMO0038</i> with <i>LmldhA</i> gene driven by a strong promoter P<i>adhB</i>, replacing <i>ZMO1650</i> with native <i>pdc</i> gene driven by P<i>tet,</i> and replacing native <i>pdc</i> with another copy of <i>LmldhA</i> driven by P<i>adhB</i> to divert carbon from ethanol to D-lactate. The resultant strain ZML-pdc-ldh produced 13.8 ± 0.2 g/L lactate and 16.9 ± 0.3 g/L ethanol using 48 g/L glucose. Lactate production of ZML-pdc-ldh was further investigated after fermentation optimization in pH-controlled fermenters. ZML-pdc-ldh produced 24.2 ± 0.6 g/L lactate and 12.9 ± 0.8 g/L ethanol as well as 36.2 ± 1.0 g/L lactate and 40.3 ± 0.3 g/L ethanol, resulting in total carbon conversion rate of 98.3% ± 2.5% and 96.2% ± 0.1% with final product productivity of 1.9 ± 0.0 g/L/h and 2.2 ± 0.0 g/L/h in RMG5 and RMG12, respectively. Moreover, ZML-pdc-ldh produced 32.9 ± 0.1 g/L D-lactate and 27.7 ± 0.2 g/L ethanol as well as 42.8 ± 0.0 g/L D-lactate and 53.1 ± 0.7 g/L ethanol with 97.1% ± 0.0% and 99.1% ± 0.8% carbon conversion rate using 20% molasses or corncob residue hydrolysate, respectively. Our study thus demonstrated that it is effective for lactate production by fermentation condition optimization and metabolic engineering to strengthen heterologous <i>ldh</i> expression while reducing the native ethanol production pathway. The capability of recombinant lactate-producer of <i>Z. mobilis</i> for efficient waste feedstock conversion makes it a promising biorefinery platform for carbon-neutral biochemical production.","dates":{"release":"2023-01-01T00:00:00Z","publication":"2023","modification":"2026-06-23T03:13:13.065Z","creation":"2025-04-19T16:26:27.704Z"},"accession":"S-EPMC9989019","cross_references":{"pubmed":["36896016"],"doi":["10.3389/fbioe.2023.1135484"]}}