Ethanol-lactate transition of Lachancea thermotolerans is linked to nitrogen metabolism

Climate change increases sugar content in grapes, resulting in unwanted increase in ethanol content of wine. Lachancea thermotolerans ferments glucose and fructose into both ethanol and lactate, decreasing final ethanol content and positively affecting wine acidity. Reported Lachancea thermotolerans strains show big variation in lactate production during fermentation. However, a mechanistic understanding of this lactate producing phenotype is currently lacking. Through a combination of metabolomics, transcriptomics, genomics and computational methods we show that the lactate production is induced by amino acid limitation in a high lactate producing strain. We found in fermentations in synthetic grape juice media that lactate production starts in the last stages of growth, marked by decreased growth rate and increased expression levels of stress related genes. This onset of lactate production is specific for the high lactate producing strain and independent of oxygen availability. The onset of lactate production was changed by increased amino acid content of the media, and it is shown by both computational methods and amino acid measurements that at the onset of lactate production amino acids become limiting for growth. This study shows that lactate production of Lachancea thermotolerans is directly linked to nitrogen availability in the media, an insight that can further aid in the improvement of wine quality

Ethanol-Lactate Transition of Lachancea Thermotolerans Is Linked to Nitrogen Metabolism

Climate change increases sugar content in grapes, resulting in unwanted increase in ethanol content of wine. Lachancea thermotolerans ferments glucose and fructose into both ethanol and lactate, decreasing final ethanol content and positively affecting wine acidity. Reported Lachancea thermotolerans strains show big variation in lactate production during fermentation. However, a mechanistic understanding of this lactate producing phenotype is currently lacking. Through a combination of metabolomics, transcriptomics, genomics and computational methods we show that the lactate production is induced by amino acid limitation in a high lactate producing strain. We found in fermentations in synthetic grape juice media that lactate production starts in the last stages of growth, marked by decreased growth rate and increased expression levels of stress related genes. This onset of lactate production is specific for the high lactate producing strain and independent of oxygen availability. The onset of lactate production was changed by increased amino acid content of the media, and it is shown by both computational methods and amino acid measurements that at the onset of lactate production amino acids become limiting for growth. This study shows that lactate production of Lachancea thermotolerans is directly linked to nitrogen availability in the media, an insight that can further aid in the improvement of wine quality

Ethanol-Lactate Transition of Lachancea Thermotolerans Is Linked to Nitrogen Metabolism

Climate change increases sugar content in grapes, resulting in unwanted increase in ethanol content of wine. Lachancea thermotolerans ferments glucose and fructose into both ethanol and lactate, decreasing final ethanol content and positively affecting wine acidity. Reported Lachancea thermotolerans strains show big variation in lactate production during fermentation. However, a mechanistic understanding of this lactate producing phenotype is currently lacking. Through a combination of metabolomics, transcriptomics, genomics and computational methods we show that the lactate production is induced by amino acid limitation in a high lactate producing strain. We found in fermentations in synthetic grape juice media that lactate production starts in the last stages of growth, marked by decreased growth rate and increased expression levels of stress related genes. This onset of lactate production is specific for the high lactate producing strain and independent of oxygen availability. The onset of lactate production was changed by increased amino acid content of the media, and it is shown by both computational methods and amino acid measurements that at the onset of lactate production amino acids become limiting for growth. This study shows that lactate production of Lachancea thermotolerans is directly linked to nitrogen availability in the media, an insight that can further aid in the improvement of wine quality

Implementation of Best Practices in Pancreatic Cancer Care in the Netherlands:A Stepped-Wedge Randomized Clinical Trial

Importance: Implementation of new cancer treatment strategies as recommended by evidence-based guidelines is often slow and suboptimal. Objective: To improve the implementation of guideline-based best practices in the Netherlands in pancreatic cancer care and assess the impact on survival. Design, setting, and participants: This multicenter, stepped-wedge cluster randomized trial compared enhanced implementation of best practices with usual care in consecutive patients with all stages of pancreatic cancer. It took place from May 22, 2018 through July 9, 2020. Data were analyzed from April 1, 2022, through February 1, 2023. It included all patients in the Netherlands with pathologically or clinically diagnosed pancreatic ductal adenocarcinoma. This study reports 1-year follow-up (or shorter in case of deceased patients). Intervention: The 5 best practices included optimal use of perioperative chemotherapy, palliative chemotherapy, pancreatic enzyme replacement therapy (PERT), referral to a dietician, and use of metal stents in patients with biliary obstruction. A 6-week implementation period was completed, in a randomized order, in all 17 Dutch networks for pancreatic cancer care. Main Outcomes and Measures: The primary outcome was 1-year survival. Secondary outcomes included adherence to best practices and quality of life (European Organisation for Research and Treatment of Cancer [EORTC] global health score). Results: Overall, 5887 patients with pancreatic cancer (median age, 72.0 [IQR, 64.0-79.0] years; 50% female) were enrolled, 2641 before and 2939 after implementation of best practices (307 during wash-in period). One-year survival was 24% vs 23% (hazard ratio, 0.98, 95% CI, 0.88-1.08). There was no difference in the use of neoadjuvant chemotherapy (11% vs 11%), adjuvant chemotherapy (48% vs 51%), and referral to a dietician (59% vs 63%), while the use of palliative chemotherapy (24% vs 30%; odds ratio [OR], 1.38; 95% CI, 1.10-1.74), PERT (34% vs 45%; OR, 1.64; 95% CI, 1.28-2.11), and metal biliary stents increased (74% vs 83%; OR, 1.78; 95% CI, 1.13-2.80). The EORTC global health score did not improve (area under the curve, 43.9 vs 42.8; median difference, -1.09, 95% CI, -3.05 to 0.94). Conclusions and Relevance: In this randomized clinical trial, implementation of 5 best practices in pancreatic cancer care did not improve 1-year survival and quality of life. The finding that most patients received no tumor-directed treatment paired with the poor survival highlights the need for more personalized treatment options. Trial Registration: ClinicalTrials.gov Identifier: NCT03513705.</p

Implementation of Best Practices in Pancreatic Cancer Care in the Netherlands:A Stepped-Wedge Randomized Clinical Trial

Importance: Implementation of new cancer treatment strategies as recommended by evidence-based guidelines is often slow and suboptimal. Objective: To improve the implementation of guideline-based best practices in the Netherlands in pancreatic cancer care and assess the impact on survival. Design, setting, and participants: This multicenter, stepped-wedge cluster randomized trial compared enhanced implementation of best practices with usual care in consecutive patients with all stages of pancreatic cancer. It took place from May 22, 2018 through July 9, 2020. Data were analyzed from April 1, 2022, through February 1, 2023. It included all patients in the Netherlands with pathologically or clinically diagnosed pancreatic ductal adenocarcinoma. This study reports 1-year follow-up (or shorter in case of deceased patients). Intervention: The 5 best practices included optimal use of perioperative chemotherapy, palliative chemotherapy, pancreatic enzyme replacement therapy (PERT), referral to a dietician, and use of metal stents in patients with biliary obstruction. A 6-week implementation period was completed, in a randomized order, in all 17 Dutch networks for pancreatic cancer care. Main Outcomes and Measures: The primary outcome was 1-year survival. Secondary outcomes included adherence to best practices and quality of life (European Organisation for Research and Treatment of Cancer [EORTC] global health score). Results: Overall, 5887 patients with pancreatic cancer (median age, 72.0 [IQR, 64.0-79.0] years; 50% female) were enrolled, 2641 before and 2939 after implementation of best practices (307 during wash-in period). One-year survival was 24% vs 23% (hazard ratio, 0.98, 95% CI, 0.88-1.08). There was no difference in the use of neoadjuvant chemotherapy (11% vs 11%), adjuvant chemotherapy (48% vs 51%), and referral to a dietician (59% vs 63%), while the use of palliative chemotherapy (24% vs 30%; odds ratio [OR], 1.38; 95% CI, 1.10-1.74), PERT (34% vs 45%; OR, 1.64; 95% CI, 1.28-2.11), and metal biliary stents increased (74% vs 83%; OR, 1.78; 95% CI, 1.13-2.80). The EORTC global health score did not improve (area under the curve, 43.9 vs 42.8; median difference, -1.09, 95% CI, -3.05 to 0.94). Conclusions and Relevance: In this randomized clinical trial, implementation of 5 best practices in pancreatic cancer care did not improve 1-year survival and quality of life. The finding that most patients received no tumor-directed treatment paired with the poor survival highlights the need for more personalized treatment options. Trial Registration: ClinicalTrials.gov Identifier: NCT03513705.</p