Biodetoxification fungus selectively degrades toxic inhibitors generated from pretreatment of lignocellulose without consuming fermentable sugars.However,one barrier for practical application is the sustained cell via...Biodetoxification fungus selectively degrades toxic inhibitors generated from pretreatment of lignocellulose without consuming fermentable sugars.However,one barrier for practical application is the sustained cell viability in the consequent fermentation step to compete the fermentable sugars with fermenting strains,resulting in sugar loss and reduced target product yield.This study investigated the competitive growth property between the biodetoxification fungus Paecilomyces variotii FN89 and the L-lactic acid bacterium Pediococcus acidilactici ZY271 under varying temperature and lactic acid osmatic stress.The results show that the L-lactic acid bacterium Ped.acidilactici ZY271 showed less thermotolerance to Pae.variotii FN89 at high temperature of 45°C to 50°C in both synthetic medium and wheat straw hydrolysate.In the higher temperature environment,the growth of the biodetoxification strian failed to compete with the lactic acid fermentation strain and was quickly eliminated from the fermentation system.The high temperature fermentation facilitated a fast transition from the detoxification stage to the fermentation stage for higher production of L-lactic acid.展开更多
The pretreatment of lignocellulosic biomass with acid generates phenolic and furanyl compounds that function as toxins by inhibiting microbial growth and metabolism.Therefore,it is necessary to detoxify acid-pretreate...The pretreatment of lignocellulosic biomass with acid generates phenolic and furanyl compounds that function as toxins by inhibiting microbial growth and metabolism.Therefore,it is necessary to detoxify acid-pretreated lignocellulosic biomass for better utilization.Among the various detoxification methods that are available,biodetoxification offers advantages that include mild reaction conditions and low energy consumption.In this study,a newly isolated Rhodococcus aetherivorans strain,N1,was found to effectively degrade various lignin-derived aromatic compounds,such as p-coumarate,ferulate,syringaldehyde,furfural,and 5-hydroxymethylfurfural.Furthermore,the metabolic pathway and genes responsible for this degradation were also identified.In addition,the overexpression of a demethylase(DesA)and 3,4-dioxygenase(DesZ)in strain N1 generated a recombinant strain,N1-S,which showed an enhanced ability to degrade syringaldehyde and 80.5%furfural,50.7%5-hydroxymethylfurfural,and 71.5%phenolic compounds in corn cob hydrolysate.The resulting detoxified hydrolysate was used directly as a feedstock for succinate production by Escherichia coli suc260.This afforded 35.3 g/l succinate,which was 6.5 times greater than the concentration afforded when nondetoxified hydrolysate was used.Overall,the results of this study demonstrate that strain N1-S is a valuable microbe for the biodetoxification of lignocellulosic biomass.展开更多
Plant-based beverages are an alternative to traditional cow milk due to intolerances and allergies as well as for ethical and environmental concerns.Nonetheless,raw materials used in the manufacture of these products ...Plant-based beverages are an alternative to traditional cow milk due to intolerances and allergies as well as for ethical and environmental concerns.Nonetheless,raw materials used in the manufacture of these products are at risk of mycotoxin contamination,being ochratoxin A(OTA)one of the mycotoxins detected.Recently,microbial enzymes have been described,some of them from microorganisms with GRAS(Generally Recognized As Safe)or QPS(Qualified Presumption of Safety)status,able to hydrolyze OTA into OTα,a much less-toxic compound.Since the use of lactic acid bacteria for the fermentation of plant-based beverages improved their nutritional and sensory properties,in this study lactic acid bacteria expressing microbial amidohydrolases from food safe microorganisms were used to ferment two plant-based beverages.Legume-based(soy)and cereal-based(oat)beverages artificially contaminated with OTA were fermented with three lactic acid bacteria strains(Lacti-lactobacillus sakei DSM 15831T Limosilactobacillus fermentum INIA 584L,and Limosilactobacillus reuteri INIA P572)expressing OTA-hydrolyzing enzymes from Aspergillus niger(AnOTA)and Brevibacterium linens(BlOTA).The OTA added to both beverages was greatly degraded during fermentation with the lactic acid bacteria assayed.The OTA-detoxification activity observed could be related to the composition and pH of the fermented beverage.The lower pH achieved in fermented oat,probably due to its high fermentable carbohydrate composition,reduced OTA-degrading activity of AnOTA ochratoxinase,mainly in Lactilactobacillus sakei.This first approach to explore OTA reduction in plant-based beverages paves the way for future applications of improved enzymes produced in food-grade expression systems.展开更多
Discovery and identification of robust biodetoxification strain is crucial for the sustainable and efficient operation of lignocellulosic biorefining process.Paecilomyces variotii FN89,a recently isolated mesophilic f...Discovery and identification of robust biodetoxification strain is crucial for the sustainable and efficient operation of lignocellulosic biorefining process.Paecilomyces variotii FN89,a recently isolated mesophilic filamentous fungi,was herein shown to be able to biodegrade lignocellulose-derived inhibitors including furfural(1.5 g/L),5-hydroxymethylfurfural(4 g/L),acetic acid(4 g/L),hydroxybenzaldehyde(0.2 g/L),syringaldehyde(0.2 g/L),and vanillin(1.5 g/L)efficiently and completely.P.variotii FN89 was adapted to mixed inhibitors and relatively low dissolved oxygen conditions,which can detoxify both the highly viscosity hydrolysate and solid biomass with the well preserve of fermentable sugars and no addition of any nutrients.Two biorefinery chains involving biodetoxification process were thus established to cope with different forms of pretreated biomass for cellulosic lactic acid production.The cellulosic lactic acid titers were above 100 g/L from 25%(w/w)solids loading pretreated wheat straw.The global transcriptome analysis of P.variotii FN89 in the presence of mixed inhibitors suggested that the glycolysis pathway and pentose phosphate pathway were repressed while tricarboxylic acid cycle was enhanced,ensuring the complete degradation of the inhibitors-derived intermediates and efficient energy supply.This study provided a unique and practical biodetoxification strain for lignocellulosic biorefinery,as well as enriched the knowledge of the molecular basis of lignocellulose-derived inhibitors tolerance and carbohydrates metabolism of P.variotii.展开更多
基金The National Key R&D Program of China(2023YFA0914400)the National Natural Science Foundation of China(32301269)+1 种基金China Postdoctoral Science Foundation(2023M741175)the Yangfan Project of Science and Technology Committee of Shanghai Municipality(23YF1409900).
文摘Biodetoxification fungus selectively degrades toxic inhibitors generated from pretreatment of lignocellulose without consuming fermentable sugars.However,one barrier for practical application is the sustained cell viability in the consequent fermentation step to compete the fermentable sugars with fermenting strains,resulting in sugar loss and reduced target product yield.This study investigated the competitive growth property between the biodetoxification fungus Paecilomyces variotii FN89 and the L-lactic acid bacterium Pediococcus acidilactici ZY271 under varying temperature and lactic acid osmatic stress.The results show that the L-lactic acid bacterium Ped.acidilactici ZY271 showed less thermotolerance to Pae.variotii FN89 at high temperature of 45°C to 50°C in both synthetic medium and wheat straw hydrolysate.In the higher temperature environment,the growth of the biodetoxification strian failed to compete with the lactic acid fermentation strain and was quickly eliminated from the fermentation system.The high temperature fermentation facilitated a fast transition from the detoxification stage to the fermentation stage for higher production of L-lactic acid.
基金supported by the National Key R&D Program of China(2023YFC3403502)the National Natural Science Foundation of China(22178169 and 22008113)+2 种基金the Jiangsu Province Natural Science Foundation for Jiangsu for Distinguished Young Scholars(BK20220052)the China Postdoctoral Science Foundation(2022M711605)the Jiangsu Synergetic Innovation Center for Advanced Biomanufacturing(XTD2215).
文摘The pretreatment of lignocellulosic biomass with acid generates phenolic and furanyl compounds that function as toxins by inhibiting microbial growth and metabolism.Therefore,it is necessary to detoxify acid-pretreated lignocellulosic biomass for better utilization.Among the various detoxification methods that are available,biodetoxification offers advantages that include mild reaction conditions and low energy consumption.In this study,a newly isolated Rhodococcus aetherivorans strain,N1,was found to effectively degrade various lignin-derived aromatic compounds,such as p-coumarate,ferulate,syringaldehyde,furfural,and 5-hydroxymethylfurfural.Furthermore,the metabolic pathway and genes responsible for this degradation were also identified.In addition,the overexpression of a demethylase(DesA)and 3,4-dioxygenase(DesZ)in strain N1 generated a recombinant strain,N1-S,which showed an enhanced ability to degrade syringaldehyde and 80.5%furfural,50.7%5-hydroxymethylfurfural,and 71.5%phenolic compounds in corn cob hydrolysate.The resulting detoxified hydrolysate was used directly as a feedstock for succinate production by Escherichia coli suc260.This afforded 35.3 g/l succinate,which was 6.5 times greater than the concentration afforded when nondetoxified hydrolysate was used.Overall,the results of this study demonstrate that strain N1-S is a valuable microbe for the biodetoxification of lignocellulosic biomass.
基金financially supported by grant PID-2021-123291OB-I00 funded by MCIN/AEI/10.13039/501100011033by ERDF A way of making Europe+1 种基金a recipient of the PRE2018-083862 FPI contract funded by MCIN/AEI/10.13039/501100011033by ESF Investing in your future.
文摘Plant-based beverages are an alternative to traditional cow milk due to intolerances and allergies as well as for ethical and environmental concerns.Nonetheless,raw materials used in the manufacture of these products are at risk of mycotoxin contamination,being ochratoxin A(OTA)one of the mycotoxins detected.Recently,microbial enzymes have been described,some of them from microorganisms with GRAS(Generally Recognized As Safe)or QPS(Qualified Presumption of Safety)status,able to hydrolyze OTA into OTα,a much less-toxic compound.Since the use of lactic acid bacteria for the fermentation of plant-based beverages improved their nutritional and sensory properties,in this study lactic acid bacteria expressing microbial amidohydrolases from food safe microorganisms were used to ferment two plant-based beverages.Legume-based(soy)and cereal-based(oat)beverages artificially contaminated with OTA were fermented with three lactic acid bacteria strains(Lacti-lactobacillus sakei DSM 15831T Limosilactobacillus fermentum INIA 584L,and Limosilactobacillus reuteri INIA P572)expressing OTA-hydrolyzing enzymes from Aspergillus niger(AnOTA)and Brevibacterium linens(BlOTA).The OTA added to both beverages was greatly degraded during fermentation with the lactic acid bacteria assayed.The OTA-detoxification activity observed could be related to the composition and pH of the fermented beverage.The lower pH achieved in fermented oat,probably due to its high fermentable carbohydrate composition,reduced OTA-degrading activity of AnOTA ochratoxinase,mainly in Lactilactobacillus sakei.This first approach to explore OTA reduction in plant-based beverages paves the way for future applications of improved enzymes produced in food-grade expression systems.
基金supported by the National Key R&D Program of China(2023YFA0914400)the National Natural Science Foundation of China(32301269)+1 种基金the Yangfan Project of Science and Technology Committee of Shanghai Municipality(23YF1409900)the Key Technology R&D Program of the Science and Technology Commission of Shanghai Municipality(25HC2820200).
文摘Discovery and identification of robust biodetoxification strain is crucial for the sustainable and efficient operation of lignocellulosic biorefining process.Paecilomyces variotii FN89,a recently isolated mesophilic filamentous fungi,was herein shown to be able to biodegrade lignocellulose-derived inhibitors including furfural(1.5 g/L),5-hydroxymethylfurfural(4 g/L),acetic acid(4 g/L),hydroxybenzaldehyde(0.2 g/L),syringaldehyde(0.2 g/L),and vanillin(1.5 g/L)efficiently and completely.P.variotii FN89 was adapted to mixed inhibitors and relatively low dissolved oxygen conditions,which can detoxify both the highly viscosity hydrolysate and solid biomass with the well preserve of fermentable sugars and no addition of any nutrients.Two biorefinery chains involving biodetoxification process were thus established to cope with different forms of pretreated biomass for cellulosic lactic acid production.The cellulosic lactic acid titers were above 100 g/L from 25%(w/w)solids loading pretreated wheat straw.The global transcriptome analysis of P.variotii FN89 in the presence of mixed inhibitors suggested that the glycolysis pathway and pentose phosphate pathway were repressed while tricarboxylic acid cycle was enhanced,ensuring the complete degradation of the inhibitors-derived intermediates and efficient energy supply.This study provided a unique and practical biodetoxification strain for lignocellulosic biorefinery,as well as enriched the knowledge of the molecular basis of lignocellulose-derived inhibitors tolerance and carbohydrates metabolism of P.variotii.
