scholarly journals Engineered yeast tolerance enables efficient production from toxified lignocellulosic feedstocks

2021 ◽  
Vol 7 (26) ◽  
pp. eabf7613
Author(s):  
Felix H. Lam ◽  
Burcu Turanlı-Yıldız ◽  
Dany Liu ◽  
Michael G. Resch ◽  
Gerald R. Fink ◽  
...  
Keyword(s):  
Cellulosic Ethanol ◽  
Lightweight Design ◽  
Cost Effective ◽  
Extracellular Potassium ◽  
Efficient Production ◽  
Single Strain ◽  
Lignocellulosic Feedstocks ◽  
Engineered Yeast ◽  
Fuels And Chemicals ◽  
Aldehyde Reduction

Lignocellulosic biomass remains unharnessed for the production of renewable fuels and chemicals due to challenges in deconstruction and the toxicity its hydrolysates pose to fermentation microorganisms. Here, we show in Saccharomyces cerevisiae that engineered aldehyde reduction and elevated extracellular potassium and pH are sufficient to enable near-parity production between inhibitor-laden and inhibitor-free feedstocks. By specifically targeting the universal hydrolysate inhibitors, a single strain is enhanced to tolerate a broad diversity of highly toxified genuine feedstocks and consistently achieve industrial-scale titers (cellulosic ethanol of >100 grams per liter when toxified). Furthermore, a functionally orthogonal, lightweight design enables seamless transferability to existing metabolically engineered chassis strains: We endow full, multifeedstock tolerance on a xylose-consuming strain and one producing the biodegradable plastics precursor lactic acid. The demonstration of “drop-in” hydrolysate competence enables the potential of cost-effective, at-scale biomass utilization for cellulosic fuel and nonfuel products alike.

scholarly journals Further engineering of R. toruloides for the production of terpenes from lignocellulosic biomass

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
James Kirby ◽  
Gina M. Geiselman ◽  
Junko Yaegashi ◽  
Joonhoon Kim ◽  
Xun Zhuang ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Copy Number ◽  
Mevalonate Pathway ◽  
Mevalonate Kinase ◽  
Metabolite Analysis ◽  
Lignocellulosic Hydrolysate ◽  
Microbial Conversion ◽  
Lignocellulosic Hydrolysates ◽  
Lignocellulosic Feedstocks ◽  
Fuels And Chemicals

Abstract Background Mitigation of climate change requires that new routes for the production of fuels and chemicals be as oil-independent as possible. The microbial conversion of lignocellulosic feedstocks into terpene-based biofuels and bioproducts represents one such route. This work builds upon previous demonstrations that the single-celled carotenogenic basidiomycete, Rhodosporidium toruloides, is a promising host for the production of terpenes from lignocellulosic hydrolysates. Results This study focuses on the optimization of production of the monoterpene 1,8-cineole and the sesquiterpene α-bisabolene in R. toruloides. The α-bisabolene titer attained in R. toruloides was found to be proportional to the copy number of the bisabolene synthase (BIS) expression cassette, which in turn influenced the expression level of several native mevalonate pathway genes. The addition of more copies of BIS under a stronger promoter resulted in production of α-bisabolene at 2.2 g/L from lignocellulosic hydrolysate in a 2-L fermenter. Production of 1,8-cineole was found to be limited by availability of the precursor geranylgeranyl pyrophosphate (GPP) and expression of an appropriate GPP synthase increased the monoterpene titer fourfold to 143 mg/L at bench scale. Targeted mevalonate pathway metabolite analysis suggested that 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGR), mevalonate kinase (MK) and phosphomevalonate kinase (PMK) may be pathway bottlenecks are were therefore selected as targets for overexpression. Expression of HMGR, MK, and PMK orthologs and growth in an optimized lignocellulosic hydrolysate medium increased the 1,8-cineole titer an additional tenfold to 1.4 g/L. Expression of the same mevalonate pathway genes did not have as large an impact on α-bisabolene production, although the final titer was higher at 2.6 g/L. Furthermore, mevalonate pathway intermediates accumulated in the mevalonate-engineered strains, suggesting room for further improvement. Conclusions This work brings R. toruloides closer to being able to make industrially relevant quantities of terpene from lignocellulosic biomass.

scholarly journals Transforming biorefinery designs with ‘Plug-In Processes of Lignin’ to enable economic waste valorization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhi-Hua Liu ◽  
Naijia Hao ◽  
Yun-Yan Wang ◽  
Chang Dou ◽  
Furong Lin ◽  
...  
Keyword(s):  
Cellulosic Ethanol ◽  
Cost Effective ◽  
Substantial Improvement ◽  
Selling Price ◽  
Waste Valorization ◽  
Lignin Valorization ◽  
Capital Costs ◽  
Carbon Efficiency ◽  
Synergistic Enhancement ◽  
Total Capital

AbstractBiological lignin valorization has emerged as a major solution for sustainable and cost-effective biorefineries. However, current biorefineries yield lignin with inadequate fractionation for bioconversion, yet substantial changes of these biorefinery designs to focus on lignin could jeopardize carbohydrate efficiency and increase capital costs. We resolve the dilemma by designing ‘plug-in processes of lignin’ with the integration of leading pretreatment technologies. Substantial improvement of lignin bioconversion and synergistic enhancement of carbohydrate processing are achieved by solubilizing lignin via lowering molecular weight and increasing hydrophilic groups, addressing the dilemma of lignin- or carbohydrate-first scenarios. The plug-in processes of lignin could enable minimum polyhydroxyalkanoate selling price at as low as $6.18/kg. The results highlight the potential to achieve commercial production of polyhydroxyalkanoates as a co-product of cellulosic ethanol. Here, we show that the plug-in processes of lignin could transform biorefinery design toward sustainability by promoting carbon efficiency and optimizing the total capital cost.

scholarly journals Efficient Production of Acetic Acid from Nipa (Nypa fruticans) Sap by Moorella thermoacetica (f. Clostridium thermoaceticum)

2019 ◽  
Author(s):  
Dung Van Nguyen ◽  
Pinthep Sethapokin ◽  
Harifara Rabemanolontsoa ◽  
Eiji Minami ◽  
Haruo Kawamoto ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Oxalic Acid ◽  
Acid Catalyst ◽  
Cost Effective ◽  
Efficient Production ◽  
Acid Fermentation ◽  
Acid Yield ◽  
Moorella Thermoacetica ◽  
Nypa Fruticans ◽  
Hydrolysis Of

To valorize the underutilized nipa sap composed mainly of sucrose, glucose and fructose, acetic acid fermentation by Moorella thermoacetica was explored. Given that M. thermoacetica cannot directly metabolize sucrose, we evaluated various catalysts for the hydrolysis of this material. Oxalic acid and invertase exhibited high levels of activity towards the hydrolysis of the sucrose in nipa sap to glucose and fructose. Although these two methods consumed similar levels of energy for the hydrolysis of sucrose, oxalic acid was found to be more cost-effective. Nipa saps hydrolyzed by these two catalysts were also fermented by M. thermoacetica. The results revealed that the two hydrolyzed sap mixtures gave 10.0 g/L of acetic acid from the 10.2 g/L of substrate sugars in nipa sap. Notably, the results showed that the oxalic acid catalyst was also fermented to acetic acid, which avoided the need to remove the catalyst from the product stream. Taken together, these results show that oxalic acid hydrolysis is superior to enzymatic hydrolysis for the pretreatment of nipa sap. The acetic acid yield achieved in this study corresponds to a conversion efficiency of 98%, which is about 3.6 times higher than that achieved using the traditional methods. The process developed in this study therefore has high potential as a green biorefinery process for the efficient conversion of sucrose-containing nipa sap to bio-derived acetic acid.

scholarly journals A novel biocatalyst for efficient production of 2-oxo-carboxylates using glycerol as the cost-effective carbon source

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Yujiao Wang ◽  
Yingxin Zhang ◽  
Tianyi Jiang ◽  
Jingjing Meng ◽  
Binbin Sheng ◽  
...  
Keyword(s):  
Carbon Source ◽  
Cost Effective ◽  
Efficient Production ◽  
The Cost

A cost-effective integrated process to convert solid-state fermented sweet sorghum bagasse into cellulosic ethanol

2014 ◽  
Vol 115 ◽  
pp. 331-336 ◽  
Author(s):  
Menghui Yu ◽  
Jihong Li ◽  
Shizhong Li ◽  
Ran Du ◽  
Yan Jiang ◽  
...  
Keyword(s):  
Solid State ◽  
Cellulosic Ethanol ◽  
Sweet Sorghum ◽  
Cost Effective ◽  
Sweet Sorghum Bagasse ◽  
Integrated Process ◽  
Sorghum Bagasse

Optimization of an acetate reduction pathway for producing cellulosic ethanol by engineered yeast

2016 ◽  
Vol 113 (12) ◽  
pp. 2587-2596 ◽  
Author(s):  
Guo-Chang Zhang ◽  
In Iok Kong ◽  
Na Wei ◽  
Dairong Peng ◽  
Timothy L. Turner ◽  
...  
Keyword(s):  
Cellulosic Ethanol ◽  
Engineered Yeast ◽  
Acetate Reduction

scholarly journals Production of alkanes from CO2 by engineered bacteria

2018 ◽  
Author(s):  
Tapio Lehtinen ◽  
Henri Virtanen ◽  
Suvi Santala ◽  
Ville Santala
Keyword(s):  
Production Systems ◽  
Liquid Fuels ◽  
Modular System ◽  
Fatty Aldehyde ◽  
Efficient Production ◽  
Acinetobacter Baylyi ◽  
Single Organism ◽  
Fuels And Chemicals ◽  
Microbial Biosynthesis ◽  
Long Chain

AbstractBackgroundMicrobial biosynthesis of alkanes is considered a promising method for the sustainable production of drop-in fuels and chemicals. Carbon dioxide would be an ideal carbon source for these production systems, but efficient production of long carbon chains from CO2is difficult to achieve in a single organism. A potential solution is to employ acetogenic bacteria for the reduction of CO2to acetate, and engineer a second organism to convert the acetate into long-chain hydrocarbons.ResultsIn this study, we demonstrate alkane production from CO2by a system combining the acetogenAcetobacterium woodiiand a non-native alkane producerAcinetobacter baylyiADP1 engineered for alkane production. Nine synthetic two-step alkane biosynthesis pathways consisting of different aldehyde- and alkane-producing enzymes were combinatorically constructed and expressed inA. baylyi.The aldehyde-producing enzymes studied were AAR fromSynechococcus elongatus,Acr1 fromA. baylyi,and Ramo, a putative dehydrogenase, fromNevskia ramosa.The alkane-producing enzymes were ADOs fromS. elongatusandNostoc punctiforme,and CER1 fromArabidopsis thaliana.The performance of the pathways was evaluated with a twin-layer biosensor, which allowed the monitoring of both the intermediate, fatty aldehyde, as well as the alkane production. The highest alkane production, as indicated by the biosensor, was achieved with a pathway consisting of AAR and ADO fromS. elongatus.The performance of this pathway was further improved by balancing the relative expression levels of the enzymes in order to limit the accumulation of the intermediate fatty aldehyde. Finally, the acetogenA. woodiiwas used to produce acetate from CO2and H2, and the acetate was used for alkane production by the engineeredA. baylyi,thereby leading to the net production of long-chain alkanes from CO2.ConclusionsA modular system for the production of drop-in liquid fuels from CO2was demonstrated. Among the studied synthetic pathways, the combination of ADO and AAR fromS. elongatuswas found to be the most efficient in heterologous alkane production inA. baylyi.Furthermore, limiting the accumulation of the fatty aldehyde intermediate was found to be beneficial for the alkane production.

scholarly journals Efficient Production of Acetic Acid from Nipa (Nypa fruticans) Sap by Moorella thermoacetica (f. Clostridium thermoaceticum)

2019 ◽  
Author(s):  
Dung Van Nguyen ◽  
Pinthep Sethapokin ◽  
Harifara Rabemanolontsoa ◽  
Eiji Minami ◽  
Haruo Kawamoto ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Oxalic Acid ◽  
Acid Catalyst ◽  
Cost Effective ◽  
Efficient Production ◽  
Acid Fermentation ◽  
Acid Yield ◽  
Moorella Thermoacetica ◽  
Nypa Fruticans ◽  
Hydrolysis Of

To valorize the underutilized nipa sap composed mainly of sucrose, glucose and fructose, acetic acid fermentation by Moorella thermoacetica was explored. Given that M. thermoacetica cannot directly metabolize sucrose, we evaluated various catalysts for the hydrolysis of this material. Oxalic acid and invertase exhibited high levels of activity towards the hydrolysis of the sucrose in nipa sap to glucose and fructose. Although these two methods consumed similar levels of energy for the hydrolysis of sucrose, oxalic acid was found to be more cost-effective. Nipa saps hydrolyzed by these two catalysts were also fermented by M. thermoacetica. The results revealed that the two hydrolyzed sap mixtures gave 10.0 g/L of acetic acid from the 10.2 g/L of substrate sugars in nipa sap. Notably, the results showed that the oxalic acid catalyst was also fermented to acetic acid, which avoided the need to remove the catalyst from the product stream. Taken together, these results show that oxalic acid hydrolysis is superior to enzymatic hydrolysis for the pretreatment of nipa sap. The acetic acid yield achieved in this study corresponds to a conversion efficiency of 98%, which is about 3.6 times higher than that achieved using the traditional methods. The process developed in this study therefore has high potential as a green biorefinery process for the efficient conversion of sucrose-containing nipa sap to bio-derived acetic acid.

scholarly journals Characterizing an engineered carotenoid-producing yeast as an anti-stress chassis for building cell factories

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Hsien-Lin Liu ◽  
Jui-Jen Chang ◽  
Caroline Thia ◽  
Yu-Ju Lin ◽  
Shou-Chen Lo ◽  
...  
Keyword(s):  
Ethanol Tolerance ◽  
Cost Effective ◽  
Carotenoid Biosynthesis ◽  
Wild Type ◽  
Cell Factories ◽  
Natural Medicine ◽  
Engineered Yeast ◽  
Radical Removal ◽  
Carotenoid Biosynthesis Pathway ◽  
Tolerance To Ethanol

Abstract Background A microorganism engineered for non-native tasks may suffer stresses it never met before. Therefore, we examined whether a Kluyveromyces marxianus strain engineered with a carotenoid biosynthesis pathway can serve as an anti-stress chassis for building cell factories. Results Carotenoids, a family of antioxidants, are valuable natural products with high commercial potential. We showed that the free radical removal ability of carotenoids can confer the engineered host with a higher tolerance to ethanol, so that it can produce more bio-ethanol than the wild type. Moreover, we found that this engineered strain has improved tolerance to other toxic effects including furfurals, heavy metals such as arsenate (biomass contaminant) and isobutanol (end product). Furthermore, the enhanced ethanol tolerance of the host can be applied to bioconversion of a natural medicine that needs to use ethanol as the delivery solvent of hydrophobic precursors. The result suggested that the engineered yeast showed enhanced tolerance to ethanol-dissolved hydrophobic 10-deacetylbaccatin III, which is considered a sustainable precursor for paclitaxel (taxol) bioconversion. Conclusions The stress tolerances of the engineered yeast strain showed tolerance to several toxins, so it may serve as a chassis for cell factories to produce target products, and the co-production of carotenoids may make the biorefinary more cost-effective.

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