Overexpression of the genes of glycerol catabolism and glycerol facilitator improves glycerol conversion to ethanol in the methylotrophic thermotolerant yeastOgataea polymorpha

Yeast ◽  
2019 ◽  
Vol 36 (5) ◽  
pp. 329-339 ◽  
Author(s):  
Marta Semkiv ◽  
Iwona Kata ◽  
Orysya Ternavska ◽  
Wladimir Sibirny ◽  
Kostyantyn Dmytruk ◽  
...  
Keyword(s):  
Glycerol Conversion ◽  
Glycerol Facilitator

DESIGN AND PERFORMANCE EVALUATION OF A PLANT FOR GLYCEROL CONVERSION TO ACROLEIN

2015 ◽  
Vol 14 (3) ◽  
pp. 509-517 ◽  
Author(s):  
Ionut Banu ◽  
Georgiana Guta ◽  
Costin Sorin Bildea ◽  
Grigore Bozga
Keyword(s):  
Performance Evaluation ◽  
Glycerol Conversion ◽  
And Performance

scholarly journals Glycerol Hydrogenolysis with In Situ Hydrogen Produced via Methanol Steam Reforming: The Promoting Effect of Pd on a Cu/ZnO/Al2O3 Catalyst

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 110
Author(s):  
Yuanqing Liu ◽  
Chau T. Q. Mai ◽  
Flora T. T. Ng
Keyword(s):  
Steam Reforming ◽  
Catalyst Activity ◽  
Promoting Effect ◽  
Glycerol Conversion ◽  
Glycerol Hydrogenolysis ◽  
Glycerol Dehydration ◽  
Effect Of Pd ◽  
Al2o3 Catalyst ◽  
Reaction Equilibrium

The glycerol hydrogenolysis to produce 1,2-propanediol without using externally supplied hydrogen was investigated using methanol present in crude glycerol to provide in situ hydrogen via its steam reforming reaction. This paper focuses on the promoting effect of Pd on the reactivity of a Cu/Zn/Al2O3 catalyst. Adding 2 wt% Pd onto a Cu/ZnO/Al2O3 catalyst significantly improved the selectivity to 1,2-propanediol from 63.0% to 82.4% and the glycerol conversion from 70.2% to 99.4%. This enhancement on the catalytic activity by Pd is mainly due to the improved hydrogenation of acetol, which is the intermediate formed during the glycerol dehydration. The rapid hydrogenation of acetol can shift the reaction equilibrium of glycerol dehydration forward resulting in a higher glycerol conversion. The improved reducibility of the catalyst by Pd allows the catalyst to be reduced in situ during the reaction preventing any loss of catalyst activity due to any potential oxidation of the catalyst. The catalyst was slightly deactivated when it was firstly recycled resulting in a 5.4% loss of glycerol conversion due to the aggregation of Cu and the deactivation became less noticeable upon further recycling.

Enhance glycerol conversion through co-etherification with isobutene and tert-butanol

2021 ◽  
Vol 218 ◽  
pp. 106838
Author(s):  
Jingjun Liu ◽  
Yuying Jiang ◽  
Peng Zhang ◽  
Bolun Yang
Keyword(s):  
Glycerol Conversion ◽  
Tert Butanol

Preparation of Ni Loaded on Zeolite and its Application for Conversion of Glycerol to Hydrogen

2013 ◽  
Vol 845 ◽  
pp. 457-461
Author(s):  
Ramli Mat ◽  
Junaidah Buhari ◽  
Mahadhir Mohamed ◽  
Anwar Johari ◽  
Tuan Amran Tuan Abdullah ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Hydrogen Gas ◽  
Biodiesel Production ◽  
Esterification Reaction ◽  
Glycerol Conversion ◽  
Reactor Temperature

Glycerol is the main by-product of biodiesel production and during the trans-esterification reaction, about 10 wt % of glycerol is produced. In this study, different amount of Ni was loaded on HZSM-5 and tested for the conversion of glycerol to hydrogen. The studies were also conducted at different reactor temperature of 450, 500, 550, 600 and 650°C respectively. The structural characterization of the catalyst was carried out using the XRD. It was found that, the addition of 15 wt % of nickel loaded on HZSM-5 shows the highest glycerol conversion of 98.54%. In addition, it produces the highest yield of hydrogen gas operated at reactor temperature of 600°C.

Rhenium-promoted Pt/WO3/ZrO2: an efficient catalyst for aqueous glycerol hydrogenolysis under reduced H2 pressure

RSC Advances ◽  
2016 ◽  
Vol 6 (89) ◽  
pp. 86663-86672 ◽  
Author(s):  
Qing Tong ◽  
Anyi Zong ◽  
Wei Gong ◽  
Lei Yu ◽  
Yining Fan
Keyword(s):  
Catalyst Surface ◽  
Surface Acidity ◽  
Efficient Catalyst ◽  
Glycerol Conversion ◽  
Glycerol Hydrogenolysis

Re improved the dispersion of Pt in Pt/WO3/ZrO2 and enhanced the catalyst surface acidity. Pt–Re/WO3/ZrO2 afforded glycerol conversion >99% and C3 alcohol selectivity >95%. The reactions were performed under reduced H2 pressure.

scholarly journals Glycerol Enhances the Antifungal Activity of Dairy Propionibacteria

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Helena Lind ◽  
Anders Broberg ◽  
Karin Jacobsson ◽  
Hans Jonsson ◽  
Johan Schnürer
Keyword(s):  
Propionic Acid ◽  
Starter Cultures ◽  
Dual Culture ◽  
Penicillium Roqueforti ◽  
Glycerol Conversion ◽  
Antifungal Effect ◽  
Dual Culture Assay ◽  
Penicillium Commune ◽  
Dairy Propionibacteria ◽  
Type Strains

Dairy propionibacteria are widely used in starter cultures for Swiss type cheese. These bacteria can ferment glucose, lactic acid, and glycerol into propionic acid, acetic acid, and carbon dioxide. This research examined the antifungal effect of dairy propionibacteria when glycerol was used as carbon source for bacterial growth. Five type strains of propionibacteria were tested against the yeastRhodotorula mucilaginosaand the moldsPenicillium communeandPenicillium roqueforti. The conversion of13C glycerol byPropionibacterium jenseniiwas followed with nuclear magnetic resonance. In a dual culture assay, the degree of inhibition of the molds was strongly enhanced by an increase in glycerol concentrations, while the yeast was less affected. In broth cultures, decreased pH in glycerol medium was probably responsible for the complete inhibition of the indicator fungi. NMR spectra of the glycerol conversion confirmed that propionic acid was the dominant metabolite. Based on the results obtained, the increased antifungal effect seen by glycerol addition to cultures of propionibacteria is due to the production of propionic acid and pH reduction of the medium.

scholarly journals Directional Selection of Microbial Community Reduces Propionate Accumulation in Glycerol and Glucose Anaerobic Bioconversion Under Elevated pCO2

2021 ◽  
Vol 12 ◽  
Author(s):  
Pamela Ceron-Chafla ◽  
Yu-ting Chang ◽  
Korneel Rabaey ◽  
Jules B. van Lier ◽  
Ralph E. F. Lindeboom
Keyword(s):  
Microbial Community ◽  
Cell Viability ◽  
Cell Density ◽  
Viable Cell ◽  
Viable Cell Density ◽  
Directional Selection ◽  
Adaptive Laboratory Evolution ◽  
Glycerol Conversion ◽  
Microbial Groups ◽  
Selection Of

Volatile fatty acid accumulation is a sign of digester perturbation. Previous work showed the thermodynamic limitations of hydrogen and CO2 in syntrophic propionate oxidation under elevated partial pressure of CO2 (pCO2). Here we study the effect of directional selection under increasing substrate load as a strategy to restructure the microbial community and induce cross-protection mechanisms to improve glucose and glycerol conversion performance under elevated pCO2. After an adaptive laboratory evolution (ALE) process, viable cell density increased and predominant microbial groups were modified: an increase in Methanosaeta and syntrophic propionate oxidizing bacteria (SPOB) associated with the Smithella genus was found with glycerol as the substrate. A modest increase in SPOB along with a shift in the predominance of Methanobacterium toward Methanosaeta was observed with glucose as the substrate. The evolved inoculum showed affected diversity within archaeal spp. under 5 bar initial pCO2; however, higher CH4 yield resulted from enhanced propionate conversion linked to the community shifts and biomass adaptation during the ALE process. Moreover, the evolved inoculum attained increased cell viability with glucose and a marginal decrease with glycerol as the substrate. Results showed differences in terms of carbon flux distribution using the evolved inoculum under elevated pCO2: glucose conversion resulted in a higher cell density and viability, whereas glycerol conversion led to higher propionate production whose enabled conversion reflected in increased CH4 yield. Our results highlight that limited propionate conversion at elevated pCO2 resulted from decreased cell viability and low abundance of syntrophic partners. This limitation can be mitigated by promoting alternative and more resilient SPOB and building up biomass adaptation to environmental conditions via directional selection of microbial community.

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