scholarly journals D-Galacturonic acid reduction by S. cerevisiae for L-galactonate production from extracted sugar beet press pulp hydrolysate

2021 ◽  
Author(s):  
J. Wagner ◽  
D. Schäfer ◽  
N. von den Eichen ◽  
C. Haimerl ◽  
S. Harth ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Sugar Beet ◽  
Galacturonic Acid ◽  
Value Added ◽  
Batch Processes ◽  
Stirred Tank ◽  
Process Conditions ◽  
Product Selectivity ◽  
Direct Production ◽  
Hydrolysis Of

Abstract Pectin-rich residues are considered as promising feedstocks for sustainable production of platform chemicals. Enzymatic hydrolysis of extracted sugar beet press pulp (SBPP) releases the main constituent of pectin, d-galacturonic acid (d-GalA). Using engineered Saccharomyces cerevisiae, d-GalA is then reduced to l-galactonate (l-GalOA) with sorbitol as co-substrate. The current work addresses the combination of enzymatic hydrolysis of pectin in SBPP with a consecutive optimized biotransformation of the released d-GalA to l-GalOA in simple batch processes in stirred-tank bioreactors. Process conditions were first identified with synthetic media, where a product concentration of 9.9 g L-1 L-GalOA was obtained with a product selectivity of 99% (L-GalOA D-GalA-1) at pH 5 with 4% (w/v) sorbitol within 48 h. A very similar batch process performance with a product selectivity of 97% was achieved with potassium citrate buffered SBPP hydrolysate, demonstrating for the first time direct production of L-GalOA from hydrolyzed biomass using engineered S. cerevisiae. Combining the hydrolysis process of extracted SBPP and the biotransformation process with engineered S. cerevisiae paves the way towards repurposing pectin-rich residues as substrates for value-added chemicals. Key points • Efficient bioreduction of D-GalA with S. cerevisiae in stirred-tank reactors • Batch production of L-GalOA by engineered S. cerevisiae with high selectivity • Direct L-GalOA production from hydrolyzed sugar beet press pulp Graphical abstract

scholarly journals Enzymatic Hydrolysis of Wheat Straw in a Stirred-Tank Reactor

2021 ◽  
Author(s):  
Ejaz Khan
Keyword(s):  
Enzymatic Hydrolysis ◽  
Wheat Straw ◽  
Reaction Medium ◽  
Operating Conditions ◽  
Stirred Tank ◽  
Atmospheric Conditions ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
Hydrolysis Of ◽  
Initial Conversion

In an attempt to elucidate the effect of some operating conditions on the rate and extent of enzymatic hydrolysis of lignocellulosic materials in a stirred tank reactor, wheat straw was hydrolyzed by mixing with two pitched-blade impellers mounted on a shaft under various atmospheric conditions: static air in headspace, N₂ gas flowing over the surface of the medium, and minimal static air by a lid touching the surface of the medium. The presence of N₂ gas over the reaction medium produced by the highest 6.9 % (w/w) conversion in 36 hours. The initial conversion when N₂ gas flowed in the headspace (2.9 % w/w), and when a lid was used (2.9 % w/w) as compared to conversion in air presence (2.3 % w/w), seems to indicate that the enzyme activity was affected due to oxidation in the presence of air. The observed low conversion yield was probably the result of the non sterile conditions imposed by industrial requirements for the production of biofuel ethanol from agricultural lignocellulosics.

Enzymatic Hydrolysis of Ammonia-Treated Sugar Beet Pulp

2001 ◽  
Vol 91-93 (1-9) ◽  
pp. 269-282 ◽  
Author(s):  
Brian L. Foster ◽  
Bruce E. Dale ◽  
Joy B. Doran-Peterson
Keyword(s):  
Enzymatic Hydrolysis ◽  
Sugar Beet ◽  
Sugar Beet Pulp ◽  
Beet Pulp ◽  
Hydrolysis Of

scholarly journals Utilization of Agricultural Waste for the Production of Xylooligosaccharides Using Response Surface Methodology and Their In Vitro Prebiotic Efficacy

2021 ◽  
Author(s):  
Nagamani Kathiresan ◽  
Lingesh Gopal ◽  
Vijay Karuppiah ◽  
Renuka Naveenethan ◽  
David Ravindran Abraham ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Enzymatic Hydrolysis ◽  
Response Surface ◽  
Sugarcane Bagasse ◽  
Agricultural Waste ◽  
Relative Yield ◽  
Value Added ◽  
A Value ◽  
Hydrolysis Of

Abstract Air pollution is a prominent problem recently faced in various parts of India due to the burning of stubbles (coconut husk, corn cob, paddy stubbles, sugarcane bagasse, etc.) which are rich in a lignocellulosic component that can be converted into a prebiotic known as Xylooliogsaccaride (XOS). They can be produced by autohydrolysis, acid hydrolysis and enzymatic hydrolysis of xylan. In the present study, Xylan was extracted from sugarcane bagasse using two alkalis (NaOH and KOH) and the yield was compared. Xylooligosaccharide produced by enzymatic hydrolysis and their factors influencing the yield were optimized using Response Surface Methodology. Xylan and Xylooligosaccharide was characterized by FTIR, NMR, XRD, TGA and ESI-MS. Xylooligosaccharides was investigated for their prebiotic potential by in vitro study. The maximum (Relative yield of 86%) yield of xylan was observed in 20% of NaOH. Xylan peaks at 3762cm− 1, 3347 cm− 1, 2917cm− 1 represents the OH and CH stretching of xylan. The main signals at 4.26 (H-1), 3.19 (H-2), 3.59 (H-3), 3.63 (H-4) and 3.98 (H-5) ppm determines the existence of xylan. The higher amount of XOS is pH 4.75, temperature 45°C, enzyme 4U/ml and for time of 16h. The spectrum of 5.0-5.40ppm and 4.30-4.60ppm represents the α anomeric and β anomeric protons in XOS. They are resistant digested and the reaching percentage to the intestine is 95% unhydrolyzed. The maximum prebiotic index was noted in L.plantarum (1.92) and L.fermentum (1.61). The highest prebiotic index and score was observed in L.plantarum (1.9) and L.fermentum (17). The maximum bacteriocin production of Enterococcus faecium against E.fecalis (13mm) and Streptococcus pyogenes (11mm). Therefore, utilization of agricultural residues for a value-added product not only shows a great impact on environmental issues but also could double the farmer’s income

Enzymatic hydrolysis of sugar beet pulp

1984 ◽  
Vol 6 (11) ◽  
pp. 723-728 ◽  
Author(s):  
L. Sidi Ali ◽  
N. Cochet ◽  
T. K. Ghose ◽  
J. M. Lebeault
Keyword(s):  
Enzymatic Hydrolysis ◽  
Sugar Beet ◽  
Sugar Beet Pulp ◽  
Beet Pulp ◽  
Hydrolysis Of

scholarly journals Complete Utilization of the Major Carbon Sources Present in Sugar Beet Pulp Hydrolysates by the Oleaginous Red Yeasts Rhodotorula toruloides and R. mucilaginosa

2021 ◽  
Vol 7 (3) ◽  
pp. 215
Author(s):  
Luís Martins ◽  
Margarida Palma ◽  
Angel Angelov ◽  
Elke Nevoigt ◽  
Wolfgang Liebl ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Sugar Beet ◽  
Galacturonic Acid ◽  
Fruits And Vegetables ◽  
Carbon Sources ◽  
Value Added ◽  
Sugar Beet Pulp ◽  
Industrial Residues ◽  
Industrial Processing ◽  
Beet Pulp

Agro-industrial residues are low-cost carbon sources (C-sources) for microbial growth and production of value-added bioproducts. Among the agro-industrial residues available, those rich in pectin are generated in high amounts worldwide from the sugar industry or the industrial processing of fruits and vegetables. Sugar beet pulp (SBP) hydrolysates contain predominantly the neutral sugars d-glucose, l-arabinose and d-galactose, and the acidic sugar d-galacturonic acid. Acetic acid is also present at significant concentrations since the d-galacturonic acid residues are acetylated. In this study, we have examined and optimized the performance of a Rhodotorula mucilaginosa strain, isolated from SBP and identified at the molecular level during this work. This study was extended to another oleaginous red yeast species, R. toruloides, envisaging the full utilization of the C-sources from SBP hydrolysate (at pH 5.0). The dual role of acetic acid as a carbon and energy source and as a growth and metabolism inhibitor was examined. Acetic acid prevented the catabolism of d-galacturonic acid and l-arabinose after the complete use of the other C-sources. However, d-glucose and acetic acid were simultaneously and efficiently metabolized, followed by d-galactose. SBP hydrolysate supplementation with amino acids was crucial to allow d-galacturonic acid and l-arabinose catabolism. SBP valorization through the production of lipids and carotenoids by Rhodotorula strains, supported by complete catabolism of the major C-sources present, looks promising for industrial implementation.

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