scholarly journals Efficient Extraction of Fermentation Inhibitors by Means of Green Hydrophobic Deep Eutectic Solvents

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 157
Author(s):  
Patrycja Makoś-Chełstowska ◽  
Edyta Słupek ◽  
Karolina Kucharska ◽  
Aleksandra Kramarz ◽  
Jacek Gębicki

The methods for hydrogen yield efficiency improvements, the gaseous stream purification in gaseous biofuels generation, and the biomass pretreatment are considered as the main trends in research devoted to gaseous biofuel production. The environmental aspect related to the liquid stream purification arises. Moreover, the management of post-fermentation broth with the application of various biorefining techniques gains importance. Chemical compounds occurring in the exhausted liquid phase after biomass pretreatment and subsequent dark and photo fermentation processes are considered as value-added by products. The most valuable are furfural (FF), 5-hydroxymethylfurfural (HMF), and levulinic acid (LA). Enriching their solutions can be carried with the application of liquid–liquid extraction with the use of a suitable solvent. In these studies, hydrophobic deep eutectic solvents (DESs) were tested as extractants. The screening of 56 DESs was carried out using the Conductor-like Screening Model for Real Solvents (COSMO-RS). DESs which exposed the highest inhibitory effect on fermentation and negligible water solubility were prepared. The LA, FF, and HMF were analyzed using FT-IR and NMR spectroscopy. In addition, the basic physicochemical properties of DES were carefully studied. In the second part of the paper, deep eutectic solvents were used for the extraction of FF, LA, and HMF from post-fermentation broth (PFB). The main extraction parameters, i.e., temperature, pH, and DES: PFB volume ratio (VDES:VPFB), were optimized by means of a Box–Behnken design model. Two approaches have been proposed for extraction process. In the first approach, DES was used as a solvent. In the second, one of the DES components was added to the sample, and DES was generated in situ. To enhance the post-fermentation broth management, optimization of the parameters promoting HMF, FF, and LA extraction was carried under real conditions. Moreover, the antimicrobial effect of the extraction of FF, HMF, and LA was investigated to define the possibility of simultaneous separation of microbial parts and denatured peptides via precipitation.

2018 ◽  
Vol 115 (12) ◽  
pp. 2970-2975 ◽  
Author(s):  
Weihua Wu ◽  
Fang Liu ◽  
Seema Singh

Efficient lignin valorization could add more than 10-fold the value gained from burning it for energy and is critical for economic viability of future biorefineries. However, lignin-derived aromatics from biomass pretreatment are known to be potent fermentation inhibitors in microbial production of fuels and other value-added chemicals. In addition, isopropyl-β-d-1-thiogalactopyranoside and other inducers are routinely added into fermentation broth to induce the expression of pathway enzymes, which further adds to the overall process cost. An autoregulatory system that can diminish the aromatics’ toxicity as well as be substrate-inducible can be the key for successful integration of lignin valorization into future lignocellulosic biorefineries. Toward that goal, in this study an autoregulatory system is demonstrated that alleviates the toxicity issue and eliminates the cost of an external inducer. Specifically, this system is composed of a catechol biosynthesis pathway coexpressed with an active aromatic transporter CouP under induction by a vanillin self-inducible promoter, ADH7, to effectively convert the lignin-derived aromatics into value-added chemicals usingEscherichia colias a host. The constructed autoregulatory system can efficiently transport vanillin across the cell membrane and convert it to catechol. Compared with the system without CouP expression, the expression of catechol biosynthesis pathway with transporter CouP significantly improved the catechol yields about 30% and 40% under promoter pTrc and ADH7, respectively. This study demonstrated an aromatic-induced autoregulatory system that enabled conversion of lignin-derived aromatics into catechol without the addition of any costly, external inducers, providing a promising and economically viable route for lignin valorization.


2020 ◽  
Vol 7 (04) ◽  
Author(s):  
SATYA NARAYAN SINGH ◽  
RAJESH G BURBADE ◽  
HITESH SANCHAVAT ◽  
P S PANDIT

The cereals of today are more nutritious and healthful than ever before. Cereals processing is one of the oldest and the most essential part of all food technologies. Pasta products and noodles have been staple foods since ancient times in many countries all over the world. In this study pasta formulation was substituted with blending sapota powder in different proportions (4 levels i.e. 0%, 10%, 20%, 30%) into semolina and maida flour separately. Pasta products were prepared using eight different formulations and adding water (approximately 31% of total weight) in DOLLY pasta extruder machine. All the samples were evaluated for physical properties: specific length (mm/g), bulk density (kg/m3), specific density (kg/m3) and porosity (%); functional properties: water absorption index (%), water solubility index (%) and oil absorption capacity (ml/g) and nutritional compositions: moisture (%), crude protein (%), fat (%) and carbohydrate (%). Highest specific length 36.20 mm/g was observed for T5 treatment, low bulk density 368.10 kg/m3 was observed for T5 and highest porosity 9.24% was found for T1 treatment. The maximum WAI, WSI values 325.83%, 17.33% respectively was observed for T1 treatment and minimum value of oil absorption capacity 1.06 ml/g for T8 treatment. The moisture content of dried pasta products was found in the range of 6 to 7%. The maximum value of crude protein 13.07% was found for T5 and minimum value 8.81% for T4 treatments. The fat contents were varied from 1.02% to 1.28 %. The maximum value of carbohydrate was 76.20% for T1 and minimum value 65.41% for T8.


2021 ◽  
Author(s):  
Rajiv CHANDRA RAJAK ◽  
Pathikrit Saha ◽  
Mamata S Singhvi ◽  
Darae Kwak ◽  
Danil Kim ◽  
...  

Pretreatment of lignocellulosic biomass to specifically depolymerise lignin moieties without loss of carbohydrates as well as to minimize the generation of harmful intermediates during the process is a major challenge...


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Pratik Prashant Pawar ◽  
Annamma Anil Odaneth ◽  
Rajeshkumar Natwarlal Vadgama ◽  
Arvind Mallinath Lali

Abstract Background Recent trends in bioprocessing have underlined the significance of lignocellulosic biomass conversions for biofuel production. These conversions demand at least 90% energy upgradation of cellulosic sugars to generate renewable drop-in biofuel precursors (Heff/C ~ 2). Chemical methods fail to achieve this without substantial loss of carbon; whereas, oleaginous biological systems propose a greener upgradation route by producing oil from sugars with 30% theoretical yields. However, these oleaginous systems cannot compete with the commercial volumes of vegetable oils in terms of overall oil yields and productivities. One of the significant challenges in the commercial exploitation of these microbial oils lies in the inefficient recovery of the produced oil. This issue has been addressed using highly selective oil capturing agents (OCA), which allow a concomitant microbial oil production and in situ oil recovery process. Results Adsorbent-based oil capturing agents were employed for simultaneous in situ oil recovery in the fermentative production broths. Yarrowia lipolytica, a model oleaginous yeast, was milked incessantly for oil production over 380 h in a media comprising of glucose as a sole carbon and nutrient source. This was achieved by continuous online capture of extracellular oil from the aqueous media and also the cell surface, by fluidizing the fermentation broth over an adsorbent bed of oil capturing agents (OCA). A consistent oil yield of 0.33 g per g of glucose consumed, corresponding to theoretical oil yield over glucose, was achieved using this approach. While the incorporation of the OCA increased the oil content up to 89% with complete substrate consumptions, it also caused an overall process integration. Conclusion The nondisruptive oil capture mediated by an OCA helped in accomplishing a trade-off between microbial oil production and its recovery. This strategy helped in realizing theoretically efficient sugar-to-oil bioconversions in a continuous production process. The process, therefore, endorses a sustainable production of molecular drop-in equivalents through oleaginous yeasts, representing as an absolute microbial oil factory.


2017 ◽  
Vol 35 (3) ◽  
pp. 267-275 ◽  
Author(s):  
PX Sotelo-Navarro ◽  
HM Poggi-Varaldo ◽  
SJ Turpin-Marion ◽  
A Vázquez-Morillas ◽  
M Beltrán-Villavicencio ◽  
...  

This research assessed the viability to use disposable diapers as a substrate for the production of biohydrogen, a valuable clean-energy source. The important content of cellulose of disposable diapers indicates that this waste could be an attractive substrate for biofuel production. Two incubation temperatures (35 °C and 55 °C) and three diaper conditioning methods (whole diapers with faeces, urine, and plastics, WD; diapers without plastic components, with urine and faeces, DWP; diapers with urine but without faeces and plastic, MSD) were tested in batch bioreactors. The bioreactors were operated in the solid substrate anaerobic hydrogenogenic fermentation with intermittent venting mode (SSAHF-IV). The batch reactors were loaded with the substrate at ca. 25% of total solids and 10% w/w inoculum. The average cumulative bioH2 production followed the order WD > MSD > DWP. The bio-H2 production using MSD was unexpectedly higher than DWP; the presence of plastics in the first was expected to be associated to lower degradability and H2 yield. BioH2 production at 55 °C was superior to that of 35 °C, probably owing to a more rapid microbial metabolism in the thermophilic regime. The results of this work showed low yields in the production of H2 at both temperatures compared with those reported in the literature for municipal and agricultural organic waste. The studied process could improve the ability to dispose of this residue with H2 generation as the value-added product. Research is ongoing to increase the yield of biohydrogen production from waste disposable diapers.


2012 ◽  
Vol 554-556 ◽  
pp. 957-961
Author(s):  
Hong An ◽  
Xi Feng He ◽  
Shu Gang Gao

Aim of this work was to establish the optimum conditions for the extraction and recovery by cationic reversed micelles of glucose oxidase (GOX) from Aspergillus niger A9, The influence of pH, temperature, solvent/co-solvents ratio on the extraction was investigated by experiment, using the residual enzyme activity to evaluate the results. The best condition for GOX extraction were ensured using iso-octane as solvent and butanol and n-hexanol co-solvent at 76/18/6 volume ratio, pH 4.80, 200mM cetyl-trimethyl ammonium bromide (CTAB) as cationic surfactant, The enzyme activity of GOX is measured by DNS method (3,5-dinitro salicylic acid method). In the extraction process, ultrasonic oscillation was adopted to mix organic solvent and water, ultrasonic oscillation temperature is 45 °C. Protein activity recovery of GOX can reach 88.2% in extraction.


2011 ◽  
Vol 236-238 ◽  
pp. 2810-2814
Author(s):  
Yong Jiang Wang ◽  
Xue Qian Wu ◽  
Shi Wang Liu ◽  
Yuan Feng Wu ◽  
Yan Ping Zhang

Water-insoluble β - ( 1 - 3 ) – D - glucan isolated from the sclerotium of Poria cocos hardly exhibits biological activity. Therefore, it is advantageous to produce a value-added product from Poria cocos. We extracted the β - ( 1 - 3 ) – D - glucan from the sclerotium of Poria cocos and synthesized a carboxymethylated derivative, carboxymethyl-pachyman (CMP). The influences on the degrees of substitution ( DS ) of CMP, for example, volume ratio of ethanol to water, [NaOH]/[MCA] ratio, reaction temperature and reaction time have been examined, respectively. The most favorable conditions for pachyman carboxymethylation are obtained with a [NaOH]/[MCA] ratio of 1.5, at 45°C for 60 minutes with a reaction medium consisting of a ethanol/water 80:20 (v/v) mixture.


2017 ◽  
pp. 259-280 ◽  
Author(s):  
Vishal Mishra ◽  
Akhilesh Dubey ◽  
Sanjeev Kumar Prajapti

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nazia Hossain ◽  
Sabzoi Nizamuddin ◽  
Gregory Griffin ◽  
Periasamy Selvakannan ◽  
Nabisab Mujawar Mubarak ◽  
...  

Abstract The recent implication of circular economy in Australia spurred the demand for waste material utilization for value-added product generations on a commercial scale. Therefore, this experimental study emphasized on agricultural waste biomass, rice husk (RH) as potential feedstock to produce valuable products. Rice husk biochar (RB) was obtained at temperature: 180 °C, pressure: 70 bar, reaction time: 20 min with water via hydrothermal carbonization (HTC), and the obtained biochar yield was 57.9%. Enhancement of zeta potential value from − 30.1 to − 10.6 mV in RB presented the higher suspension stability, and improvement of surface area and porosity in RB demonstrated the wastewater adsorption capacity. Along with that, an increase of crystallinity in RB, 60.5%, also indicates the enhancement of the catalytic performance of the material significantly more favorable to improve the adsorption efficiency of transitional compounds. In contrast, an increase of the atomic O/C ratio in RB, 0.51 delineated high breakdown of the cellulosic component, which is favorable for biofuel purpose. 13.98% SiO2 reduction in RB confirmed ash content minimization and better quality of fuel properties. Therefore, the rice husk biochar through HTC can be considered a suitable material for further application to treat wastewater and generate bioenergy.


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