scholarly journals Batch Syngas Fermentation by Clostridium carboxidivorans for Production of Acids and Alcohols

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1075
Author(s):  
Fabiana Lanzillo ◽  
Giacomo Ruggiero ◽  
Francesca Raganati ◽  
Maria Elena Russo ◽  
Antonio Marzocchella
Keyword(s):  
Critical Role ◽  
Volume Ratio ◽  
Liquid Volume ◽  
Syngas Fermentation ◽  
Co Concentration ◽  
Depletion Rate ◽  
Growth Differences ◽  
Gas Volume ◽  
Clostridium Carboxidivorans ◽  
Kinetics Of

Syngas (CO, CO2, and H2) has attracted special attention due to the double benefit of syngas fermentation for carbon sequestration (pollution reduction), while generating energy. Syngas can be either produced by gasification of biomasses or as a by-product of industrial processes. Only few microorganisms, mainly clostridia, were identified as capable of using syngas as a substrate to produce medium chain acids, or alcohols (such as butyric acid, butanol, hexanoic acid, and hexanol). Since CO plays a critical role in the availability of reducing equivalents and carbon conversion, this work assessed the effects of constant CO partial pressure (PCO), ranging from 0.5 to 2.5 atm, on cell growth, acid production, and solvent production, using Clostridium carboxidivorans. Moreover, this work focused on the effect of the liquid to gas volume ratio (VL/VG) on fermentation performances; in particular, two VL/VG were considered (0.28 and 0.92). The main results included—(a) PCO affected the growth kinetics of the microorganism; indeed, C. carboxidivorans growth rate was characterized by CO inhibition within the investigated range of CO concentration, and the optimal PCO was 1.1 atm (corresponding to a dissolved CO concentration of about 25 mg/L) for both VL/VG used; (b) growth differences were observed when the gas-to-liquid volume ratio changed; mass transport phenomena did not control the CO uptake for VL/VG = 0.28; on the contrary, the experimental CO depletion rate was about equal to the transport rate in the case of VL/VG = 0.92.

scholarly journals Ultrafiltration Method for Plasma Protein Binding Studies and Its Limitations

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 382
Author(s):  
Camelia-Maria Toma ◽  
Silvia Imre ◽  
Camil-Eugen Vari ◽  
Daniela-Lucia Muntean ◽  
Amelia Tero-Vescan
Keyword(s):  
Protein Binding ◽  
Plasma Protein Binding ◽  
Plasma Protein ◽  
Specific Binding ◽  
Critical Role ◽  
Volume Ratio ◽  
Binding Studies ◽  
Experimental Conditions ◽  
Key Aspects

Plasma protein binding plays a critical role in drug therapy, being a key part in the characterization of any compound. Among other methods, this process is largely studied by ultrafiltration based on its advantages. However, the method also has some limitations that could negatively influence the experimental results. The aim of this study was to underline key aspects regarding the limitations of the ultrafiltration method, and the potential ways to overcome them. The main limitations are given by the non-specific binding of the substances, the effect of the volume ratio obtained, and the need of a rigorous control of the experimental conditions, especially pH and temperature. This review presents a variety of methods that can hypothetically reduce the limitations, and concludes that ultrafiltration remains a reliable method for the study of protein binding. However, the methodology of the study should be carefully chosen.

scholarly journals Effect of temperature and surfactant on biomass growth and higher-alcohol production during syngas fermentation by Clostridium carboxidivorans P7

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Shaohuang Shen ◽  
Guan Wang ◽  
Ming Zhang ◽  
Yin Tang ◽  
Yang Gu ◽  
...  
Keyword(s):  
Tween 80 ◽  
Biofuel Production ◽  
Effect Of Temperature ◽  
Biomass Growth ◽  
Syngas Fermentation ◽  
Higher Alcohol ◽  
Alcohol Production ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Clostridium Carboxidivorans

Abstract Hexanol–butanol–ethanol fermentation from syngas by Clostridium carboxidivorans P7 is a promising route for biofuel production. However, bacterial agglomeration in the culture of 37 °C severely hampers the accumulation of biomass and products. To investigate the effect of culture temperature on biomass growth and higher-alcohol production, C. carboxidivorans P7 was cultivated at both constant and two-step temperatures in the range from 25 to 37 °C. Meanwhile, Tween-80 and saponin were screened out from eight surfactants to alleviate agglomeration at 37 °C. The results showed that enhanced higher-alcohol production was contributed mainly by the application of two-step temperature culture rather than the addition of anti-agglomeration surfactants. Furthermore, comparative transcriptome revealed that although 37 °C promoted high expression of genes involved in the Wood–Ljungdahl pathway, genes encoding enzymes catalyzing acyl-condensation reactions associated with higher-alcohol production were highly expressed at 25 °C. This study gained greater insight into temperature-effect mechanism on syngas fermentation by C. carboxidivorans P7.

The need to complement in vitro gas production measurements with residue determinations from in sacco degradabilities to improve the prediction of voluntary intake of hays

1997 ◽  
Vol 64 (1) ◽  
pp. 71-75 ◽  
Author(s):  
M. Blümmel ◽  
P. Bullerdieck
Keyword(s):  
Volume Ratio ◽  
Gas Production ◽  
Published Data ◽  
Fatty Acid Production ◽  
Residue Determination ◽  
In Vitro Gas Production ◽  
Gas Volume ◽  
In Sacco Degradability ◽  
In Sacco

AbstractThe need to complement in vitro gas production measurements with residue determination is demonstrated by the recalculation and reassessment of published data on in vitro gas production, in sacco degradabilities and voluntary dry matter intake (DMI). The in sacco degradability — gas volume ratio was determined at 24 and 48 h of incubation, termed partitioning factor (PF) and combined with rate and extent parameters of in sacco degradability and in vitro gas production to predict DMI. In vitro gas production and in sacco degradability characteristics (a + b) and c as described by the equation y = a + b(1−ect) explained 0·373 and 0·668 respectively of the variation in DMI of 19 legume and grass hays. The complementation of gas production parameters by the PF24 increased the R2 value to 0·744 with PF24 accounting for 0·407 of the variation in DMI, the rate of gas production (c) for 0·218 and the extent of gas production (a + b) for 0·119 of the variation in DMI. As a single parameter, PF48 showed the highest correlation (R2 = 0·597) with DMI but the combination of PF4S with rate and extent of in sacco or in vitro gas production measurements did not improve the correlation further, probably due to an intercorrelation between rates of fermentation and PF4S. Hays which were degraded at faster rates had higher PF values indicating proportionally higher microbial yield and lower short-chain fatty acid production per unit substrate degraded. Generally, hays with high in sacco degradabilities but proportionally low gas production i.e. hays with high PF values showed higher DMI.

Cooling of Fruit with Arbitrary Shape: Simulation Using Galerkin-Based Integral Method

2017 ◽  
Vol 10 ◽  
pp. 1-15
Author(s):  
P. Morais Pessôa ◽  
A.G. Barbosa de Lima ◽  
R. Swarnakar ◽  
J.P. Gomes ◽  
W.M.P. Barbosa de Lima
Keyword(s):  
Integral Method ◽  
Arbitrary Shape ◽  
Heat Conduction Equation ◽  
Low Cost ◽  
Experimental Studies ◽  
Volume Ratio ◽  
Transient Heat Conduction ◽  
Cooling Time ◽  
Time Required ◽  
Kinetics Of

Cooling has been used for the preservation of fresh produce such as fruit and vegetables due to its low cost and high effectiveness in maintaining the product quality. Recently, several researchers have conducted theoretical and experimental studies for obtaining the kinetics of cooling and cooling time for fruits with different geometries. Present work, therefore, aims to simulate the cooling of fruits with particular reference to banana, orange, strawberry and Tahiti lemon. The transient heat conduction equation and its analytical solution using Galerkin based integral method are presented. It has been found that the strawberry has lower dimensionless cooling time compared with time required to cool other fruits, which is due to its higher surface area/volume ratio value. In orange and lemon the temperature distribution was found to be homogeneous in the angular direction, while in banana and strawberry it was two-dimensional due to shape of the fruits.

scholarly journals Kinetics of solanidine hydrolytic extraction from potato (Solanum tuberosum L) haulm solid-liquid systems

2003 ◽  
Vol 68 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Nada Nikolic ◽  
Mihajlo Stankovic
Keyword(s):  
Solanum Tuberosum ◽  
Hydrochloric Acid ◽  
Solid Phase ◽  
Solanum Tuberosum L ◽  
Volume Ratio ◽  
Single Step ◽  
Ethanolic Solution ◽  
Liquid Systems ◽  
Solid Liquid ◽  
Kinetics Of

Dried and milled haulm of potato (Solanum tuberosum L) was used as the solid phase. An ethanolic solution of hydrochloric acid mixed with chloroform in different volume ratios was the liquid phase. The aim of paper was to unite in a single step the processes of glycoalkaloids extraction from haulm, their hydrolysis to solanidine and the extraction of solanidine. This could make the procedure of obtaining solanidine faster and simpler. The best degree of solanidine hydrolytic extraction of 84.5% was achieved using 10% w/v hydrochloric acid in 96% vol. ethanol mixed with chloroform in a volume ratio of 2:3, after 120 min of hydrolytic extraction.

Factors Controlling Oxygen Depletion in Ice-Covered Lakes

1980 ◽  
Vol 37 (2) ◽  
pp. 185-194 ◽  
Author(s):  
Jack A. Mathias ◽  
Jan Barica
Keyword(s):  
Volume Ratio ◽  
Lake Management ◽  
Eddy Diffusion ◽  
Oxygen Depletion ◽  
Eutrophic Lakes ◽  
Experimental Lakes Area ◽  
Lake Volume ◽  
Basin Morphometry ◽  
Depletion Rate ◽  
Prairie Lakes

Winter oxygen depletion rates from four sets of Canadian lakes (prairie, southeastern Ontario, Arctic, and Experimental Lakes Area) differing in morphometry and trophic state, were analyzed. An inverse relationship was found between oxygen depletion rate and mean depth. The effect of lake trophic status on oxygen depletion rate was demonstrable after the influence of basin morphometry was removed by regression of oxygen depletion rate against the sediment area: lake volume ratio. The sediments of eutrophic lakes consumed oxygen about 3 times faster (0.23 g∙m−2∙d−1) than those of oligotrophic lakes (0.08 g∙m−2∙d−1), but water column respiration was about the same (0.01 g∙m−3∙d−1) for both groups of lakes. Data from prairie lakes showed that the winter oxygen consumption was limited by oxygen supply below an average whole-lake oxygen concentration of 3.8 mg∙L−1. The rate of eddy diffusion near the sediments in ice-covered prairie lakes was 3.72 ± 1.41 × 10−3 cm2∙s−1. Implications for lake management during the winter are discussed.Key words: oxygen, depletion, respiration, lakes, ice-covered, winter, sediments, model, consumption

scholarly journals Experimental Design to Improve Cell Growth and Ethanol Production in Syngas Fermentation by Clostridium carboxidivorans

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 59 ◽  
Author(s):  
Carolina Benevenuti ◽  
Alanna Botelho ◽  
Roberta Ribeiro ◽  
Marcelle Branco ◽  
Adejanildo Pereira ◽  
...  
Keyword(s):  
Cell Growth ◽  
Ethanol Production ◽  
Yeast Extract ◽  
Biomass Gasification ◽  
Culture Collection ◽  
Medium Composition ◽  
Syngas Fermentation ◽  
The Cost ◽  
Clostridium Carboxidivorans ◽  
Peptone Yeast Extract Glucose

Fermentation of gases from biomass gasification, named syngas, is an important alternative process to obtain biofuels. Sequential experimental designs were used to increase cell growth and ethanol production during syngas fermentation by Clostridium carboxidivorans. Based on ATCC (American Type Culture Collection) 2713 medium composition, it was possible to propose a best medium composition for cell growth, herein called TYA (Tryptone-Yeast extract-Arginine) medium and another one for ethanol production herein called TPYGarg (Tryptone-Peptone-Yeast extract-Glucose-Arginine) medium. In comparison to ATCC® 2713 medium, TYA increased cell growth by 77%, reducing 47% in cost and TPYGarg increased ethanol production more than four-times, and the cost was reduced by 31%. In 72 h of syngas fermentation in TPYGarg medium, 1.75-g/L of cells, 2.28 g/L of ethanol, and 0.74 g/L of butanol were achieved, increasing productivity for syngas fermentation.

Hydrocarbon-Phase Behaviors in Shale Nanopore/Fracture Model: Multiscale, Multicomponent, and Multiphase

SPE Journal ◽  
2019 ◽  
Vol 24 (06) ◽  
pp. 2526-2540 ◽  
Author(s):  
Yinuo Zhao ◽  
Zhehui Jin
Keyword(s):  
Oil Recovery ◽  
Density Functional ◽  
Critical Role ◽  
Volume Ratio ◽  
Phase Region ◽  
Bulk Phase ◽  
Two Phase ◽  
Well Productivity ◽  
Pressure Drops ◽  
Shale Reservoirs

Summary Hydrocarbon recovery from shale subformations has greatly contributed to the global energy supply and has been constantly reshaping the energy sector. Oil production from shale is a complex process in which multicomponent–fluid mixtures experience multiphase transitions in multiscale volumes (i.e., nanoscale pores are connected to fractures/macropores). Understanding such complicated phenomena plays a critical role in the estimation of ultimate oil recovery, well productivity, and reserves estimation, and ultimately in policy making. In this work, we use density–functional theory (DFT) to explicitly consider fluid/surface interactions, inhomogeneous–density distributions in nanopores, volume partitioning in nanopores, and connected macropores/natural fractures to study the complex multiphase transitions of multicomponent fluids in multiscale volumes. We found that vapor–like and liquid–like phases can coexist in nanopores when pressure is between the bubblepoint and dewpoint pressures of nanoconfined fluids, both of which are much lower than those of the originally injected hydrocarbon mixtures. As the volume ratio of the bulk at the initial condition to pores decreases, both the bubblepoint and the dewpoint in nanopores increase and the pore two–phase region expands. Within the pore two–phase region, both C1 and C3 are released from the nanopores to the bulk phase as pressure declines. Meanwhile, both liquid and vapor phases become denser as pressure drops. By further decreasing pressure below the dewpoint of confined fluids, C3 in the nanopore can be recovered. Throughout the process, the bulk–phase composition varies, which is in line with the field observation. Collectively, this work captures the coupled complexity of multicomponent and multiphase fluids in multiscale geometries that is inherent to shale reservoirs and provides a theoretical foundation for reservoir simulation, which is significant for the accurate prediction of well productivity and ultimate oil recovery in shale reservoirs.

Effect of surface on the gas-phase oxidation of methanol catalysed by nitric oxide

1964 ◽  
Vol 17 (5) ◽  
pp. 539
Author(s):  
JJ Batten
Keyword(s):  
Nitric Oxide ◽  
Gas Phase ◽  
Marked Effect ◽  
Volume Ratio ◽  
Oxidation Of Methanol ◽  
Inorganic Substances ◽  
Phase Oxidation ◽  
Gas Phase Oxidation ◽  
Kinetics Of ◽  
Effect Of Surface

A study has been made of the effect of the surface-to-volume ratio of the reaction vessel and of coatings of various inorganic substances on the vessel walls on the gas-phase oxidation of methanol catalysed by nitric oxide. The results show that, whereas packing the vessel does not have a marked effect on the rate, the kinetics of the reaction are profoundly influenced by the nature of the surface. The results suggest that the methanol-oxidation chains are initiated at the surface by reaction between methanol and nitrogen dioxide, and that HO2 radicals play an important role in the subsequent chain reaction.

Velocity fluctuations in a homogeneous dilute dispersion of high-Reynolds-number rising bubbles

2002 ◽  
Vol 453 ◽  
pp. 395-410 ◽  
Author(s):  
FRÉDÉRIC RISSO ◽  
KJETIL ELLINGSEN
Keyword(s):  
Reynolds Number ◽  
High Reynolds Number ◽  
Liquid Velocity ◽  
Liquid Volume ◽  
Equivalent Radius ◽  
Velocity Fluctuations ◽  
Rising Bubble ◽  
High Reynolds ◽  
Conditional Statistics ◽  
Gas Volume

An experimental investigation of a homogeneous swarm of rising bubbles is presented. The experimental arrangement ensures that all the bubbles have the same equivalent radius, a = 1.25 mm. This particular size corresponds to high-Reynolds-number ellipsoidal rising bubbles. The gas volume fractions α is small, ranging from 0.5 to 1.05%. The results are compared with the reference situation of a single rising bubble, which was investigated in a previous work. From the use of conditional statistics, the existence of two regions in which the liquid velocity fluctuations are of a different nature are distinguished. In the vicinity of the bubbles, the liquid fluctuations are the same as those measured close to a single rising bubble. They therefore do not depend on α. Far from the bubble, the liquid fluctuations are controlled by the nonlinear interactions between the wakes of all the bubbles. Their probability density function scales as α0.4, exhibiting a self-similar behaviour. The total fluctuation combines the contributions of these two regions weighted by the fraction of the liquid volume they occupy. The contribution of the bubble vicinity is thus shown to vary linearly with α while the wake contribution does not. Both are non-isotropic since strong upward vertical fluctuations are more probable.

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