Ethanol production by a newly isolated anaerobe, Clostridium saccharolyticum: effects of culture medium and growth conditions

1983 ◽  
Vol 29 (3) ◽  
pp. 342-347 ◽  
Author(s):  
William D. Murray ◽  
A. W. Khan
Keyword(s):  
Ethanol Production ◽  
Culture Medium ◽  
Ethanol Concentration ◽  
Growth Conditions ◽  
Glucose Medium ◽  
Fermentation Products ◽  
Standard Temperature ◽  
Temperature And Pressure ◽  
Acetate Formation ◽  
Ferment Glucose

Clostridium saccharolyticum was shown to ferment glucose, cellobiose, and xylose to CO2, H2, ethanol, acetate, and lactate. The addition of 0.12 M CaCO3 and 1% yeast extract (w/v) to the glucose medium was found to shift the ethanol–acetate mole ratio from 1.36 to 2.6. Although the addition of exogenous H2 (240 kPa) did not affect the growth of C. saccharolyticum, it did alter the pattern of fermentation products. Both H2 and acetate formation decreased, while ethanol production increased. Ethanol production also increased at the expense of H2 and acetate when C. saccharolyticum was incubated without shaking. Stationary incubation under a H2 headspace (standard temperature and pressure) resulted in an ethanol concentration, at 25 °C, of 1.7% (v/v), an efficiency of conversion of 1.8 mol ethanol/mol glucose, and ethanol–acetate ratios of 7.6 at 35 °C and 9.4 at 20 °C. These results indicate that H2 concentration plays a significant role in the regulation of C. saccharolyticum catabolism.

The influence of the initial concentrations of glucose and yeast extract on the ethanolic fermentation by Pachysolen tannophilus

1990 ◽  
Vol 55 (3) ◽  
pp. 854-866 ◽  
Author(s):  
Rodríguez V. Bravo ◽  
Rubio F. Camacho ◽  
Villasclaras S. Sánchez ◽  
Vico M. Castro
Keyword(s):  
Cell Growth ◽  
Ethanol Production ◽  
Yeast Extract ◽  
Culture Medium ◽  
Ethanolic Fermentation ◽  
Pachysolen Tannophilus ◽  
Significant Component ◽  
Batch Cultures

The ethanolic fermentation in batch cultures of Pachysolen tannophilus was studied experimentally varying the initial concentrations of two of the components in the culture medium: glucose between 0 and 200 g l-1 and yeast extract between 0 and 8 g l-1. The yeast extract appears to be a significant component both in cell growth and for ethanol production.

scholarly journals Hemicellulosic Bioethanol Production from Fast-Growing Paulownia Biomass

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 173
Author(s):  
Elena Domínguez ◽  
Pablo G. del Río ◽  
Aloia Romaní ◽  
Gil Garrote ◽  
Lucília Domingues
Keyword(s):  
Ethanol Production ◽  
Ethanol Concentration ◽  
Ethanol Yield ◽  
Xylose Reductase ◽  
Energy Crop ◽  
Scheffersomyces Stipitis ◽  
Fractionation Process ◽  
Renewable Source ◽  
Fast Growing ◽  
Engineered Strain

In order to exploit a fast-growing Paulownia hardwood as an energy crop, a xylose-enriched hydrolysate was obtained in this work to increase the ethanol concentration using the hemicellulosic fraction, besides the already widely studied cellulosic fraction. For that, Paulownia elongata x fortunei was submitted to autohydrolysis treatment (210 °C or S0 of 4.08) for the xylan solubilization, mainly as xylooligosaccharides. Afterwards, sequential stages of acid hydrolysis, concentration, and detoxification were evaluated to obtain fermentable sugars. Thus, detoxified and non-detoxified hydrolysates (diluted or not) were fermented for ethanol production using a natural xylose-consuming yeast, Scheffersomyces stipitis CECT 1922, and an industrial Saccharomyces cerevisiae MEC1133 strain, metabolic engineered strain with the xylose reductase/xylitol dehydrogenase pathway. Results from fermentation assays showed that the engineered S. cerevisiae strain produced up to 14.2 g/L of ethanol (corresponding to 0.33 g/g of ethanol yield) using the non-detoxified hydrolysate. Nevertheless, the yeast S. stipitis reached similar values of ethanol, but only in the detoxified hydrolysate. Hence, the fermentation data prove the suitability and robustness of the engineered strain to ferment non-detoxified liquor, and the appropriateness of detoxification of liquor for the use of less robust yeast. In addition, the success of hemicellulose-to-ethanol production obtained in this work shows the Paulownia biomass as a suitable renewable source for ethanol production following a suitable fractionation process within a biorefinery approach.

scholarly journals Single-step ethanol production from raw cassava starch using a combination of raw starch hydrolysis and fermentation, scale-up from 5-L laboratory and 200-L pilot plant to 3000-L industrial fermenters

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Morakot Krajang ◽  
Kwanruthai Malairuang ◽  
Jatuporn Sukna ◽  
Krongchan Rattanapradit ◽  
Saethawat Chamsart
Keyword(s):  
Ethanol Production ◽  
Ethanol Concentration ◽  
Consolidated Bioprocessing ◽  
Scale Up ◽  
Cassava Starch ◽  
Single Step ◽  
Starch Hydrolysis ◽  
Yield Coefficient ◽  
Raw Starch ◽  
Raw Starch Hydrolysis

Abstract Background A single-step ethanol production is the combination of raw cassava starch hydrolysis and fermentation. For the development of raw starch consolidated bioprocessing technologies, this research was to investigate the optimum conditions and technical procedures for the production of ethanol from raw cassava starch in a single step. It successfully resulted in high yields and productivities of all the experiments from the laboratory, the pilot, through the industrial scales. Yields of ethanol concentration are comparable with those in the commercial industries that use molasses and hydrolyzed starch as the raw materials. Results Before single-step ethanol production, studies of raw cassava starch hydrolysis by a granular starch hydrolyzing enzyme, StargenTM002, were carefully conducted. It successfully converted 80.19% (w/v) of raw cassava starch to glucose at a concentration of 176.41 g/L with a productivity at 2.45 g/L/h when it was pretreated at 60 °C for 1 h with 0.10% (v/w dry starch basis) of Distillase ASP before hydrolysis. The single-step ethanol production at 34 °C in a 5-L fermenter showed that Saccharomyces cerevisiae (Fali, active dry yeast) produced the maximum ethanol concentration, pmax at 81.86 g/L (10.37% v/v) with a yield coefficient, Yp/s of 0.43 g/g, a productivity or production rate, rp at 1.14 g/L/h and an efficiency, Ef of 75.29%. Scale-up experiments of the single-step ethanol production using this method, from the 5-L fermenter to the 200-L fermenter and further to the 3000-L industrial fermenter were successfully achieved with essentially good results. The values of pmax,Yp/s, rp, and Ef of the 200-L scale were at 80.85 g/L (10.25% v/v), 0.42 g/g, 1.12 g/L/h and 74.40%, respectively, and those of the 3000-L scale were at 70.74 g/L (8.97% v/v), 0.38 g/g, 0.98 g/L/h and 67.56%, respectively. Because of using raw starch, major by-products, i.e., glycerol, lactic acid, and acetic acid of all three scales were very low, in ranges of 0.940–1.140, 0.046–0.052, 0.000–0.059 (% w/v), respectively, where are less than those values in the industries. Conclusion The single-step ethanol production using the combination of raw cassava starch hydrolysis and fermentation of three fermentation scales in this study is practicable and feasible for the scale-up of industrial production of ethanol from raw starch.

A New Type of Muffler Based on Microperforated Tubes

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
S. Allam ◽  
M. Åbom
Keyword(s):  
Acoustic Impedance ◽  
Noise Control ◽  
Wave Impedance ◽  
Sound Waves ◽  
Submillimeter Range ◽  
Perforated Plates ◽  
Characteristic Wave ◽  
Standard Temperature ◽  
New Type ◽  
Temperature And Pressure

Microperforated plate (MPP) absorbers are perforated plates with holes typically in the submillimeter range and perforation ratios around 1%. The values are typical for applications in air at standard temperature and pressure (STP). The underlying acoustic principle is simple: It is to create a surface with a built in damping, which effectively absorbs sound waves. To achieve this, the specific acoustic impedance of a MPP absorber is normally tuned to be of the order of the characteristic wave impedance in the medium (∼400 Pa s/m in air at STP). The traditional application for MPP absorbers has been building acoustics often combined with a so called panel absorber to create an absorption peak at a selected frequency. However, MPP absorbers made of metal could also be used for noise control close to or at the source for noise control in ducts. In this paper, the possibility to build dissipative silencers, e.g., for use in automotive exhaust or ventilation systems, is investigated.

Paper Mulberry Fruit Juice: a Novel Biomass Resource For Bioethanol Production

2021 ◽  
Author(s):  
Pleasure Chisom Ajayo ◽  
Mei Huang ◽  
Li Zhao ◽  
Dong Tian ◽  
Qin Jiang ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Fruit Juice ◽  
Ethanol Concentration ◽  
Fuel Ethanol ◽  
Inoculum Size ◽  
Process Conditions ◽  
Mulberry Fruit ◽  
Biomass Resource ◽  
Yeast Concentration ◽  
First Time

Abstract By way of broadening the use of diverse sustainable bioethanol feedstocks, the potentials of Paper mulberry fruit juice (PMFJ), as a non-food, sugar-based substrate, was for the first time evaluated for fuel ethanol production. Without any external nutrient supplementation, the suitability of PMFJ was proven, as maximum ethanol concentration (56.4 g/L), and yield (0.39 g/g), were achieved within half a day of the start of fermentation, corresponding to a very high ethanol productivity of 4.7 g/L/hr. Using Response Surface Methodology, established potentials were further maximized through statistical optimization of process conditions of temperature (20 – 40 ⁰C), yeast concentration (0.5 – 2 g/L), and pH (4 – 6). At the optimal temperature of 30 ⁰C, inoculum size of 0.55 g/L, and pH of 5, ethanol concentration, productivity, and yield obtained were 73.69 g/L, 4.61 g/L/hr, and 0.48 g/g, respectively. Under this ideal process conditions, bioethanol from PMFJ compares favorably with typical sugar-based energy crops, highlighting its resourcefulness as a high value biomass resource for fuel ethanol production.

Differential activities of H+extrusion systems in MDCK cells due to extracellular osmolality and pH

1997 ◽  
Vol 273 (4) ◽  
pp. F499-F506 ◽  
Author(s):  
Elisabeth Feifel ◽  
Markus Krall ◽  
John P. Geibel ◽  
Walter Pfaller
Keyword(s):  
Culture Medium ◽  
Mdck Cells ◽  
Collecting Duct ◽  
Growth Conditions ◽  
Culture Conditions ◽  
Fluid Composition ◽  
Buffering Power ◽  
Outer Stripe ◽  
Acid Load ◽  
Extrusion Mechanism

The aim of the present study was to obtain detailed information on MDCK cell proton secretion characteristics under various growth conditions. Confluent monolayers cultured on glass coverslips were adapted over 48 h to media with different osmolality and pH (200 mosmol/kgH2O, pH 7.4; 300 mosmol/kgH2O, pH 7.4; and 600 mosmol/kgH2O, pH 6.8) corresponding to the luminal fluid composition of the collecting duct segments found in the in renal cortex, the outer stripe of outer medulla and inner medulla. Proton fluxes were determined from the recovery of intracellular pH following an acid load induced by an NH4Cl pulse times the corresponding intrinsic buffering power (βi). The intracellular buffering power was found to change only with culture medium osmolality but not with culture medium pH. In addition to an amiloride and Hoe-694-sensitive Na+/H+exchange, Madin-Darby canine kidney (MDCK) cells possess a Sch-28080-sensitive, K+-dependent H+ extrusion mechanism that is increased upon adaptation of monolayers to hyperosmotic-acidic culture conditions. A significant contribution of the bafilomycin A1-sensitive vacuolar H+-ATPase could be found only in cells adapted to hyposmotic culture conditions. Exposure of MDCK cells to 10−5 or 10−7 M aldosterone for either 1 or 18 h did not alter the H+ extrusion characteristics significantly. The results obtained show that different extracellular osmolality and pH induce different MDCK phenotypes with respect to their H+-secreting systems.

Ethanol Production from Non-Detoxified Steam-Exploded Corn Stover Subsequent Enzymatic Hydrolysis by Two Toxin-Tolerant Yeast Strains

2011 ◽  
Vol 365 ◽  
pp. 145-149
Author(s):  
Xun Men ◽  
Xiu Shan Yang ◽  
Shen Tian
Keyword(s):  
Enzymatic Hydrolysis ◽  
Ethanol Production ◽  
Corn Stover ◽  
Fermentation Process ◽  
Ethanol Concentration ◽  
Enzymatic Hydrolysate ◽  
Yeast Strains ◽  
Inhibitory Compounds ◽  
Operation Cost ◽  
Detoxification Process

Fermentation process for ethanol production from steam-exploded corn stover using toxin-tolerant yeast strains was carried out in order to reduce the water consumption and operation cost. The substrate from steam-exploded did not undergo a detoxification process by wash, and was directly hydrolyzed by enzymes. Two toxin-tolerant stains, Y1 and Y5, were tested to ferment the enzymatic hydrolysate slurry directly to ethanol. In the enzymatic hydrolysate slurry containing inhibitory compounds, the strain Y1 and Y5 could convert the sugar to ethanol with ethanol concentration of 47.0 g/L and 47.2 g/L corresponding to 95.9% and 96.4% of the theoretical maximum, respectively.

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