High Hydrogen Yield by Fermentation Using Clostridium Saccharoperbutylacetonicum N1-4

2009 ◽  
Author(s):  
Walid M. Alalayah ◽  
Mohd Sahaid Kalil ◽  
Abdul Amir H. Kadhum ◽  
Jamaliah Md. Jahim ◽  
Najeeb M. Alauj
Keyword(s):  
Glucose Concentration ◽  
Hydrogen Yield ◽  
Medium Ph ◽  
Initial Glucose Concentration ◽  
High Hydrogen ◽  
Initial Substrate ◽  
Initial Ph ◽  
Organic Carbon Source ◽  
Initial Medium ◽  
Initial Substrate Concentration

High hydrogen yield was carried out using Clostridium saccharoperbutylacetonicum N1-4 (ATCC 13564). The ability of this Clostridium on hydrogen production was studied in 250 mL batch culture with glucose as the sole organic carbon source. The effect of initial substrate concentration, initial medium pH, addition of Fe2+ and temperature were investigated. Results show that the highest yield (Yp/s) of hydrogen produced was about 3.10 mol (mol glucose)−1 when the initial glucose concentration was 10 gL−1, initial pH of 6.0 ± 0.2 and temperature 37°C. The yield of hydrogen produced decreased when higher initial glucose concentration was applied. The yield of hydrogen was increased when 25 mg L−1 Fe2+ was added to the medium.

scholarly journals Biohydrogen Production and Kinetic Modeling Using Sediment Microorganisms of Pichavaram Mangroves, India

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
P. Mullai ◽  
Eldon R. Rene ◽  
K. Sridevi
Keyword(s):  
Trace Metal ◽  
Ferrous Sulphate ◽  
Model Fitting ◽  
Biohydrogen Production ◽  
Hydrogen Yield ◽  
Influence Of Process Parameters ◽  
Initial Substrate ◽  
Initial Ph ◽  
Initial Medium ◽  
Good Agreement

Mangrove sediments host rich assemblages of microorganisms, predominantly mixed bacterial cultures, which can be efficiently used for biohydrogen production through anaerobic dark fermentation. The influence of process parameters such as effect of initial glucose concentration, initial medium pH, and trace metal (Fe2+) concentration was investigated in this study. A maximum hydrogen yield of 2.34, 2.3, and 2.6 mol H2mol−1glucose, respectively, was obtained under the following set of optimal conditions: initial substrate concentration—10,000 mg L−1, initial pH—6.0, and ferrous sulphate concentration—100 mg L−1, respectively. The addition of trace metal to the medium (100 mg L−1FeSO4·7H2O) enhanced the biohydrogen yield from 2.3 mol H2 mol−1glucose to 2.6 mol H2mol−1glucose. Furthermore, the experimental data was subjected to kinetic analysis and the kinetic constants were estimated with the help of well-known kinetic models available in the literature, namely, Monod model, logistic model and Luedeking-Piret model. The model fitting was found to be in good agreement with the experimental observations, for all the models, with regression coefficient values >0.92.

scholarly journals The effect of low initial medium pH on in vitro white poplar growth

2013 ◽  
pp. 67-80
Author(s):  
Branislav Kovacevic ◽  
Dragana Miladinovic ◽  
Marina Katanic ◽  
Zoran Tomovic ◽  
Sasa Pekec
Keyword(s):  
Biomass Accumulation ◽  
Dry Mass ◽  
White Poplar ◽  
Medium Ph ◽  
Shoot Height ◽  
Initial Ph ◽  
The Media ◽  
Initial Medium ◽  
Shoot Mass

The effect of low initial medium pH on shoot and root development of five white poplar (Populus alba L.) genotypes was tested. The shoot height, fresh mass of shoots per jar, dry mass of shoots per jar, number of roots, as well as the length of the longest root were measured and final pH of the media determined, after 35 days of culture in vitro. Three initial pH values of the medium were tested: 3.0, 4.0 and 5.5 as control. Agar solidification at pH 3.0 was not achieved after sterilization in autoclave, but it was successful after sterilizing in a microwave oven. The obtained results indicate that the tested genotypes are able to significantly influence the changes of media pH during culture. The effect of differences among the examined media was significant for biomass accumulation and final media pH. Generally, significantly higher values of fresh and dry shoot mass, shoot height and the longest root length were recorded on a medium with initial pH 3.0 then on a standard medium with pH 5.5.The implications of the obtained results for the improvement of in vitro propagation of white poplars are discussed.

Monitoring Initial Glucose Concentration for Optimum pH Control during Fermentation of Microbial Cellulose in Rotary Discs Reactor

2013 ◽  
Vol 594-595 ◽  
pp. 319-324 ◽  
Author(s):  
Khairul Azly Zahan ◽  
Norhayati Pa’e ◽  
Kok Fook Seng ◽  
Ida Idayu Muhamad
Keyword(s):  
Glucose Concentration ◽  
Ph Control ◽  
Fermentation Medium ◽  
Initial Glucose Concentration ◽  
Cellulose Production ◽  
Microbial Cellulose ◽  
Cellulose Yield ◽  
Optimum Ph ◽  
Initial Ph ◽  
Wet Weight

The study aimed to investigate the effect of initial glucose concentration on the microbial cellulose production using Acetobacter xylinum in a Rotary Discs Reactor (RDR-2 liter volume). The fermentations were carried out for four days at temperature 28°C, initial pH 6.5, and 9 rpm of rotation speed; meanwhile, the initial glucose concentration was manipulated in the range of 0.5-5.0 % (w/v). The cell growth was stimulated using 1.4% (v/v) ethanol in the fermentation medium. The result indicated that 1% (w/v) of initial glucose concentration provided the highest microbial cellulose yield with total wet weight of 296.1657g/l. The increase of initial glucose concentration resulted to the decrease of microbial cellulose yield and greater pH drop after fermentation. It can be conclude that production of microbial cellulose using RDR could produce relatively much higher microbial cellulose with less amounts of glucose in a shorter fermentation period compared to static fermentation due to more efficient oxygen uptake during rotary movements and homogenous environment for microbial growth.

Synthesis of (S)-Tert-Butyl 3-Hydroxybutyrate by Asymmetric Reduction of Tert-Butyl Acetoacetate with Saccharomyces cerevisiae B5

2013 ◽  
Vol 704 ◽  
pp. 12-17
Author(s):  
Zhi Min Ou ◽  
Wen Fei Feng ◽  
Li Xu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Substrate Concentration ◽  
Asymmetric Reduction ◽  
Optical Purity ◽  
Lower Amount ◽  
High Optical Purity ◽  
Initial Substrate ◽  
Initial Ph ◽  
H 30 ◽  
Initial Substrate Concentration

S)-tert-butyl 3-hydroxybutyrate was synthesized by asymmetric reduction of tert-butyl acetoacetate with Saccharomyces cerevisiae B5 as catalyst. The enantiometric excess of (S)-tert-butyl 3-hydroxybutyrate increased with addition of more amount of substrate. High optical purity of product can be obtained when 6 g/L chloroform was used as inhibitor. The optimum reduction time, temperature, and initial pH of reaction mixture were 60 h, 30 °C, and 6.2. Addition of more biomass and lower amount of substrate helped to get high conversion. Conversion and enantiometric excess of product reached 100% when initial substrate concentration and biomass were 2.0 g/L and 140 g/L with 6 g/L chloroform as inhibitor.

scholarly journals 546 Quantifying the Dose Response of Several Basic Chemicals on pH of Soilless Media

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 540B-540
Author(s):  
A.J. Bishko ◽  
P.R. Fisher
Keyword(s):  
Calcium Hydroxide ◽  
Dose Response ◽  
Potassium Hydroxide ◽  
Potassium Bicarbonate ◽  
Distilled Water ◽  
Water Control ◽  
Medium Ph ◽  
Soilless Media ◽  
Initial Ph ◽  
Initial Medium

Our objective was to systematically quantify the dose response from applications of several basic materials recommended for raising pH in acidic media. A peat (70%)/perlite (30%) medium was mixed with a pre-plant nutrient charge, a wetting agent, and 0, 0.3, 0.6, 0.9, 1.2, or 1.5 kg dolomitic hydrated lime/m3, resulting in a range in initial pH from 3.4 to 6.4. Five rates of flowable dolomitic limestone, five rates of potassium bicarbonate, two rates of potassium hydroxide, a supernatant of calcium hydroxide and a distilled water control were applied as single drenches. The medium was irrigated with distilled water when it dried to 50% container capacity as determined by weight. Media pH and EC of four replicates were tested at 1 day and 1, 2, 3, and 4 weeks after application as a saturated media extract. Flowable limestone and potassium bicarbonate both significantly raised medium pH by up to 2 units compared with the control, depending on concentration. As initial medium pH increased, the effect of the basic chemicals on medium pH decreased. For example, flowable lime applied at 0.5 L·100 L–1 of distilled water increased pH by 2 units at an initial medium pH of 3.4 and by 0.4 units at an initial pH of 6.4. Potassium hydroxide and calcium hydroxide drenches did not significantly raise pH. Potassium bicarbonate was easier to apply than the suspension of flowable limestone, however both chemicals provide practical methods for raising pH of soilless media.

Influence of Initial pH and Temperature on Fermentative Biohydrogen Production of Biohydrogenbacterium R3 sp.nov. from Glucose

2011 ◽  
Vol 71-78 ◽  
pp. 2929-2932 ◽  
Author(s):  
Yong Feng Li ◽  
Hong Chen ◽  
Wei Han ◽  
Fang Jing Liu ◽  
Zhan Qing Wang
Keyword(s):  
Cell Growth ◽  
Hydrogen Production ◽  
Glucose Concentration ◽  
Ph Value ◽  
Initial Glucose Concentration ◽  
Noticeable Effect ◽  
Dry Cell Weight ◽  
Initial Ph ◽  
Maximum Cell ◽  
Dry Cell

This study investigated the effects of initial pHs and temperatures to the hydrogen production ration and cell growth ofBiohydrogenbacteriumR3sp.nov.. The initial pHs were set at 4.0, 4.5, 5.0, 5.5, 6.0, 6.5 and 6.7, respectively and the temperatures were increased from 25 °C to 45 °C in regular intervals of 5 °C at 10 g/L of the initial glucose concentration. The results indicated that pH value had a noticeable effect on the cell growth and hydrogen production. The dry cell weight and hydrogen production yield got the maximum of 0.6308 g/L and 34.2 mmol/L, respectively when the initial pH was 5.5. The final pH in the culture were always kept at 3.0~4.0. Temperature is also known to affect the maximum cell growth and specific hydrogen production ration (SHPR). And they got the maximum of 0.6682 g/L and 1.0145mol H2/mol glucose, respectively when the temperature was 30 °C. It is obvious that hydrogen production and biomass will be inhibited gradually with increasing this pH and temperature or decreasing it.

Utilization of glucose and cellobiose by Candida molischiana

1995 ◽  
Vol 41 (2) ◽  
pp. 177-185 ◽  
Author(s):  
S. N. Freer
Keyword(s):  
Enzyme Activity ◽  
Glucose Concentration ◽  
Glucose Repression ◽  
Carbon Sources ◽  
Soluble Starch ◽  
Complex Medium ◽  
Initial Glucose Concentration ◽  
Carbohydrate Source ◽  
Glucosidase Activity ◽  
Initial Ph

Some of the factors that influence the biosynthesis of the Candida molischiana β-glucosidase were investigated. The yeast produced maximal enzyme activity when grown at 28 °C in a carbohydrate-containing complex medium (YM) in which the initial pH was adjusted to 6.0. The enzyme appeared to be produced constitutively, as activity was detected when either ethanol, glycerol, xylose, glucitol, mannitol, maltose, trehalose, cellobiose, cellodextrins, or soluble starch was used as the carbohydrate source. The presence of either glucose, mannose, or fructose (> 25 g/L) repressed β-glucosidase expression; however, C. molischiana did produce β-glucosidase when the initial glucose concentration was <25 g/L. When the yeast was grown in YM medium containing glucose plus cellobiose, diauxic utilization of the carbon sources was observed, and β-glucosidase activity was not detected until the glucose was depleted from the medium.Key words: β-glucosidase, glucose repression, fermentation, yeast.

scholarly journals A Phenomenological Study on the Synergistic Role of Precious Metals and the Support in the Steam Reforming of Logistic Fuels on Monometal Supported Catalysts

2010 ◽  
Vol 2010 ◽  
pp. 1-15 ◽  
Author(s):  
Abdul-Majeed Azad ◽  
Desikan Sundararajan
Keyword(s):  
Steam Reforming ◽  
High Efficiency ◽  
Phenomenological Study ◽  
Supported Catalysts ◽  
Precious Metals ◽  
Sulfur Poisoning ◽  
Jet Fuels ◽  
Hydrogen Yield ◽  
High Hydrogen

Clean power source utilizing vast logistic fuel reserves (jet fuels, diesel, and coal) would be the main driver in the 21st century for high efficiency. Fuel processors are required to convert these fuels into hydrogen-rich reformate for extended periods in the presence of sulfur, and deliver hydrogen with little or no sulfur to the fuel cell stack. However, the jet and other logistic fuels are invariably sulfur-laden. Sulfur poisons and deactivates the reforming catalyst and therefore, to facilitate continuous uninterrupted operation of logistic fuel processors, robust sulfur-tolerant catalysts ought to be developed. New noble metal-supported ceria-based sulfur-tolerant nanocatalysts were developed and thoroughly characterized. In this paper, the performance of single metal-supported catalysts in the steam-reforming of kerosene, with 260 ppm sulfur is highlighted. It was found that ruthenium-based formulation provided an excellent balance between hydrogen production and stability towards sulfur, while palladium-based catalyst exhibited rapid and steady deactivation due to the highest propensity to sulfur poisoning. The rhodium supported system was found to be most attractive in terms of high hydrogen yield and long-term stability. A mechanistic correlation between the role of the nature of the precious metal and the support for generating clean desulfurized -rich reformate is discussed.

The Physiology of Sea-Urchin Spermatozoa

1950 ◽  
Vol 26 (4) ◽  
pp. 396-409
Author(s):  
LORD ROTHSCHILD
Keyword(s):  
Sea Urchin ◽  
Seminal Plasma ◽  
Human Blood ◽  
Phosphate Buffer ◽  
Dry Weight ◽  
O2 Uptake ◽  
Low Concentrations ◽  
Initial Substrate ◽  
Rough Calculation ◽  
Initial Substrate Concentration

1. Spermatozoa and seminal plasma of Echinus esculentus contain catalase. 2. At 15° C., 4 ml. of a suspension of semen diluted with neutral phosphate buffer in the ratio 1:13 produced in 1 min. 90µl. O2 from an H2O2 solution containing 150 µl. O2. The dry weight of semen in the suspension was 45 mg. and the number of spermatozoa 8.55x109. Under the same conditions, seminal plasma obtained by centrifuging semen produced 50 µl. O2 in 1 min. The dry weight of seminal plasma in the suspension was 12 mg. Human blood, dry weight 229.3 mg./ml., must be diluted with phosphate buffer in the ratio 1:1700 to produce the same amount of O2 in 1 min. as the above suspension of semen. If catalatic activity is defined by the equation Ac = (gt)-1 In {a/(a-x)}, where g = weight in g./ml. of the catalase-containing material, t = 1 min., a = initial substrate concentration (H2O2), and x = amount of H2O2 decomposed in 1 min. at 15° C., Ac = 80-100, 150-200 and 6800 respectively for sea-urchin semen, sea-urchin seminal plasma and human blood. 3. The catalatic activity of semen and seminal plasma is strongly inhibited by hydroxylamine. 4. The O2 uptake and motility of sea-urchin spermatozoa is unaffected by M/5000 H2O2. Higher concentrations of H2O2, M/3000-5000, produce a pronounced ‘shock’ effect, from which the spermatozoa often completely recover. 5. Low concentrations of hydroxylamine, M/3000, reduce O2 uptake and motility. 6. Sea-urchin spermatozoa are almost instantly killed by combinations of hydroxylamine and H2O2, at concentrations which are relatively innocuous when the substances are added separately. 7. A rough calculation indicates that a single spermatozoon contains less than 500 molecules of catalase. 8. A new method of adding H2O2 to catalase-containing material in a manometer is described.

scholarly journals Biodegradation of main carbon sources in vinasse stillage by a mixed culture of bacteria: influence of temperature and pH of the medium

2018 ◽  
Vol 78 (4) ◽  
pp. 764-775 ◽  
Author(s):  
Agnieszka Ryznar-Luty ◽  
Edmund Cibis ◽  
Krzysztof Lutosławski
Keyword(s):  
Mixed Culture ◽  
Organic Pollutants ◽  
Carbon Sources ◽  
Oxygen Demand ◽  
Aerobic Biodegradation ◽  
Medium Ph ◽  
Initial Ph ◽  
Fourth Series ◽  
Soluble Chemical Oxygen Demand ◽  
Available Carbon

Abstract The aim of the study was to examine how temperature and the pH influence the progress and efficiency of an aerobic biodegradation process, where major organic pollutants are removed from beet molasses vinasse by a mixed culture of Bacillus bacteria. It was conducted in an aerated bioreactor with a stirring system in four experimental series, each composed of five processes run at temperatures of 27, 36, 45, 54 and 63 °C. In the first and second series, medium pH was not controlled, the initial pH amounted to 6.5 and 8.0, respectively. In the third and fourth series, medium pH was controlled at 6.5 and 8.0, respectively. Under optimal conditions, the pollution load of the vinasse stillage expressed as soluble chemical oxygen demand was removed with an 88.73% efficiency. The bacterial culture assimilated all organic pollutants simultaneously, but the rate of assimilation was different. An exception was the process of betaine assimilation, which intensified only when readily available carbon sources were depleted in the medium. Synthesis and assimilation of organic acids were observed in all experiments. Advantages of the proposed method include: possibility of its use at high temperatures, and no necessity for medium pH adjustment during the process.

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