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.

Production of β-glucosidase and diauxic usage of sugar mixtures byCandida molischiana

1996 ◽  
Vol 42 (5) ◽  
pp. 431-436 ◽  
Author(s):  
Shelby N. Freer ◽  
Christopher D. Skory
Keyword(s):  
Enzyme Activity ◽  
Key Words ◽  
Yeast Species ◽  
Glucose Repression ◽  
Carbon Sources ◽  
Substrate Preference ◽  
Glucosidase Activity ◽  
Key Words Glucose ◽  
Sugar Mixtures

The fermentation of cellobiose is a rare trait among yeasts. Of the 308 yeast species that utilize cellobiose aerobically, only 12 species ferment it, and only 2 species, Candida molischiana and Candida wickerhamii, also ferment cellodextrins. Candida molischiana produced β-glucosidase activity on all carbon sources tested, except glucose, mannose, and fructose. When these sugars were added to cultures growing on cellobiose, the synthesis of β-glucosidase ceased. However, the total amount of enzyme activity remained constant, indicating that the C. molischiana β-glucosidase is catabolite repressed and not catabolite inactivated. When grown in medium initially containing glucose plus xylose, cellobiose, maltose, mannitol, or glucitol, C. molischiana preferentially utilized glucose and produced little β-glucosidase activity until glucose was nearly depleted from the medium. When grown in medium containing cellobiose plus either fructose or mannose, the yeast preferentially utilized the monosaccharides and produced little β-glucosidase activity. Candida molischiana produced β-glucosidase and co-utilized cellobiose and xylose, maltose, or trehalose. Glucose and fructose, mannose, or trehalose were co-utilized; however, no β-glucosidase activity was detected. Thus, the order of substrate preference groups appeared to be (glucose, trehalose, fructose, mannose) > (cellobiose, maltose, xylose) > (mannitol, glucitol).Key words: glucose repression, trehalase, diauxic utilization, yeast.

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.

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.

GLUCOSE INHIBITION OF ASPARTASE SYNTHESIS BY AEROBACTER AEROGENES

1963 ◽  
Vol 9 (6) ◽  
pp. 835-842 ◽  
Author(s):  
Margaret A. Farley ◽  
Herman C. Lici-Istein
Keyword(s):  
Molecular Mechanism ◽  
Glucose Concentration ◽  
Glucose Repression ◽  
Enzyme Synthesis ◽  
Initial Glucose Concentration ◽  
Aerobacter Aerogenes ◽  
Complete Utilization ◽  
Glucose Inhibition ◽  
Lower Glucose ◽  
Suitable System

Studies were made comparing aspartase synthesis by Aerobacter aerogents grown in the presence and in the absence of glucose, and with or without agitation. It was observed that when a sufficient initial glucose concentration was employed, enzyme synthesis was not resumed to maximum levels even after complete utilization of the sugar. At a lower glucose concentration, however, synthesis did occur, suggesting that the specific repressor metabolite(s) produced from the glucose was not accumulated to inhibitory concentrations after the sugar was metabolized. A difference between stationary and aerobic (shaken) cultures was noted, perhaps affording a suitable system for investigating the molecular mechanism of glucose repression.

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.

Pengaruh Penambahan Molases Pada Kulit Pisang Kapendis Untuk Media Produksi Xilanase B.Stearothermophillus DSM 22

2019 ◽  
Vol 15 (3) ◽  
Author(s):  
Trismillah
Keyword(s):  
Enzyme Activity ◽  
Ammonium Sulfate ◽  
Banana Peel ◽  
Partial Purification ◽  
Temperature Conditions ◽  
Cavendish Banana ◽  
Working Volume ◽  
Initial Ph ◽  
Xylanase Enzyme

Cavendish banana peel can be used as a substitute for the expensive xylan, while molasses than as a source of carbon as well as nitrogen, minerals and nutrients needed for the growth of microbes that can produce the enzyme. Xylanase produced from Bacillus stearothermopillus DSM 22, using media cavendish banana peels with the addition of molasses 1%, 2%, and 3%. Fermentation is done in a shaker incubator at 550C temperature conditions, initial pH 8, and 250 rpm agitation. The result showed the highest enzyme activity of 4,14 ± 0,16 U/mL min., on the addition 2% molasses after 24 hours. Further fermentation carried out in the fermenter working volume of 3.5 liters, with the condition of temperature 550C, pH 8, aeration 1 vvm, agitation 250 rpm, the highest spesific enzyme of activity of 51,62 ± 0,16 U/mg after 24 hours. Partial purification of xylanase enzyme fermentation is done with the results of microfiltration, ultrafiltration, ammonium sulfate (0-80%) and dialysis. There is an increase in the purity of the enzyme at each stage of purification, the highest purity on dialysis 3.23 times of crude enzymes.Kulit buah pisang kapendis dapat digunakan sebagai pengganti xilan yang harganya mahal, sementara molases selain sebagai sumber karbon serta nitrogen, mineral dan nutrisi dibutuhkan untuk pertumbuhan mikroba yang dapat menghasilkan enzim. Xilanase yang dihasilkan dari Bacillus stearothermopillus DSM 22, menggunakan media kulit pisang kapendis dengan penambahan molase 1%, 2%, dan 3%. Fermentasi dilakukan dalam shaker inkubator pada temperatur 550C, pH awal 8, dan agitasi 250 rpm. Hasilnya menunjukkan aktivitas enzim tertinggi 4,14 ± 0,16 U/mL min., pada penambahan 2% molases setelah 24 jam. Selanjutnya fermentasi dilakukan di dalam fermentor, volume kerja dari 3,5 liter, dengan kondisi temperatur 550C, pH 8, aeration 1 vvm, agitasi 250 rpm, aktivitas spesifik tertinggi 51,62 ± 0,16 U/mg setelah 24 jam. Pemurnian parsial fermentasi enzim xilanase dilakukan dengan hasil mikrofiltrasi, ultrafiltrasi, amonium sulfat (0-80%) dan dialisis. Ada peningkatan kemurnian enzim pada setiap tahap pemurnian, kemurnian tertinggi pada dialisis 3,23 kali dari enzim kasar.Keywords: Xylanase, B. stearothermophillus DSM 22, Cavendish banana peel, molasses, enzyme activity

scholarly journals Multicopy FZF1 (SUL1) Suppresses the Sulfite Sensitivity but Not the Glucose Derepression or Aberrant Cell Morphology of a grr1 Mutant of Saccharomyces cerevisiae

Genetics ◽  
1996 ◽  
Vol 144 (2) ◽  
pp. 511-521 ◽  
Author(s):  
Dorina Avram ◽  
Alan T Bakalinsky
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcription Factor ◽  
Glucose Metabolism ◽  
Cell Morphology ◽  
Glucose Repression ◽  
Carbon Sources ◽  
Single Copy ◽  
Aberrant Cell ◽  
Growth Defects ◽  
Putative Transcription Factor

Abstract An ssu2 mutation in Sacccharomyces cermisiae, previously shown to cause sulfite sensitivity, was found to be allelic to GRR1, a gene previously implicated in glucose repression. The suppressor rgt1, which suppresses the growth defects of grr1 strains on glucose, did not fully suppress the sensitivity on glucose or nonglucose carbon sources, indicating that it is not strictly linked to a defect in glucose metabolism. Because the Cln1 protein was previously shown to be elevated in grr1 mutants, the effect of CLN1 overexpression on sulfite sensitivity was investigated. Overexpression in GRR1 cells resulted in sulfite sensitivity, suggesting a connection between CLN1 and sulfite metabolism. Multicopy FZF1, a putative transcription factor, was found to suppress the sulfite sensitive phenotype of grr1 strains, but not the glucose derepression or aberrant cell morphology. Multicopy FZF1 was also found to suppress the sensitivity of a number of other unrelated sulfite-sensitive mutants, but not that of ssu1 or met20, implying that FZF1 may act through Ssulp and Met20p. Disruption of FZF1 resulted in sulfite sensitivity when the construct was introduced in single copy at the FZF1 locus in a GRR1 strain, providing evidence that FZF1 is involved in sulfite metabolism.

OBSERVATIONS ON AMYLOLYTIC BACTERIA: III. CULTURAL CONDITIONS INFLUENCING THE BREAKDOWN OF STARCH BY STENOTHERMOPHILIC BACTERIA BELONGING TO BACILLUS STEAROTHERMOPHILUS

1952 ◽  
Vol 30 (4) ◽  
pp. 360-370 ◽  
Author(s):  
Egon Stark ◽  
P. A. Tetrault
Keyword(s):  
Yeast Extract ◽  
Bacillus Stearothermophilus ◽  
Soluble Starch ◽  
The Other ◽  
Ph Changes ◽  
Proteose Peptone ◽  
Cultural Conditions ◽  
Initial Ph ◽  
Commercial Medium ◽  
Agar Media

Thirty-five cultures of Bacillus stearothermophilus hydrolyzed five starches under various cultural conditions. Hydrolysis occurred regardless of the type, brand, or batch of starch; regardless of the initial pH or of the subsequent pH changes of the medium. Starch in broth was better attacked than in agar media. Some cultures hydrolyzed 0.5%, but not 1% starch; others hydrolyzed easily 10% soluble starch. Length of incubation was important. Certain cultures never formed acid or sugar from starch. Dextrinization was a more reliable indication of starch hydrolysis than was the formation of acid or sugar. Soluble starch gave more consistent results in repeated experiments than did nonsoluble starches. The type of protein medium determines strongly the formation of amylase. Trypticase was the best commercial medium, yeast extract came second. The other 10 media yielded fewer amylolytic cultures. Yeast extract added to media enhanced amylase formation, except with trypticase. Tryptose, proteose-peptone, and neopeptone inhibited the growth of most cultures.

Optimization of the Fermentation Conditions for 1-Deoxynojirimycin Production by Streptomyces lawendulae Applying the Response Surface Methodology

2011 ◽  
Vol 7 (3) ◽  
Author(s):  
Zhao-Jun Wei ◽  
Le-Chun Zhou ◽  
Hua Chen ◽  
Gui-Hai Chen
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Starch Content ◽  
Ultra Violet ◽  
Soluble Starch ◽  
High Yield ◽  
Yield Strain ◽  
Fermentation Time ◽  
Ethyl Sulfate ◽  
Initial Ph

Moranoline (1-Deoxynojirimycin, DNJ) is a piperidine alkaloid, and shows high inhibit activities to glucoamylase and ?-glucosidase. One DNJ high-yield strain of Streptomyces lawendulae was obtained after isolated form soil and mutated with the ultra violet (UV) and ethyl sulfate (DES), which named as TB-412, and can produce DNJ with 35.925 mg/L. Response surface methodology (RSM) was applied to optimize the parameters of DNJ yield from S. lawendulae TB-412. The effects of independent variables of fermentation, including time, temperature, initial pH and the soluble starch content were investigated. The statistical analysis showed that the fermentation time, pH and the soluble starch content, and the quadratics of time, temperature, pH and the soluble starch content, as well as the interactions between fermentation time and pH, and time and the soluble starch content, showed significant effects on DNJ yield. The optimal process parameters for DNJ production within the experimental range of the variables researched was at 11d, 27 °C, pH 7.5, and 8% soluble starch content. At this condition, the DNJ yield was predicted to be 42.875 mg/L.

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