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Pinar Calik - One of the best experts on this subject based on the ideXlab platform.
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recombinant protein production by sucrose utilizing escherichia coli w untreated Beet Molasses based feeding strategy development
Journal of Chemical Technology & Biotechnology, 2015Co-Authors: Burcu Akdag, Pinar CalikAbstract:BACKGROUND Untreated Beet Molasses feeding strategy was developed for recombinant thermostable glucose isomerase (GI) production by sucrose-utilizing Escherichia coli W. RESULTS pRSETA::xylA plasmid carrying GI encoding gene of Thermus thermophilus (xylA) was transferred into E. coli W, and the effects of carbon sources, i.e. glucose, sucrose, and Beet Molasses containing 50% sucrose, on GI production were investigated. 32 g L−1 Beet Molasses-based medium resulted in the highest recombinant GI production (A = 4364.1 U L−1) and cell concentration (CX = 4.2 g L−1) in laboratory-scale shake-bioreactors. Using Beet Molasses as the carbon source, pulse and exponential feeding strategies were designed. The highest recombinant GI production was achieved as 35 265 U L−1 at t = 16 h in V = 3.0 L controlled bioreactors, where the cell concentration was CX = 17 g L−1, by the application of a three-stage strategy: Stage I (0
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Beet Molasses based exponential feeding strategy for thermostable glucose isomerase production by recombinant escherichia coli bl21 de3
Journal of Chemical Technology & Biotechnology, 2013Co-Authors: Vahideh Angardi, Pinar CalikAbstract:BACKGROUND: The effects of pretreated Beet Molasses based feeding strategies on thermostable glucose isomerase (GI) production by recombinant Escherichia coli BL21 (DE3) pLysS were investigated. RESULTS: The thermostable GI encoding gene of Thermus thermophilus (xylA) was recombined with pRSETA vector, and the pRSETA::xylA obtained was transferred into E.coli BL21 (DE3) pLysS and used for GI production. The highest soluble GI activity was obtained at t = 30 h, as A = 16 400 U L−1 (20.6 U mg−1 protein) under Molasses based fed-batch operation, with a specific growth rate µ = 0.1 h−1 (M-0.1); on the other hand, the highest cell concentration was obtained at µ = 0.15 h−1 operation as 9.6 g L−1 at t = 32 h. The highest oxygen uptake was 4.57 mol m−3 s−1 at M-0.1 operation. CONCLUSIONS: Molasses based fed-batch operations were more successful in terms of cell concentration and thermostable enzyme production due to the existence of a natural sugar inducer, galactose, in the Molasses composition. This study demonstrates the significance of proper feeding strategy development for over-production of enzymes by recombinant E. coli strains. © 2012 Society of Chemical Industry
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effects of pretreated Beet Molasses on benzaldehyde lyase production by recombinant escherichia coli bl21 de3 plyss
Journal of Applied Microbiology, 2009Co-Authors: Pinar Calik, Hande LeventAbstract:Aims: To investigate the effects of pretreated-Beet Molasses on Escherichia coli fermentation using benzaldehyde lyase (BAL) production by recombinant E. coli BL21(DE3)pLySs process as the model system. Methods and Results: The effect of the initial pretreated (hydrolysed) Beet Molasses concentration was investigated at 16, 24, 30 and 56 g l−1 at a dissolved oxygen condition of 40% air saturation cascade to airflow, at N = 625 min−1 and pHC = 7·2 controlled-pH operation conditions. The highest cell concentration and BAL activity were obtained as CX = 5·3 g l−1 and A = 1617 U cm−3, respectively, in the medium containing 30 g l−1 pretreated Beet Molasses consisting of 7·5 g l−1 glucose and 7·5 g l−1 fructose. Production with and without IPTG (isopropyl-β-d-thiogalactopyranoside) induction using the medium containing 30 g l−1 of pretreated Beet Molasses yielded the same amount of BAL production, where the overall cell yield on the substrate was 0·37 g g−1, and the highest oxygen transfer coefficient was KLa = 0·048 s−1. Conclusions: Pretreated Beet Molasses was used in the fermentation with E. coli for the first time and it yielded higher cell and BAL production compared with the glucose-based medium. Significance and Impact of the Study: Pretreated Beet Molasses was found to be a good carbon source for E. coli fermentation. Furthermore, IPTG addition was not required to induce recombinant protein production as galactose, one of the monomers of trisaccharide raffinose present in the Beet Molasses (1·2%), induced the lac promoter.
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Effects of pulse feeding of Beet Molasses on recombinant benzaldehyde lyase production by Escherichia coli BL21(DE3)
Applied Microbiology and Biotechnology, 2009Co-Authors: Pinar Calik, Hande LeventAbstract:The effect of fed-batch operation (FBO) strategy was investigated using pretreated-Beet Molasses, containing galactose that induces the lac promoter, on benzaldehyde lyase (BAL) production by recombinant Escherichia coli BL21(DE3)pLySs. After batch cultivation with 30 g l^−1 pretreated-Beet Molasses consisting of 7.5 g l^−1 glucose and 7.5 g l^−1 fructose, three FBO strategies were applied at dissolved oxygen (=40%) cascade to air-flow rate. In FBO1 when air-flow rate decreased considerably, feed was given to the system in pulses in such a way that pretreated-Beet Molasses concentration increased by 10 kg m^−3 (containing 2.5 g l^−1 glucose+2.5 g l^−1 fructose); however, decrease in air-flow rate demonstrated only the absence of glucose but not fructose. Thus, in FBO2 when fructose and glucose were completely utilized, pretreated-Beet Molasses was pulse-fed and its concentration increased by 10 g l^−1. In FBO3 with the decreased amount of pretreated-Beet Molasses (6 g l^−1), shift response time from glucose to fructose consumption was avoided, and glucose and fructose consumptions were well correlated with air-flow rate, and the highest C _X (8.04 g l^−1) and BAL (2,315 U ml^−1) production were obtained ( t = 24 h) with the highest substrate yield on cell and product formation.
Hande Levent - One of the best experts on this subject based on the ideXlab platform.
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effects of pretreated Beet Molasses on benzaldehyde lyase production by recombinant escherichia coli bl21 de3 plyss
Journal of Applied Microbiology, 2009Co-Authors: Pinar Calik, Hande LeventAbstract:Aims: To investigate the effects of pretreated-Beet Molasses on Escherichia coli fermentation using benzaldehyde lyase (BAL) production by recombinant E. coli BL21(DE3)pLySs process as the model system. Methods and Results: The effect of the initial pretreated (hydrolysed) Beet Molasses concentration was investigated at 16, 24, 30 and 56 g l−1 at a dissolved oxygen condition of 40% air saturation cascade to airflow, at N = 625 min−1 and pHC = 7·2 controlled-pH operation conditions. The highest cell concentration and BAL activity were obtained as CX = 5·3 g l−1 and A = 1617 U cm−3, respectively, in the medium containing 30 g l−1 pretreated Beet Molasses consisting of 7·5 g l−1 glucose and 7·5 g l−1 fructose. Production with and without IPTG (isopropyl-β-d-thiogalactopyranoside) induction using the medium containing 30 g l−1 of pretreated Beet Molasses yielded the same amount of BAL production, where the overall cell yield on the substrate was 0·37 g g−1, and the highest oxygen transfer coefficient was KLa = 0·048 s−1. Conclusions: Pretreated Beet Molasses was used in the fermentation with E. coli for the first time and it yielded higher cell and BAL production compared with the glucose-based medium. Significance and Impact of the Study: Pretreated Beet Molasses was found to be a good carbon source for E. coli fermentation. Furthermore, IPTG addition was not required to induce recombinant protein production as galactose, one of the monomers of trisaccharide raffinose present in the Beet Molasses (1·2%), induced the lac promoter.
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Effects of pulse feeding of Beet Molasses on recombinant benzaldehyde lyase production by Escherichia coli BL21(DE3)
Applied Microbiology and Biotechnology, 2009Co-Authors: Pinar Calik, Hande LeventAbstract:The effect of fed-batch operation (FBO) strategy was investigated using pretreated-Beet Molasses, containing galactose that induces the lac promoter, on benzaldehyde lyase (BAL) production by recombinant Escherichia coli BL21(DE3)pLySs. After batch cultivation with 30 g l^−1 pretreated-Beet Molasses consisting of 7.5 g l^−1 glucose and 7.5 g l^−1 fructose, three FBO strategies were applied at dissolved oxygen (=40%) cascade to air-flow rate. In FBO1 when air-flow rate decreased considerably, feed was given to the system in pulses in such a way that pretreated-Beet Molasses concentration increased by 10 kg m^−3 (containing 2.5 g l^−1 glucose+2.5 g l^−1 fructose); however, decrease in air-flow rate demonstrated only the absence of glucose but not fructose. Thus, in FBO2 when fructose and glucose were completely utilized, pretreated-Beet Molasses was pulse-fed and its concentration increased by 10 g l^−1. In FBO3 with the decreased amount of pretreated-Beet Molasses (6 g l^−1), shift response time from glucose to fructose consumption was avoided, and glucose and fructose consumptions were well correlated with air-flow rate, and the highest C _X (8.04 g l^−1) and BAL (2,315 U ml^−1) production were obtained ( t = 24 h) with the highest substrate yield on cell and product formation.
Vesna M Vucurovic - One of the best experts on this subject based on the ideXlab platform.
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bioethanol production from sugar Beet Molasses and thick juice using saccharomyces cerevisiae immobilized on maize stem ground tissue
Fuel, 2012Co-Authors: Radojka N Razmovski, Vesna M VucurovicAbstract:Abstract The potential of by-products and intermediate products of sugar Beet processing as raw materials for bioethanol production in Vojvodina region has a big scope in view of the demand of ethanol as an alternative for fossil fuels. Also, from ecological point of view, use of agricultural waste as carriers for cells immobilization is justifiable. The biocatalyst prepared by immobilization of Saccharomyces cerevisiae on maize stem ground tissue was used for batch fermentation of sugar Beet Molasses and thick juice under normal and very high gravity (VHG) conditions. Cell immobilization was observed by electron microscopy. The carrier was effective for cell immobilization and provided strength and stability to the yeast cell mass and functioned as a fortification against toxins and inhibitors, enabling efficient ethanol fermentation, particularly in VHG conditions. Three different initial glucose concentrations were tested: 100, 150 and 300 g/l. The maximum ethanol concentration of 83.20 g/l for Molasses and 132.39 g/l for thick juice were achieved in VHG fermentation by immobilized cells, whereas the free yeast cells were unsuccessful in the same media. Taking into consideration significant process parameters sugar Beet thick juice was found to be economically favorable, compared to Molasses, particularly in the VHG fermentation process.
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ethanol production from sugar Beet Molasses by s cerevisiae entrapped in an alginate maize stem ground tissue matrix
Enzyme and Microbial Technology, 2011Co-Authors: Radojka N Razmovski, Vesna M VucurovicAbstract:A new alginate-maize stem ground tissue matrix was developed as a Saccharomyces cerevisiae carrier for ethanol fermentation from sugar Beet Molasses. There were several fermentation procedures in the present study: using free cells and alginate-entrapped cells with and without maize stem ground tissue supplementation (F; F+C; AB; AB+C), and using a new combined alginate-maize stem ground tissue carrier (ABC). It was found that addition of maize stem ground tissue meal (C), with honeycomb configuration, provided high surface areas for cell attachment and biofilm growth, and also increased alginate matrix porosity, enabling better mass transfer characteristic, better physical strength and stability of beads. The highest values of process parameters were obtained in the case of new carrier (ABC): the ethanol concentration of 60.36 g/l, percentage of the theoretical ethanol yield of 96.56%, ethanol yield of 0.493 g/g and the volumetric ethanol productivity of 2.51 g/lh. The medium supplementation with maize stem ground tissue significantly decreased acetaldehyde and acetic acid content, did not affect fusel alcohol and ethylacetate content of the distillate.
Yekta Goksungur - One of the best experts on this subject based on the ideXlab platform.
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optimization of the production of chitosan from Beet Molasses by response surface methodology
Journal of Chemical Technology & Biotechnology, 2004Co-Authors: Yekta GoksungurAbstract:Chitosan was produced by Rhizopus oryzae 00.4367 in shake flask culture and a stirred tank fermenter. Synthetic medium, treated and untreated Beet Molasses were used as cultivation media in shake flask cultures. In the stirred tank fermenter, the cultivation media were synthetic medium and untreated Beet Molasses. Shake flask culture containing untreated Molasses with a sugar concentration of 40 g dm−3 produced the maximum chitosan yield (961 mg dm−3). Chitosan concentration reached its maximum value at the late exponential growth phase of R oryzae. In all experiments almost 8–10% of biomass and 32–38% of alkali-insoluble material was extracted as chitosan. A central composite design was employed to determine the optimum values of process variables (aeration rate, agitation speed and initial sugar concentration) leading to maximum chitosan concentration in the stirred tank fermenter. In all cases, the fit of the model was found to be good. Aeration rate, agitation speed and initial sugar concentration had a strong linear effect on chitosan concentration. Moreover, the concentration of chitosan was significantly influenced by the negative quadratic effects of the given variables and by their positive or negative interactions. A maximum chitosan concentration of 1109.32 mg dm−3 was obtained in untreated Molasses medium containing an initial sugar concentration of 45.37 g dm−3 with an aeration rate and agitation speed of 2.10 vvm and 338.93 rpm, respectively. Copyright © 2004 Society of Chemical Industry
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production of ethanol from Beet Molasses by ca alginate immobilized yeast cells in a packed bed bioreactor
Turkish Journal of Biology, 2001Co-Authors: Yekta Goksungur, Nefle ZorluAbstract:The continuous production of ethanol from Beet Molasses by Ca-alginate immobilized Saccharomyces cerevisiae in a packed-bed bioreactor was investigated. The temperature was maintained at 30iC and the dilution rate was 0.22 h -1 . Maximum ethanol (4.62%), theoretical yield (82.9%) and volumetric productivity (10.16 gl -1 h -1 ) were obtained from the Beet Molasses medium containing 10.90% total sugar with 2.0-2.4 mm diameter beads prepared from 2% (w/v) sodium alginate solution. At higher substrate concentrations, substrate was recirculated through the packed- bed bioreactor to increase yields and to decrease residual sugar content. The bioreactor system was operated at a constant dilution rate of 0.22 h -1 for 25 days without loss of original fermentation capacity. Compared to packed-bed bioreactor, lower ethanol concentration (3.94%), theoretical yield (70.7%) and productivity (8.67 gl -1 h -1 ) were obtained in the continuous stirred bioreactor. Ozet: Bu cal›flmada dolgulu yatak biyoreaktor kullan›larak Ca-aljinatta tutuklanm›fl Saccharomyces cerevisiae hucreleri ile pancar melas›ndan surekli yontemde etil alkol uretimi araflt›r›lm›flt›r. Cal›flma s›cakl›¤›n›n 30iC, kullan›lan seyreltme h›z›n›n 0.22 h -1 olduu cal›flmada en yuksek etil alkol (4.62%), teorik verim (82.9%) ve hacimsel verimlilik (10.16 gl -1 h -1 ) deerleri %10.90 bafllang›c fleker konsantrasyonu iceren ortamda, %2 Na-aljinattan uretilen, 2.0-2.4 mm cap›ndaki boncuklarla elde edilmifltir. Daha yuksek substrat konsantrasyonlar›nda verim deerlerini art›rmak ve ortamda kullan›lmadan kalan fleker miktar›n› azaltmak icin substrat biyoreaktorden tekrar sirkule edilmifltir. Biyoreaktor 0.22 h -1 seyreltme h›z›nda fermentasyon kapasitesinde onemli deifliklik olmadan surekli sistemde 25 gun boyunca cal›flt›r›lm›flt›r. Surekli kar›flt›rmal› tank tipi biyoreaktorde yap›lan denemede ise dolgulu yatak biyoreaktore gore daha dufluk etil alkol konsantrasyonu (3.94%), teorik verim (70.7%) ve verimlilik (8.67 gl -1 h -1 ) deerleri elde edilmifltir.
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production of lactic acid from Beet Molasses by calcium alginate immobilized lactobacillus delbrueckii ifo 3202
Journal of Chemical Technology & Biotechnology, 1999Co-Authors: Yekta Goksungur, Ulgar GuvencAbstract:Lactic acid was produced from pretreated Beet Molasses by the homofermentative organism Lactobacillus delbrueckii subsp delbrueckii IFO 3202 entrapped in calcium alginate gel using batch, repeated batch and continuous fermentation systems. In batch fermentation studies successful results were obtained with 2.0–2.4 mm diameter beads prepared from 2% sodium alginate solution. The highest effective yield (82.0%) and conversion yield (90.0%) were obtained from substrate concentrations of 52.1 and 78.2 g dm−3 respectively. The gel beads produced lactic acid for 14 consecutive batch fermentations without marked activity loss and deformation. In the continuous fermentation, the highest lactic acid (4.22%) was obtained at a dilution rate of 0.1 h−1 while the highest productivity (13.92 g dm−3 h−1) was obtained at a dilution rate of 0.4 h−1. © 1999 Society of Chemical Industry
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batch and continuous production of lactic acid from Beet Molasses by lactobacillus delbrueckii ifo 3202
Journal of Chemical Technology & Biotechnology, 1997Co-Authors: Yekta Goksungur, Ulgar GuvencAbstract:Process variables were optimized for the production of lactic acid from pretreated Beet Molasses by Lactobacillus delbrueckii IFO 3202 for batch and continuous fermentations. In the batch fermentation, maximum yields (95·4% conversion, 77·1% effective) and maximum lactic acid volumetric productivity (4·83 g dm−3 h−1) was achieved at 45°C, pH 6·0, 78·2 g dm−3 sugar concentration with 10 g dm−3 yeast extract. Various cheaper nitrogen sources were replaced with yeast extract on equal nitrogen bases in batch fermentation. Of all the nitrogen sources tested, yeast extract yielded the highest and malt sprouts yielded the second highest level of lactic acid. In the continuous fermentation, maximum lactic acid (4·15%) was obtained at a dilution rate of 0·1 h−1. Maximum volumetric lactic acid productivity (11·20 g dm−3 h−1) occurred at D = 0·5 h−1 dilution rate. © 1997 SCI.
Ulgar Guvenc - One of the best experts on this subject based on the ideXlab platform.
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production of lactic acid from Beet Molasses by calcium alginate immobilized lactobacillus delbrueckii ifo 3202
Journal of Chemical Technology & Biotechnology, 1999Co-Authors: Yekta Goksungur, Ulgar GuvencAbstract:Lactic acid was produced from pretreated Beet Molasses by the homofermentative organism Lactobacillus delbrueckii subsp delbrueckii IFO 3202 entrapped in calcium alginate gel using batch, repeated batch and continuous fermentation systems. In batch fermentation studies successful results were obtained with 2.0–2.4 mm diameter beads prepared from 2% sodium alginate solution. The highest effective yield (82.0%) and conversion yield (90.0%) were obtained from substrate concentrations of 52.1 and 78.2 g dm−3 respectively. The gel beads produced lactic acid for 14 consecutive batch fermentations without marked activity loss and deformation. In the continuous fermentation, the highest lactic acid (4.22%) was obtained at a dilution rate of 0.1 h−1 while the highest productivity (13.92 g dm−3 h−1) was obtained at a dilution rate of 0.4 h−1. © 1999 Society of Chemical Industry
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batch and continuous production of lactic acid from Beet Molasses by lactobacillus delbrueckii ifo 3202
Journal of Chemical Technology & Biotechnology, 1997Co-Authors: Yekta Goksungur, Ulgar GuvencAbstract:Process variables were optimized for the production of lactic acid from pretreated Beet Molasses by Lactobacillus delbrueckii IFO 3202 for batch and continuous fermentations. In the batch fermentation, maximum yields (95·4% conversion, 77·1% effective) and maximum lactic acid volumetric productivity (4·83 g dm−3 h−1) was achieved at 45°C, pH 6·0, 78·2 g dm−3 sugar concentration with 10 g dm−3 yeast extract. Various cheaper nitrogen sources were replaced with yeast extract on equal nitrogen bases in batch fermentation. Of all the nitrogen sources tested, yeast extract yielded the highest and malt sprouts yielded the second highest level of lactic acid. In the continuous fermentation, maximum lactic acid (4·15%) was obtained at a dilution rate of 0·1 h−1. Maximum volumetric lactic acid productivity (11·20 g dm−3 h−1) occurred at D = 0·5 h−1 dilution rate. © 1997 SCI.