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Christophe Lacroix - One of the best experts on this subject based on the ideXlab platform.
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lactobacillus helveticus growth and lactic acid production during ph controlled batch cultures in Whey Permeate yeast extract medium part i multiple factor kinetic analysis
Enzyme and Microbial Technology, 2002Co-Authors: Adolf Willem Schepers, Jules Thibault, Christophe LacroixAbstract:Abstract Twenty pH-controlled batch cultures with Lactobacillus helveticus were carried out in Whey Permeate-yeast extract medium according to a composite design with three factors: pH setpoint, and yeast extract and initial Whey Permeate concentrations. Growth and production parameters were estimated from experimental data with the Richards and Luedeking and Piret models, respectively, and analyzed statistically with response surfaces. The maximum specific growth rate, μ max , depended primarily on pH, with an optimum of 0.7 h −1 near pH 5.5. Whey Permeate concentration had no direct effect on maximum specific growth rate, but showed a strong interaction with pH. Yeast extract addition had a strong positive effect on maximum specific growth rate. During nitrogen-limited batch cultures X max depended on yeast extract concentration and pH, as well as on interactions of these variables with Whey Permeate concentration. The growth-associated lactic acid production parameter a was constant at 4.5 g lactic acid (g biomass) −1 , while the nongrowth-associated production parameter b, estimated during growth and early stationary phase, was a linear function of pH. This study allowed for the first detailed multifactor kinetic analysis of Lb. helveticus growth and lactic acid production, with a limited number of experiments, and demonstrated the importance of interactions among tested culture conditions.
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Lactobacillus helveticus growth and lactic acid production during pH-controlled batch cultures in Whey Permeate/yeast extract medium. Part I. Multiple factor kinetic analysis
Enzyme and Microbial Technology, 2002Co-Authors: Adolf Willem Schepers, Jules Thibault, Christophe LacroixAbstract:Abstract Twenty pH-controlled batch cultures with Lactobacillus helveticus were carried out in Whey Permeate-yeast extract medium according to a composite design with three factors: pH setpoint, and yeast extract and initial Whey Permeate concentrations. Growth and production parameters were estimated from experimental data with the Richards and Luedeking and Piret models, respectively, and analyzed statistically with response surfaces. The maximum specific growth rate, μ max , depended primarily on pH, with an optimum of 0.7 h −1 near pH 5.5. Whey Permeate concentration had no direct effect on maximum specific growth rate, but showed a strong interaction with pH. Yeast extract addition had a strong positive effect on maximum specific growth rate. During nitrogen-limited batch cultures X max depended on yeast extract concentration and pH, as well as on interactions of these variables with Whey Permeate concentration. The growth-associated lactic acid production parameter a was constant at 4.5 g lactic acid (g biomass) −1 , while the nongrowth-associated production parameter b, estimated during growth and early stationary phase, was a linear function of pH. This study allowed for the first detailed multifactor kinetic analysis of Lb. helveticus growth and lactic acid production, with a limited number of experiments, and demonstrated the importance of interactions among tested culture conditions.
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Effect of medium supplementation on exopolysaccharide production by Lactobacillus rhamnosus RW-9595M in Whey Permeate
International Dairy Journal, 2002Co-Authors: Maria G. Macedo, Christophe Lacroix, Nancy J. Gardner, Claude P. ChampagneAbstract:Abstract Exopolysaccharide (EPS) production by Lactobacillus rhamnosus RW-9595M was studied in Whey Permeate medium supplemented with different nitrogen sources or with yeast extract and vitamins, salts and amino acids used in the formulation of defined basal minimum medium (BMM). All nitrogen sources tested exhibited very limited or no effect on biomass production using acidification and automated spectrophotometry test. A multilevel-factorial design was used to determine the main effects and interactions of BMM nutrient groups during pH-controlled batch fermentations in order to find the limiting nutrient group for EPS production in a Whey Permeate medium supplemented with yeast extract. Maximum populations during batch fermentations in Whey Permeate medium with yeast extract and BMM components varied between 4.4×10 9 and 1.1×10 10 CFU mL −1 , with the highest population obtained when salts and amino acids or the three groups of supplements were added. Maximum EPS productions were very high, in the range from 440 to 2775 mg L −1 . The addition of salts largely increased this production, and a strong interaction was observed between amino acids and salts. In this study, the EPS production (2767 mg L −1 ) obtained using Lb. rhamnosus RW-9595M in the culture medium containing salts and vitamins is the highest reported for lactobacilli.
Adolf Willem Schepers - One of the best experts on this subject based on the ideXlab platform.
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Lactobacillus helveticus growth and lactic acid production during pH-controlled batch cultures in Whey Permeate/yeast extract medium. Part I. Multiple factor kinetic analysis
Enzyme and Microbial Technology, 2002Co-Authors: Adolf Willem Schepers, Jules Thibault, Christophe LacroixAbstract:Abstract Twenty pH-controlled batch cultures with Lactobacillus helveticus were carried out in Whey Permeate-yeast extract medium according to a composite design with three factors: pH setpoint, and yeast extract and initial Whey Permeate concentrations. Growth and production parameters were estimated from experimental data with the Richards and Luedeking and Piret models, respectively, and analyzed statistically with response surfaces. The maximum specific growth rate, μ max , depended primarily on pH, with an optimum of 0.7 h −1 near pH 5.5. Whey Permeate concentration had no direct effect on maximum specific growth rate, but showed a strong interaction with pH. Yeast extract addition had a strong positive effect on maximum specific growth rate. During nitrogen-limited batch cultures X max depended on yeast extract concentration and pH, as well as on interactions of these variables with Whey Permeate concentration. The growth-associated lactic acid production parameter a was constant at 4.5 g lactic acid (g biomass) −1 , while the nongrowth-associated production parameter b, estimated during growth and early stationary phase, was a linear function of pH. This study allowed for the first detailed multifactor kinetic analysis of Lb. helveticus growth and lactic acid production, with a limited number of experiments, and demonstrated the importance of interactions among tested culture conditions.
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lactobacillus helveticus growth and lactic acid production during ph controlled batch cultures in Whey Permeate yeast extract medium part i multiple factor kinetic analysis
Enzyme and Microbial Technology, 2002Co-Authors: Adolf Willem Schepers, Jules Thibault, Christophe LacroixAbstract:Abstract Twenty pH-controlled batch cultures with Lactobacillus helveticus were carried out in Whey Permeate-yeast extract medium according to a composite design with three factors: pH setpoint, and yeast extract and initial Whey Permeate concentrations. Growth and production parameters were estimated from experimental data with the Richards and Luedeking and Piret models, respectively, and analyzed statistically with response surfaces. The maximum specific growth rate, μ max , depended primarily on pH, with an optimum of 0.7 h −1 near pH 5.5. Whey Permeate concentration had no direct effect on maximum specific growth rate, but showed a strong interaction with pH. Yeast extract addition had a strong positive effect on maximum specific growth rate. During nitrogen-limited batch cultures X max depended on yeast extract concentration and pH, as well as on interactions of these variables with Whey Permeate concentration. The growth-associated lactic acid production parameter a was constant at 4.5 g lactic acid (g biomass) −1 , while the nongrowth-associated production parameter b, estimated during growth and early stationary phase, was a linear function of pH. This study allowed for the first detailed multifactor kinetic analysis of Lb. helveticus growth and lactic acid production, with a limited number of experiments, and demonstrated the importance of interactions among tested culture conditions.
Conly L. Hansen - One of the best experts on this subject based on the ideXlab platform.
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Antioxidant Capacity, Phenolic Content, and Polysaccharide Content of Lentinus edodes Grown in Whey Permeate-Based Submerged Culture
Journal of Food Science, 2007Co-Authors: Conly L. HansenAbstract:Total antioxidant capacity (TAC), phenolic content, and crude water-soluble polysaccharide (WSP) were determined for Lentinus edodes mycelia grown on both Whey Permeate (WP)-based medium with lactose content of 4.5% and controlled medium, and harvested after 5, 10, 15, or 20 d of fermentation at 25 degrees C. Both methanol extracts and water extracts of L. edodes in this study were found to exhibit high free radical scavenging capacity. The harvesting time was found to contribute to most of the variability in the free radical scavenging capacity. High levels of antioxidant capacities (0.28 +/- 0.03 and 0.29 +/- 0.06 mmol TAE/g dry weight for methanol and water extracts, respectively) were observed in mycelia grown on Whey Permeate and harvested on day 10. Harvesting time and the type of media can interact to alter the chemical content of mycelia. Mycelia grown in Whey Permeate had greater (P < 0.05) WSP than mycelia grown in the synthetic media. High levels of WSP (4.1 x 10(2)+/- 71 mg polysaccharide/g dried mycelia) were found in mycelia grown in Whey Permeate and harvested on day 10. Whey Permeate grown mycelia had phenolic compounds ranging from 4.2 +/- 0.1 to 8.0 +/- 0.8 mg GAE/g dried mycelia. The overall means of total phenolic contents of mycelia grown in Whey Permeate were 5.9 +/- 0.5 and 6.2 +/- 0.6 mg GAE/g dried mycelia for methanol and water extracts, respectively.
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Short Communication: Cultivation of Lentinus edodes Mycelia Using Whey Permeate as an Alternative Growth Substrate
Journal of Dairy Science, 2006Co-Authors: B.s. Inglet, Conly L. Hansen, Minkyung Song, Sun-kuen HwangAbstract:The major objective of this research was to use Whey Permeate as an alternative growth medium for the cultivation of mycelia of the edible mushroom Lentinus edodes and to find an optimum condition for solid-state cultivation. Response surface analysis was applied to determine the combination of substrate concentration (40 to 60 g of lactose/L), temperature (20 to 30°C), and pH (4 to 6) resulting in a maximal mycelial growth rate. The radial extension rates, estimated by measuring the diameters of growing colonies on the Petri dishes, were used as the growth rate of the mycelia at different conditions. The conditions predicted to maximize the mycelial growth of 6.41 ± 0.47 mm/d were determined to be 40 g of lactose/L, temperature 23.6°C, and pH 5.0. It was concluded that a partial cubic equation could accurately model the response surface of, and predict optimal growth conditions for, L. edodes mycelia using Whey Permeate because the model prediction agreed with the experimental growth rate, 6.39 ± 0.22 mm/d. The results suggest that Whey Permeate could be utilized as a growth substrate for the cultivation of mycelia from the edible mushroom L. edodes, enhancing the use of this by-product by the cheese manufacturing industry.
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Biokinetics of an upflow anaerobic sludge blanket reactor treating Whey Permeate
Bioresource Technology, 2003Co-Authors: Seokhwan Hwang, Conly L. Hansen, D.k. StevensAbstract:Abstract A laboratory study was performed to determine the kinetic model and to evaluate kinetic coefficients of continuous upflow anaerobic sludge blanket (UASB) reactors treating Whey Permeate. Eight hydraulic retention times (5·-0·4 day) were investigated at fixed influent substrate concentration (10·4 ± 0·2 g COD/litre). The maximum substrate utilization rate, k, and half saturation coefficient, K L , were determined to be 0·941 kg COD rmvd /kg VSS/day and 0·773 kg COD/kg VSS/day. The yield coefficient, Y, and sludge decay rate coefficient, K d , were also determined to be 0·153 kg VSS/kg COD and 0·022/day, respectively.
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Performance of Upflow Anaerobic Sludge Blanket (UASB) Reactor Treating Whey Permeate
Transactions of the ASABE, 1992Co-Authors: Seokhwan Hwang, Conly L. HansenAbstract:Whey Permeate was anaerobically digested in laboratory scale upflow anaerobic sludge blanket (UASB) reactors. Eight hydraulic retention times (HRT) between 0.4 and 5 days were examined with a fixed influent concentration of 10.4 ± 0.2 g COD/L.
Shang-tian Yang - One of the best experts on this subject based on the ideXlab platform.
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Continuous nisin production in laboratory media and Whey Permeate by immobilized Lactococcus lactis
Process Biochemistry, 2004Co-Authors: Xia Liu, Shang-tian Yang, Yoon-kyung Chung, Ahmed E. YousefAbstract:Abstract Continuous production of nisin in laboratory media and Whey Permeate was investigated using a packed-bed bioreactor. Lactococcus lactis subsp. lactis ATCC 11454 was immobilized by natural attachment to fibre surfaces and entrapment in the void volume within spiral wound fibrous matrix. The inoculated bioreactor was fed M17 medium and effect of pH, temperature, dilution rate, and substrate concentrations on nisin production was examined. Bioreactor performance was monitored by checking cell density, lactic acid production, lactose consumption, and nisin activity. Optimal nisin activity was observed at pH 5.5, 31 °C, 0.2–0.3/h dilution rate, and 30 g/l lactose in M17. The maximum nisin titre was 2.6×10 4 AU/ml against a nisin sensitive strain, Lactobacillus leichmannii ATCC 4797. The bioreactor was fed Whey Permeate, supplemented with casein hydrolysate, and growth of L. lactis and associated nisin production were monitored. Optimal conditions for continuous nisin production in Whey Permeate were pH 5.5, 31 °C, 10–20 g/l casein hydrolysate, and 0.2/h dilution rate. Under these conditions, a maximum nisin titre of 5.1×10 4 AU/ml was observed. The bioreactor was operated continuously for 6 months without encountering any clogging, degeneration, or contamination problems. The cell density in the bioreactor was 52.0 g/l with 96.4% of the cells immobilized. This study illustrates the possibility of continuous production of high concentration of bacteriocins by lactic acid bacteria for use as food biopreservatives.
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Continuous propionate production from Whey Permeate using a novel fibrous bed bioreactor.
Biotechnology and Bioengineering, 1994Co-Authors: Shang-tian Yang, Hui Zhu, Gene HongAbstract:Continuous production of propionate from Whey lactose by Propionibacterium acidipropionici immobilized in a novel fibrous bed bioreactor was studied. In conventional batch propionic acid fermentation, Whey Permeate without nutrient supplementation was unable to support cell growth and failed to give satisfactory fermentation results for over 7 days. However, with the fibrous bed bioreactor, a high fermentation rate and high conversion were obtained with plain Whey Permeate and de-lactose Whey Permeate. About 2% (wt/vol) propionic acid was obtained from a 4.2% lactose feed at a retention time of 35 to 45 h. The propionic acid yield was ∼46% (wt/vol) from lactose. The optimal pH for fementation was 6.5, and lower fermentation rates and yields were obtained at lower pH values. The optimal temperature was 30°C, but the temperature effect was not dramatic in the range of 25 to 35°C. Addition of yeast extract and trypticase to Whey Permeate hastened reactor startup and increased the fermentation rate and product yields, but the addition was not required for long-term reactor performance. The improved fermentation results with the immobilized cell bioreactor can be attributed to the high cell density, ∼50 g/L, attained in the bioreactor, Cells were immobilized by loose attachement to fiber surfaces and entrapment in the void spaces within the fibrous matrix, thus allowing constant renewal of cells. Consequently, this bioreactor was able to operate continuously for 6 months without encountering any clogging, degeneration, or contamination problems. Compared to conventional batch fermentors, the new bioreactor offers many advantages for industrial fermentation, including a more than 10-fold increase in productivity, acceptance of low-nutrient feedstocks such as Whey Permeate, and resistance to contamination. © 1994 John Wiley & Sons, Inc.
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continuous propionate production from Whey Permeate using a novel fibrous bed bioreactor
Biotechnology and Bioengineering, 1994Co-Authors: Shang-tian Yang, Hui Zhu, Gene HongAbstract:Continuous production of propionate from Whey lactose by Propionibacterium acidipropionici immobilized in a novel fibrous bed bioreactor was studied. In conventional batch propionic acid fermentation, Whey Permeate without nutrient supplementation was unable to support cell growth and failed to give satisfactory fermentation results for over 7 days. However, with the fibrous bed bioreactor, a high fermentation rate and high conversion were obtained with plain Whey Permeate and de-lactose Whey Permeate. About 2% (wt/vol) propionic acid was obtained from a 4.2% lactose feed at a retention time of 35 to 45 h. The propionic acid yield was approximately 46% (wt/vol) from lactose. The optimal pH for fementation was 6.5, and lower fermentation rates and yields were obtained at lower pH values. The optimal temperature was 30 degrees C, but the temperature effect was not dramatic in the range of 25 to 35 degrees C. Addition of yeast extract and trypticase to Whey Permeate hastened reactor startup and increased the fermentation rate and product yields, but the addition was not required for long-term reactor performance. The improved fermentation results with the immobilized cell bioreactor can be attributed to the high cell density, approximately 50 g/L, attained in the bioreactor, Cells were immobilized by loose attachement to fiber surfaces and entrapment in the void spaces within the fibrous matrix, thus allowing constant renewal of cells. Consequently, this bioreactor was able to operate continuously for 6 months without encountering any clogging, degeneration, or contamination problems. Compared to conventional batch fermentors, the new bioreactor offers many advantages for industrial fermentation, including a more than 10-fold increase in productivity, acceptance of low-nutrient feedstocks such as Whey Permeate, and resistance to contamination. (c) 1994 John Wiley & Sons, Inc.
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Calcium magnesium acetate (CMA) production from Whey Permeate: process and economic analysis
Resources Conservation and Recycling, 1992Co-Authors: Shang-tian Yang, Hui Zhu, Vivian P. Lewis, I-ching TangAbstract:Abstract About 28 billion lbs of liquid Whey produced from cheese manufacture are being wasted in the US. An anaerobic fermentation process is developed to produce calcium magnesium acetate (CMA) from Whey Permeate. CMA can be used to replace salt as a noncorrosive road deicer. A co-culture consisting of homolactic and homoacetic bacteria was used to convert Whey lactose to lactate and then to acetate in continuous, immobilized cell bioreactors. The acetate yield from lactose was ∼ 95% (w/w), and the final concentration of acetic acid obtained from this homofermentative process was 4%. The acetic acid produced from fermentation can be readily recovered by solvent extraction with a tertiary amine and reacted with dolomitic lime (CA/MgO) to form a concentrated (>25%) CMA solution. This CMA solution can then be dried to form the granular CMA deicer. About 40 tons CMA can be produced from a plant processing 1.5 million lbs Whey Permeate per day, at a cost of $215/ton. The total capital investment is estimated at ∼ 7 million dollars, with a return rate of less than 1.5 years at the current market price of $600/ton.
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A kinetic model for methanogenesis from Whey Permeate in a packed bed immobilized cell bioreactor
Biotechnology and Bioengineering, 1991Co-Authors: Shang-tian Yang, Meining QuoAbstract:The fermentation kinetics of methane production from Whey Permeate in a packed bed immobilized cell bioreactor at mesophilic temperatures and pHs around neutral was studied. Propionate and acetate were the only two major organic intermediates found in the methanogenic fermentation of lactose. Based on this finding, a three-step reaction mechanism was proposed: lactose was first degraded to propionate, acetate, CO2, and H2 by fermentative bacteria; propionate was then converted to acetate by propionate-degrading bacteria; and finally, CH4 and CO2 were produced from acetate, H2, and CO2 by methanogenic bacteria. The second reaction step was found to be the rate-limiting step in the overall methanogenic fermentation of lactose. Monod-type mathematical equations were used to model these three step reactions. The kinetic constants in the models were sequentially determined by fitting the mathematical equations with the experimental data on acetate, propionate, and lactose concentrations. A mixed-culture fermentation model was also developed. This model simulates the methanogenic fermentation of Whey Permeate very well.
Gene Hong - One of the best experts on this subject based on the ideXlab platform.
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Continuous propionate production from Whey Permeate using a novel fibrous bed bioreactor.
Biotechnology and Bioengineering, 1994Co-Authors: Shang-tian Yang, Hui Zhu, Gene HongAbstract:Continuous production of propionate from Whey lactose by Propionibacterium acidipropionici immobilized in a novel fibrous bed bioreactor was studied. In conventional batch propionic acid fermentation, Whey Permeate without nutrient supplementation was unable to support cell growth and failed to give satisfactory fermentation results for over 7 days. However, with the fibrous bed bioreactor, a high fermentation rate and high conversion were obtained with plain Whey Permeate and de-lactose Whey Permeate. About 2% (wt/vol) propionic acid was obtained from a 4.2% lactose feed at a retention time of 35 to 45 h. The propionic acid yield was ∼46% (wt/vol) from lactose. The optimal pH for fementation was 6.5, and lower fermentation rates and yields were obtained at lower pH values. The optimal temperature was 30°C, but the temperature effect was not dramatic in the range of 25 to 35°C. Addition of yeast extract and trypticase to Whey Permeate hastened reactor startup and increased the fermentation rate and product yields, but the addition was not required for long-term reactor performance. The improved fermentation results with the immobilized cell bioreactor can be attributed to the high cell density, ∼50 g/L, attained in the bioreactor, Cells were immobilized by loose attachement to fiber surfaces and entrapment in the void spaces within the fibrous matrix, thus allowing constant renewal of cells. Consequently, this bioreactor was able to operate continuously for 6 months without encountering any clogging, degeneration, or contamination problems. Compared to conventional batch fermentors, the new bioreactor offers many advantages for industrial fermentation, including a more than 10-fold increase in productivity, acceptance of low-nutrient feedstocks such as Whey Permeate, and resistance to contamination. © 1994 John Wiley & Sons, Inc.
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continuous propionate production from Whey Permeate using a novel fibrous bed bioreactor
Biotechnology and Bioengineering, 1994Co-Authors: Shang-tian Yang, Hui Zhu, Gene HongAbstract:Continuous production of propionate from Whey lactose by Propionibacterium acidipropionici immobilized in a novel fibrous bed bioreactor was studied. In conventional batch propionic acid fermentation, Whey Permeate without nutrient supplementation was unable to support cell growth and failed to give satisfactory fermentation results for over 7 days. However, with the fibrous bed bioreactor, a high fermentation rate and high conversion were obtained with plain Whey Permeate and de-lactose Whey Permeate. About 2% (wt/vol) propionic acid was obtained from a 4.2% lactose feed at a retention time of 35 to 45 h. The propionic acid yield was approximately 46% (wt/vol) from lactose. The optimal pH for fementation was 6.5, and lower fermentation rates and yields were obtained at lower pH values. The optimal temperature was 30 degrees C, but the temperature effect was not dramatic in the range of 25 to 35 degrees C. Addition of yeast extract and trypticase to Whey Permeate hastened reactor startup and increased the fermentation rate and product yields, but the addition was not required for long-term reactor performance. The improved fermentation results with the immobilized cell bioreactor can be attributed to the high cell density, approximately 50 g/L, attained in the bioreactor, Cells were immobilized by loose attachement to fiber surfaces and entrapment in the void spaces within the fibrous matrix, thus allowing constant renewal of cells. Consequently, this bioreactor was able to operate continuously for 6 months without encountering any clogging, degeneration, or contamination problems. Compared to conventional batch fermentors, the new bioreactor offers many advantages for industrial fermentation, including a more than 10-fold increase in productivity, acceptance of low-nutrient feedstocks such as Whey Permeate, and resistance to contamination. (c) 1994 John Wiley & Sons, Inc.
