Kinetics of Lactococcus lactis growth and metabolite formation under aerobic and anaerobic conditions in the presence or absence of hemin. Export

@article{citeulike:1750620, abstract = {The study of batch kinetics of Lactococcus lactis cell growth and product formation reveals three distinct metabolic behaviors depending upon the availability of oxygen to the culture and the presence of hemin in the medium. These three cultivation modes, anerobic homolactic fermentation, aerobic heterolactic fermentation, and hemin-stimulated respiration have been studied at pH 6.0 and 30 degrees C with a medium containing a high concentration of glucose (60 g/L). A maximum cell density of 5.78 g/L was obtained in the batch culture under hemin-stimulated respiration conditions, about three times as much as that achieved with anerobic homolactic fermentation (1.87 g/L) and aerobic heterolactic fermentation (1.80 g/L). The maximum specific growth rate was 0.60/h in hemin-stimulated respiration, slightly higher than that achieved in homolactic fermentation (0.56/h) and substantially higher than that in heterolactic fermentation (0.40/h). Alteration of metabolism caused by the supplementation of oxygen and hemin is evidenced by changes in both cell growth kinetics and metabolite formation kinetics, which are characterized by a unique pseudo-diauxic growth of L. lactis. We hypothesise that Lactococcus lactis generates bioenergy (ATP) through simultaneous lactate formation and hemin-stimulated respiration in the primary exponential phase, when glucose is abundant, and utilizes lactate for cell growth and cell maintenance in the stationary phase, after glucose is exhausted. We also examined the applicability of a modified logistic model and the Luedeking-Piret model for cell growth kinetics and metabolite formation kinetics, respectively.}, address = {Department of Chemical Engineering, University of Ottawa, A408 CBY, 161 Louis Pasteur St., ON, K1N 6N5, Canada. clan@uottawa.ca}, author = {Lan, C. Q. and Oddone, G. and Mills, D. A. and Block, D. E.}, citeulike-article-id = {1750620}, citeulike-linkout-0 = {http://dx.doi.org/10.1002/bit.21070}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/16807924}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=16807924}, day = {20}, doi = {10.1002/bit.21070}, issn = {0006-3592}, journal = {Biotechnol Bioeng}, keywords = {aerobic, anaerobic, formation, growth, hemin, kinetics, lactis, lactococcus, metabolite}, month = {December}, number = {6}, pages = {1070--1080}, posted-at = {2007-10-10 14:39:28}, priority = {2}, title = {Kinetics of Lactococcus lactis growth and metabolite formation under aerobic and anaerobic conditions in the presence or absence of hemin.}, url = {http://dx.doi.org/10.1002/bit.21070}, volume = {95}, year = {2006} }

TY - JOUR ID - citeulike:1750620 L3 - citeulike-article-id:1750620 N2 - The study of batch kinetics of Lactococcus lactis cell growth and product formation reveals three distinct metabolic behaviors depending upon the availability of oxygen to the culture and the presence of hemin in the medium. These three cultivation modes, anerobic homolactic fermentation, aerobic heterolactic fermentation, and hemin-stimulated respiration have been studied at pH 6.0 and 30 degrees C with a medium containing a high concentration of glucose (60 g/L). A maximum cell density of 5.78 g/L was obtained in the batch culture under hemin-stimulated respiration conditions, about three times as much as that achieved with anerobic homolactic fermentation (1.87 g/L) and aerobic heterolactic fermentation (1.80 g/L). The maximum specific growth rate was 0.60/h in hemin-stimulated respiration, slightly higher than that achieved in homolactic fermentation (0.56/h) and substantially higher than that in heterolactic fermentation (0.40/h). Alteration of metabolism caused by the supplementation of oxygen and hemin is evidenced by changes in both cell growth kinetics and metabolite formation kinetics, which are characterized by a unique pseudo-diauxic growth of L. lactis. We hypothesise that Lactococcus lactis generates bioenergy (ATP) through simultaneous lactate formation and hemin-stimulated respiration in the primary exponential phase, when glucose is abundant, and utilizes lactate for cell growth and cell maintenance in the stationary phase, after glucose is exhausted. We also examined the applicability of a modified logistic model and the Luedeking-Piret model for cell growth kinetics and metabolite formation kinetics, respectively. IS - 6 JF - Biotechnol Bioeng SN - 0006-3592 AD - Department of Chemical Engineering, University of Ottawa, A408 CBY, 161 Louis Pasteur St., ON, K1N 6N5, Canada. clan@uottawa.ca EP - 1080 TI - Kinetics of Lactococcus lactis growth and metabolite formation under aerobic and anaerobic conditions in the presence or absence of hemin. VL - 95 SP - 1070 KW - aerobic KW - anaerobic KW - formation KW - growth KW - hemin KW - kinetics KW - lactis KW - lactococcus KW - metabolite AU - Lan, CQ AU - Oddone, G AU - Mills, DA AU - Block, DE PY - 2006/12/20/ UR - http://dx.doi.org/10.1002/bit.21070 ER -