Improved production of live cells of Lactobacillus rhamnosus by continuous cultivation using glucose-yeast extract medium.
In this study, the growth kinetics of Lactobacillus rhamnosus and lactic acid production in continuous culture were assessed at a range of dilution rates (0.05 h(-1) to 0.40 h(-1)) using a 2 L stirred tank fermenter with a working volume of 600 ml. Unstructured models, predicated on the Monod and Luedeking-Piret equations, were employed to simulate the growth of the bacterium, glucose consumption, and lactic acid production at different dilution rates in continuous cultures. The maximum specific growth rate of L. rhamnosus, mu-max, was estimated at 0.40 h(-1), and the Monod cell growth saturation constant, Ks, at approximately 0.25 g/L. Maximum cell viability (1.3 x 10(10) CFU/ml) was achieved in the dilution rate range of D = 0.28 h(-1) to 0.35 h(-1). Both maximum viable cell yield and productivity were achieved at D = 0.35 h(-1). The continuous cultivation of L. rhamnosus at D = 0.35 h(-1) resulted in substantial improvements in cell productivity, of 267% (viable cell count) that achieved via batch cultivation.
Ling
Liew Siew
LS
Laboratory of Enzyme and Microbial Technology, Institute of Bioscience Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
Mohamad
Rosfarizan
R
Rahim
Raha Abdul
RA
Wan
Ho Yin
HY
Ariff
Arbakariya Bin
AB
D003470:Culture Media; D005285:Fermentation; D007700:Kinetics; D052201:Lacticaseibacillus rhamnosus / Q000254:growth & development* / Q000378:metabolism; D050296:Microbial Viability; D008954:Models, Biological; D015233:Models, Statistical
D003470:Culture Media