Immobilized Lactobacillus cells

Tan et al. [29] demonstrated the use of a plug flow reactor of immobilized Lactobacillus kefiri cells for the synthesis of the intermediate (5I )-hydroxyhexane-2-one. This immobilized-cell reactor operated at a maximum conversion yield of 100% and a selectivity of 95%. The production of (5/ )-hydroxyhexane-2-one was extended to an operation time of 6 days. During this time (91 residence times), a space-time yield of 87gL xday 1 and a productivity of 07 8 gwet cell weight 1 were obtained. 

Kosseva, M., Beschkov, V., Kennedy, J.F., and Lloyd, L.L. 1998. Malolactic fermentation in Char-donnay wine by immobilized Lactobacillus casei cells. Process Biochem. 33, 793-797. 

Crapisi, A., Nuti, M.P., Zamorani, A., and Spettoh, P. (1987) Improved sta-bihty of immobilized Lactobacillus sp. cells for the control of malolactic fermentation in wine. Am. J. Enol Vitic., 38, 310-312. 

Huang, J., Mei, L.-H., Wu, H., and Lin, D.-Q. (2007) Biosynthesis of y-aminobutyric acid (GABA) using immobilized whole cells of Lactobacillus brevis. World J. Microbiol. 

Other approaches to enhance the conversion of LA to CLA are found in immobilization techniques. Immobilized cells of Lactobacillus reuteri were 5.5 times more efficient in producing CLA than washed cells grown under optimized conditions (Lee et al, 2003a, 2003b). Improved CLA production was also observed with the immobilized cells of L. delbrueckii ssp. bulgaricus and L. acidophilus in polyacrylamide and chitosan (Lin et al., 2005). The major CLA isomers produced by these immobilized cells were c9, tll-CLA and t9, tll-CLA. 

Lin, T. Y., Hung, T.-H., and Cheng, T.-S. J. 2005. Conjugated linoleic acid production by immobilized cells of Lactobacillus delbrueckii ssp. bulgaricus and Lactobacillus acidophilus. Food Chem., 92, 23-28. 

Vitamins may be assayed by means of microbial electrodes constructed from cells whose metabolic activity or growth is dependent on the vitamin assayed. Such microbial strains are well known from the commonly used microbiological assays. For instance, the assessment of thiamine was performed by means of yeast cells immobilized in a calcium al inatte membrane. The difference in oxygen consumption before and after incubation with thiamine in the sample is related to the thiamine content [269]. Similar biosensors have been worked out for nicotinic acid (with Lactobacillus arabinosa) [270], nicotine amide (with B. pumilus and E. coli) [271], and L-ascorbic acid (with Enterobacter agglomerans) [272]. 

An alternative method of propionic acid production from sugars by propionibacteria has been suggested (Tyree et al., 1991). In this process two cultures, Lactobacillus xylosus and P. shermanii, are used in a system of two consecutive reactor vessels. Lactate, formed by L. xylosus in a batch process with constant stirring, enters the second vessel with immobilized cells of P. shermanii, where propionate is synthesized. The system is characterized by a high total productivity for propionate. 

Shen, X.L. and Xia, L.M. (2006) Lactic acid production from cellulosic waste by immobilized cells of Lactobacillus delbrueckii. World J. Microbiol. BiotechnoL, 22, 1109-1114. 

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