Continuous process technology for bottom-up synthesis of soluble cello-oligosaccharides by immobilized cells co-expressing three saccharide phosphorylases

Table 3 Key performance metrics of repetitive batch and continuous production of soluble COS (G2 to G6) with free (semi-permeabilized) and PAM immobilized cells, respectively

Performance metric	Repetitive batch production/mixed vessel reactor	Continuous production/packed-bed reactor
Performance metric	Semi-permeabilized whole-cell catalysts (45 °C)	PAM immobilized whole-cell catalysts (30 °C)
Operation time [h]	30 (5 cycles of 6 h each)	624
COS [g/L]	68	66
STY [g/L/h]	11	6.6 (24%)^a
Product solution [mL]	1250	2250
Total COS [g]	85	150
COS composition [mM]	G2–G6: 70, 49, 22, 5, 1	G2–G6: 66, 42, 17, 9, 3
Cell dry mass (CDM) [g]	0.75	1.85
TTN [g_COS/g_CDW]	113	81
Normalized COS yield [gCOS/gCDM/h]	3.8	0.13

^a Percent mass-based efficiency of the PAM catalyst in the packed-bed reactor compared to the mixed vessel reactor used for repetitive batch production

ISSN: 1475-2859