Comparison of suspended and immobilized yeast metabolism using 31P nuclear magnetic resonance spectroscopy

Summary ³¹P nuclear magnetic resonance has been employed to monitor noninvasively Saccharomyces cerevisiae anaerobic glucose metabolism in suspended and immobilized cells. Results show that cell entrapment in Ca-alginate beads alters cell metabolism compared to that in suspended cells. Assuming similar intracellular ionic strength, differences in intracellular phosphate chemical shift indicate that the internal pH of the immobilized cells is lower than the suspended cell internal pH. This result is consistent with higher ethanol production rates exhibited by immobilized yeast.