title: Microcalorimetric study on the growth and metabolism of microencapsulated microbial cell culture.
abstract: The rate of heat output is one of the suitable measurements of metabolic activity of the organism or its parts, down to the cellular or even the sub-cellular levels. In this paper, microcalorimetry was first applied to study the metabolic activity of microbial in both alginate-polylysine-alginate and alginate-chitosan-alginate microencapsulated cultures as well as in free non-encapsulated culture. The organisms used for the measurements were Escherichia coli and Saccharomyces cerevisiae. As a result of this work, it was found that, despite E. coli cell in free non-encapsulated culture has the highest metabolic rate due to the highest value of heat output, the proliferation of the cells terminates quickly with a lowest biomass formed. And we found also an obviously longer stationary phase in microencapsulated culture. As far as S. cerevisiae was concerned, it was found that there was also the highest value of heat output in free non-encapsulated culture, but the cell density was lower than that in microencapsulated culture. On account of the microcalorimetric and metabolic measurements, it can be concluded that more substrate can be used to convert to biomass in microencapsulated culture which means a higher biomass yield existed.
authors.affiliation: Laboratory of Biomedical Material Engineering, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.
authors.forename: J
authors.initials: J
authors.lastname: Ma
authors.forename: W T
authors.initials: WT
authors.lastname: Qi
authors.forename: L N
authors.initials: LN
authors.lastname: Yang
authors.forename: W T
authors.initials: WT
authors.lastname: Yu
authors.forename: Y B
authors.initials: YB
authors.lastname: Xie
authors.forename: W
authors.initials: W
authors.lastname: Wang
authors.forename: X J
authors.initials: XJ
authors.lastname: Ma
authors.forename: F
authors.initials: F
authors.lastname: Xu
authors.forename: L X
authors.initials: LX
authors.lastname: Sun
mesh_terms: D000464:Alginates; D001431:Bacteriological Techniques / Q000379:methods; D018533:Biomass; D002151:Calorimetry / Q000379:methods*; D002214:Capsules; D048271:Chitosan; D004926:Escherichia coli / Q000254:growth & development* / Q000378:metabolism*; D011107:Polylysine / Q000031:analogs & derivatives; D012441:Saccharomyces cerevisiae / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D000464:Alginates; D002214:Capsules; C051546:alginate-polylysine-alginate; D011107:Polylysine; D048271:Chitosan