Trehalose production at high temperature exploiting an immobilized cell bioreactor.
The enzymatic production of trehalose from dextrins was studied as a series reaction in a packed bed reactor containing immobilized recombinant Escherichia coli cells, expressing either the Sulfolobus solfataricus (strain MT4) trehalosyl-dextrin forming enzyme (TDFE) or the trehalose-forming enzyme (TFE). The cells, subjected to thermal treatments to increase cell permeability and to inactivate the unwanted host proteins, were entrapped separately or together in a calcium alginate polymeric matrix. The biocatalyst beads were used to pack a tubular glass reactor that was operated in a recycle mode. The performances of a bioreactor containing alternate layers of EcTFE and EcTDFE alginate beads were evaluated and compared with the performance of the co-immobilized biocatalysts. The latter showed a superior throughput, therefore the bioreactor packed with the co-entrapped biocatalysts was tested for the production of trehalose from concentrated dextrin solutions (10%-30% w/v) and a conversion up to 90% was obtained. This conversion corresponded to a production of 127 g trehalose h(-1) kg(-1) of biocatalyst. The results obtained suggest that the bioprocess described may be of interest in the development of a large-scale industrial process for trehalose production at high temperature.
Di Lernia
Isabella
I
Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, Second University of Naples-CRIB, via Costantinopoli 16, 80138 Naples, Italy.
Schiraldi
Chiara
C
Generoso
Maddalena
M
De Rosa
Mario
M
D019149:Bioreactors; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D004926:Escherichia coli / Q000378:metabolism; D006358:Hot Temperature; D016944:Sulfolobus / Q000378:metabolism; D014199:Trehalose / Q000096:biosynthesis* / Q000302:isolation & purification
D014199:Trehalose