ISSN:
0006-3592
Keywords:
poly(3-hydroxybutyrate)
;
PHB recovery
;
sodium hypochlorite
;
chloroform
;
Alcaligenes eutrophus
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Optimization was carried out for the recovery of microbiol poly(3-hydroxybutyrate) (PHB) from Alcaligenes eutrophus. This process involved the use of a dispersion made of sodium hypochlorite solution and chloroform. The dispersion enabled us to take advantage of both differential digestion by hypochlorite and solvent extraction by chloroform. The PHB recovery (%) from cell powder was maximized using a 30% hypochlorite concentration, a 90-min treatment time, and a 1:1 (v/v) chloroform-to-aqueous-phase ratio. Under these optimal conditions, the recovery was about 91% and the purity of recovered PHB was higher than 97%. The number average molecular weight, Mn of recovered PHB was about 300,000 and the weight average molecular weight Mw was about 1,020,000, compared to the original Mn of 530,000 and Mw of 1,272,000. The moderate decrease in both Mn and Mw might be ascribed to the shielding effect of chloroform. In addition, the relatively small decrease in Mw probably resulted from the loss of short PHB chains which might be water soluble. The crystallinity of recovered PHB was in the range of 60 to 65%although a slightly higher crystallinity was observed when the dispersion was used. © 1994 John Wiley & Sons, Inc.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bit.260440215
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