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Title:2,3-Butanediol production from whey permeate using immobilized cell systems
Author(s):Martinez, Sarah Baradas
Director of Research:Speckman, Ray A.
Doctoral Committee Chair(s):Witter, Lloyd D.
Doctoral Committee Member(s):Cheryan, Munir; Siedler, Arthur J.; Wei, Lun-Shin
Department / Program:Food Science
Discipline:Food Science
Degree Granting Institution:University of Illinois at Urbana-Champaign
Subject(s):Biology, Microbiology
Abstract:This research sought to improve 2,3-butanediol production from whey permeate by using immobilized cell systems. Two types of immobilized cell systems were developed for substrate hydrolysis and the fermentation: a $\beta$-galactosidase-active biocatalyst consisting of non-viable cells of Kluyveromyces fragilis and immobilized cells of Bacillus polymyxa.
Non-viable yeast cells with minimum protease activity and optimum $\beta$-galactosidase activity were obtained by careful control of heat and solvent permeabilization. The cells were immobilized by adsorption onto a diatomite carrier. Cell and carrier surface charge were studied to better understand the adsorption process. Lactose hydrolysis of up to 85% could be attained. This is comparable to the hydrolysis obtained when soluble enzymes are used.
For fermentation purposes, the hydrolyzed whey permeate was further supplemented with yeast extract and acetate for better productivity and increased gel stability. Cells of B. polymyxa were immobilized in calcium alginate. The properties of the calcium alginate gel was studied for maximum stability in batch and continuous fermentations. A continuous stirred tank reactor was designed and used for the fermentation. Volumetric productivities of up to 14.7 g/ could be achieved at a dilution rate of 1.03 hr$\sp{-1}$, with 93.3% substrate concentration, 0.53 molar yield and a product concentration of 14.12 g/l.
Issue Date:1989
Rights Information:Copyright 1989 Martinez, Sarah Baradas
Date Available in IDEALS:2011-05-07
Identifier in Online Catalog:AAI9000078
OCLC Identifier:(UMI)AAI9000078

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