Efficient production of ethanol by cells immobilized in loofa ( Luffa cylindrica) sponge

• Published in: Journal of fermentation and bioengineering Vol. 84; no. 3; pp. 271 - 274
• Main Authors: Ogbonna, James C., Tomiyama, Shota, Liu, Ying-Chun, Tanaka, Hideo
• Format: Journal Article
• Language: English
• Published: Osaka Elsevier B.V 01.01.1997; Society for Fermentation and Bioengineering
• Subjects: Biological and medical sciences; Bioreactors; Biotechnology; CANDIDA; carrier for cell immobilization; cell flocculation; Cell immobilization; Chitin; Composition effects; ETANOL; ETHANOL; ethanol production; FLOCCULATION; FLOCULACION; FLOCULATION; Fundamental and applied biological sciences. Psychology; IMMOBILIZED MICROORGANISMS; loofa sponge; LUFFA; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; MICROORGANISME IMMOBILISE; MICROORGANISMOS INMOVILIZADOS; Microorganisms; carrier for cell immobilization; ethanol production; cell flocculation; loofa sponge; Yeast; Ethanol; Support; Cucurbitaceae; Fixed bed reactor; Fungi; Continuous process; Bioreactor; Candida krusei; Vegetable crop; Dicotyledones; Flocculation; Angiospermae; Production; Microorganism culture; Ascomycetes; Spermatophyta; Fungi Imperfecti; Entrapped microorganism; Saccharomyces cerevisiae; Thallophyta
• ISSN: 0922-338X
• DOI: 10.1016/S0922-338X(97)82069-7

Both flocculating and non-flocculating cells were immobilized in loofa ( Luffa cylindrica) sponge and used for continuous ethanol production in column-type bioreactors. Immobilization of non-flocculating cells ( Candida brassicae) was achieved by addition of chitosan to the reactor. However, the amount of immobilized non-flocculating cells per unit sponge was lower, and consequently the volumetric ethanol productivity was about 20% less than that of the flocculating cells. In comparison with a fixed bed made of a single cylindrical loofa sponge, the amount of sponge per unit reactor volume was 2 times higher when sliced loofa sponge was used to construct the fixed bed. Furthermore, the use of sliced loofa sponge resulted in 2- and 4-fold increases in the amount of immobilized flocculating and non-flocculating cells per unit sponge, respectively. Consequently, higher volumetric ethanol productivities were obtained when sliced loofa sponge was used for bed construction. In the case of flocculating ( Saccharomyces cerevisiae IR-2) cells, the volumetric ethanol productivity was 66% higher than that obtained with a cylindrical loofa sponge.