Saccharification and fermentation of sugar cane bagasse by Klebsiella oxytoca P2 containing chromosomally integrated genes encoding the Zymomonas mobilis ethanol pathway

Journal Article · Mon Jun 20 04:00:00 EDT 1994 · Biotechnology and Bioengineering; (United States)

DOI:https://doi.org/10.1002/bit.260440213· OSTI ID:7076788

Doran, J B; Aldrich, H C; Ingram, L O ^[1]

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1. Univ. of Florida, Gainesville, FL (United States). Dept. of Microbiology and Cell Science

Pretreatment of sugar cane bagasse is essential for a simultaneous saccharification and fermentation (SSF) process which uses recombinant Klebsiella oxytoca strain P2 and Genencor Spezyme CE. Strain P2 has been genetically engineered to express Zymomonas mobilis genes encoding the ethanol pathway and retains the native ability to transport and metabolize cellobiose (minimizing the need for extracellular cellobiase). In SSF studies with this organism, both the rate of ethanol production and ethanol yield were limited by saccharification at 10 and 20 filter paper units (FPU) g[sup [minus]1] acid-treated bagasse. Dilute slurries of biomass were converted to ethanol more efficiently (over 72% of theoretical yield) in simple batch fermentations than slurries containing high solids, albeit with the production of lower levels of ethanol. With high solids (i.e., 160 g acid-treated bagasse L[sup [minus]1]), a combination of 20 FPU cellulase g[sup [minus]1] bagasse, preincubation under saccharification conditions, and additional grinding (to reduce particle size) were required to produce ca. 40 g ethanol L[sup [minus]1]. Alternatively, almost 40 g ethanol L[sup [minus]1] was produced with 10 FPU cellulase g[sup [minus]1] bagasse by incorporating a second saccharification step (no further enzyme addition) followed by a second inoculation and short fermentation. In this way, a theoretical ethanol yield of over 70% was achieved with the production of 20 g ethanol 800 FPU[sup [minus]1] of commercial cellulase.

• DOE Contract Number: FG05-86ER13574
• OSTI ID: 7076788
• Journal Information: Biotechnology and Bioengineering; (United States), Journal Name: Biotechnology and Bioengineering; (United States) Vol. 44:2; ISSN BIBIAU; ISSN 0006-3592
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
090900* -- Biomass Fuels-- Processing-- (1990-)
ALCOHOLS
BACTERIA
BIOCONVERSION
BIOSYNTHESIS
BIOTECHNOLOGY
CARBOHYDRATES
CELLULOSE
CHEMICAL REACTIONS
DECOMPOSITION
ETHANOL
FERMENTATION
GENETIC ENGINEERING
GRAMINEAE
HYDROLYSIS
HYDROXY COMPOUNDS
KLEBSIELLA
LILIOPSIDA
LYSIS
MAGNOLIOPHYTA
MICROORGANISMS
ORGANIC COMPOUNDS
PLANTS
POLYSACCHARIDES
REEDS
SACCHARIDES
SACCHARIFICATION
SOLVOLYSIS
SUGAR CANE
SYNTHESIS