Secretion of clostridium cellulase by E. coli
- 1885 California St., #62, Mountain View, CA 94041
A gene, encoding an endocellulase from a newly isolated mesophilic Clostridium strain IY-2 which can digest bamboo fibers, cellulose, rice straw, and sawdust, was isolated by shotgun cloning in an E. coli expression plasmid pLC2833. E. coli positive clones were selected based on their ability to hydrolyze milled bamboo fibers and cellulose present in agar plates. One clone contained a 2.8 kb DNA fragment that was responsible for cellulase activity. Western blot analyses indicated that the positive clone produced a secreted cellulase with a mass of about 58,000 daltons that was identical in size to the subunit of one of the three major Clostridium cellulases. The products of cellulose digestion by this cloned cellulase were cellotetraose and soluble higher polymers. The cloned DNA contained signal sequences capable of directing the secretion of heterologous proteins from an E. coli host. The invention describes a bioprocess for the treatment of cellulosic plant materials to produce cellular growth substrates and fermentation end products suitable for production of liquid fuels, solvents, and acids.
- Research Organization:
- Univ. of California (United States)
- DOE Contract Number:
- FG03-87ER13705
- Assignee:
- Yu, Ida Kuo (1885 California St., #62, Mountain View, CA 94041)
- Patent Number(s):
- US 5759845
- OSTI ID:
- 871590
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
clostridium
cellulase
coli
encoding
endocellulase
newly
isolated
mesophilic
strain
iy-2
digest
bamboo
fibers
cellulose
rice
straw
sawdust
shotgun
cloning
expression
plasmid
plc2833
positive
clones
selected
based
ability
hydrolyze
milled
agar
plates
clone
contained
kb
dna
fragment
responsible
activity
western
blot
analyses
indicated
produced
secreted
mass
58
000
daltons
identical
size
subunit
major
cellulases
products
digestion
cloned
cellotetraose
soluble
polymers
signal
sequences
capable
directing
heterologous
proteins
host
describes
bioprocess
treatment
cellulosic
plant
materials
produce
cellular
growth
substrates
fermentation
suitable
production
liquid
fuels
solvents
acids
liquid fuel
liquid fuels
cloned dna
dna fragment
blot analyses
signal sequence
selected based
selected base
cellulase activity
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