Biomedical Engineering Reference
In-Depth Information
Table 11.2
Raw materials used in the cellulase fermentation process
Carbon
Nitrogen
Inducer
Inorganic salts
Rice straw
Urea
Sophorose
Calcium chloride
Corn stover
Ammonium sulfate
Fructose
Zinc chloride
Corncob
Sodium glutamate
Sorbose
Cobalt chloride
Pulp
Sodium nitrate
Gentiobiose
Potassium dihydrogen
phosphate
Bran
Peptone
Methyl
“
-
anhydroglucose
Magnesium sulfate
Furfural residues
Ammonium
dihydrogen
phosphate
Cellubiose
Ferrous sulfate
Monosaccharide (glucose,
rhamnose, xylose, sorbitol,
mannitol, mannose,
arabinose, galactose)
Ammonium
carbonate
Cellobiose lactone
Manganese sulfate
Disaccharide (cellobiose,
sucrose, lactose)
Ammonium
oxalate
Lactose
Sodium acetate
Polysaccharide (cellulose
powder, carboxymethyl
cellulose, microcrystalline
cellulose)
Triammonium
citrate
Rice straw
Sodium carboxymethyl
cellulose
Soybean meal
Corn stover
Yeast extract
Corncob
Beef extract
Pulp
Bran
Furfural residues
Cellulose powder
derivatives, and so on could induce
T. reesei
and
T. viride
to produce cellulase,
with cellobiose having a special role. At lower concentrations, cellobiose induces
generation of cellulase. However, at higher concentrations, it inhibits the formation
of cellulase. The effect of carbohydrate with low molecular weight (LMW) varies
with the strain.
The amount of inducer used should be appropriate. Within a certain concentration
range, the amount of enzyme production is proportional to the amount of inducer
used. When there is excess inducer, it may be used by microbes, leading to an
inhibition effect on cellulase synthesis. Microbes may also be cultured at first. After
the massive growth of bacterial cells, inducer is added to save inducing agent. Raw
materials used in cellulase fermentation process are shown in Table
11.2
.
④
Metabolites
Cellulase synthesis is not difficult to inhibit by easily metabolic substrates such as
glucose, glycerol, and so on. As long as the medium contains a certain amount
of inhibitor, enzyme can no longer be synthesized in the strain metabolism. Such
inhibition is thought to occur in the synthesis of the translational or posttranslational
level.
