expenditures are minimized. Having this in mind, it seems useful to consider
that
(a) Enzyme application should not require pure enzymes, or even more, should be
benefited by the use of crude enzyme preparations.
(b) Enzyme recovery should include biological stabilization of the material
without affecting the desired catalytic activities.
(c) Crude preparations should be free from toxic or other undesirable properties.
(d) Possible recycling of final residues in a profitable and environmental friendly
way.
(e) There should be a significant reduction of the carbon foot print of integrated
processes.
(f) Integration between the production of SSF solids and their use should be costeffective.
11.7.1 The Use of Wet SSF Solids in the Production of Foods
and Feedstuffs
As mentioned in preceding sections traditional soybean and rice fermentations are
very important in food industries of several Asian countries. In Japan, koji (wet
fermented rice) is used as a biocatalyst to transform soybean paste into a bouillon
base called miso (Ebine 2004). The process involves the blending of koji with a
paste of steamed and salted soybeans and is incubated in closed vats until the
desired reaction point is reached (Hesseltine 1967, 1983). In saké (rice wine)
production, koji is blended with steamed rice and inoculated with yeast, letting the
fungal enzymes supply sugar to yeast in order to produce alcohol (Akita 2007).
An interesting adaptation of Japanese SSF technology was developed in Spain
by Murado et al. (2008). They found a way to produce shochu, a liquor distilled
from moromi (a traditional alcoholic bagasse), which in turn is produced from a
chestnut porridge by a combined action of A. oryzae and Saccharomyces cerevisiae.
The liquor was produced in Galicia to be exported to Japan. A similar approach was
followed by Schmidt et al. (2001) by blending the SSF fermented mash with alfalfa
silage and improving roughage digestibility. This approach is amenable for
biorefinery operations in order to transform starch, cellulose, and hemicelluloses
into fermentable substrates with significant reduction of energy costs.
The practical importance of koji approach is related to important downstream
savings because product recovery is the most expensive part of enzyme production.
To illustrate this point is worth noticing that SmF beers never surpass the level of
E S = 50 g L
-1 and protein recovery involves time and energy consuming operations such as: ultra filtration, fractionated precipitation, or affinity chromatography.
Also, the remaining liquid effluents require expensive operations because of their
high BOD loads in such a way that the investment on the treatment plant is as high
11 New Horizons for the Production of Industrial Enzymes
333
that
(a) Enzyme application should not require pure enzymes, or even more, should be
benefited by the use of crude enzyme preparations.
(b) Enzyme recovery should include biological stabilization of the material
without affecting the desired catalytic activities.
(c) Crude preparations should be free from toxic or other undesirable properties.
(d) Possible recycling of final residues in a profitable and environmental friendly
way.
(e) There should be a significant reduction of the carbon foot print of integrated
processes.
(f) Integration between the production of SSF solids and their use should be costeffective.
11.7.1 The Use of Wet SSF Solids in the Production of Foods
and Feedstuffs
As mentioned in preceding sections traditional soybean and rice fermentations are
very important in food industries of several Asian countries. In Japan, koji (wet
fermented rice) is used as a biocatalyst to transform soybean paste into a bouillon
base called miso (Ebine 2004). The process involves the blending of koji with a
paste of steamed and salted soybeans and is incubated in closed vats until the
desired reaction point is reached (Hesseltine 1967, 1983). In saké (rice wine)
production, koji is blended with steamed rice and inoculated with yeast, letting the
fungal enzymes supply sugar to yeast in order to produce alcohol (Akita 2007).
An interesting adaptation of Japanese SSF technology was developed in Spain
by Murado et al. (2008). They found a way to produce shochu, a liquor distilled
from moromi (a traditional alcoholic bagasse), which in turn is produced from a
chestnut porridge by a combined action of A. oryzae and Saccharomyces cerevisiae.
The liquor was produced in Galicia to be exported to Japan. A similar approach was
followed by Schmidt et al. (2001) by blending the SSF fermented mash with alfalfa
silage and improving roughage digestibility. This approach is amenable for
biorefinery operations in order to transform starch, cellulose, and hemicelluloses
into fermentable substrates with significant reduction of energy costs.
The practical importance of koji approach is related to important downstream
savings because product recovery is the most expensive part of enzyme production.
To illustrate this point is worth noticing that SmF beers never surpass the level of
E S = 50 g L
-1 and protein recovery involves time and energy consuming operations such as: ultra filtration, fractionated precipitation, or affinity chromatography.
Also, the remaining liquid effluents require expensive operations because of their
high BOD loads in such a way that the investment on the treatment plant is as high
11 New Horizons for the Production of Industrial Enzymes
333