7.2.2 Measuring pH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
7.2.3 Estimation of Biomass . . . . . . . . . . . . . . . . . . . . . . . . . . 122
8
Downstream Processing and Waste Disposal from SSF Processes . . 124
8.1 Products for Which Extraction from the Fermented Solid is Not
Needed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
8.2 Methods for Recovery of Fungal Spores . . . . . . . . . . . . . . . . 125
8.3 Leaching of Enzymes . . . . . . . . . . . . . . . . . . . . . . . . . . 126
8.3.1 Properties of the Leaching Solution . . . . . . . . . . . . . . . . . . 126
8.3.2 Retention of Leaching Solution in the Substrate Particles . . . . . . 127
8.3.3 Leaching Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
8.4 Recovery by Direct Pressing . . . . . . . . . . . . . . . . . . . . . . . 128
8.5 Recovery of Non-Volatile Small Organic Molecules . . . . . . . . . . 128
8.6 Recovery of Volatile Products by Stripping . . . . . . . . . . . . . . 129
8.7 Waste Treatment and Ecological Aspects . . . . . . . . . . . . . . . . 130
9
Evaluation of the Current Status and Future Prospects . . . . . . . 131
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
List of Abbreviations
a w
water activity
a w0
optimal water activity for growth
A
fitting constant
B
fitting constant
C
humidity (kg-water kg-dry air
–1 )
DDF dimensionless design factor
E a1
activation energy (J mol
–1 )
E a2
activation energy (J mol
–1 )
C
concentration (gl
–1 or mol l
–1 )
C pa
heat capacity of the air (J kg
–1 °C
–1 )
D
drum diameter (m)
Da M modified Damkohler number (dimensionless)
f
slope of a linear approximation to the humidity curve (kg-water kgair
–1 °C
–1 )
F a
air flowrate (m
3 h
–1 )
ƒ
fraction of maximum specific growth rate (dimensionless)
H
bed height (m)
h A
overall coefficient for heat transfer (J h
–1 K
–1 )
K F a
biofilm conductance (mol-O 2 h
–1 )
K L a
overall oxygen mass transfer coefficient (mol-O 2 h –1 )
k
first order decay constant for loss of viability of hyphal tips
k do
frequency factor for death (h –1 )
k md
constant (h –1 )
K
saturation constant (gl –1 or mol l –1 )
K i
substrate inhibition constant (g l –1 or mol l –1 )
Biochemical Engineering Aspects of Solid State Bioprocessing
63
7.2.3 Estimation of Biomass . . . . . . . . . . . . . . . . . . . . . . . . . . 122
8
Downstream Processing and Waste Disposal from SSF Processes . . 124
8.1 Products for Which Extraction from the Fermented Solid is Not
Needed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
8.2 Methods for Recovery of Fungal Spores . . . . . . . . . . . . . . . . 125
8.3 Leaching of Enzymes . . . . . . . . . . . . . . . . . . . . . . . . . . 126
8.3.1 Properties of the Leaching Solution . . . . . . . . . . . . . . . . . . 126
8.3.2 Retention of Leaching Solution in the Substrate Particles . . . . . . 127
8.3.3 Leaching Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
8.4 Recovery by Direct Pressing . . . . . . . . . . . . . . . . . . . . . . . 128
8.5 Recovery of Non-Volatile Small Organic Molecules . . . . . . . . . . 128
8.6 Recovery of Volatile Products by Stripping . . . . . . . . . . . . . . 129
8.7 Waste Treatment and Ecological Aspects . . . . . . . . . . . . . . . . 130
9
Evaluation of the Current Status and Future Prospects . . . . . . . 131
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
List of Abbreviations
a w
water activity
a w0
optimal water activity for growth
A
fitting constant
B
fitting constant
C
humidity (kg-water kg-dry air
–1 )
DDF dimensionless design factor
E a1
activation energy (J mol
–1 )
E a2
activation energy (J mol
–1 )
C
concentration (gl
–1 or mol l
–1 )
C pa
heat capacity of the air (J kg
–1 °C
–1 )
D
drum diameter (m)
Da M modified Damkohler number (dimensionless)
f
slope of a linear approximation to the humidity curve (kg-water kgair
–1 °C
–1 )
F a
air flowrate (m
3 h
–1 )
ƒ
fraction of maximum specific growth rate (dimensionless)
H
bed height (m)
h A
overall coefficient for heat transfer (J h
–1 K
–1 )
K F a
biofilm conductance (mol-O 2 h
–1 )
K L a
overall oxygen mass transfer coefficient (mol-O 2 h –1 )
k
first order decay constant for loss of viability of hyphal tips
k do
frequency factor for death (h –1 )
k md
constant (h –1 )
K
saturation constant (gl –1 or mol l –1 )
K i
substrate inhibition constant (g l –1 or mol l –1 )
Biochemical Engineering Aspects of Solid State Bioprocessing
63