Advances in Biochemical Engineering/
Biotechnology, Vol. 68
Managing Editor: Th. Scheper
© Springer-Verlag Berlin Heidelberg 2000
Biochemical Engineering Aspects of Solid State
Bioprocessing
David A. Mitchell 1 , Marin Berovic 2 , Nadia Krieger 3
1 Departamento de Solos, Setor de Ciências Agrárias, Universidade Federal do Paraná,
Rua dos Funcionários 1540, Juvevê, Curitiba 80035–050, Paraná, Brazil
2 Department of Chemical and Biochemical Engineering, University of Ljubljana,
Hajdrihova 19, Ljubljana, Slovenia
3 Departamento de Química, Universidade Federal do Paraná, Cx. P. 19081, 81531–990 Curitiba,
Paraná, Brazil
E-mail: marin.berovic@ki.si
Despite centuries of use and renewed interest over the last 20 years in solid-state fermentation (SSF) technology, and despite its good potential for a range of products, there are currently relatively few large-scale commercial applications. This situation can be attributed to
the complexity of the system: Macroscale and microscale heat and mass transfer limitations
are intrinsic to the system, and it is only over the last decade or so that we have begun to
understand them. This review presents the current state of understanding of biochemical
engineering aspects of SSF processing, including not only the fermentation itself, but also the
auxiliary steps of substrate and inoculum preparation and downstream processing and waste
disposal.
The fermentation step has received most research attention. Significant advances have
been made over the last decade in understanding how the performance of SSF bioreactors can
be controlled either by the intraparticle processes of enzyme and oxygen diffusion or by the
macroscale heat transfer processes of conduction, convection, and evaporation. Mathematical
modeling has played an important role in suggesting how SSF bioreactors should be designed
and operated. However, these models have been developed on the basis of laboratory-scale
data and there is an urgent need to test these models with data obtained in large-scale bioreactors.
Keywords. Mathematical modeling, Heat transfer, Mass transfer, Upstream processing,
Downstream processing
1
Definition and Applications . . . . . . . . . . . . . . . . . . . . . . 65
1.1 Microbial Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
1.2 Culture Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
1.3 A General SSF Process . . . . . . . . . . . . . . . . . . . . . . . . . . 73
2
Upstream Processing . . . . . . . . . . . . . . . . . . . . . . . . . . 75
2.1 Inoculum Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . 75
2.2 Preparation of Substrates . . . . . . . . . . . . . . . . . . . . . . . . 75
2.2.1 Size and Shape of the Particles . . . . . . . . . . . . . . . . . . . . . 77
2.2.2 Substrate Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
2.2.3 Substrate Sterilization . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Biotechnology, Vol. 68
Managing Editor: Th. Scheper
© Springer-Verlag Berlin Heidelberg 2000
Biochemical Engineering Aspects of Solid State
Bioprocessing
David A. Mitchell 1 , Marin Berovic 2 , Nadia Krieger 3
1 Departamento de Solos, Setor de Ciências Agrárias, Universidade Federal do Paraná,
Rua dos Funcionários 1540, Juvevê, Curitiba 80035–050, Paraná, Brazil
2 Department of Chemical and Biochemical Engineering, University of Ljubljana,
Hajdrihova 19, Ljubljana, Slovenia
3 Departamento de Química, Universidade Federal do Paraná, Cx. P. 19081, 81531–990 Curitiba,
Paraná, Brazil
E-mail: marin.berovic@ki.si
Despite centuries of use and renewed interest over the last 20 years in solid-state fermentation (SSF) technology, and despite its good potential for a range of products, there are currently relatively few large-scale commercial applications. This situation can be attributed to
the complexity of the system: Macroscale and microscale heat and mass transfer limitations
are intrinsic to the system, and it is only over the last decade or so that we have begun to
understand them. This review presents the current state of understanding of biochemical
engineering aspects of SSF processing, including not only the fermentation itself, but also the
auxiliary steps of substrate and inoculum preparation and downstream processing and waste
disposal.
The fermentation step has received most research attention. Significant advances have
been made over the last decade in understanding how the performance of SSF bioreactors can
be controlled either by the intraparticle processes of enzyme and oxygen diffusion or by the
macroscale heat transfer processes of conduction, convection, and evaporation. Mathematical
modeling has played an important role in suggesting how SSF bioreactors should be designed
and operated. However, these models have been developed on the basis of laboratory-scale
data and there is an urgent need to test these models with data obtained in large-scale bioreactors.
Keywords. Mathematical modeling, Heat transfer, Mass transfer, Upstream processing,
Downstream processing
1
Definition and Applications . . . . . . . . . . . . . . . . . . . . . . 65
1.1 Microbial Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
1.2 Culture Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
1.3 A General SSF Process . . . . . . . . . . . . . . . . . . . . . . . . . . 73
2
Upstream Processing . . . . . . . . . . . . . . . . . . . . . . . . . . 75
2.1 Inoculum Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . 75
2.2 Preparation of Substrates . . . . . . . . . . . . . . . . . . . . . . . . 75
2.2.1 Size and Shape of the Particles . . . . . . . . . . . . . . . . . . . . . 77
2.2.2 Substrate Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
2.2.3 Substrate Sterilization . . . . . . . . . . . . . . . . . . . . . . . . . . 78