First, they need to be extended to describe more phenomena: Most attention
has been given to the energy balance, and more attention needs to be given to
the water balance. Second, better values of system parameters must be determined. Until very recently there has been a tendency to borrow values of parameters from other systems. These parameters are sometimes even borrowed
from non-SSF systems which operate under quite different conditions (e.g.,
high temperatures) than those under which SSF systems operate. Finally, there
is no description in the literature of how mathematical modeling has actually
been used to guide the scale-up from laboratory through pilot scale to commercial scale. This is the crucial test of the usefulness of the biochemical
engineering approaches discussed in this review, and will greatly accelerate the
refinement of the models.
Also, there is a need to develop effective systems for the measurement and
control of large-scale processes, a task made challenging by the microscale and
macroscale heterogeneity within the substrate bed: It is difficult not only to obtain reliable on-line measurements but also to achieve fine control over system
parameters.
Finally, relatively few efforts have been made to analyze the economic
performance of SSF processes relative to SLF processes. Urgent attention must
be given to this aspect since it is on economic performance criteria that the
future of the technology will ultimately rest.
Achievement of these improvements will greatly improve our ability to operate SSF processes reliably and reproducibly near their maximum potential,
allowing us to use SSF technology routinely for those products for which it has
better potential than SLF.
References
1. Cannel E, Moo-Young M (1980) Proc Biochem 15(5) : 2
2. Durand A, Chereau D (1988). Biotechnol Bioeng 31: 476
3. Knapp JS, Howell JA (1977) Solid substrate fermentation. In: Wiseman A (ed) Topics in
enzyme and fermentation biotechnology, vol 4. Ellis Horwood, Chichester, p 85
4. Moo-Young M, Moreira AR, Tengerdy RP (1983) Principles of solid-substrate fermentation. In: Smith JE, Berry DR, Kristiansen B (eds) The filamentous fungi, vol 4. Edward
Arnold, London, p 117
5. Steinkraus KH (1984) Acta Biotechnol 4 : 83
6. Stanton WR, Wallbridge A (1969) Proc Biochem April:45
7. Ralph BJ (1976) Food Tech Aust 28 : 247
8. Takamine J (1914) J Ind Engng Chem 6 : 824
9. Mial LM (1975) Historical development of the fungal fermentation industry. In: Smith
JE, Berry DR, Kristiansen B (eds) The filamentous fungi, vol 1. Edward Arnold, London,
p 104
10. Stentiford EI, Dodds CM (1992) Composting. In: Doelle HW, Mitchell DA, Rolz CE (eds)
Solid substrate cultivation. Elsevier, London, p 211
11. Doelle HW, Mitchell DA, Rolz CE (eds) (1992) Solid substrate cultivation. Elsevier,
London
12. Selvakumar P, Ashakumary L, Pandey A (1998) Biores Technol 65 : 83
13. Arasaratnam V, Mylvaganam K, Balasubramaniam K (1997) Int J Food Sci Technol
32 : 299
132
D.A. Mitchell et al.
has been given to the energy balance, and more attention needs to be given to
the water balance. Second, better values of system parameters must be determined. Until very recently there has been a tendency to borrow values of parameters from other systems. These parameters are sometimes even borrowed
from non-SSF systems which operate under quite different conditions (e.g.,
high temperatures) than those under which SSF systems operate. Finally, there
is no description in the literature of how mathematical modeling has actually
been used to guide the scale-up from laboratory through pilot scale to commercial scale. This is the crucial test of the usefulness of the biochemical
engineering approaches discussed in this review, and will greatly accelerate the
refinement of the models.
Also, there is a need to develop effective systems for the measurement and
control of large-scale processes, a task made challenging by the microscale and
macroscale heterogeneity within the substrate bed: It is difficult not only to obtain reliable on-line measurements but also to achieve fine control over system
parameters.
Finally, relatively few efforts have been made to analyze the economic
performance of SSF processes relative to SLF processes. Urgent attention must
be given to this aspect since it is on economic performance criteria that the
future of the technology will ultimately rest.
Achievement of these improvements will greatly improve our ability to operate SSF processes reliably and reproducibly near their maximum potential,
allowing us to use SSF technology routinely for those products for which it has
better potential than SLF.
References
1. Cannel E, Moo-Young M (1980) Proc Biochem 15(5) : 2
2. Durand A, Chereau D (1988). Biotechnol Bioeng 31: 476
3. Knapp JS, Howell JA (1977) Solid substrate fermentation. In: Wiseman A (ed) Topics in
enzyme and fermentation biotechnology, vol 4. Ellis Horwood, Chichester, p 85
4. Moo-Young M, Moreira AR, Tengerdy RP (1983) Principles of solid-substrate fermentation. In: Smith JE, Berry DR, Kristiansen B (eds) The filamentous fungi, vol 4. Edward
Arnold, London, p 117
5. Steinkraus KH (1984) Acta Biotechnol 4 : 83
6. Stanton WR, Wallbridge A (1969) Proc Biochem April:45
7. Ralph BJ (1976) Food Tech Aust 28 : 247
8. Takamine J (1914) J Ind Engng Chem 6 : 824
9. Mial LM (1975) Historical development of the fungal fermentation industry. In: Smith
JE, Berry DR, Kristiansen B (eds) The filamentous fungi, vol 1. Edward Arnold, London,
p 104
10. Stentiford EI, Dodds CM (1992) Composting. In: Doelle HW, Mitchell DA, Rolz CE (eds)
Solid substrate cultivation. Elsevier, London, p 211
11. Doelle HW, Mitchell DA, Rolz CE (eds) (1992) Solid substrate cultivation. Elsevier,
London
12. Selvakumar P, Ashakumary L, Pandey A (1998) Biores Technol 65 : 83
13. Arasaratnam V, Mylvaganam K, Balasubramaniam K (1997) Int J Food Sci Technol
32 : 299
132
D.A. Mitchell et al.