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A simplified material and energy balance approach for process development and scale‐up of Coniothyrium minitans conidia production by solid‐state cultivation in a packed‐bed reactor
Author(s) -
Weber Frans J.,
Tramper Johannes,
Rinzema Arjen
Publication year - 1999
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/(sici)1097-0290(19991120)65:4<447::aid-bit9>3.0.co;2-k
Subject(s) - solid state fermentation , moisture , packed bed , water activity , yield (engineering) , conidium , spore , chemistry , materials science , water content , botany , fermentation , food science , chromatography , biology , composite material , geotechnical engineering , organic chemistry , engineering
Production of conidia of the biocontrol fungus Coniothyrium minitans by solid‐state cultivation in a packed‐bed reactor on an industrial scale is feasible. Spore yield and oxygen consumption rate of C. minitans during cultivation on oats and three inert solids (hemp, perlite, and bagasse) saturated with a liquid medium were determined in laboratory‐scale experiments. The sensitivity of the fungus to reduced a w , and the water desorption isotherms of the four solid materials were also determined. C. minitans is very sensitive to reduced a w : 50% inhibition of respiration was found at a w 0.95, spore formation was completely inhibited at a w 0.97. A simplified mathematical model taking into account convective and evaporative cooling was used to simulate temperature and moisture gradients in the bed during cultivation. Adequate temperature control can be achieved with acceptable air flow rates for all four solid matrices. Moisture control is the limiting factor for cultivation in a packed bed. Oats cannot be used due to the shrinkage and a w reduction caused by evaporative cooling. Of the three inert supports tested, hemp provides the best spore yield and control of water activity, due to its high water uptake capacity. A spore yield of 9 × 10 14 conidia per m 3 packed bed can be achieved in 18 days, using hemp impregnated with a solution containing 100 g dm −3 glucose and 20 g dm −3 potato extract. Sufficient water is predicted to be available after 18 days, to allow a higher initial nutrient concentration, which may lead to higher spore yields. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 65: 447–458, 1999.