Response of Rhizopus oligosporus to temporal temperature profiles in a model solid-state fermentation system

✍ Scribed by Lilik Ikasari; David A. Mitchell; Deidre M. Stuart

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 134 KB
• Volume: 64
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/(sici)1097-0290(19990920)64:6<722::aid-bit12>3.0.co;2-7

✦ Synopsis

Membrane overcultures of Rhizopus oligosporus were shifted from 37 to 50°C for 10 h and then re- turned to 37°C, mimicking the temporal temperature profiles which typically occur in SSF due to heat transfer limitations. Analysis with a modified two-phase growth model suggests that the temperature upshift causes a 48% decrease in the number of actively extending hyphal tips, and that the first order death rate constant of tips increases from 0.059 to 0.073 h -1 . The fungus did not immediately recover when the temperature was returned to 37°C. The model assumed that the specific growth rate constant µ g was not affected by the increase of temperature, although contradictory data was obtained from radial growth rate experiments.