Aims: To investigate the effects of temperature, pH, water activity (aw)
and CO2 concentration on the growth of Rhizopus oligosporus NRRL 2710.
Methods and Results: Hyphal extension rates from mycelial and spore
inocula were measured on media with different aw (˜ 1·0, 0·98 and 0·96)
and pH (3·5, 5·5 and 7·5) incubated at 30, 37 or 42°C in atmospheres
containing 0·03, 12·5 or 25% (v/v) CO2. The effects of environmental
conditions on hyphal extension rate were modelled using surface response
methodology. The rate of hyphal extension was very sensitive to pH,
exhibiting a pronounced optimum at pH 5·5–5·8. The hyphal extension rate
was less sensitive to temperature, aw or CO2, exhibiting maximum rates
at 42°C, aw˜ 1·0 and 0·03% (v/v) CO2.
Conclusions: The fastest hyphal extension rate (1·7 mm h−1) was
predicted to occur at 42°C, pH 5·85, aw˜ 1·0 and 0·03% CO2.
Significance and Impact of the Study: The present work is the first to
model the simultaneous effects of temperature, pH, aw and CO2
concentration on mould growth. The information relates to tempe
fermentation and to possible control of the microflora in Tanzanian
cassava heap fermentations.
Sparringa, R.A.; Kendall, M.N.; Westby, A.; Owens, J.D. Effects of temperature, pH, water activity and CO2 concentration on growth of Rhizopus oligosporus NRRL 2710. Journal of Applied Microbiology (2002) 92 (2) 329-337. [DOI: 10.1046/j.1365-2672.2002.01534.x]
Effects of temperature, pH, water activity and CO2 concentration on growth of Rhizopus oligosporus NRRL 2710