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Sporulation at minimum specific growth rate in Aspergillus nidulans chemostat culture predicted using protein synthesis efficiency estimations
Author(s) -
Bushell M.E.,
Bull A.T.
Publication year - 1999
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/(sici)1521-4028(199912)39:5/6<293::aid-jobm293>3.0.co;2-c
Subject(s) - chemostat , spore , chemistry , biology , biochemistry , microbiology and biotechnology , bacteria , genetics
Ribosomal efficiency (RE) estimates provide a quantitative descriptor of intrinsic growth rate of cell populations using readily‐obtainable experimental data. In Aspergillus nidulans chemostat cultures, RE increased linearly with growth rate over the range 25—60% of maximum growth rate ( μ max ), consistent with increasing ribosomal usage with increased growth rate. Above 60%, RE did not in‐crease significantly, suggesting that all ribosomes were functional at 60% of μ max , further increases in growth rate, presumably resulting from increased polypeptide chain elongation rate. Extrapolating the linear part of the RE/growth rate curve predicted zero RE at a growth rate of 0.04 h —1 . Chemostat steady state cultures at 0.04 h —1 contained spores (conidia), apparently undergoing a continuous spo‐rulation/germination cycle. We propose that the RE estimates provide a means of predicting the value of minimum specific growth rate ( μ min ) below which net growth cannot take place.