Comparisons of ethanol production between CP4 and HYM at different temperature. Strains were grown in RM medium (10 g/l yeast extract, 1 g KH₂PO₄, 1 g/l carbamide, 0.5 g/l MgSO₄·6H₂O) with 23 % glucose as the carbon source under anaerobic conditions. All strains were tested by three parallel experiments. When the temperature reached 42 °C from 32 °C, after 60-h fermentation, the average ethanol concentrations of CP4 and HYM were reduced dramatically. When the temperature was 42 °C, the ethanol yield of HYM based on consumed glucose was 0.19 g/g (ethanol/glucose), significantly different from CP4 (ethanol yield based on consumed glucose was 0.12 g/g). It is apparent that HYM was much less sensitive to high temperatures than CP4