UNIVERSITÉ PAUL CÉZANNE, AIX MARSEILLE III - IMEP

Résultats et discussion. Chapitre 2: Optimisation de la production du spawn
3.4. Growth curves of spawn
The growth curves of L. edodes Le 119 shiitake strains on different preparation of
Ebly® (white and brown spawn) presented by ergosterol content and CO2 production by
mycelium are shown in Figure 4. On Ebly® supplemented with 10% OMW, the biomass
produced, which was represented and determined by measuring ergosterol contained in
spawn, was higher than on wheat without supplementation [0.6 and 1.8 mg (biomass).g -1 dw
(spawn) respectively after 20 days of incubation]. These results indicated that presence of
OMW is more efficient for spawn production of Le119 strain of L. edodes. At the end of the
growth period, high variation of ergosterol was observed for both media.
CO2 production (mL .h -1 .g -1 dw)
Time (day)
Figure 4. Time course of biomass production (mg.g -1 substrate dw) (solid lines) and CO2
production (dashed lines) of Le119 strain on wheat with ( , ) and without OMW ( , ) at
25°C.
The time courses of CO2 production were similar for all two media. Strong CO2
production was observed after 6-8 days until 14-16. After this period, the amount of CO2
produced was slightly increased. The mycelial biomass produced on both media was
estimated using conversion factor of 281 (f = 1/3.56 x 1 000, average of factor conversion
found by culturing of mycelium on EbA). Estimating ergosterol in spawn preparation, close
correlation coefficient between ergosterol content in spawn and CO2 production was found for
the both media WS (r 2 = 0.965 and 0.956 for BS and WS respectively) (Fig. 5).
Ergosterol content (mg.g -1 )
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