UNIVERSITÉ PAUL CÉZANNE, AIX MARSEILLE III - IMEP

Résultats et discussion. Chapitre 2: Optimisation de la production du spawn
3.2. Conversion factor of Lentinula edodes in solid state culture:
In solid state culture, the biomass produced in PDA, PDA supplemented with 10% of
OMW and EbA is shown in Table1. Maintain of mycelium on agar slants in the presence of
OMW was successful to produce high biomass yield compared to that produced in PDA (268
and 75 mg respectively at 20 days of incubation), while the biomass produced in EbA was
moderate (105 mg at 20 days of incubation). EbA was used to determine conversion factor
(ergosterol content in mycelium) in medium that contain the substrate used for production of
spawn. The agar media used were analyzed and were found not to contain ergosterol (Data
not shown). Differences among media were not significant when all data were analyzed
together. In 20-day old mycelium, ergosterol content exhibited the highest variability in all
culture media (Table1).
Table1. Effect of age and substrate on mycelial ergosterol contents
Medium Culture age Biomass Ergosterol content
(days) (mg)
(mg.g -1 of dry weight)
PDA 5 20 3,46 ± 0,28
PDA +10 %
of OMW
12 45 3,72 ± 0,32
20 75 3,17 ± 0,74
5 75 3,97 ± 0,21
12 170 3,82 ± 0,54
20 268 3,32 ± 1,02
EbA 5 43 3,64 ± 0,45
12 65 3,71 ± 0,23
20 105 3,32 ± 0,95
Straight line relationship between fungal dry biomass and ergosterol content was
observed and the statistical analysis proved a high correlation (r 2 =0.99) (Fig. 3). Under the
HPLC conditions tested, the calibration curve was established by plotting the peak area and
peak height against ergosterol standard.
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