biologia - Studia

M.. DRĂGAN-BULARDA,. R. CARPA, M. MIŞCA, V.-CĂLEAN
These data indicate that the enzyme production is in this case, a poor one.
The Fig. 2 presents the enzyme production related to the biomass, and the relation
proved to be a constant one, after the lag phase. This result indicates also that the
enzyme production is constitutive.
Absorbance at 600 nm
Enzymatic activity (U/ml/min)
Time (h)
Fig. 2. Relation between the increase of biomass (circles) and the enzymatic activity
(squares) of the Bacillus strain.
Using the values obtained for q p and Y p/x we calculated the value of the
biomass increase rate, and it resulted that µ = 7.4/7370 60, so µ = 0.0602 h -1 . This
increase rate is a relatively poor one, probably because of the low oxygen supply,
which proved to be a limitative factor.
3. Obtaining the raw and the purified enzymatic preparation
The data we obtained in this respect are shown in Table 3, respectively in Fig. 3.
It was observed that the activity of alpha-amylase oscillated depending on
the temperature at which the enzymatic activity took place, with a maximum value
at 40 0 C, and a decrease of the values after this temperature, probably because of the
inactivation or thermal distortion of the alpha –amylase. We also observed that the
raw extract had a higher enzymatic activity than the purified preparation (see Fig.3).
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