Biomedical Engineering Reference
In-Depth Information
antagonistic activity of the strain towards test cultures. Since growth characteristics and
antagonistic activity of bacteria
B.subtilis
BIM B454D have only minor distinctions at
aeration rates 1 and 1.5 l/l·min and more intense air supply (1.5 l/l·min) triggers enhansed
foam generation, aeration regimen 1 l/l·min was accepted as optimal for growth and synthesis
of antimicrobial metabolites by
B. subtilis
BIM B454 D. At this aeration rate mass exchange
favoring culture development was achieved at rotation of the stirrer 200-220 rpm.
Temperature regimen of culturing bacteria
B. subtilis
BIM B454D (optimum 30ºC)
elaborated in lab fermenters ANKUM 2M was not changed in scale-up experiments.
Active consumption of reducing substances (RS) (80% of total amount) and growth of
the culture (maximal CFU titer - 3·10
9
by 24 h) was recorded during the first day of
fermentation at optimized conditions (aeration rate 1 l air/l l medium·min, temperature 30ºC.
agitation rate 200±20 rpm) (Table 2).
Spore titer reached peak value (1·10
9
) by 36-42 h of bacterial growth, whereas maximum
antagonistic activity towards various test cultures was registered by 24-48 h (table 2). At
longer fermentation period reduction of activity and decrease of cell and spore titer occurred
so that continuation of fermentation over 2 days appeared not expedient.
Table 2. Growth parameters and antagonistic activity of bacteria B. subtilis B-454 D
cultured in large-scale fermenter
Fermentation
time, h
pH
Reducing
substances, g/l
Titer
E. coli
099
growth inhibition
zone, mm
free
inverted
CFU/ml
Spores/ml
0
7.05
7.0
10.6
2.3·10
7
-
-
1.0·10
8
2.3·10
5
6
7.05
6.75
8.55
-
1.4·10
8
1.2·10
6
12
6.90
4.5
6.0
15.0±0.4
18
6.95
0.62
3.2
1.5·10
9
1.3·10
7
18.0±0.7
24
6.45
0.56
2.1
3.0·10
9
1.0·10
9
19.0±0.5
30
6.90
0.74
0.80
3.0·10
8
1.1·10
9
23.0±0.2
36
7.60
0.54
0.82
2.9·10
9
8.9·10
8
25.5±0.4
42
7.60
0.46
0.52
2.8·10
9
1.0·10
9
26.5±0.3
48
7.60
0.48
0.50
2.8·10
9
8.4·10
8
25.5±0.5
54
7.60
0.47
0.51
1.5·10
9
8.0·10
8
22.8±0.2
Probiotic Bacinil produced according to optimized pilot plant technology is distinguished
by elevated titers of CFU, spores and antagonistic activity exceeding activity of liquid
preparation grown under laboratory conditions by 8-14%. Pilot plant process regulations for
manufacturing probiotic product were elaborated based on obtained results.
To optimize probiotic application technology doses and regime of Bacinil administration
were tested on young farm stock - calves and piglets.
For enteritis cases 5 groups of calves with malfunctions of gastrointestinal tract were
formed, each including 5-8 animals aged 20 days. It was found that a single application of
probiotic at 10 ml dose reduces rehabilitations period, yet recurrence of pathology is not ruled
out. 15-20 ml dose of probiotic shortens duration of disease by 45.9-49.4 %, results in 100%
recovery of treated calves and secures infection will not come back.
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