full issue - Association of Biotechnology and Pharmacy
full issue - Association of Biotechnology and Pharmacy
full issue - Association of Biotechnology and Pharmacy
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Current Trends in <strong>Biotechnology</strong> <strong>and</strong> <strong>Pharmacy</strong><br />
Vol. 5 (3) 1325 -1337 July 2011, ISSN 0973-8916 (Print), 2230-7303 (Online)<br />
1332<br />
values <strong>and</strong> ranks for the system. Rank <strong>and</strong> delta<br />
values help to assess which factors have the<br />
greatest effect on the response characteristic <strong>of</strong><br />
interest. Delta measures the size <strong>of</strong> the effect by<br />
taking the difference between the highest <strong>and</strong><br />
lowest characteristic average for a factor. A<br />
higher delta value indicates greater effect <strong>of</strong> that<br />
component. ‘Rank’ orders the factors from the<br />
greatest effect (based on the delta values) to the<br />
least effect on the response characteristic. The<br />
order in which the individual components<br />
selected in the present study effect the<br />
fermentation process can be ranked as Na 2<br />
S 2<br />
O 3<br />
> yeast extract > K 2<br />
HPO 4<br />
> L-glutamic acid ><br />
MgSO 4<br />
> FeSO 4<br />
> glycerol > NaCl suggesting<br />
that Na 2<br />
S 2<br />
O 3<br />
had a major effect, <strong>and</strong> NaCl has<br />
the least effect on cephamycin C production by<br />
N. lactamdurans.<br />
Fig 4 represents the main effects plot for<br />
the system. Main effects plot show how each<br />
factor affects the response characteristic. A main<br />
effect is said to be present when different levels<br />
<strong>of</strong> a factor affect the characteristic differently.<br />
MINITAB creates the main effects plot by<br />
plotting the characteristic average for each factor<br />
level. These averages are the same as those<br />
displayed in the response Table 4. A line connects<br />
the points for each factor. A horizontal line<br />
(parallel to the x-axis) indicates absence <strong>of</strong> main<br />
effect. Each level <strong>of</strong> the factor affects the<br />
characteristic in the same way <strong>and</strong> the<br />
characteristic average is the same across all factor<br />
levels. A main effect is present when the line is<br />
not horizontal (not parallel to the x-axis).<br />
Different levels <strong>of</strong> the factor affect the<br />
characteristic differently. The greater the<br />
difference in the vertical position <strong>of</strong> the plotted<br />
points (the more the line is not parallel to the x-<br />
axis), the greater is the magnitude <strong>of</strong> the main<br />
effect.<br />
In the present study it was seen that among<br />
the 8 variables at 2 levels, one level increased<br />
the mean compared to the second level. This<br />
difference is a main effect. Variables like<br />
glycerol, NaCl <strong>and</strong> MgSO 4<br />
showed greater mean<br />
at level one whereas yeast extract, L-glutamic<br />
acid, K 2<br />
HPO 4<br />
, FeSO 4<br />
<strong>and</strong> Na 2<br />
S 2<br />
O 3<br />
showed<br />
greater mean at level two.<br />
Glycerol Yeast Extract L-Glutamicacid KZHPO 4<br />
NaCl MgSO 4<br />
FeSO 4<br />
Na2SO3<br />
Mean cephamycin C (mg/L)<br />
Fig. 4. Main effects plot for means<br />
Lalit D. Kagliwal et al