Ijpsr (2009), Issue 1, Vol

TABLE 3: 
ANTIMICROBIAL ACTIVITY OF MICROBIAL METABOLITES AGAINST TEST ORGANISMS
Test Organism 
Control 
Bacillus 
metabolite 
Penicillium
 metabolite 
Streptomyces
 metabolite 
Staphylococcus aureus 
(ATCC 29213)
 
26 mm
 
13.4 mm
 
17mm
 
7.2mm
 
Pseudomonas aeruginosa
ATCC 27853)
 
27 mm
 
13.8 mm
 
11.0mm
 
7.5mm
 
Escherichia coli 
(ATCC 25922)
 
25 mm
 
0 mm
 
19.8mm
 
10.6mm
 
Klebsiella pneumonia 
(ATCC 4352)
 
25 mm
 
0 mm
 
8.2mm
 
0mm
 
 
CONCLUSION: 
In search of new antibiotics, 
relatively simple and rapid methods have been 
developed for screening microorganisms for 
antibiotic producing ability. Soil samples are 
commonly employed in the isolation of antibiotic 
producing organism. 
The detection of these antagonistic substances
revealed interesting properties that justify its 
importance and its study on the potential
application in biological control of pathogenic 
microorganisms and spoilage food. For these
reasons, the biochemical nature and the best
conditions to production of the substances
studied in this work are being investigated to
further 
purification 
experiments. 
Many
microorganisms have been evaluated for the
production of antimicrobial substance. However 
the high cost and low yields have been the main 
problem for its industrial production 
25
.
In the present study, the microbial isolates with 
antimicrobial activity from soil were isolated. 
Among 
all 
screened 
isolates, 
Penicillium 
chrysogenum
metabolite 
showed 
maximum 
inhibition against both gram positive as well as 
gram negative bacteria. Production of antibiotic by 
microorganisms from soil is affected by many 
factors including nitrogen and carbon source. 
Therefore there is a great need to optimize with 
different 
substrates 
that 
provides 
maximum 
production of antimicrobial substance.