Mobasheri N, Hamedi J, Rashedi H. Arapid and inexpensive method for biomass assay using relative electric potential difference . Iran J Med Microbiol 2013; 6 (4) :34-39
URL:
http://ijmm.ir/article-1-45-en.html
1- Dept. of Microbiology, College of Science, Azad University of Qom, Qom, Iran.
2- Microbial Biotechnology Lab, Dept. of Microbiology, School of Biology, College of Science, University of Tehran, Tehran, Iran , jhamedi@ut.ac.ir
3- School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran
Abstract: (15141 Views)
Background and objectives: Microbial biomass assay is used in food, pharmaceutical,
cosmetics and biotechnological industries in order to determine the rate of
contamination, longevity and the possibility of use of the desired material in those
industries. Measurement of physico-chemical properties and specterophotometric
methods are used to monitor the culture medium variations induced by bacteria. These
methods have substantial advantages over traditional plate counting and dilution
techniques and significantly reduce the time needed to determine the microbial biomass
amount.
Material and Methods: Series of flasks containing microbiological media were added
appropriate concentrations of chloramphenicol, ampicillin, vancomycin hydrochloride,
ciprofloxacin hydrochloride, penicillin G procaiene, tetracyclin hydrochloride. The
flasks were inoculated with Salmonella typhi Escherichia coli, Meticillin resistant
Staphylococcus aureus, Pseudomonas aeruginosa Streptococcus pneumonia,
Streptococcus pyogenes, respectively. The flasks were incubated at 37oC, 180 rpm. At
intervals of 2h, total bacterial count, conductivity, resistivity, total dissolved solids,
salinity, pH and electric potential difference (EPD) of culture broth weremeasured.
Results:There is good correlation between EPD and OD. In the media containing no
bacteria, EPD was constant. In the other media, an increase of EPD has been seen after
4-6h of incubation. Also, a sharp reduction of EPD has been seen in the middle of
logarithmic phase. Conclusion:
Correlation of biomass with cyclic voltametry had been reported in the literatures.
However, there is no report on the correlation between EPD and bacterial growth. In
this research, significant correlation has been seen between EPD and increase of
bacterial biomass amount.
Type of Study:
Original Research Article |
Subject:
Medical Bacteriology Received: 2013/11/5 | Accepted: 2013/11/11 | ePublished: 2013/11/11