Production of microbial medium from defatted brebra (Milletia ferruginea) seed flour to substitute commercial peptone agar.
OBJECTIVE
To investigate and optimize microbial media that substitute peptone agar using brebra seed defatted flour.


METHODS
Defatted process, inoculums preparation, evaluation of bacterial growth, preparation of cooked and hydrolyzed media and growth turbidity of tested bacteria were determined.


RESULTS
Two percent defatted flour was found to be suitable concentration for the growth of pathogenic bacteria: Escherichia coli (ATCC 25922) (E. coli), Pseudomonas aeruginosa (ATCC 27853), Salmonella (NCTC 8385) and Shigella flexneri (ATCC 12022) (S. flexneri), while 3% defatted flour was suitable for Staphylococcus aureus (ATCC 25923) (S. aureus). E. coli (93±1) and S. flexneri (524±1) colony count were significantly (P≤0.05) greater in defatted flour without supplement than in supplemented medium. E. coli [(3.72×10(9)±2) CFU/mL], S. aureus [(7.4×10(9)±2) CFU/mL], S. flexneri [(4.03×10(9)±2) CFU/mL] and Salmonella [(2.37×10(9)±1) CFU/mL] in non-hydrolyzed sample were statistically (P≤0.05) greater than hydrolyzed one and commercial peptone agar. Colony count of Salmonella [(4.55×10(9)±3) CFU/mL], S. flexneri [(5.40×10(9)±3) CFU/mL] and Lyesria moncytogenes (ATCC 19116) [(5.4×10(9)±3) CFU/mL] on raw defatted flour agar was significantly (P≤0.05) greater than cooked defatted flour and commercial peptone agar. Biomass of E. coli, S. aureus, Salmonella and Enterococcus faecalis in non-hydrolyzed defatted flour is highly increased over hydrolyzed defatted flour and commercial peptone broth.


CONCLUSIONS
The defatted flour agar was found to be better microbial media or comparable with peptone agar. The substances in it can serve as sources of carbon, nitrogen, vitamins and minerals that are essential to support the growth of microorganisms without any supplements. Currently, all supplements of peptone agar are very expensive in the market.
Department of Biotechnology, Faculty of Natural and Computational Sciences, University of Gondar, Gondar, Ethiopia, P.O. Box 196, Gondar, Ethiopia. Electronic address: tberhanu2007@gmail.com.
Berhanu
B
Andualem
Amare
A
Gessesse
D000362:Agar / Q000737:chemistry*; D001419:Bacteria / Q000254:growth & development; D015169:Colony Count, Microbial; D003470:Culture Media / Q000737:chemistry*; D010461:Peptones / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry*
D003470:Culture Media; D010461:Peptones; D000362:Agar
Colony counts; Commercial media; Defatted flour; Microbial media; Pathogenic bacteria; Peptone agar