Production of Microbiological Peptone From Hydrolysis of Slaughterhouse Offal Using Bacterial Protease

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Addis Ababa University


Proteases are the most important class of industrial enzymes accounting for 60% of the global industrial enzyme market. Microorganisms are the major source of these enzymes. Production of hyrolysates from different protein sources is among the different application of proteases. Protein hydrolysates have a variety of food and non-food applications. Although different proteases are available in the market, there is always a need for the development of new enzymes from bacterialsources. This is especially important in countries like Ethiopia where there are no local enzyme producers. The aim of this study was, therefore, to isolate new protease producing bacterial isolates to be used for the hydrolysis of slaughterhouse offal, optimize enzyme production and hydrolysis conditions, and test hydrolysates as a microbiological growth media. Based on screening data on solid and liquid media, one bacterial isolate designated as aau5 was selected for further study. The isolate grew under solid-state fermentation (SSF) and produced up to 5,773 U/g of enzyme. Enzyme production was optimal when the solid to moisture ratiowas 1:2(66.7 % moisture content) and in the presence of organic nitrogen sources. Protease aau5 was optimally active at pH 7.5 and temperature of 55°C. After one hour incubation, the enzyme retained up to 66% and 41% of its original activity at 50°C and 55°C, respectively. Protease aau5 was used for the hydrolysis of slaughter house offal (lung and bone) and soybean protein. The hydrolysate (peptone) was then tested as a microbiological media for the growth of different bacterial species. Compared to commercial peptone, hydrolysate obtained from lung (LPA) and bone extracted protein (BPA) supported better growth of the test organisms. So, by using waste and by products of slaughter houses, beneficial hydrolysate like peptone can be produced through enzymatic hydrolysis



Source of Proteins, Protein, Animal Proteases, Microbial Proteases