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Production of recombinant proteins such as β-NGF using prokaryotic hosts is the topic of many recent researches. However, bacterial cell culture media are cheaper than eukaryotic cell culture media, but in industrial production scale they are not cost effective at all for biotech companies. Therefore, survey to find inexpensive cell culture medium that bacterial cells not only can grow in it but also produce recombinant proteins is very important. In this study, for the first time date syrup and yeast extract mixture was used as an inexpensive medium. In RSM (response surface methodology) studies different concentrations of date syrup and yeast extract were used as carbon and nitrogen sources respectively. The results indicate that the 20 g/lit of carbon and 5 g/lit of nitrogen are optimum for bacterial growth. Also the data show that recombinant bacteria not only can grow but also can produce recombinant proteins such as β-NGF using this synthetic medium.

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Production of recombinant proteins in Escherichia coli has been very common in recent decades. Many studies and experiments have been done in order to optimize the production and expression of recombinant proteins in E.coli. One strategy is using high cell density to increase recombinant protein production such as β-NGF in the cell. Therefore, in this study for the first time bacterial cell culture in high cell density was done using glycerol and yeast extract as carbon and nitrogen sources and MgCl2 as a growth effective factor. Also the effects of overnight culture conditions on bacterial growth were evaluated. Meanwhile culture conditions were optimized using response surface methodology (RSM) and the optimum conditions were as follows: 18/23 g/lit glycerol, 14.44 g/lit yeast extract and 10mM MgCl2. Also the obtained results indicated that the 14 hours incubation at 37 °C and 180 rpm were optimum conditions for the overnight culture. Our results showed that the rate of cell growth and recombinant β-NGF production in optimized condition is significantly higher than in basic medium.