Iraninan Biology Society Journal of Cellular and Molecular Research (Iranian Journal of Biology) 2383-2738 33 1 2020 04 20 Isolation and Identification of Halobacillus sp. SL-7: A moderately halophilic bacterium with potential biological converting L-tyrosine into L-dopa Isolation and Identification of Halobacillus sp. SL-7: A moderately halophilic bacterium with potential biological converting L-tyrosine into L-dopa 1 13 1595 FA Morahem Ashengroph Associate Professor in Industrial Microbiology, University of Kurdistan, Faculty of Sciences, Department of Biological Sciences, Sanandaj, Iran. 0000-0001-6821-0192 Mina Sayyadi Biological sciences, Faculty of sciences, University of Kurdistan, Sanandaj, Iran Journal Article 2018 03 27 L-DOPA (L-3, 4-dihydroxyphenylalanine) was first discovered in the 1960s as the most effective treatment for Parkinson's disease. In the present research, for the first time, isolation and identification of L-tyrosine-degrading moderately halophilic bacteria and evaluation their ability as biocatalyst for the bioconversion of L-tyrosine into L-dopa was studied. Using enrichment technique in tyrosine-containing medium, the L-tyrosine-degrading strain SL-7 with the highest ability to bioconvert L-tyrosine into L-dopa was phenotypically and molecularly characterized and its 16S rDNA sequence was submitted as Halobacillus sp. SL-7. In order to increase the reaction efficiency and prevent the degradation of the metabolites (L-dopa), One-factor-at-a-time optimization method was used to improve the yield of L-dopa in conversion reaction under resting cells of Halobacillus sp. SL-7. Based on our results, the optimum bioconversion conditions for the production of L-dopa can be summarized as follows: initial tyrosine concentration 1.5 g/l, biomass concentration 7.5 g/l, copper concentration 0.03 g/l and peptone at the concentration 1 g/l as cosubstrate. Under these conditions, the maximal L-dopa concentration (0.75 g/l with a molar yield of 46.2%) was achieved after a 36 h reaction. This is the first report on the potential of resting cells of Halobacillus sp. SL-7, A moderately halophilic bacterium with ability biological converting L-tyrosine into L-dopa. L-DOPA (L-3, 4-dihydroxyphenylalanine) was first discovered in the 1960s as the most effective treatment for Parkinson's disease. In the present research, for the first time, isolation and identification of L-tyrosine-degrading moderately halophilic bacteria and evaluation their ability as biocatalyst for the bioconversion of L-tyrosine into L-dopa was studied. Using enrichment technique in tyrosine-containing medium, the L-tyrosine-degrading strain SL-7 with the highest ability to bioconvert L-tyrosine into L-dopa was phenotypically and molecularly characterized and its 16S rDNA sequence was submitted as Halobacillus sp. SL-7. In order to increase the reaction efficiency and prevent the degradation of the metabolites (L-dopa), One-factor-at-a-time optimization method was used to improve the yield of L-dopa in conversion reaction under resting cells of Halobacillus sp. SL-7. Based on our results, the optimum bioconversion conditions for the production of L-dopa can be summarized as follows: initial tyrosine concentration 1.5 g/l, biomass concentration 7.5 g/l, copper concentration 0.03 g/l and peptone at the concentration 1 g/l as cosubstrate. Under these conditions, the maximal L-dopa concentration (0.75 g/l with a molar yield of 46.2%) was achieved after a 36 h reaction. This is the first report on the potential of resting cells of Halobacillus sp. SL-7, A moderately halophilic bacterium with ability biological converting L-tyrosine into L-dopa. https://cell.ijbio.ir/article_1595_d88518acbcc3d08d1f18da62f9bb26ec.pdf