کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6491432 43411 2014 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Enhancing precursors availability in Pichia pastoris for the overproduction of S-adenosyl-l-methionine employing molecular strategies with process tuning
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
Enhancing precursors availability in Pichia pastoris for the overproduction of S-adenosyl-l-methionine employing molecular strategies with process tuning
چکیده انگلیسی
S-Adenosyl-l-methionine (SAM) is an important metabolite having prominent role in treating various diseases. Due to increasing demand of SAM, improvement in its production is essential. For this purpose, S-adenosyl-l-methionine synthetase gene (sam2) was overexpressed in the present study, and we studied the effect of coexpression of methionine permease (mup1) and adenylate kinase (adk1) genes. From the recombinant strains expressing individual genes, we observed that SAM2 synthetase is the primary limiting factor and its overexpression is essential to increase the SAM productivity. Coexpression of mup1 with sam2 did not enhance SAM production, while coexpression of adk1 with sam2 improved SAM production, clearly indicating that ATP is the primary limiting precursor in SAM production. However, coexpression of all three genes synergistically improved SAM productivity with better L-methionine (L-met) conversion efficiency in every stage, and it was 77% more compared to overexpressing sam2 alone. Sparging pure oxygen reduced cultivation time. Feeding nitrogen source and additional L-met during induction phase enhanced SAM yield by 38.4% and 55.1%, respectively. Moreover, building up biomass before induction resulted in 145% increase in specific yield and 83% higher L-met conversion efficiency. This is the first report on increasing both the precursors L-met and ATP availability through molecular strategies using microorganisms for the production of SAM.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Biotechnology - Volume 188, 20 October 2014, Pages 112-121
نویسندگان
, , ,