RESUMO
S-adenosyl-l-methionine (SAM) is ubiquitous in living organisms and plays important roles in transmethylation, transsulfuration and transamination in organisms. Due to its important physiological functions, production of SAM has attracted increasing attentions. Currently, researches on SAM production mainly focus on microbial fermentation, which is more cost-effective than that of the chemical synthesis and the enzyme catalysis, thus easier to achieve commercial production. With the rapid growth in SAM demand, interests in improving SAM production by developing SAM hyper-producing microorganisms aroused. The main strategies for improving SAM productivity of microorganisms include conventional breeding and metabolic engineering. This review summarizes the recent research progress in improving microbial SAM productivity to facilitate further improving SAM productivity. The bottlenecks in SAM biosynthesis and the solutions were also addressed.
Assuntos
S-Adenosilmetionina/metabolismo , Melhoramento Vegetal , Fermentação , Engenharia MetabólicaRESUMO
Objective To investigate the value of serum pentraxins-3 (PTX-3) together with triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C) as predictor risk factors of future acute coronary syndrome(ACS). Methods One hundred and seventy-one cases of selective coronary angiography from July 2008 to December 2009 were collected and analyzed. According to the situation on admission and coronary angiography, patients were divided into three groups: normal control group (25 cases), stable angina pectoris (SAP) group (23 cases) and ACS group (123 cases). Fasting venous blood was extracted for measuring serum PTX-3 and lipids (TG, HDL-C) in the next morning, and the statistical significanc was analyzed. Results The level of serum PTX-3 and the ratio of TG to HDL-C in ACS group [(6.39 ± 3.01)μ g/L, 2.38 ± 2.00] were significantly higher than those in SAP group[(3.87 ± 2.05 ) μ g/L, 1.70 ± 1.01] and normal control group [(2.90 ± 1.94)μg/L,0.95 ±0.35] (P ＜0.01 or ＜0.05). Conclusion Increased serum PTX-3 levels and ratio of TG to HDL-C in patients are closely related with ACS, both of which increase the accuracy of early diagnosis of ACS.