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The beta-hydroxy acid 3-hydroxypropionic acid (3-HP) is an attractive platform compound that can be used as a precursor for many commercially interesting compounds. In order to reduce the dependence on petroleum and follow sustainable development, 3-HP has been produced biologically from glucose or glycerol. It is reported that 3-HP synthesis pathways can be constructed in microbes such as Escherichia coli, Klebsiella pneumoniae and the yeast Saccharomyces cerevisiae. Among these host strains, yeast is prominent because of its strong acid tolerance which can simplify the fermentation process. Currently, the malonyl-CoA reductase pathway and the ß-alanine pathway have been successfully constructed in yeast. This review presents the current developments in 3-HP production using yeast as an industrial host. By combining genome-scale engineering tools, malonyl-CoA biosensors and optimization of downstream fermentation, the production of 3-HP in yeast has the potential to reach or even exceed the yield of chemical production in the future.

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In recent years, a variety of genetic tools have been developed and applied to various filamentous fungi, which are widely applied in agriculture and the food industry. However, the low efficiency of gene targeting has for many years hampered studies on functional genomics in this important group of microorganisms. The emergence of CRISPR/Cas9 genome-editing technology has sparked a revolution in genetic research due to its high efficiency, versatility, and easy operation and opened the door for the discovery and exploitation of many new natural products. Although the application of the CRISPR/Cas9 system in filamentous fungi is still in its infancy compared to its common use in E. coli, yeasts, and mammals, the deep development of this system will certainly drive the exploitation of fungal diversity. In this review, we summarize the research progress on CRISPR/Cas9 systems in filamentous fungi and finally highlight further prospects in this area.

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Plant hormones are a class of organic substances which are synthesized during the plant metabolism. They have obvious physiological effect on plant growth at very low concentrations. Generally, plant hormones are mainly divided into 5 categories: auxins, cytokinins, ethylene, gibberellins (GAs) and abscisic acid (ABA). With the deepening of research, some novel plant hormones such as brassinosteroid and salicylates have been found and identified. The plant hormone products are mainly obtained through plant extraction, chemical synthesis as well as microbial fermentation. However, the extremely low yield in plants and relatively complex chemical structure limit the development of the former 2 approaches. Therefore, more attention has been paid into the microbial fermentative production. In this commentary, the developments and technological achievements of the 2 important plant hormones (GAs and ABA) have been discussed. The discovery, producing strains, fermentation technologies, and their accumulation mechanisms are first introduced. Furthermore, progresses in the industrial mass scale production are discussed. Finally, guidelines for future studies for GAs and ABA production are proposed in light of the current progress, challenges and trends in the field. With the widespread use of plant hormones in agriculture, we believe that the microbial production of plant hormones will have a bright future.

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<p><b>BACKGROUND</b>Vascular access (VA) dysfunction is a major clinical complication in the hemodialysis population and has a direct effect on dialysis outcome. This study was conducted to explore the role of microinflammation in the VA dysfunction in maintenance hemodialysis patients.</p><p><b>METHODS</b>Forty-seven patients (male 35 and female 12) receiving maintenance hemodialysis were included for this study. They were divided into three groups: group 1 (n = 15), patients with initial hemodialysis and new arteriovenous fistula (AVF); group 2 (n = 18), patients treated with hemodialysis for long term with well-functional VA; group 3 (n = 14), maintenance hemodialysis patients with VA dysfunction. Biochemical parameters and serum tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) were determined. High-sensitivity C-reactive protein (hs-CRP) was determined by latex-enhanced immuno-nephelometric method. Tissues of radial artery were taken from group 1 and group 3 for the histological study. Expression of CD68 and MCP-1 in the radial artery was determined by immunohistochemistry.</p><p><b>RESULTS</b>Serum hs-CRP in group 3 was significantly higher than those in group 1 and group 2 ((7.40 +/- 2.42) mg/L vs (4.21 +/- 1.62) mg/L and (5.04 +/- 3.65) mg/L, P < 0.01 and P < 0.05, respectively). Serum TNF-alpha in group 3 was significantly higher than those in group 1 and group 2 ((64.03 +/- 9.29) pg/ml vs (54.69 +/- 12.39) pg/ml and (54.05 +/- 7.68) pg/ml, P < 0.05 and P < 0.01, respectively). Serum IL-6 in group 3 was also significantly higher than those in group 1 and group 2 ((70.09 +/- 14.53) pg/ml vs (56.43 +/- 10.11) pg/ml and (60.77 +/- 9.70) pg/ml, P < 0.01 and P < 0.05, respectively). Patients in group 3 had a thicker internal layer of vessels than in group 1 ((0.356 +/- 0.056) mm vs (0.111 +/- 0.021) mm, P < 0.01). Expression of CD68 and MCP-1 in the fistula vessel walls in group 3 were much higher than those in group 1 (P < 0.01). Moreover, serum hs-CRP level was positively correlated with the neointimal hyperplasia, the expression of CD68 and MCP-1 in fistula vessel (P < 0.01, respectively).</p><p><b>CONCLUSION</b>Microinflammation might be involved in the dysfunction of AVF in patients with maintenance hemodialysis.</p>

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