Microbial production of glycolate from acetate by metabolically engineered Escherichia coli.

Escherichia coli was metabolically engineered to synthesize glycolate using acetate as the carbon source. The native glyoxylate bypass pathway was reinforced by the overexpression of isocitrate lyase and isocitrate dehydrogenase kinase/phosphatase. Glyoxylate/hydroxypyruvate reductase was overexpressed to convert glyoxylate to glycolate.

Indentation with atomic force microscope, Saccharomyces cerevisiae cell gains elasticity under ethanol stress.

During bioethanol fermentation process, Saccharomyces cerevisiae cell membrane is the first target to be attacked by the accumulated ethanol. In such a prominent position, S. cerevisiae cell membrane could reversely provide protection through changing fluidity or elasticity secondary to remodeled membrane components or structure during the fermentation process.

Four homoisoflavonoids isolated from traditional Chinese medicine: "gan luo xin".

Two new homoisoflavonoids, ( ± )-5,7-dihydroxy-8-methyl-3-(2',4'-dihydroxybenzyl) chroman-4-one (1) and ( ± )-5,7-dihydroxy-6,8-dimethyl-3-(2',4'-dihydroxybenzyl) chroman-4-one (2), along with two known homoisoflavonoids, 5,7-dihydroxy-6-methyl-3-(2',4'-dihydroxybenzyl)chroman-4-one (3) and disporopsin (4), were isolated from the EtOAc extract of traditional Chinese medicine--"Gan Luo Xin." Their structures were determined on the basis of spectroscopic analysis (UV, IR, HR-ESI-MS, 1D NMR, and 2D NMR).

A novel cleaning process for industrial production of xylose in pilot scale from corncob by using screw-steam-explosive extruder.

Steam explosion is the most promising technology to replace conventional acid hydrolysis of lignocellulose for biomass pretreatment. In this paper, a new screw-steam-explosive extruder was designed and explored for xylose production and lignocellulose biorefinery at the pilot scale. We investigated the effect of different chemicals on xylose yield in the screw-steam-explosive extrusion process, and the xylose production process was optimized as followings: After pre-impregnation with sulfuric acid at 80 °C for 3 h, corncob was treated at 1.

Microbial biotransformation of kurarinone by Cunninghamella echinulata AS 3.3400.

In this paper, microbial transformation of kurarinone (1) by Cunninghamella echinulata AS 3.3400 was investigated and four transformed products were isolated and identified as 6″-hydroxykurarinone (2), 4″,5″,8″-trihydroxynorkurarinone (3), norkurarinone (4), and kurarinone-7-O-β-glucoside (5), respectively. Among them, 3 and 5 are new compounds, and the rare glycosylation in microbial transformation was observed.

Microbial transformation of Norkurarinone by Cunninghamella blakesleana AS 3.970.

In this paper, microbial transformation of norkurarinone (1) by Cunninghamella blakesleana AS 3.970 was investigated and seven transformed products were isolated and characterized as kurarinone (2), 4″,5″-dihydroxykurarinone (3), 6″-hydroxyl-2'-methoxyl-norkurarinone 7-O-β-d-glucoside (4), 6″-hydroxyl-norkurarinone 4'-O-β-d-glucoside (5), 4″,5″-dihydroxynorkurarinone (6), 7-methoxyl-norkurarinone (7), and 7-methoxyl-4″,5″-dihydroxynorkurarinone (8), respectively. Among them, 3-5 are new compounds, and the glycosylation reaction in microbial transformation process was reported rarely.

Molecular cloning and functional expression of two key carotene synthetic genes derived from Blakeslea trispora into E. coli for increased β-carotene production.

Blakeslea trispora is used commercially to produce β-carotene. Isopentenyl pyrophosphate isomerase (IPI) and geranylgeranyl pyrophosphate synthase (GGPS) are key enzymes in the biosynthesis of carotenoids. The cDNAs of genes ipi and carG were cloned from the fungus and expressed in Escherichia coli.

Improved lycopene production by Blakeslea trispora with isopentenyl compounds and metabolic precursors.

The highest lycopene production in mated cultures of Blakeslea trispora was 578 mg/l by adding 42 mg geraniol/l to the medium after 48 h of growth. The control gave 317 mg/l. Adding isopentenyl alcohol at 40 mg/l, mevalonic acid at 17.

Preparation and characterization of poly glycidyl methacrylete-zirconium dioxide-beta-cyclodextrin composite matrix for separation of isoflavones through expanded bed adsorption.

The specially prepared adsorbent is most important in realizing the expanded bed adsorption (EBA) process. In the present work, a novel poly glycidyl methacrylete-zirconium dioxide-beta-cyclodextrin (PGMA-ZrO(2)-beta-CD) composite matrix for EBA has been first prepared. Wet density, water content and pore properties of the composite beads have been investigated, which shows good expansion and stability in EBA.

Microbial transformation of dehydroandrographolide by Cunninghamella elegans.

The biotransformation of dehydroandrographolide (1) by Cunninghamella elegans was performed and four transformed products were obtained. Based on their extensive spectral data, the structures of these metabolites were identified as 3-oxo-dehydroandrographolide (2), 3-oxo-2beta-hydroxy-dehydroandrographolide (3), 3-oxo-8beta,17alpha-epoxydehydroandrographolide (4), 3,19-dihydroxy-7,11,13-ent-labdatrien-15,16-olide (5), respectively. Among them, products 3-5 are new compounds.

Enhanced production of coenzyme Q10 by overexpressing HMG-CoA reductase and induction with arachidonic acid in Schizosaccharomyces pombe.

Coenzyme Q10 (CoQ10) is a vitamin-like substance which plays a crucial role in the respiratory chain ranging from bacteria to humans and in the radical scavenging in human body. In this study, the full-length hmgR gene (encoding 3-hydroxy-3-methyl-glutaryl-CoA reductase, HMG-CoA reductase) was cloned and overexpressed in Schizosaccharomyces pombe. Using the pREPG yeast depressed under the thiamine as the control, CoQ10 contents increased up to 2.

Effects of an ergosterol synthesis inhibitor on gene transcription of terpenoid biosynthesis in Blakeslea trispora.

Highly efficient induction of carotene biosynthesis of Blakeslea trispora by ketoconazole (KCZ), an inhibitor of ergosterol biosynthesis, was found previously. To get some insight into the regulatory mechanisms of KCZ controlling terpenoid (including carotene) biosynthesis, the transcript levels of gene hmgR, encoding HMGR, which initiates the biosynthesis of all terpenoids, and gene carRA, encoding lycopene cyclase and phytoene synthase in the carotene biosynthsis pathway, were investigated in B. trispora cells treated with KCZ.

[Cloning and secretion expression of hepcidin in Pichia pastoris].

Hepcidin is a liver-expressed, small cysteine rich peptide that acts as a regulator of systemic iron homeostasis. In this work, according to the partiality codon of Pichia pastoris, a DNA fragment containing the coding sequence of hepcidin was designed and synthesized, especially a Kex2 signal cleavage site was fused in 5' end of the antibacterial peptide genes. Then the modified hepcidin gene was inserted into the Pichia pastoris expression vector plasmid pPICZalpha-A.

[Properties and advance of hepcidin].

Hepcidin is a small cystein-rich cationic peptide produced mainly by the liver. It was initially isolated from human plasma and exhibited antimicrobial activity. Recently, several lines of evidence have suggested that hepcidin is a key regulator of iron metabolism at the whole body level and is relative to inflammation, infection, hypoxia and anemia.

A novel approach for improving the productivity of ubiquinone-10 producing strain by low-energy ion beam irradiation.

Agrobacterium tumefaciens ATCC4452 cells were irradiated by nitrogen ion beam, a new mutagen, with energy of 10 keV and fluence ranging from 2.6x10(14) ions/cm2 to 6.5x10(15) ions/cm2.

Effect of iontophoresis on skin permeation of defibrase.

Aim: To investigate the effect of iontophoresis on skin permeation of defibrase.

Methods: Iontophoresis was carried out in side-by-side chambers, excised rat skin membrane (RSM) or human epidermis membrane (HEM). The effects of electrode polarity, permeation medium pH and ionic strength were evaluated.