Complete mitochondrial genome of the mulberry psyllid Enderlein (Hemiptera: Psyllidae) and phylogenetic analysis.

(Enderlein, 1914) (Hemiptera: Psyllidae) is a species of a psyllid distributed in Asia. Mulberry is the only known host for until now. The complete mitogenome of (accession number: MT759765) 14,963 bp in size, including 13 protein-coding genes, 22 transfer RNAs, and two ribosomal RNAs genes.

[Biosynthesis analysis of hederagenin pathway and its construction in yeast cells].

Hederagenin is an effective constituent of many medical plants, such as Clematidis Radix, and has a wide range of applications in anti-tumor, anti-inflammatory, antidepressant, hepatoprotective antibacterial, et al. In order to obtain the efficient production of yeast cells for hederagenin,we successfully cloned and screened out a P450 gene MdMA02 from Malus×domestica which can catalyze oleanolic acid C-23 oxidation with our developed plug and play platform. Its amino acid homology is only 32% as compared to characterized CYP72A68v2.

[Construction of Saccharomyces cerevisiae cell factories for lycopene production].

For microbial production of lycopene, the lycopene synthetic genes from Pantoea agglomerans were integrated into Saccharomyces cerevisiae strain BY4742, to obtain strain ZD-L-000 for production of 0.17 mg · L(-1) lycopene. Improving supplies of isoprenoid precursors was then investigated for increasing lycopene production.

Purification and characterization of a thermostable xylanase from Paenibacillus sp. NF1 and its application in xylooligosaccharides production.

High levels of extracellular xylanase activity (211.79 IU/mg) produced by Paenibacillus sp. NF1 were detected when it was submerged-cultured.

Construction of Escherichia coli strains producing L-serine from glucose.

L-Serine is usually produced from glycine. We have genetically engineered Escherichia coli to produce L-serine from glucose intracellularly. D-3-Phosphoglycerate dehydrogenase (PGDH, EC 1.

Optimization of nitrogen source for enhanced production of squalene from thraustochytrid Aurantiochytrium sp.

Nitrogen (N) sources, the critical medium component, were optimized for squalene production by microalga Aurantiochytrium sp. in heterotrophic cultures. In screening experiments monosodium glutamate, yeast extract and tryptone were found to enhance cell growth and squalene production.

Screening and characterization of squalene-producing thraustochytrids from Hong Kong mangroves.

Eighteen strains of thraustochytrids were newly isolated from Hong Kong mangroves, and their fatty acid and squalene contents were analyzed. All strains could grow well heterotrophically with glucose as the sole carbon source. All of them had the typical fatty acid profile of thraustchytrids and could produce a large amount of docosahexaenoic acid.

[Cloning, characterization and application of the promoter region of the alkaline protease gene in Bacillus alcalophillus PB92].

Promoter function fragment of alkaline protease gene (GenBank accession number: EU130686) was cloned from Bacillus alcalophillus PB92 genome by TAIL-PCR. Sequenced and analyzed revealed that it contains several typical promoter characterized regions. Two reverse translation frames were located in -538~-370 bp and-275~-128 bp.

Expression, purification, and characterization of phosphatidylserine synthase from Escherichia coli K12 in Bacillus subtilis.

Although phosphatidylserine synthase (PSS) from Escherichia coli is an ideal enzyme for phospholipid production, its application in the food industry has been limited because of the low PSS yield. In this study, the pss gene was cloned from E. coli K(12) and expressed in Bacillus subtilis DB104, and the recombinant PSS was characterized subsequently.

Acid stabilization of Bacillus licheniformis alpha amylase through introduction of mutations.

This paper provided further understanding of the relationships between acid resistance and structural features of different mutants in Bacillus licheniformis alpha amylase (BLA) due to the changes of two crucial positions Leu134 and Ser320. In order to investigate effect of the two positions on the acid stability, we described the detailed characterization of wild-type and the single mutants L134R and S320A as well as the double mutant L134R/S320A. The highest k(cat)/Km with pH 4.

Natamycin production by Streptomyces gilvosporeus based on statistical optimization.

Natamycin has been widely used as a natural preservative to prevent mold contamination in food. In this study, statistically based experimental designs were employed for the optimization of medium components for natamycin production by Streptomyces gilvosporeus. After glucose, yeast extract, and soy peptone were screened as suitable carbon and nitrogen sources, a full factorial design was used to evaluate the effects of various factors on natamycin production.

Expression, purification, and characterization of a thermophilic neutral protease from Bacillus stearothermophilus in Bacillus subtilis.

The gene coding for a thermophilic neutral protease from Bacillus stearothermophilus was expressed in Bacillus subtilis DB104, under the control of the sacB gene promoter. This was followed by either the native signal peptide sequence of this protease or the signal peptide sequence of the sacB gene. The protease was purified 3.

Characterisation of mutagenised acid-resistant alpha-amylase expressed in Bacillus subtilis WB600.

Based on the original thermostable alpha-amylase gene from Bacillus licheniformis, two amino acids were site-directed mutagenised by polymerase chain reaction to obtain a new gene. This gene, with Leu134-->Arg and Ser320-->Ala, was substituted for acid-resistant capability previously. To favor purification of the product, high-level expression and secretion of mature, authentic and stable recombinant mutagenised alpha-amylase were achieved with protease-deficient strain Bacillus subtilis WB600 as the host.

Statistical optimization of medium components for avilamycin production by Streptomyces viridochromogenes Tü57-1 using response surface methodology.

A fermentation medium for avilamycin production by Streptomyces viridochromogenes Tü57-1 has been optimized. Important components and their concentrations were investigated using fractional factorial design and Box-Behnken Design. The results showed that soybean flour, soluble starch, MgSO4.

Regulation of avilamycin biosynthesis in Streptomyces viridochromogenes: effects of glucose, ammonium ion, and inorganic phosphate.

Effects of glucose, ammonium ions and phosphate on avilamycin biosynthesis in Streptomyces viridochromogenes AS4.126 were investigated. Twenty grams per liter of glucose, 10 mmol/L ammonium ions, and 10 mmol/L phosphate in the basal medium stimulated avilamycin biosynthesis.

[Overexpression of a sweet protein monellin in Escherichia coli].

According to the amino acid sequence of monellin, a single chain 294bp monellin gene was synthesized and inserted into vector pET-22b to yield the recombinant secretion plasmid pETMO. The single-chain monellin gene was designed based on the biased codons of E. coli so that its expression would be then optimized.

[Characteristics of a new fibrinolytic enzyme produced from Rhizopus chinensis 12#].

As a therapeutic agent in thrombosis the fibrinolytic enzymes are of interest and the search for a new enzyme continues. A novel fibrinolytic enzyme was produced from Rhizopus chinensis 120, which was screened from the starter for brewing rice wine in the South of China, by solid fermentation, and purified through ammonium sulfate precipitation, hydrophobic interaction, ionic exchange and gel filtration chromatographies. The purified enzyme hydrolyzed fibrin, it cleaved the alpha-, beta- and gamma-chains of fibrinogen simultaneously, and it also activated plasminogen to plasmin.

[Differential acute mortality among the allozyme genotypes of Oxya chinensis by pesticide avermectin].

The rice grasshopper Oxya chinensis exhibits polymorphic loci at Ldh, Gpi, Pgm and Me. The data of the mean number of alleles per locus (A = 2.8), percentage of polymorphic loci (P = 80.

[Impacts of malathion on population genetic structure of Oxya chinensis].

Allozyme electrophoresis was employed to compare the difference in mortality among the genotypes at two polymorphic loci of Pgm and Me of grasshopper Oxya chinensis individuals acutely exposed to 1.5g/L malathion which resulted in 56% mortality in 24 hours. The selective lethal effects were observed among the genotypes at Pgm locus but not at Me locus.

Purification and characterization of a novel fibrinolytic enzyme from Rhizopus chinensis 12.

A novel fibrinolytic enzyme from Rhizopus chinensis 12 was purified through ammonium sulfate precipitation, hydrophobic interaction, ionic exchange, and gel filtration chromatography. The purification protocol resulted in a 893-fold purification of the enzyme, with a final yield of 42.6%.