[Vulnerability assessment of agro-ecological environment in Karst mountain based on set pair analysis model of grey trigonometrically whitening weight].

Ecological vulnerability is a hot issue in the study of global change and sustainable development. Understanding the vulnerability of agro-ecological environment is conducive to rational utilization of regional agricultural resources, which could put forward effective measures for prote-cting agro-ecological environment. Given that the evaluation of agricultural eco-environment vulnerability generally does not consider the relationships among different indicators in different evaluation levels, we used the grey trigonometrically whitening weight set pair analysis (SPA) model to evaluate the vulnerability of agricultural eco-environment in Karst mountain by selecting 11 indicators such as population density, per capita arable land area and per capita afforestation area from the external vulnerability of ecological environment.

Identification and characterization of a novel diacylglycerol acyltransferase gene from Mortierella alpina.

Objectives: To clone and express a diacylglycerol acyltransferase (DGAT) gene from Mortierella alpina in Saccharomyces cerevisiae and characterize oil production and fatty acid composition of the resulting recombinant RESULTS: A new, full-length cDNA, putatively encoding a DGAT, was cloned from M. alpina. We subsequently cloned the gene, except the transmembrane-encoding region, termed MaDGAT, its molecular mass was 31.

Four-stage dissolved oxygen strategy based on multi-scale analysis for improving spinosad yield by Saccharopolyspora spinosa ATCC49460.

Dissolved oxygen (DO) is an important influencing factor in the process of aerobic microbial fermentation. Spinosad is an aerobic microbial-derived secondary metabolite. In our study, spinosad was used as an example to establish a DO strategy by multi-scale analysis, which included a reactor, cell and gene scales.

Influence of initial pH on the precipitation and crystal morphology of calcium carbonate induced by microbial carbonic anhydrase.

The dynamics of calcium carbonate (CaCO(3)) precipitation induced by microbial intracellular or extracellular carbonic anhydrase (CA) at initial pH 6.0, 6.5, 7.

Isolation of eicosapentaenoic acid-producing fungi from soil based on polymerase chain reaction amplification.

A method was developed for rapid screening and isolation of eicosapentaenoic acid (EPA)-producing soil fungi through polymerase chain reaction (PCR) amplification. Genes coding for delta6 fatty acid desaturase and delta5 fatty acid desaturase were used as molecular markers for screening these EPA-producing fungi from soil. Three out of 65 soil fungi gave positive results through PCR amplification.

Agrobacterium tumefaciens-mediated transformation of a taxol-producing endophytic fungus, Cladosporium cladosporioides MD2.

In this study, an Agrobacteriurn tumefaciens-mediated transformation (ATMT) protocol was successfully developed for the genetic transformation of a taxol-producing fungus, Cladosporium cladosporioides MD2, and the co-cultivation conditions affecting the transformation efficiency were optimized. The optimal transformation conditions were that 1 ml of C. cladosporioides MD2 spore suspension (10(8) spores/ml) was mixed with an equal volume of A.

Microbial production of docosahexaenoic acid by a low temperature-adaptive strain Thraustochytriidae sp. Z105: screening and optimization.

As an alternative source in addition to fish oil, microbial production of docosahexaenoic acid has been recieved more and more attentions owing to their culture advantage. A unicellular eukaryotic microbe with high DHA production and capable of low temperature-adaptive growth was isolated from seawater and identified as Thraustochytriidae sp. Z105.

An endophytic taxol-producing fungus from Taxus media, Cladosporium cladosporioides MD2.

Fermentation processes using taxol-producing fungi other than Taxus spp. may be an alternative way to produce taxol, which is an important antitumor agent used widely in the clinic setting. In this study, a taxol-producing endophytic fungus strain MD2 was isolated from the inner bark of Taxus media.

Improvement of arachidonic acid and eicosapentaenoic acid production by increasing the copy number of the genes encoding fatty acid desaturase and elongase into Pichia pastoris.

Genes encoding Delta6 desaturase, Delta6 fatty acid elongase, and Delta5 desaturase from the alga, Phaeodactylum tricornutum, were co-expressed in Pichia pastoris to produce arachidonic acid (ARA; 20:4 Delta(5, 8, 11, 14)) and eicosapentaenoic acid (EPA; 20:5 Delta(5, 8, 11, 14, 17)). A panel of Pichia clones carrying progressively increasing copies of the heterologous gene expression cassette was created using an in vitro multimerization approach. ARA and EPA accumulated up to 0.

An endophytic taxol-producing fungus from Taxus x media, Aspergillus candidus MD3.

An endophytic taxol-producing fungus (strain MD3) isolated from the inner bark of Taxus x media was identified as Aspergillus candidus according to its morphological characteristics, physiological and biochemical characteristics, and 18S rRNA gene sequence analysis. Taxol produced by A. candidus MD3 was shown to be identical to authentic taxol analyzed by UV, HPLC, MS and nuclear magnetic resonance spectroscopy.

Screening of Taxol-producing fungi based on PCR amplification from Taxus.

Genes coding for 10-deacetylbaccatin III-10-O-acetyl transferase and C-13 phenylpropanoid side chain-CoA acyltransferase were used as molecular markers for screening of Taxol-producing endophytic fungi. Using PCR, three out of 90 endophytic fungi, isolated from Taxus x media and Taxus yunnanensis, gave positive results. These 3 strains, when grown in 300 ml potato/dextrose liquid medium at 25 degrees C for 10 days, contained 100-160 microg Taxol/g dry wt of mycelium.

Limestone dissolution induced by fungal mycelia, acidic materials, and carbonic anhydrase from fungi.

Microorganisms influence the dissolution of a number of minerals. Limestone is one of the most abundant rock types in karst areas, and is predominantly calcium carbonate. Two types of experimental systems were designed in this paper, to make comparisons of limestone dissolution rate among the acidic materials and extracellular carbonic anhydrase (CA) excreted by fungi and the enwrapping effect of fungal mycelia.