ABSTRACT
CoQ10 has been used not only as a medicine but also as food supplements because of its various physiological and biochemical activities. A full-factorial central composite design and response surface methodology were used for optimizing three precursors Solanesol, 4-hydroxybenzoic acid and methionine to maximize the production of CoQ10 by Rhodopseudomonas palustris J001. The optimization of the model predicted a maximum response 40.6 [(mg CoQ10)(g dried biomass)-1] CoQ10 production with 124.8 mg l-1 Solanesol, 267.7 mg l-14-hydroxybenzoic acid and 130.2 mg l-1 methionine, respectively. A new combination was prepared according to the result. The observed response was 40.5 ± 0.2 [(mg CoQ10)(g dried biomass)-1] and was 109.8%higher than in the control with no addition of the three precursors.
ABSTRACT
CoQ10 has been used not only as a medicine but also as food supplements because of its various physiological and biochemical activities. A full-factorial central composite design and response surface methodology were used for optimizing three precursors Solanesol, 4-hydroxybenzoic acid and methionine to maximize the production of CoQ10 by Rhodopseudomonas palustris J001. The optimization of the model predicted a maximum response 40.6 [(mg CoQ10)(g dried biomass)-1] CoQ10 production with 124.8 mg l-1 Solanesol, 267.7 mg l-14-hydroxybenzoic acid and 130.2 mg l-1 methionine, respectively. A new combination was prepared according to the result. The observed response was 40.5 ± 0.2 [(mg CoQ10)(g dried biomass)-1] and was 109.8%higher than in the control with no addition of the three precursors.
ABSTRACT
The culture of Magnetospirillum magneticum WM-1 depends on several control factors that have great effect on the magnetic cells concentration. Investigation into the optimal culture conditions needs a large number of experiments. So it is desirable to minimize the number of experiments and maximize the information gained from them. The orthogonal design of experiments and mathematical statistical method are considered as effective methods to optimize the culture condition of magnetotactic bacteria WM-1 for high magnetic cells concentration. The effects of the four factors, such as pH value of medium, oxygen concentration of gas phase in the serum bottle, C:C (mtartaric acid: msuccinic acid) ratio and NaNO3 concentration, are simultaneously investigated by only sixteen experiments through the orthogonal design L16(44) method. The optimal culture condition is obtained. At the optimal culture condition (pH 7.0, a oxygen concentration 4.0%, C: C (mtartaric acid: msuccinic acid) ratio 1:2 and NaNO3 100 mg l-1), the magnetic cells concentration is promoted to 6.5×107 cells ml-1, approximately 8.3% higher than that under the initial conditions. The pH value of medium is very important factor for magnetic cells concentration. It can be proved that the orthogonal design of experiment is of 90% confidence. The results from the hysteresis of WM-1 shows that Hc = 230 Oe, Ms = 0.9 emu/g dry wt. Cells,and Mr / Ms = 0.50.
ABSTRACT
The culture of Magnetospirillum magneticum WM-1 depends on several control factors that have great effect on the magnetic cells concentration. Investigation into the optimal culture conditions needs a large number of experiments. So it is desirable to minimize the number of experiments and maximize the information gained from them. The orthogonal design of experiments and mathematical statistical method are considered as effective methods to optimize the culture condition of magnetotactic bacteria WM-1 for high magnetic cells concentration. The effects of the four factors, such as pH value of medium, oxygen concentration of gas phase in the serum bottle, C:C (mtartaric acid: msuccinic acid) ratio and NaNO3 concentration, are simultaneously investigated by only sixteen experiments through the orthogonal design L16(44) method. The optimal culture condition is obtained. At the optimal culture condition (pH 7.0, a oxygen concentration 4.0%, C: C (mtartaric acid: msuccinic acid) ratio 1:2 and NaNO3 100 mg l-1), the magnetic cells concentration is promoted to 6.5×107 cells ml-1, approximately 8.3% higher than that under the initial conditions. The pH value of medium is very important factor for magnetic cells concentration. It can be proved that the orthogonal design of experiment is of 90% confidence. The results from the hysteresis of WM-1 shows that Hc = 230 Oe, Ms = 0.9 emu/g dry wt. Cells,and Mr / Ms = 0.50.
ABSTRACT
Arachidonic acid is an essential fatty acid in human nutrition and a biogenetic precursor of the biologically active prostaglandins and leukotrienes. ?~5 desaturase catalyzes the ?~5 dehydrogenation of di-homo-?-linolenic acid to form arachidonic acid in biosynthetic pathway of arachidonic acid. Using real time PCR technology,the transcriptional expression levels of gene encoding ?5 desaturase in three Mortierella alpina strains M10,M6 and M23,and in different growth phase of high arachidonic acid yielding strain M6,were determined. Results showed that there was a distinct corelationship between mRNA transcript level of ?~5 desaturase gene and biosynthesis of arachidonic acid. Results indicated that ?~5 desaturase plays an important role in arachidonic acid biosynthesis.
ABSTRACT
<p><b>AIM</b>To develop a rapid analytical method for small amount biological samples of taxanes by using liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-ESI-MS) in small amount biological samples.</p><p><b>METHODS</b>A solution containing five given taxane constituents and the extract from cell cultures of Taxus chinensis were analysed separately. According to the performance of the given taxanes in ESI-MS/MS, run parameters of the mass spectrometer were optimized. Positive and negative electrospray modes were employed to simultaneously scan the cell cultures sample, and the full ion chromatogram and the molecular weight of individual peak were obtained. The qualitative analysis of taxanes was achieved by comparison of the retention time and molecular weight with those of the reference substances or was based on the interpretation of the MS/MS spectra of the analytes and the knowledge of the concerning genetic backgrounds of taxanes published in literatures.</p><p><b>RESULTS</b>The taxanes with several acetyl substituents tended to produce ammonium adduct ions peak, while multi-hydroxy taxanes were subject to give protonized molecular ion peaks in positive ion ESI-MS. Thirteen taxanes in cell samples were assigned. Eight compounds of them were identified to be 1 -acetyl-5, 7, 10-deacetyl-baccatin I (DAB-I, 1) , baccatin III (B-III, 3), baccatin VI (B-VI, 8), taxol (9), yunnanxane (10 ), taxuyunnanine C (Tc, 11), sinenxane B (12), sinenxane C (13), separately. For the other five constituents, character of taxane and the number of substituents were deduced.</p><p><b>CONCLUSION</b>The results confirm the feasibility of characterizing taxanes in biological samples by LC-ESI-MS analysis. The analytical methodology provided a rapid, conventional and reliable tool to study metabolic profiling of taxanes for structural elucidation in taxol biosynthesis.</p>
Subject(s)
Alkaloids , Chemistry , Bridged-Ring Compounds , Chemistry , Cells, Cultured , Chromatography, Liquid , Methods , Molecular Structure , Molecular Weight , Paclitaxel , Chemistry , Plant Extracts , Chemistry , Plants, Medicinal , Chemistry , Cell Biology , Spectrometry, Mass, Electrospray Ionization , Methods , Taxoids , Chemistry , Taxus , Chemistry , Cell BiologyABSTRACT
Two distinct routes (classical mevalonate pathway and a novel mevalonate-independent pathway) are utilized by plants for the biosynthesis of isopentenyl diphosphate, the universal precursor of isoprenoids (Fig. 1). Present researches indicated that taxol was synthesized mainly via non-mevalonate pathway, but not genetic evidence was showed. The second step in non-mevalonate pathway involves an intramolecular rearrangement and subsequent reduction of deoxyxylulose phosphate to yield 2-C-methyl-D-erythritol-4-phosphate, and 1-Deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) with responsibility for this reaction was considered as a key enzyme. As a tool for the isolation of genes in terpenoid biosynthesis in plants, total RNA was prepared from Taxus chinensis suspension cells, a cell type highly specialized for diterpene (taxol). A reverse transcription-PCR strategy based on the design of degenerated oligonucleotides was developed for isolating the gene encoding a gymnosperm homolog of this enzyme from Taxus chinensis. Through sequence analysis by Blast P online, the resulting cDNA showed highly homologous to 1-deoxy-D-xylulose 5-phosphate reductoisomerases, with 95% identification compared with Arabidopsis thaliana (Q9XFS9), 94% with Mentha x piperita (Q9XESO), 80% with Synechococcus elongatus (Q8DK30), 78% with Synechocystis sp. PCC 6803 (Q55663) and Nostoc sp. PCC 7120 (Q8YP49), and 73% with Synechococcus leopoliensis (Q9RKT1). Deduced amino acid sequences were also analyzed by PROSITE, ClustalX (1.81) and Phylio (3.6 alpha), and data present evidence for the existence of this deoxyxyluose phosphate reductoisomerase in Taxus chinensis. This is the first report of the dxr gene cloned from gymnosperm.
Subject(s)
Aldose-Ketose Isomerases , Genetics , Cloning, Molecular , DNA, Complementary , Chemistry , Mevalonic Acid , Metabolism , Multienzyme Complexes , Genetics , Oxidoreductases , Genetics , Phylogeny , RNA , Reverse Transcriptase Polymerase Chain Reaction , Taxus , GeneticsABSTRACT
Effects of main environmental factors, such as temperature, pH , metal ions and anions, on expression and activity of bacterial extracellular car bonic anhydrase(CA) were studied, exemplified by a bacterium named GLRT102Ca, wh ich was separated from karst ecosystems of Southwest China. The results showed that the tested strain could express different activity of extracellular carboni c anhydrase within the scope of experimental temperature (10℃~50℃) and pH (5. 5~9.0). The activity of extracellular carbonic anhydrase was higher at tempera ture of 20℃~30℃ and at neutral and alkaline trending condition. Moreover, the expression of activity of extracellular carbonic anhydrase could be generally p romoted at the experimental range of concentration of 4 kinds of metal ions such as Ca2+, Mg2+, Zn2+ and Co2+, along with 8 kinds of ani ons such as SO2-_4, H_2PO-_4, NO-_3, NO-_2, Cl-,Br-, I- and HCO-_3. This research provides a cert ain theoretical basis for further study on the role of microbial CA in karst pro cesses.