Bioinformatics Analysis of QoD1PO Gene of Mangrove Endophytic Fungus Aspergillus terreus

[Objectives]To analyze the gene structure of the protein that predicts 6-hydroxymellein synthase of Aspergillus terreus and predict the characteristics and functions of the protein structure encoded by the gene.[Methods]Various information analysis tools in NCBI,CBS and ExPASy websites were adopted.[Results]The QODIPO gene had a full length of 2954 bp,with 952 amino acids in the coding area,and QODIPO had the highest homology with the hypothetical protein ATETN484_0003008800.The molecular weight of QOD1PO protein was 105040.56,the theoretical isoelectric point(pl)was 5.69 and the grand average of hydropathieity was-0.242.It was speculated that QODIPO was an unstable and non-secretory hydrophilic protein located in cytoplasm without transmembrane domain or signal peptide.It could be predicted that the secondary structure of QODIPO encoding protein consisted mainly of random coil,α-helix and a PKS-DH anhydrase domain.[Conclusions]The results will lay a theoretical foundation for cloning and expression of 6-hydroxymellein synthase and further understanding of its activity and function.

内生菌Aspergillus terreus PC-038次生代谢产物中抗菌化学成分研究

研究内生菌Aspergillus terreus PC-038次生代谢物中抗菌活性成分。采用现代分离技术对A.terreus次生代谢物中活性组分进行分离纯化,利用现代质谱和核磁等波谱技术鉴定其结构,采用96孔板二倍稀释法测试单体化合物的抗菌作用。从A.terreus代谢物的活性组分中分离得到17个化合物。化合物3~7和10~14均为从内生菌A.terreus代谢物中首次分离,其中烟曲霉酸为主要成分。抗菌结果显示1,2-二氢烟曲酶酸和烟曲霉酸对Staphylococcus aureus ATCC25923有显著的抑制作用,MIC分别为8μg/mL和4μg/mL。研究丰富了A.terreus次生代谢物的化合物库,明确了1,2-二氢烟曲酶酸和烟曲霉酸为A.terreus PC-038的抗菌主要活性成分,为新型抗生素的研发奠定了基础。

一株太子参内生真菌Aspergillus terreus TZS-201607中抗肿瘤活性代谢产物研究

为研究太子参内生真菌Aspergillus terreus TZS-201607所产的次级代谢产物,利用硅胶柱层析、Sephadex LH-20凝胶柱层析、反相柱层析及半制备高效液相色谱等技术,从其PDB培养基发酵产物的乙酸乙酯萃取物中分离纯化得到16个单体化合物。利用波谱学方法结合文献数据分析分别鉴定为柄曲霉素(1)、5-甲氧基柄曲霉素(2)、variecoxanthone A(3)、chryxanthone A(4)、6,8-di-O-methylaverufin(5)、6,8-di-O-methylnidurufin(6)、6,8,1′-tri-O-methyl averantin(7)、(22E,24R)-ergosta-7,9(11),22-trien-3β-ol(8)、(22E,24R)-ergosta-4,6,8(14),22-trtraen-3-one(9)、(22E,24R)-3β,5α-dihydroxy-ergosta-7,22-dien-6-one(10)、(22E,24R)-3β,5α,9α-trihydroxy-ergosta-7,22-diene-6-one(11)、(22E,24R)-3α-ureido-ergosta-4,6,8(14),22-tetraene(12)、(22E,24R)-ergosta-7,22-dien-3β,5α,6β-triol(13)、(22E,24R)-5α,8α-epidioxyergosta-6,22-dien-3β-ol(14)、demethylincisterol A3(15)和(17R)-17-methylincisterol(16)。化合物1~7、12、14~16为首次从A.terreus中分离得到。体外抗肿瘤活性测试显示,化合物6、7和14对人肿瘤细胞株A549、BT-549、HeLa和THP-1表现出较强的细胞毒活性(IC50<10μM)。

Lovastatin production by Aspergillus terreus in solid-state fermentation

Lovastatin production by Aspergillus terreus ATCC 20542 in solid-state fermentation （SSF） was studied. Various substrates were used to evaluate the ability ofA. terreus to produce lovastatin. The results showed that either rice or wheat bran was suitable substrate for lovastatin production in SSF. The maximum yield of lovastatin （2.9 mg/g dry substrate） using rice as substrate was achieved after incubating for 11 d at the following optimized process parameters： 50%-60% initial moisture content, pH 5.5, incubation temperature 28 ℃.

Production of Cellulase and Xylanase by Aspergillus terreus KJ829487 Using Cassava Peels as Subtrates

Cassava (Manihot esculenta, Crantz) is one of the most important food plants in West Africa. Its peels are made up of cellulose, hemicellulose and lignin. This lignocellulolytic biomass can be converted using microbial enzymes to fermentable sugars which have wide range of biotechnological relevance in many fermentation processes. The aim of this study is to screen filamentous fungi from decaying cassava peels that are good producers of xylanases and cellulases. Decaying parts of cassava peels were obtained and brought to the laboratory for further work. Fungi were isolated, identified and screened for cellulase and xylanase production. Isolate with highest frequency of occurrence and enzyme production was identified using phenotypic and molecular method. Optimisation of growth conditions for enzymes production was monitored using the DNSA method, also saccharification of cassava peel were carried out using the enzymes obtained from the isolate. Aspergillus terreus KJ829487 was the predominant fungus. It produces cellulases and xylanases optimally at 40°C, pH 6 and 8, utilising carboxymethylcellulose (CMC) or xylose and yeast extracts as its carbon and nitrogen sources respectively. Saccharification of the peels yielded 584 mg/L glucose, 78 mg/L xylose and 66 mg/L rhamnose. Aspergillus terreus KJ829487 obtained from cassava peels have the ability to produce high concentration cellulases and xylanases which effectively hydrolysed the lignocelluloses’ biomass to fermentable sugars.

Purification and Biochemical Characterization of Native and Pegylated Form of L-Asparaginase from Aspergillus terreus and Evaluation of Its Antiproliferative Activity

L-asparaginase is a chemotherapeutic drug used in the treatment of lymphoblastic leukemia. In the present study, the extracellular L-asparaginase produced by strain (PC-1.7A) of Aspergillus terreus was purified, characterized, and modified with polyethylene glycol. Moreover, its antiproliferative activity was evaluated. The apparent molecular weight of the enzyme was found to be 136 kDa. The optimal pH and temperature for the enzyme were 9.0℃ and 40℃, respectively. The enzyme retained 100% of the activity at 40℃ for 120 min. Pegylated L-asparaginase was more thermostable and more resistant to trypsin than native enzyme. Native L-asparaginase against human normal cells did not show cytotoxicity. However, in the leukemia cell lines RS4;11 and HL60 the antiproliferative effects of native L-asparaginase were observed after 96 and 72 h of incubation, respectively. For the first time, an L-asparaginase from fungus was evaluated as an antitumor agent in human cells lines and further investigations should be conducted to improve the knowledge about this enzyme.

Prolonged Production of L-DOPA Using Immobilized Aspergillus Terreus

The objective of this study is to improve the production of L-DOPA from fungal source like Aspergillus terreus that can be further used to large-scale commercial production of this important drug from microbial sources. L-DOPA, a dopamine precursor that can pass the blood-brain barrier, is presently the drug of choice for Parkinson＇s disease. Microbial production and isolation of L-DOPA from natural sources is yet to be achieved an economical process. In this study, the mycelial pellets ofAspergillus terreus 104 were entrapped in 2% calcium alginate and were studied for their capacity for L-3, 4-dihydroxyphenylalanine production. Results showed that the immobilized pellets produced L-DOPA to the extent of 0.74 mg·G^-1 biomass while the free pellets produced 0.8 mg·G^-1 biomass. Further, storage of immobilized pellets for 96 h at 4 ℃ resulted in the reduction of the original L-DOPA producing activity of the gel beads only 40% and that of free pellets lost completely. In order to improve the production yield, further experiments were designed. It was found that L-DOPA production could be prolonged with repeated batch wise use of immobilized mycelial pellets in calcium alginate retaining 80% of their L-DOPA producing capacity for a period of 72 h while free pellets lost completely within 24 h. Results of this kind therefore is interesting and promising for commercial scale production of L-DOPA from microbial sources.

蓝花黄芩内生真菌Aspergillus terreus HQ100X-1次级代谢产物研究

从蓝花黄芩内生真菌土曲霉(Aspergillusterreus)HQ100X-1发酵产物中分离得到2个新化合物[terrustone(1)和asperteretone G (2)], 10个已知化合物(3~12), terrustone (1)为具有4个连续手性中心的三羟基环戊酮类化合物,它们的结构以及绝对构型是通过1D/2D NMR结合电子圆二色谱(ECD)计算来确定.抗菌实验表明,化合物rbrolide R (4)对金黄色葡萄球菌有一定的抑菌活性,其最低抑菌浓度(MIC)值为2.5μg/mL.

Characterization of β-glucosidase from Aspergillus terreus and its application in the hydrolysis of soybean isoflavones

An extracellular β-glucosidase produced by Aspergillus terreus was identified, purified, characterized and was tested for the hydrolysis of soybean isofiavone. Matrix-assisted laser desorption/ionization with tandem time-of- flight/time-of-flight mass spectrometry （MALDI-TOF/TOF MS） revealed the protein to be a member of the glycosyl hydrolase family 3 with an apparent molecular mass of about 120 kDa. The purified 13-glucosidase showed optimal activity at pH 5.0 and 65℃ and was very stable at 50℃. Moreover, the enzyme exhibited good stability over pH 3.0-8.0 and possessed high tolerance towards pepsin and trypsin. The kinetic parameters Km （apparent Michaelis- Menten constant） and Vmax （maximal reaction velocity） for p-nitrephenyl-β-D-cjlucopyranoside （pNPG） were 1.73 mmol/L and 42.37 U/mg, respectively. The Krn and Vmax for cellobiose were 4.11 mmol/L and 5.7 U/mg, respectively. The enzyme efficiently converted isoflavone glycosides to aglycones, with a hydrolysis rate of 95.8% for daidzin, 86.7% for genistin, and 72.1% for glycitin. Meanwhile, the productivities were 1.14 mmol/（L.h） for daidzein, 0.72 mmol/（L.h） for genistein, and 0.19 mmol/（L.h） for glycitein. This is the first report on the application of A. terreus β-glucosidase for converting isoflavone glycosides to their aglycones in soybean products.

Asperterzine,a symmetric aromatized derivative of epipolythiodioxopiperazine,from the endophytic fungus Aspergillus terreus PR-P-2

A new epipolythiodioxopiperazine （ETP）, asperterzine （1）, along with two known analogs, bisdethiobis （methylthio）-acetylaranotin （2） and bisdethiobis（methylthio）-acetylapoaranotin （3）, was isolated from the plant endophytic fungus Aspergillus terreus PR-P-2. The structure elucidation of 1 was accomplished by a combination of spectral methods and electronic circular dichroism （ECD） spectrum. Asperterzine （1） was a symmetric aromatized ETP found as a natural product for the first time. Compounds 2 and 3 showed strong cytotoxicity against HL-60 cell line. The putative biosynthetic pathway of 1 was also detailed in the text.

Effect of combination of ultraviolet radiation and biocide on fungal-induced corrosion of high-strength 7075 aluminum alloy

The effect of ultraviolet(UV)radiation and biocide benzalkonium chloride(BKC)on fungal-induced corrosion of AA7075 induced by Aspergillus terreus(A.terreus)was deeply studied using analysis of biological activity,surface analysis,and electrochemical measurements.Results demonstrated that the planktonic and sessile spore concentrations decline by more than two orders of magnitude when UV radiation and BKC are combinedly used compared with the control.UV radiation can inhibit the biological activity of A.terreus and influence the stability of passive film of AA7075.Except for direct disinfection,the physical adsorption of BKC on the specimen can effectively inhibit the attachment of A.terreus.The combination of UV radiation and BKC can much more effectively inhibit the corrosion of AA,especially pitting corrosion,due to their synergistic effect.The combined application of UV radiation and BKC can be a good method to effectively inhibit fungal-induced corrosion.

A Morphologically Structured Model for Mycelial Growth and Secondary Metabolite Formation

A morphologically structured model is proposed to describe the batch fermentation of lovastatin according to the growth kinetics of filamentous microorganisms. Three kinds of hyphae are considered in the model: actively growing hyphae, non-growing hyphae and deactivated hyphae. Furthermore, actively growing hyphae consist of three morphological compartments: apical compartment which gives rise to hyphal tip extension; subapical compartment which is related to hyphal branching; and hyphal compartment which is only responsible for secondary metabolite formation. The kinetics of mycelial growth mechanism is summarized and applied in modeling lovastatin fermentation. A Michaelis-Menten kinetic model with substrate inhibition is proposed for product formation. As expected, the model simulations fit well with experimental data obtained either from a laboratory scale 10L fer-menter or from a pilot-plant scale fermenter.

烟草内生真菌土曲霉中一个新的苯乙酸类化合物

目的研究分离自烟草中内生真菌土曲霉(Aspergillus terreus)的次生代谢产物。方法运用硅胶柱色谱、C18反相硅胶柱色谱、Sephadex LH-20凝胶柱色谱和薄层制备等色谱技术对菌株A.terreus的发酵液粗提物进行分离纯化,采用波谱方法对化合物进行结构鉴定。结果从烟草内生真菌A.terreus的发酵粗提物中分离得到10个化合物,分别鉴定为(2′R)-westerdijkin B(1)、(2′R)-westerdijkin A(2)、4-羟基苯乙酸甲酯(3)、ampelopyrone(4)、sporogen-AO 1(5)、(S)-(+)-11-dehydrosydonic acid(6)、sydowic acid(7)、asperdemin(8)、asperversin E(9)和asperversin G(10)。其中,化合物1为新化合物,化合物2~5为首次从菌株A.terreus中分离获得。结论在抑菌活性测试中,化合物1对大肠杆菌具有明显的抑制活性,其MIC值为4 mg·L^(-1)。化合物5具有显著的抗植物病原真菌活性,对苹果黑腐皮壳菌的MIC为4 mg·L^(-1)。

Production of Itaconic Acid Through Microbiological Fermentation of Inexpensive Materials

Itaconic acid(IA)is a precursor of various chemicals,which has been on the US Department of Energy’s list of the top 12 platform chemicals that can potentially be produced from biomass.The IA is mainly produced through a bio-fermentation method with sugar as raw material.However,the high cost and low yield restrict the industrial application of the IA.This review summarized research advances in the IA production from alternative substrates.In particular,the types of substrates as well as existing problems in the IA fermentation,strain breeding,and process regulation were discussed.And it is pointed that decreasing the price of the IA through use of alternative substrates and increasing the titer of the IA through genetic engineering should be further focused on to support the industrialization of the IA.