一株蓝麻黄拮抗内生真菌的分离鉴定及代谢物的初步分析

[目的]分离获得对农作物致病菌有高效拮抗作用的植物内生菌,并对其进行系统鉴定和代谢成分分析.[方法]用研磨法从蓝麻黄中分离内生真菌,并用琼脂扩散法筛选具有抗农作物致病菌活性的内生真菌;利用菌株形态特征和ITS-5.8S rDNA序列分析进行拮抗菌鉴定,经酚硫酸法测定多糖含量.[结果]从蓝麻黄中分离得到5株内生真菌,其中XJEG-GF-79对葡萄白腐病菌的抑菌圈直径为23 mm.经形态学观察和分子分类学分析鉴定,内生拮抗真菌XJEG-GF-79与Pleosporaceae sp. SN-2008同源性达到100;,该菌株代谢产物中含有生物碱和多糖,其经测定,发酵液中多糖含量为1.914 mg/mL.[结论]蓝麻黄内生真菌XJEG-GF-79对葡萄白腐病菌有明显的拮抗作用,最终鉴定为链格孢霉 Pleosporaceae sp..     

青钱柳次生代谢产物及其生理功能

综述了在青钱柳中提取、分离并鉴定的近50种具生物活性的次生代谢产物。其中黄酮类11种、酚酸类7种、甾醇类3种、三萜类达12种之多。除了功能已知、在其他植物中发现的代谢产物外,还有5种青钱柳所特有的三萜皂甙,即青钱柳酸A、青钱柳酸B、青钱柳甙Ⅰ、青钱柳甙Ⅱ、青钱柳甙Ⅲ,并论述青钱柳提取物的生理功能。     

芽胞杆菌中的喷他霉素检测与分析

采用高效液相四级杆飞行时间质谱分析巴达维亚芽胞杆菌Bacillus bataviensis FJAT-10043发酵液中胞外代谢物的成分。运用安捷伦公司的MassHunter软件,对数据进行分子特征提取,并通过Metlin代谢物质谱数据库检索,获得总体代谢物的信息。在巴达维亚芽胞杆菌Bacillus bataviensis FJAT-10043发酵液中,用液相质谱检测到656种代谢物,通过Metlin谱库搜索得到初步鉴定结果的有121种。其中,喷他霉素是相对含量最高的成分。喷他霉素占该菌发酵液总代谢物相对含量的4.22%,匹配得分达到96.39,保留时间为2.7339 min。喷他霉素发现为巴达维亚芽胞杆菌来源的抗真菌抗生素的开发与利用提供理论依据。     

马蓝次生代谢产物研究进展

马蓝是一种常用的道地药材,地下根茎与根常作为生产板蓝根及制剂的原料,具有多种药效功能。药用植物中有效成分大多数为植物次生代谢产物,但当前就马蓝次生代谢方面的研究却鲜有报道。本研究以植物的次生代谢为出发点,结合马蓝目前已经报道的药效成分研究现状,着重从酚类、萜类、含氮化合物3种次生代谢产物对马蓝次生代谢产物研究概况进行阐述,旨在为马蓝药效成分形成的分子机制研究提供理论基础,为进一步开展马蓝种质创新工作奠定基础。     

Antifungal activity toPhytophthora infestans of sesquiterpenoids from infected potato tubers

Summary The sesquiterpenes 2-(1',2'-dihydroxy-1'-methylethyl)-6,10-dimethyl-spiro-[4,5]dec-6-en-8-on (1) and its 2'-O-β-d-glucopyranoside (2) were isolated from the stress zones of potato tubers infected withPhoma foveata andFusarium spp., and rishitin and solavetivone from tuber slices inoculated withErwinia carotovora. The influence of these compounds, and of the naturally occurring plant sesquiterpenoids abscisic acid, cedrol and farnesol, on the mycelial growth ofPhytophthora infestans were tested on agar plates using a defined medium. All sesquiterpenoids suppressed the growth of the pathogen, except for1 and its glucoside2 which induced a slight, however significant, growth stimulation. Compounds1 and2 could not be isolated fromE. carotovora orP. infestans-inoculated tuber tissue.     

Subsequent bone and metabolic responses of broilers to high-non-phytate phosphorus diets in the starter period

1. An experiment was performed to elucidate the subsequent effects of high-non-phytate phosphorus (NPP) diets on growth performance, blood metabolites, bone characteristics and P retention of broilers fed on low-NPP grower diets. The 42-d study was designed as a 2 × 2 × 2 + 1 factorial, which included two starter NPP concentrations (4.5 and 5.5 g/kg; d 0–21), two grower NPP concentrations (1.5 and 2.3 g/kg; d 22–42), with or without phytase (1000 FTU/kg), with a reference diet containing an adequate NPP concentration over the course of the trial.

2. In the starter period, growth performance and P retention were not affected by experimental diets. The high-NPP diet increased plasma P concentration, increased tibia ash and tibia P contents and decreased plasma alkaline phosphatase (ALP) activity at d 21.

3. No significant interaction was observed between NPP concentrations in the starter and grower periods and phytase. The main effect data indicated that the increase in NPP concentration in the starter diets had no effects on growth performance in the grower period and overall. The high-NPP diet in the early stage of growth reduced plasma P concentration, plasma ALP activity and tibia ash content at d 42. The main effect data also showed that exogenous phytase increased body weight gain in the grower period and overall.

4. It can be concluded that feeding increased NPP diets have no effects on growth performance in the starter period. This feeding strategy results in negative effects on plasma P concentration and bone ash content at d 42. Also, exogenous phytase is effective in improving growth performance, bone characteristics and apparent P retention of growing broilers fed diets that are inadequate in phosphorus.     

不同肥力土壤中分解几丁质微生物代谢产物对玉米的促生效果研究

从吉林省不同玉米栽培区土壤中以胶状几丁质为碳源分离筛选分解几丁质微生物,最终筛选出功能菌株并命名为CC-1,采用16 Sr RNA序列扩增法鉴定为芽孢杆菌Bacillus sp,通过SDS-PAGE分析法进一步确定该菌株的几丁质酶生产能力和几丁质酶的蛋白分子量为30 k Da。通过盆栽试验进行微生物肥料对不同肥力中的玉米促生效果的研究,结果表明,以CC-1菌株生产的微生物肥料效果受土壤的基础肥力状况影响较大,土壤的肥力状况与微生物的增产效应成反比,相对贫瘠的土壤对微生物处理的响应较为敏感,对玉米的生物学性状及产量表现出了一定的促进作用,增产达到了13.08%。     

LC-MS-Based Metabolomics Study of Marine Bacterial Secondary Metabolite and Antibiotic Production in Salinispora arenicola

An LC-MS-based metabolomics approach was used to characterise the variation in secondary metabolite production due to changes in the salt content of the growth media as well as across different growth periods (incubation times). We used metabolomics as a tool to investigate the production of rifamycins (antibiotics) and other secondary metabolites in the obligate marine actinobacterial species Salinispora arenicola, isolated from Great Barrier Reef (GBR) sponges, at two defined salt concentrations and over three different incubation periods. The results indicated that a 14 day incubation period is optimal for the maximum production of rifamycin B, whereas rifamycin S and W achieve their maximum concentration at 29 days. A “chemical profile” link between the days of incubation and the salt concentration of the growth medium was shown to exist and reliably represents a critical point for selection of growth medium and harvest time.     

Alkaloids with Cardiovascular Effects from the Marine-Derived Fungus Penicillium expansum Y32

Three new alkaloids (1, 4 and 8), together with nine known analogues (2, 3, 5–7, and 9–12), were isolated from the marine-derived fungus Penicillium expansum Y32. Their structures including the absolute configurations were elucidated by spectroscopic and Mosher’s and Marfey’s methods, along with quantum electronic circular dichroism (ECD) calculations. Each of the compounds was evaluated for cardiovascular effects in a live zebrafish model. All of the compounds showed a significant mitigative effect on bradycardia caused by astemizole (ASM) in the heart rate experiments. Compounds 4–6 and 8–12 exhibited potent vasculogenetic activity in vasculogenesis experiments. This is the first study to report that these types of compounds show cardiovascular effects in zebrafish. The results suggest that these compounds could be promising candidates for cardiovascular disease lead compounds.     

Effect of relative humidity at either acute or chronic moderate temperature on growth performance and droppings' corticosterone metabolites of broilers

The present study aimed to investigate the effect of relative humidity(RH) at either acute or chronic moderate ambient temperature(Ta) on growth performance and droppings' corticosterone metabolites of broilers.Two experiments were conducted: effect of RH(35,60 or 85%) on average daily feed intake(ADFI) and droppings' corticosterone metabolites at acute(1 d: 20–26 or 31–20°C,26 or 31°C for 6 h d–1 at 10:00–16:00) moderate Ta(experiment 1) and effect of RH(35,60 or 85%) on growth performance and droppings' corticosterone metabolites at chronic(step-wisely increasing temperature by 3°C every 3 d from 20 to 32°C within 15 d: 20–23–26–29–32°C) moderate Ta(experiment 2).Droppings were collected at the 2,4,6,8,and 22 h after Ta-RH controlled in experiment 1 and at the 2,4,6,and 22 h after Ta controlled to 32°C in experiment 2.The results showed that: 1) In experiment 1,85% RH increased(P0.05) the droppings' corticosterone metabolites at the 2,6,8,and 22 h and 35% RH increased(P0.05) it at the 2 and 22 h compared to the 60% RH.Moreover,85% RH further increased(P0.05) it compared to the 35% RH,however,no difference(P0.05) was found in ADFI among the three RH groups at acute moderate 26°C; 35 and 85% RH increased(P0.05) droppings' corticosterone metabolites at the 2,6,8 and 22 h and decreased(P0.05) ADFI compared to the 60% RH,moreover,85% RH further increased(P0.05) droppings' corticosterone metabolites and further decreased(P0.05) ADFI compared to the 35% RH at acute moderate 31°C; and the average of droppings' corticosterone metabolites in the whole period had a negative correlation(P0.02) with the ADFI.2) In experiment 2,85% RH increased(P0.01) droppings' corticosterone metabolites only at the 2 h and decreased(P0.02) ADFI and average daily gain(ADG) compared to the 60% RH,no difference(P0.05) in droppings' corticosterone metabolites was found between the 35 and 60% RH,however,35% RH decreased(P0.01) ADG compared to the 60% RH,and the average of droppings' corticosterone metabolites in the whole period also had a negative correlation(P0.02) with ADFI and ADG.In conclusion,droppings' corticosterone metabolites could be used as a RH stress index and low and high RH,especially high RH,reduced growth performance possibly through inducing RH stress at moderate temperature.