纤溶酶产生菌—藤黄微球菌的筛选、鉴定及纤溶酶基因的克隆

通过血粉培养基富集、纤维蛋白培养基筛选,从自然环境中分离到一株纤溶酶产生菌,命名为ML909.利用传统细菌分类鉴定方法对其形态和生理生化特征进行了研究,发现其与藤黄微球菌的特征相符,16S rDNA序列分析的结果也表明它与藤黄微球菌的16S rDNA序列的同源性高达99%,因此该茵在系统分类学上属于微球茵属(Micrococcus Cohn)藤黄微球菌(Micrococcus luteus).通过PCR方法对其纤溶酶的编码区序列进行了克隆和序列分析,基因登录GenBank,登录号为EU232121.     

产氢红杆菌类胡萝卜素突变株的诱变和筛选

用紫外线照射和氯化锂夹层平板培养法对产氢红杆菌(Rhodobacter sp. R7)进行复合诱变, 分离获得了一株产氢效率提高的类胡萝卜素突变株R726。该突变株在表观特征、光谱学特征、色谱特征、生长和产氢性能等方面与出发菌株有明显不同, 但16S rDNA序列一致。R726菌株有 550 nm类胡萝卜素特征性吸收峰, 类胡萝卜素组成上比出发菌株少一黄色类胡萝卜素组分, 生长和产氢性能均高于出发菌株, 产氢效率比出发菌株提高了33.3%, 类胡萝卜素含量比出发株提高了53.8%。     

云南抚仙湖产类胡萝卜素酵母菌的资源调查

【目的】对分离自云南抚仙湖湖水的379株酵母菌进行产类胡萝卜素的筛选,以期获得具有开发应用价值的产类胡萝卜素酵母菌。【方法】采用酸热法提取类胡萝卜素,紫外分光光度计测定类胡萝卜素含量,SPSS软件分析产类胡萝卜素酵母的分布特征。【结果】318株酵母菌(占供试菌株的83.91%)具有产类胡萝卜素的能力,大多数菌株类胡萝卜素产量在10-300μg/g之间,最高达590.83μg/g。产类胡萝卜素酵母集中分布于红冬孢酵母属(Rhodosporidium)和红酵母属(Rhodotorula);担子菌酵母产类胡萝卜素的能力高于子囊菌酵母;筛选到9株产类胡萝卜素活性较强的菌株:双倒卵形红冬孢酵母(Rhodosporidium diobovatum)3株、沼泽生红冬孢酵母(Rhodosporidium paludigenum)2株、粘红酵母(Rhodotorula glutinis)、禾本红酵母(Rhodotorula graminis)、瑞纳锁掷孢酵母(Sporidiobolus ruineniae)及Cystofilobasidium macerans各1株。【结论】高原湖泊抚仙湖生存着大量产类胡萝卜素的酵母菌,"红色酵母"(Red yeasts)具有较强的产类胡萝卜素的能力,红冬孢酵母属(Rhodosporidium)和红酵母属(Rhodotorula)是抚仙湖产类胡萝卜素酵母菌的主要类群。     

一株微囊藻毒素降解辅助菌的分离和鉴定

以从太湖蓝藻中提取的微囊藻毒素作为微囊藻毒素降解菌的筛选物质, 通过稀释平板涂布法从腐烂的蓝藻中富集分离到一菌株, 经形态特征、生理生化特征和16S rDNA 序列分析将该菌株(GenBank 序列登录号为GQ143751)鉴定为藤黄微球菌(Micrococcus luteus); 微囊藻毒素降解实验结果表明该菌株几乎不能降解微囊藻毒素, 但可以明显促进一株微囊藻毒素降解菌微嗜酸寡养单胞菌(Stenotrophomonas acidaminiphila)对微囊藻毒素的降解能力, 将筛选菌株与微嗜酸寡养单胞菌混合培养, 混合菌对微囊藻毒素的降解能力比微嗜酸寡养单胞菌单独培养时提高66.7%。     

产氢红杆菌类胡萝卜素突变株的诱变和筛选

用紫外线照射和氯化锂夹层平板培养法对产氢红杆菌(Rhodobacter sp.R7)进行复合诱变,分离获得了一株产氢效率提高的类胡萝卜素突变株R726.该突变株在表观特征、光谱学特征、色谱特征、生长和产氢性能等方面与出发菌株有明显不同,但16S rDNA序列一致.R726菌株有550 nm类胡萝卜素特征性吸收峰,类胡萝卜素组成上比出发菌株少一黄色类胡萝卜素组分,生长和产氢性能均高于出发菌株,产氢效率比出发菌株提高了33.3%,类胡萝卜素含量比出发株提高了53.8%.     

冰冷杆菌PG-2的基因组测序及生物信息学分析

冰冷杆菌PG-2(Gelidibacter sp. PG-2)是一株能产类胡萝卜素的菌株,为深入研究其产类胡萝卜素的机制,对该菌株进行了全基因组测序。从PG-2中提取类胡萝卜素后通过LC-MS/MS进行定性分析,通过液体紫外全波长扫描计算其含量,基于全基因组测序结果对该菌株产类胡萝卜素的代谢通路进行了预测分析。结果表明,PG-2所产类胡萝卜素为玉米黄质,含量为185.81μg/g菌体干重,PG-2全基因组大小为3 850 413 bp,GC含量为37.91%,rRNA共计5个,tRNA共计37个,sRNA共计19个,在COG、GO、KEGG数据库分别注释到基因3 401、1 797、1 495个。菌株PG-2含有3个与产类胡萝卜素相关的核心基因crtI、crtZ、lcyB,并对其代谢通路进行了预测。基因组框架测序数据提交至NCBI获得GenBank登录号为JAMJTV000000000。上述结果表明,菌株PG-2具有产类胡萝卜素的能力,推测它产类胡萝卜素与基因crtI、crtZ和lcyB有关。     

藤黄微球菌V017基因组测序及对辐照的转录组响应

[背景]耐辐射微生物是一类重要的极端微生物资源,在研究其耐受机制以及环境保护等方面具有重大的意义.[目的]从基因组和转录组角度解析耐辐射藤黄微球菌(Micrococcus luteus) V017的抗性遗传背景以及对辐照的转录组响应.[方法]利用PacBio平台对菌株V017进行基因组测序,通过比较基因组分析菌株V01...     

脱氮菌株的诱变育种及其脱氮条件的优化

以一株具有脱氮功能的玫瑰色微球菌(Micrococcus roseus)为出发菌株,经紫外线(UV)、硫酸二乙酯(DES)、氯化锂(LiCl)诱变剂反复诱变处理,并通过纳氏试剂法初筛和氨氮滴定法复筛,得到一株脱氮能力较强的菌株Mc32,脱氮率比出发菌株提高了36.8 %.采用正交设计实验优化Mc32菌株的脱氮条件,优化后的菌株脱氮率达到74 %,多次传代实验表明该菌株遗传稳定性较好.     

玫瑰色微球菌的生物学特性及其培养基的优化

对本实验室分离纯化的玫瑰色微球菌（Micrococcus roseus）M1进行生物学特性研究,包括形态与培养特征的观察,细胞色素的测定,菌体对碳氮源和生长因子的利用,以及该菌株的最适生长条件。通过单因素试验,获得菌株最适生长条件为：培养温度30℃、p H7.5、振荡频率120 r/min、盐度0.5%。采用均匀设计法优化菌株M1的培养基,得到最优培养基（g.L-1）：CH3COONa 6;NH4Cl 2.4;Na HCO30.1;Mg SO40.1;维生素溶液12 m L/L;微量元素溶液1 m L/L。在最适生长条件下,接种菌株M1于最优培养基,培养72 h后,菌体和类胡萝卜素的OD值分别达到2.753和4.733,而在基础培养基上的生物量和类胡萝卜素的OD值为1.895和3.258,分别提高了45%和50%。     

一株利用内醚糖产类胡萝卜素菌株的分离及鉴定

【目的】筛选一株能高效利用内醚糖的菌株,该菌株能以内醚糖为碳源产类胡萝卜素,以实现对生物质的有效利用。【方法】以纤维素生物质热解产物内醚糖为唯一碳源,筛选得到的真菌ZS1菌株。通过rDNA ITS基因序列分析,构建进化树,并结合菌落形态特征确定菌株系统发育学地位。通过高效液相色谱分析其利用内醚糖的能力,利用分光光度法检测类胡萝卜素含量。【结果】实验表明筛选得到的真菌ZS1对内醚糖有很好的同化能力,培养4 d后内醚糖的利用率为67.0%,经ITS测序和菌落形态特征鉴定该菌为红冬孢酵母菌(CGMCC No:6365)。优化培养条件后,内醚糖的利用率在5 d内达98.7%,菌体中类胡萝卜素含量为427.1μg/g(干重)。以内醚糖为碳源得到的类胡萝卜素量为460.4μg/g(内醚糖)。【结论】筛选得到的红冬孢酵母菌Rhodosporidium Kantochvilovae,能有效地利用内醚糖并产类胡萝卜素。     

Recent progress in structural studies of carotenoids in animals and plants

About 750 naturally occurring carotenoids had been reported as of 2004. Furthermore, annually, more than 20 new structures of carotenoids are reported. Improvements of analytical instruments such as NMR, MS, HPLC, etc., have made it possible to perform the structural elucidation of very minor carotenoids in nature. Interesting new structural carotenoids can still be identified in aquatic animals and higher plants. The present paper provides a review of new structural carotenoids isolated from aquatic animals and higher plants by our group over the last five years.     

Carotenoids of Marine Sponges

The 42 identified carotenoids isolated from 36 different marine spontes may, from structural considerations, be divided into four groups; (a) native phytoplankton-type carotenoids; (b) intact carotenoids of possible zooplankton origin, 9c) intact carotenoids of probable bacterial of fungal origin; and (d) sponge metabolized carotenoids. Groups (a) and (d) are the major categories, group (d) comprises several mono- and diaryl carotenoids and some oxygenated carotenoids so far peculiar to the Demospongiae. Chemosystematic considerations suggest that highest capacity for carotenoid accumulation and transformation is to be found within the orders Poecilosclerida and Axinellida, which exhibit similar carotenoid patterns. The screening of carotenoids in 34 coloured species from the Australian RRIMP collection showed a total carotenoid content of 0.1–90 × 10^?3% of the ry wt. individual carotenoids were characterized for 16 species including 11 previously known carotenoids, two new partly characterized methoxylated carotenoids and some phenolic carotenoids.     

Lutein, zeaxanthin, and the macular pigment

The predominant carotenoids of the macular pigment are lutein, zeaxanthin, and meso-zeaxanthin. The regular distribution pattern of these carotenoids within the human macula indicates that their deposition is actively controlled in this tissue. The chemical, structural, and optical characteristics of these carotenoids are described. Evidence for the presence of minor carotenoids in the retina is cited. Studies of the dietary intake and serum levels of the xanthophylls are discussed. Increased macular carotenoid levels result from supplementation of humans with lutein and zeaxanthin. A functional role for the macular pigment in protection against light-induced retinal damage and age-related macular degeneration is discussed. Prospects for future research in the study of macular pigment require new initiatives that will probe more accurately into the localization of these carotenoids in the retina, identify possible transport proteins and mechanisms, and prove the veracity of the photoprotection hypothesis for the macular pigments.     

Chemical induction of poly-cis carotenoid biosynthesis

A new class of synthetic bioregulators is reported which cause the accumulation of poly-cis carotenoids in the flavedo of Marsh white seedless grapefruit. The compounds tested were all secondary amines: dibenzylamine, substituted dibenzylamines (4-F; 4-Cl; 4-Br; 2-, 3-and 4-Me; 4-NO₂; 4-CN; 4-Cl, 4′-Me; 4-Me, 4′-NO₂), N-benzyl phenethylamine and N-benzyl 2-naphthalenemethylamine. The most effective, 4-chlorodibenzylamine, caused the accumulation of 74μgg/g dry wt of poly-cis carotenoids. Prolycopene was the predominant pigment but substantial amounts of proneurosporene, poly-cis-γ-carotenes and other cis carotenes were also present. The mode of action of these new bioregulators is probably gene derepression, the same as that of the lycopene inducers. However, the secondary amines probably derepress a recessive gene governing the biosynthesis of poly-cis carotenoids; whereas, the lycopene inducers derepress the dominant gene that gives rise to the normal all-trans carotenoids. The new compounds did not seem to inhibit the cyclase(s), as the lycopene inducers do.     

The crop milk: a potential new route for carotenoid-mediated parental effects

Allocation of carotenoid pigments, either through nutritional provisioning or from endogenous reserves, makes up a form of non-genetic parental investment to progeny that may contribute to fitness. To date, carotenoids derived from endogenous reserves have been acknowledged as important vectors in translating only avian female phenotype and environmental conditions experienced prior to laying. Here, we show that in columbidae, crop milk delivered by both parents may provide chicks with a large amount of endogenous carotenoids at the postzygotic stage. Major carotenoids were xanthophylls and beta-carotene, but their concentrations showed large variation among individuals. Interestingly, a large amount of this variation was explained by brood identity, suggesting either environmental influences and/or phenotypic influences on a parent's ability to transfer these biomolecules. Our study therefore illuminates a potential new route for endogenous carotenoid-mediated parental effects.     

Mechanistic understanding of β-cryptoxanthin and lycopene in cancer prevention in animal models

To better understand the potential function of carotenoids in the chemoprevention of cancers, mechanistic understanding of carotenoid action on genetic and epigenetic signaling pathways is critically needed for human studies. The use of appropriate animal models is the most justifiable approach to resolve mechanistic issues regarding protective effects of carotenoids at specific organs and tissue sites. While the initial impetus for studying the benefits of carotenoids in cancer prevention was their antioxidant capacity and pro-vitamin A activity, significant advances have been made in the understanding of the action of carotenoids with regards to other mechanisms. This review will focus on two common carotenoids, provitamin A carotenoid β-cryptoxanthin and non-provitamin A carotenoid lycopene, as promising chemopreventive agents or chemotherapeutic compounds against cancer development and progression. We reviewed animal studies demonstrating that β-cryptoxanthin and lycopene effectively prevent the development or progression of various cancers and the potential mechanisms involved. We highlight recent research that the biological functions of β-cryptoxanthin and lycopene are mediated, partially via their oxidative metabolites, through their effects on key molecular targeting events, such as NF-κB signaling pathway, RAR/PPARs signaling, SIRT1 signaling pathway, and p53 tumor suppressor pathways. The molecular targets by β-cryptoxanthin and lycopene, offer new opportunities to further our understanding of common and distinct mechanisms that involve carotenoids in cancer prevention.This article is part of a Special Issue entitled Carotenoids recent advances in cell and molecular biology edited by Johannes von Lintig and Loredana Quadro.     

宁夏枸杞‘中科绿川1号’果实和叶片的主要成分分析

以国家林业局审定的宁夏枸杞新品种‘中科绿川1号’为实验材料,研究不同月份采集的枸杞叶片芦丁含量,以及果实总黄酮、总多糖、总类胡萝卜素、玉米黄素双棕榈酸酯的含量变化。结果显示,叶片芦丁含量在枸杞盛果期较低,抽条期较高;果实总黄酮、总类胡萝卜素、玉米黄素双棕榈酸酯的含量在头茬果中含量较高,盛果期果实含量较低;果实总多糖可能与果实量呈负相关;褐化果(俗称"油果")总黄酮含量与正常果差异不大,可用作提取枸杞黄酮类物质的原材料。研究结果可为枸杞果实分级、成分提取提供新思路。     

Carotenoid limitation of sexual coloration along an environmental gradient in guppies

Carotenoids produce most of the brilliant orange and yellow colours seen in animals, but animals cannot synthesize these pigments and must rely on dietary sources. The idea that carotenoids make good signals because they are a scarce limiting resource was proposed two decades ago and has become the leading hypothesis for the role of carotenoids in animal communication. To our knowledge, until now, however, there has been no direct evidence that carotenoids are a limiting resource in nature. We showed that carotenoid availability in the wild limits the expression of sexual coloration in guppies (Poecilia reticulata), a species in which females prefer males with brighter orange carotenoid-containing spots. Further, the degree of carotenoid limitation varies geographically along a replicated environmental gradient (rainforest canopy cover), which opens new avenues for testing signal evolution theory.     

Cancer prevention by carotenoids

Various natural carotenoids seem to be valuable for cancer prevention, and these carotenoids may be more suitable in combinational use, rather than in single use. In fact, we have proven that combinational use of natural carotenoids resulted in significant suppression of liver cancer. Patients of viral hepatitis with cirrhosis were administered with β-cryptoxanthin-enriched Mandarin orange juice, in addition to capsules of carotenoids mixture. Cumulative incidence of hepatocellular carcinoma development was compared with that in the group treated with carotenoids mixture capsules alone, or in the group without treatment (control group). In the data analysis at year 2.5, cumulative incidence of liver cancer in β-cryptoxanthin-enriched orange juice with carotenoids mixture capsules-treated group was lower than that in the control group (p = 0.05). Cumulative incidence of liver cancer in the group treated with carotenoids mixture capsules alone was also lower than that in the control group, but not statistically significant.     

Comparative study of the endemic freshwater fauna of Lake Baikal-VII. Carotenoid composition of the deep-water amphipod crustaceanAcanthogammarus (Brachyuropus)grewingkii

The carotenoid composition of the deep-water gammaride is reported. Astaxanthin and their derivatives were determined to be major components of the carotenoids (58.4%). Astaxanthin-glycoside-esters comprised 21.6% of total carotenoids. A new carotenoid glycoside ester (CGE) was isolated from the deep-water gammarideAcanthogammarus (Brachyuropus)grewingkii and its structure was elucidated. The structures were determined from spectra (¹H-NMR,¹³C-NMR, MS, IR) after their isolation and quantification by means of semipreparative RP-HPLC and capillary GC-MS.