Genome Sequence of a Nicotine-Degrading Strain of Arthrobacter

We announce a 4.63-Mb genome assembly of an isolated bacterium that is the first sequenced nicotine-degrading Arthrobacter strain. Nicotine catabolism genes of the nicotine-degrading plasmid pAO1 were predicted, but plasmid function genes were not found. These results will help to better illustrate the molecular mechanism of nicotine degradation by Arthrobacter.     

全球微生态药物研发现状及发展趋势 *

微生态药物在许多复杂性和慢性疾病中显示出极大的潜力,逐渐成为国际制药行业的新趋势。基于科睿唯安旗下的Cortellis数据库,采用定量分析和专家智慧相结合的方法,从总体研发现状、主要国家/地区、主要适应症、重点企业研发管线、重点在研药物、商业化交易多个维度展现全球微生态药物的研发和商业化全景。分析结果显示:全球共有142个在研微生态药物,其中49个药物处于临床阶段。美国在微生态药物研发和商业化方面遥遥领先,其数量占在研药物总量的70%。在研药物的适应症主要集中于炎症性肠病、艰难梭菌感染、溃疡性结肠炎等肠道感染性疾病。4D pharma公司的在研药物数量最多,微生态药物重点研发企业均建立起核心技术平台。处于临床3期的微生态药物共有7个,全球微生态药物商业化交易共有303起,最大的交易金额是27.8亿美元。未来,微生态药物有望在更难被人类征服的肿瘤和神经系统疾病方面取得突破性进展。     

上海农作物种质资源数据库的设计和构建

随着农作物种质资源数量的不断增加,种质资源交流的日益频繁以及种质资源利用的逐步深入,农作物种质资源数据库的建设对农作物的应用研究和基础性研究至关重要。上海市农业生物基因中心借助于本中心保存的近21万份种质资源的信息,开发了一套上海农作物种质资源数据库,本文主要阐述了该数据库设计和构建的目的、原则和数据库的架构、运行环境以及主要功能模块。上海农作物种质资源数据库采用了B/S结构,平台系统利用多层逻辑架构实现了对农作物种质资源数据信息的收集、存储、查询、统计分析等功能。外部用户通过浏览器即可访问平台系统,浏览查询种质资源信息。内部管理员可使用平台的受限功能,需要认证成功后才可使用后台管理功能,实现对整个平台数据的管理。注册用户还可通过基因资源数据库提交引种申请,管理员结合管理信息系统实现对外供种全流程的网络化,借此可提高工作效率,增加工作流程的透明度。     

灵芝线粒体及其对菌丝生长、主要活性成分影响的分析

线粒体是为细胞提供能量（ATP）的细胞器,携带着自己的DNA——mtDNA,已有多种灵芝属菌株的线粒体基因组相继报道,但对于种内的线粒体基因组的分析较少,对核相同、线粒体不同的菌株间差异的研究也鲜有报道。本研究对两株灵芝线粒体基因组进行组装注释,根据差异片段构建分子标记进行种间分类。结果显示：两株灵芝线粒体基因组大小分别为49 233bp、61 563bp的闭环结构,含有15个常见蛋白编码基因,rRNA大小亚基基因及26个携带氨基酸的tRNA基因,其差异区段主要为内含子序列、大亚基及基因间区。根据cob、cox2基因序列能够进行灵芝种间区分,用于灵芝种间鉴定。本研究还根据灵芝119、灵芝无孢的单核菌株构建同核异质体（TY-119、TY-W）,分析线粒体对菌落形态、菌丝生长速度及多糖、三萜成分的影响,结果显示：同核异质体TY-W与TY-119菌落形态上有一定差异,同核异质体TY-W菌丝生长速度为4.77mm/d,是TY-119菌丝生长速度4.50mm/d的1.06倍,同核异质体TY-119菌丝、子实体阶段多糖含量分别为4.45mg/g、12.14mg/g是TY-W菌丝体多糖含量（3.23mg/g）的1.38倍、子实体多糖含量（10.24mg/g）的1.19倍;同核异质体TY-W菌丝、子实体阶段的三萜含量分别为6.82mg/g、11.45mg/g是同核异质体TY-119菌丝体三萜含量（9.26mg/g）的0.74倍,子实体三萜含量（9.10mg/g）的1.26倍。利用高效液相色谱分析同核异质体中灵芝酸含量显示同核异质体TY-W灵芝酸A、灵芝酸E、灵芝酸F含量分别为3.77μg/mL、14.29μg/mL、12.91μg/mL;是TY-119灵芝酸A含量（2.59μg/mL）的1.46倍、灵芝酸E含量（13.65μg/mL）的1.17倍、灵芝酸F含量（12.72μg/mL）的1.06倍。对同核异质体菌丝、子实体阶段多糖、三萜合成通路关键基因（pgm、ugp、gls、hmgs、hmgr、mvd、fps、sqs）表达量进行检测,显示两菌株间多数基因具有显著性差异。结果表明线粒体的不同会影响灵芝菌落形态、菌丝生长速度及多糖、三萜的含量,有助于我们进一步研究线粒体基因组。     

奶油栓孔菌子实体多糖的理化性质、抗氧化活性与保肝作用

本研究旨在探讨奶油栓孔菌子实体多糖（TLFPS）的化学性质和酒精性肝损伤的保护作用。首先用水提醇沉法提取得到多糖,通过化学组成分析、紫外吸收光谱法、傅里叶红外光谱法和刚果红染色法对多糖结构进行初步表征,以DPPH、ABTS、超氧阴离子自由基的清除能力和铁离子还原能力为指标评价了多糖体外抗氧化能力,在小鼠急性肝损伤之前连续灌喂多糖8d,比较各组小鼠血清和肝的相关生化指标以及组织病理切片来确定多糖对酒精性肝损伤小鼠的保护作用。结果显示：多糖具有β-吡喃糖环结构,含有较高含量的糖醛酸和硫酸根基团,空间构型不具备三股螺旋结构。在体外抗氧化活性方面,多糖对DPPH、ABTS和超氧阴离子自由基均有良好的清除活性,铁离子还原能力也呈良好的剂量依赖性。在小鼠保肝实验中,与模型组相比,多糖能够显著延长小鼠的醉酒时间和缩短醒酒时间,降低了酒精性肝损伤小鼠的肝指数,并且显著降低血清中谷丙转氨酶（alanine aminotransferase,ALT）、谷草转氨酶（aspartate aminotransferase,AST）、甘油三酯（triglyceride,TG）、总胆固醇（total cholesterol,TC）和肝脏中丙二醛（malondialdehyde,MDA）的含量,同时明显提高了肝脏中超氧化物歧化酶（superoxide dismutase,SOD）和过氧化氢酶（catalase,CAT）的活性。结果证实奶油栓孔菌子实体多糖具有良好的抗氧化能力,可以减轻由酒精引起的急性肝细胞损伤,而且对机体的毒害作用很小。肝组织病理切片也进一步证实了奶油栓孔菌多糖的保肝活性。研究结果不仅丰富了奶油栓孔菌的药用价值,而且对多糖在功能食品领域的应用提供了药效基础。     

Cryptochrome‐mediated hypocotyl phototropism was regulated antagonistically by gibberellic acid and sucrose in Arabidopsis

Both phototropins(phot1 and phot2) and cryptochromes(cry1 and cry2) were proven as the Arabidopsis thaliana blue light receptors. Phototropins predominately function in photomovement, and cryptochromes play a role in photomorphogenesis. Although cryptochromes have been proposed to serve as positive modulators of phototropic responses, the underlying mechanism remains unknown. Here, we report that depleting sucrose from the medium or adding gibberellic acids(GAs) can partially restore the defects in phototropic curvature of the phot1 phot2 double mutants under high-intensity blue light; this restoration does not occur in phot1 phot2 cry1 cry2 quadruple mutants and nph3(nonphototropic hypocotyl 3) mutants which were impaired phototropic response in sucrose-containing medium. These results indicate that GAs and sucrose antagonistically regulate hypocotyl phototropism in a cryptochromes dependent manner, but it showed a crosstalk with phototropin signaling on NPH3.Furthermore, cryptochromes activation by blue light inhibit GAs synthesis, thus stabilizing DELLAs to block hypocotyl growth, which result in the higher GAs content in the shade side than the lit side of hypocotyl to support the asymmetric growth of hypocotyl. Through modulation of the abundance of DELLAs by sucrose depletion or added GAs, it revealed that cryptochromes have a function in mediating phototropic curvature.     

Identification of small RNAs involved in nitrogen fixation in Anabaena sp. PCC 7120 based on RNA-seq under steady state conditions

The aim of the present study was to investigate the tolerance of five new Achromobacter and Pseudomonas strains to kerosene and to establish if the production of several secondary metabolites increases or not when these bacteria were grown in the presence of kerosene. The biodegradation of kerosene by isolated bacteria was also investigated in this study. Five Proteobacteria were isolated from different samples polluted with petroleum and petroleum products. Based on their morphological, biochemical, and molecular characteristics, isolated bacteria were identified as Achromobacter spanius IBBPo18 and IBBPo21, Pseudomonas putida IBBPo19, and Pseudomonas aeruginosa IBBPo20 and IBBPo22. All these bacteria were able to tolerate and degrade kerosene. Higher tolerance to kerosene and degradation rates were observed for P. aeruginosa IBBPo20 and IBBPo22, compared with that observed for A. spanius IBBPo18 and IBBPo21, and P. putida IBBPo19. All these bacteria were able to produce several secondary metabolites, such as surfactants and pigments. Glycolipid surfactants produced by P. aeruginosa IBBPo20 and IBBPo22, A. spanius IBBPo18 and IBBPo21, and P. putida IBBPo19 have a very good emulsification activity, and their activity increased when they were grown in the presence of kerosene. The production of rhamnolipid surfactants by P. aeruginosa IBBPo20 and IBBPo22 was confirmed by detection of rhlAB gene involved in their biosynthesis. Pyocyanin and pyoverdin pigments were produced only by P. aeruginosa IBBPo20 and IBBPo22, while carotenoid pigments were produced by all the isolated bacteria. Significant changes in pigments production were observed when P. aeruginosa IBBPo20 and IBBPo22, A. spanius IBBPo18 and IBBPo21, and P. putida IBBPo19 were grown in the presence of kerosene. Due to their ability to tolerate and degrade kerosene, and also to produce several secondary metabolites, the isolated bacteria could be used in the bioremediation of kerosene-polluted environments.     

Alterations in the phosphodiesterase type 5 pathway and oxidative stress correlate with erectile function in spontaneously hypertensive rats

To explore how alterations in the phosphodiesterase type 5 (PDE5) signalling pathway and oxidative stress correlate with changes in the expression of relaxation and contraction molecules and erectile dysfunction (ED) in the corpus cavernosum smooth muscle (CCSM) of spontaneously hypertensive rats (SHR). In this study, SHR and Wistar‐Kyoto (WKY) rats were used. Erectile function was determined by apomorphine test and electrical stimulation (ES) of cavernous nerve. Masson''s trichrome staining and confocal microscopy were performed. Nitric oxide synthase (NOS), PDE5, phosphorylated‐PDE5 and α1‐adrenergic receptor (α1AR) were determined by RT‐PCR and Western blotting while oxidative stress in CC was determined by colorimetric analysis. SHR exhibited obvious ED. CC of SHR showed less SM but more collagen fibres. The expression of NOS isoforms in SHR was significantly decreased while all α1AR isoforms were increased. In addition, PDE5 and phosphorylated‐PDE5 were down‐regulated and its activity attenuated in the hypertensive rats. Meanwhile, the SHR group suffered oxidative stress, which may be modulated by endoplasmic reticulum stress and NADPH oxidase up‐regulation. Dysregulation of NOS and α1AR, histological changes and oxidative stress in CC may be associated with the pathophysiology of hypertension‐induced ED. In addition, PDE5 down‐regulation may lead to the decreased efficacy of PDE5 inhibitors in some hypertensive ED patients and treatment of oxidative stress could be used as a new therapeutic target for this type of ED.