Antrodia camphorata ATCC 200183 sporulates asexually in submerged culture

Antrodia camphorata is a well-known Chinese medicinal mushroom that protects against diverse health-related conditions. Submerged fermentation of A. camphorata is an alternative choice for the effective production of bioactive metabolites, but the effects of nutrition and environment on mycelial morphology are largely unknown. In this study, we show that A. camphorata American Type Culture Collection 200183 can form arthrospores in the end of liquid fermentation. Different morphologies of A. camphorata in submerged culture were analyzed using scanning electron microscopy. The optimal carbon and nitrogen sources for sporulation were soluble starch and yeast extract. We found that a carbon-to-nitrogen ratio (C/N) of 40:1, MgSO₄ (0.5 g/l), KH₂PO₄ (3.0 g/l), an initial pH?5.0, and an inoculum size of 1.5?×?10⁵ spores/ml led to maximum production of arthroconidia. Our results will be useful in the regulation and optimization of A. camphorata cultures for efficient production of arthroconidia in submerged culture, which can be used as inocula in subsequent fermentation processes.     

裸花紫珠提取物及其主要成分抗氧化活性研究

裸花紫珠是海南一种道地药材,具有消炎止血的功效。裸花紫珠富含黄酮类和苯乙醇苷类化学成分,它们已经被证实是天然抗氧化剂的主要来源之一。为了考察裸花紫珠药材的抗氧化活性,该研究采用DPPH.自由基清除法测定裸花紫珠醇提物、4个不同极性部位(石油醚、乙酸乙酯、正丁醇、水)及其7个主要成分的抗氧化作用。结果表明：裸花紫珠醇提物、醇提物的水部位、正丁醇部位、乙酸乙酯部位和化合物木犀草素、木犀草苷、毛蕊花糖苷具有较强的抗氧化活性,而5-羟基-3,7,3′,4′-四甲氧基黄酮的抗氧化活性则较弱。该研究结果为裸花紫珠的保健功能开发提供了依据。     

Genome-based analysis of virulence genes in a non-biofilm-forming Staphylococcus epidermidis strain (ATCC 12228)

Staphylococcus epidermidis strains are diverse in their pathogenicity; some are invasive and cause serious nosocomial infections, whereas others are non-pathogenic commensal organisms. To analyse the implications of different virulence factors in Staphylococcus epidermidis infections, the complete genome of Staphylococcus epidermidis strain ATCC 12228, a non-biofilm forming, non-infection associated strain used for detection of residual antibiotics in food products, was sequenced. This strain showed low virulence by mouse and rat experimental infections. The genome consists of a single 2499 279 bp chromosome and six plasmids. The chromosomal G + C content is 32.1% and 2419 protein coding sequences (CDS) are predicted, among which 230 are putative novel genes. Compared to the virulence factors in Staphylococcus aureus, aside from delta-haemolysin and beta-haemolysin, other toxin genes were not found. In contrast, the majority of adhesin genes are intact in ATCC 12228. Most strikingly, the ica operon coding for the enzymes synthesizing interbacterial cellular polysaccharide is missing in ATCC 12228 and rearrangements of adjacent genes are shown. No mec genes, IS256, IS257, were found in ATCC 12228. It is suggested that the absence of the ica operon is a genetic marker in commensal Staphylococcus epidermidis strains which are less likely to become invasive.     

Quality control system of the endoplasmic reticulum and related diseases

The quality control (QC) system of the endoplasmic reticulum (ER) is an important monitoringmechanism in the protein maturation process,which ensures export of properly folded proteins from the ER.Incorrectly or incompletely folded proteins are retained in the ER for refolding or degradation by the ER-residing proteasome.The calnexin/calreticulin cycle and ER-associated degradation are the key elements inQC.These two mechanisms work together to allow incorrectly folded proteins have additional opportunitiesto achieve their native conformations.The QC dysfunction is involved in many diseases caused by mutantproteins,many of which are causes of neurodegenerative disorders.A better understanding of molecularregulation in the QC system will uncover the molecular pathogenic mechanisms of many diseases caused byprotein misfolding and help discover novel strategies for preventing or treating these diseases.     

热带季节雨林林冠上方和林内近地层CO2浓度的时空动态及其成因分析

 为探讨西双版纳独特地方气候背景下,热带季节雨林CO₂浓度的时空变化特征和不同时间尺度上环境因素对森林CO₂浓度时间分布的作用,以及 为研究热带季节雨林的碳通量、净生态系统交换量(Net ecosystem exchange, NEE)等提供支持,我们利用热带季节雨林林冠上方和林内近地层 CO₂浓度连续监测资料,结合同步气象资料进行了统计分析。研究结果表明：在植被生理活动、土壤呼吸以及林内湍流的共同作用下,西双版纳 热带季节雨林CO₂浓度表现出明显的日变化、季节变化和林冠上下差异。在日尺度上,林冠上方的CO₂浓度时间变化曲线为“单峰型”,林内近 地层CO₂浓度时间变化曲线为“双峰型”,造成林内近地层傍晚第二个峰值的主要因子是地形因子作用下形成的局地环流。在季节尺度上,林冠 上方CO₂浓度主要受林冠代谢作用的影响,呈现雨季低、干季高的特点,而林内近地层的CO₂浓度则主要受地表呼吸过程所控制,季节变化趋势 与林冠上方相反。林冠上方CO₂浓度低于林内近地层CO₂浓度,且差异较大;在日尺度上,各月（除12月外）CO₂浓度的最大差值皆大于80 mg·m ^－3,且出现在傍晚;在季节尺度上,最大值为-62.9 mg·m^－3,出现在10月,最小值为-8.4 mg·m^－3,出现在12月。     

不同干扰素应答慢性乙型肝炎患者的基因组DNA甲基化谱差异分析

α干扰素,包括长效干扰素——聚乙醇化α干扰素(PEG-IFNα),是临床用以治疗慢性乙型肝炎的首选药物。但干扰素治疗通常只能在有限的患者中获得完全应答。目前干扰素治疗应答相关指标预测的灵敏度与特异度远未令人满意,因此继续寻找潜在的与干扰素疗效预测相关的分子标记仍是一个十分有意义的工作。为探讨慢性乙型肝炎患者基因组DNA甲基化状态与干扰素治疗疗效的关系,本研究采用RocheNimbleGen人甲基化DNA免疫共沉淀-芯片(MeDIP-chip)技术,分析20例不同干扰素疗效慢性乙型肝炎患者的血浆基因组启动子甲基化谱差异,并利用MeDIP-定量聚合酶链反应(MeDIP-qPCR)检验部分基因启动子区域DNA甲基化的水平。结果显示,与快速应答组相比,无应答组中有588个基因启动子区甲基化水平存在显著差异(P0.05)。这些基因主要涉及多个信号通路,即钙离子信号通路、细胞周期调节通路、肝脏代谢相关通路等。MeDIP-qPCR验证与芯片结果的一致性超过80%。本研究为探讨差异甲基化基因在干扰素应答中的作用及发现潜在的预测干扰素疗效的血液分子标记奠定了基础。