Energy status regulated umami compound metabolism in harvested shiitake mushrooms(Lentinus edodes)with spores triggered to release

The molecular mechanisms of energy status related to the umami taste of postharvest shiitake mushrooms during spore release remain poorly understood.In this study,the variations of energy status and umami taste of mushrooms were measured at 25℃.At 24 h storage,slight spore prints of mushrooms were first pictured,respiration peaked.Significant ATP decrease and ADP increase were also observed as the initiation of postharvest senescence(P<0.05).Meanwhile,the activities of phosphohexose isomerase,succinate dehydrogenase,glucose-6-phosphate dehydrogenase and cytochrome c oxidase and the contents of umami nucleotides and amino acids were maintained at higher levels in mushrooms with spore release.Notably,the equivalent umami concentration(EUC)was strongly correlated with energy levels(R=0.80).Fifteen related gene expression levels in the energy metabolism pathway were downregulated.LecpdP1 and LeAK were significantly expressed in the conversion of ATP into AMP and played key roles in connecting the energy state and umami level.These results provided valuable insights on the umami taste associated with energy metabolism mechanism during postharvest mushroom spore release.

The Overwintering Capability of Ulva prolifera Spores and Gametes in the Yellow Sea,China

Green tides caused by the bloom of Ulva prolifera have affected the Yellow Sea annually since 2007.To explore the intrinsic causes of successive blooms,field investigations and indoor simulation experiments were conducted using micro-propagules of U.prolifera.From January to February 2014,micro-propagules of various green algae,including U.prolifera,Ulva flexuosa,and Ulva linza,were prevalent in the coastal waters of Rudong,Lianyungang,and Qingdao.However,in March 2014,micro-propagules of U.prolifera were not detected in the coastal waters of Lianyungang and Qingdao.Neither the spores nor gametes of U.prolifera can germinate at temperatures below 5℃.At 2℃and 5℃,U.prolifera spores and gametes could survive for 1-3 months at a light intensity range of 0-30μmol m^(-2)s^(-1)and for less than 1 month if the light intensity exceeded 30μmol m^(-2)s^(-1).By integrating indoor experiments and field investigations,this study found that U.prolifera spores and gametes could overwinter in the Rudong coastal area,which is an important factor for the annual emergence of recurring green tides in the Yellow Sea.

Aqueous-soluble components of sporoderm-removed Ganoderma lucidum spore powder promote ferroptosis in oral squamous cell carcinoma

Objective: Ferroptosis is a novel cell death process which displays a promising role in cancer treatment.However, clinically available drugs targeting ferroptosis are rarely used, and yet there are no studies reporting on inducing ferroptosis via Chinese herbal extracts. Here we explored the tumor inhibition effects of Ganoderma lucidum(G. lucidum) on oral squamous cell carcinoma(OSCC). Specifically, we aimed to clarify the biological mechanism of components in the dietary, aqueous-soluble sporoderm-removed G. lucidum spore powder(A-GSP).Methods: Preliminary transcriptome analysis revealed the significant enrichment of the ferroptosis pathway.Cellular Fe2+, glutathione(GSH), malondialdehyde(MDA), reactive oxygen species(ROS) and lipid peroxide levels were measured to identify ferroptosis occurrence. Western blotting was used to measure ferroptosis-related proteins. Changes in mitochondria morphology and function were observed with transmission electron microscopy(TEM) and ATP detection assays. Ferroptosis inhibitor ferrostatin-1 was then used to verify the anti-tumor effects of A-GSP. Finally, nude mice xenograft models of oral cancer confirmed that A-GSP inhibited tumor growth.Results: A-GSP promoted ferroptosis in oral cancer cells by inducing Fe2+influx, GSH depletion, as well as lipid peroxide and ROS accumulation. Ferroptosis-related proteins exhibited corresponding changes, particularly Acylco A synthetase long chain family member 4(ACSL4) increase and glutathione peroxidase 4(GPX4) decrease. A-GSP considerably lowered mitochondrial volume and ridge number, while significantly decreasing ATP production. Ferrostatin-1 reversed all of these A-GSP-induced changes. In vivo, A-GSP exerted a ferroptosismediated tumor-suppressing effect without observable adverse reactions.Conclusions: Our findings demonstrate the therapeutic potential of A-GSP for treating patients with OSCC by targeting ferroptosis.

Effects of polyamines on the early development of cystocarps,spore release,survival,and germination rate of Gracilariopsis lemaneiformis

Three polyamines(PAs)(spermidine(Spd),spermine(Spm),and putrescine(Put))were used as growth regulators to the marine macroalgae Gracilariopsis lemaneiformis and to female gametophyte and reproductive tissues(cystocarps were constructed),which led to early maturation of cystocarps and spore release.Laboratory cultivation revealed that exogenous PA application accelerated the development of cystocarps,and the mean sporeling growth rate was 20%–50%/d during the initial week of cultivation.The spore count(SC),survival rate(SR),and germination rate(GR)of G.lemaneiformis showed different responses to PA(10-6 mol/L and 10-3 mol/L)treatments under different temperatures(18,26,and 34℃),light intensities(30,60,and 90μmol photons/(m^(2)·s)),salinities(25,30,and 35),and nutrient levels(25꞉2.5,50꞉5.0,and 75꞉7.5μmol/L NH4Cl꞉K2HPO4),and the optimal conditions were 26℃,light intensity of 60μmol/(m^(2)·s),salinity of 35,and nutrient level of 50꞉5.0μmol/L NH4Cl꞉K2HPO4.Under the optimum conditions,the SC per cystocarp increased by 82.38%,and the spore SR and GR increased by 33.07%and 46.44%,respectively.Each experiment lasted for 7 days,with the highest SC on Day 4 and plateauing on Day 7.The results indicate that PAs could promote the early maturation,spore release,survival,and germination of G.lemaneiformis under laboratory conditions.

Single-cell analysis reveals microbial spore responses to microwave radiation

To determine the effects of microwave radiation at the molecular level as well as on the germination,growth and morphology of dry spores at the single-cell level.Dry Bacillus aryabhattai MCCC 1K02966 spores were microwave-treated at different powers and characterized using single-cell optical technology.As determined by laser tweezers Raman spectroscopy,the Ca^(2+)-dipicolinic acid content increased and nucleic acid denaturation occurred in response to microwave treatment.Livecell microscopy revealed that the germination and growth rates decreased as the microwave power increased.With respect to morphology,atomic force microscopy(AFM)demonstrated that spores became wrinkled and rough after microwave treatment.Furthermore,spores became smaller as the microwave power increased.Microwave treatment can damage DNA,and high-power microwaves can inhibit the germination of spores and reduce spore volumes.These results provide a new perspective on the responses of living single cells to microwave radiation and demonstrate the application of various new techniques for analyses of microorganisms at the single-cell level.

Sexual spores in edible mushroom: bioactive components, discharge mechanisms and effects on fruiting bodies quality

Edible mushroom sexual spores have been gaining more interest due to their bioactive components and functions.Spore discharge(SD)is an important factor affecting the quality of edible mushrooms.In this review,the bioactive nutrients of sexual spores of edible mushrooms were summarized,the SD mechanism was described,and the relationship between postharvest SD and the quality of edible mushrooms was analyzed.Spores contain various bioactive nutrients that are benefi cial to the human body.Mature mushrooms can actively discharge spores in a process affected by light,relative humidity,and temperature.During storage,the physiological metabolism of spore-bearing gill tissue is vigorous,promoting the release of postharvest spores and changing the nutritional value of fruiting bodies.The flavor of the fruiting bodies also varied signifi cantly during SD.Edible mushroom sexual spores have the potential to become new raw materials for functional food and medical resources.Research on the effect of the mechanism of SD on the quality of edible mushrooms and the development of SD regulation technology may be a new trend in the quality control of edible mushrooms,which will promote the development of the edible mushroom industry.

Mycorrhizal Fungi Spore Abundance in Old-Growth Forest Soil

Soil samples were collected from the base of Aplectrum hymale individuals to assess mycorrhizal spores abundance. The hypothesis that mycorrhizal spore abundance would increase with proximity to the plant was not supported;however, spores increased significantly with distance from the Aplectrum hymale plants up to one meter.

Volatile Components and Antitumor Activity of Ganoderma lucidum Spore Oil and Its Molecular Distillation Components

[Objectives]To compare the effects of molecular distillation on the flavor and antitumor activity of Ganoderma lucidum spore oil.[Methods]G.lucidum spore oil was separated and purified by molecular distillation technology,and the volatile components of different components of molecular distillation were analyzed by gas chromatography-ion mobility spectrometry(GC-IMS)technology.Human liver carcinoma cells(HepG2),human breast cancer cells(MCF-7),and human cervical cancer cells(Hela)were selected as the tumor cell lines to be tested,and the cell viability was detected by the MTT assay.[Results]Molecular distillation effectively reduced small molecular substances produced by oil oxidation in G.lucidum spore oil,such as heptanal,octanal,linalool,hexanal,E-2-octanal,3-ethylpyridine,etc.Among the heavy components,the content of esters was relatively high,mainly including ethyl levulinate,ethyl crotonate,and amyl butyrate.The MTT cytotoxicity test indicated that G.lucidum spore oil and its molecular distillation components had certain inhibitory effects on the growth of three tumor cells,and G.lucidum spore oil crude oil had the most significant antitumor activity.G.lucidum spore oil crude oil,heavy component,and light component had the most significant antitumor activity on HepG2 cells,followed by MCF-7 cells,and the weakest antitumor activity on Hela cells.The quality of G.lucidum spore oil became higher after molecular distillation,and the rancid smell was reduced,and molecular distillation had little effect on the antitumor activity of G.lucidum spores.[Conclusions]Molecular distillation technology can be applied to the refining of G.lucidum spore oil to improve product quality.

松科2井早白垩世沙河子组孢粉组合及其古气候意义

为探讨黑龙江省安达市松科2井深层(3395.46~3901.35 m)地层的时代特征,分析地史时期的古植被及古气候条件演变,利用孢粉学方法对松科2井进行研究。结果显示,研究井段可划分为Leiotriletes sp.-Cyathidites australis-Chasmatosporites sp.孢粉组合(3832.94~3901.35 m)和Klukisporites triangulus-Aequitriradites sp.-Pristinuspollenites sp.孢粉组合(3395.46~3613.62 m),孢粉组合指示的地质时代为早白垩世欧特里夫期(Hauterivian)—巴列姆期(Barremian)早期,可作为松辽盆地沙河子组上部生物地层学对比的标志;此外,孢粉组合反映的植被类型演化规律是针叶林、灌草丛—常绿阔叶林—针叶林、灌木丛—针阔叶混交林,揭示研究区沙河子组后期气候带演替规律是暖温带—南亚热带—暖温带—温带,气候干湿变化规律为湿润—半湿润—湿润—半湿润。

生防枯草芽孢杆菌Czk1固体发酵工艺条件优化

枯草芽孢杆菌(Bacillus subtilis)Czk1是一株具广谱拮抗、促生和诱导植株产生抗病性的根际益生菌。为了全面资源化利用农业废弃物中的有机养分和促进对植物土传病害的生物防治,本研究以Czk1为研究对象,以鸡粪为底肥,分别利用玉米秸秆、菌糠、椰糠堆肥为原料,采用液固两相发酵工艺,以稀释平板菌落计数法测定活菌总数和芽孢数,经过单因素和正交试验方法,明确Czk1固体发酵物料的配方、工艺参数和培养条件。得出Czk1固体发酵的最优条件:最佳原料为菌糠鸡粪堆肥,Czk1接种重量为10%,黄豆粉添加量为10%,含水量为40%,发酵温度为37℃,翻抛1次/72h,在此条件下,Czk1菌株中的芽孢活菌数量总量可以达到8.63×10^(8)CFU/g,芽孢数为8.37×10^(8)CFU/g。其次,发酵效果较佳的原料为秸秆鸡粪堆肥,Czk1接种量为10%,添加5%黄豆粉,40%含水量,发酵温度为37℃,翻抛1次/72 h,此条件下,Czk1接种菌株中的活菌数量总量可达到6.53×10^(8)CFU/g,芽孢数为5.97×10^(8)CFU/g;另外,在此配方条件下再添加30%菌糠,Czk1菌株的活菌数量总量及芽孢数分别可达到8.70×10^(8)CFU/g和6.90×10^(8)CFU/g。4种发酵生物肥原料的理化性质测定表明,其有机质含量、碳氮比均有较大差异,其中以鸡粪为原料其pH、全磷和全钾含量均最高,碳氮比最低,氮、磷、钾总含量均高于秸秆、椰糠和菌糠;秸秆为原料其电导率、有机质含量最高;椰糠为原料其全氮含量最高,菌糠为原料碳氮比最高。不同鸡粪与菌糠、秸秆及椰糠组合的生物有机肥的种子发芽指数均大于80%。因此,枯草芽孢杆菌Czk1具有良好的开发利用价值,选择合适的发酵生产条件可将农业废弃物制备出高质量的生物有机肥。

氧浓度对丝绸上霉菌生长的影响

以黑曲霉、桔青霉为例,利用物联网系统监测培养箱温度、湿度和氧浓度,研究氧浓度对黑曲霉、桔青霉生长的影响。结果发现,在温度(28±1)℃、湿度60%~80%条件下培养7 d,黑曲霉生长所需的氧浓度最低值为0.7%。高浓度氧气能满足其有氧代谢,从而使生长发育达到饱和状态;低浓度氧气不能满足其有氧代谢,从而导致生长发育不充分。当氧浓度低至0.7%时,黑曲霉停止代谢活动。氧浓度对桔青霉生长存在类似的影响。研究丝绸文物上的常见霉菌生长与氧浓度的规律以及氧浓度阈值,为丝绸文物保藏及其装置开发设计提供了理论依据。

淡豆豉的多菌种协同发酵工艺优化

目的优化淡豆豉多菌种(环状芽孢杆菌、黑曲霉、少根根霉)协同发酵工艺,为淡豆豉发酵工艺改进和创新提供参考。方法以发酵时间、发酵温度、混合菌种比例、接种量为考察因素,以总黄酮、大豆苷元、黄豆黄素、染料木素的含量为考察指标,通过单因素考查对淡豆豉多菌种协同发酵工艺进行优化。结果淡豆豉多菌种协同发酵最佳工艺条件为:发酵温度30℃,发酵时间8 d,接种量5%,混合菌种接种比例为环状芽孢杆菌∶黑曲霉∶少根根霉=1∶2∶1。结论淡豆豉多菌种协同发酵工艺可避免杂菌干扰、利于工艺标准化,可为淡豆豉工艺改进和创新以及为中药多菌种协同发酵工艺研究提供参考。

观赏蕨类姬蕨同配子体自交的孢子体萌发和发育特性

[目的]评估交配形式对蕨类繁殖的影响。[方法]以姬蕨(Hypolepis punctata)为例,设计配子体单独培养(同配自交)和混合培养(混交)比较试验,比较两种交配系统下孢子体萌发状态(萌发率、存活率),孢子体成长情况及生长速率。[结果]尽管自交幼苗生长趋势弱于混交个体,单独培养产生的完全纯合的姬蕨孢子体最终存活率达到62.5%,说明蕨类的自交确实可以导致近交衰退,但仍然具有可接受的存活能力,单个孢子仍有很大概率上延续种群。蕨类植物由于其特殊的生活史特性,可通过单独培养得到完全纯合的自交个体,从而得到性状稳定的品系。[结论]该研究中单独培养技术在园艺育种方向具有很好的应用前景。

破壁灵芝孢子粉中多种重金属元素及硒含量检测方法探讨

采用微波消解进行前处理,三重四极杆-电感耦合等离子体质谱法测定破壁灵芝孢子粉中镉、铬、镍、砷、铅、汞及硒元素含量,对方法条件进行优化和讨论,并对20批次破壁灵芝孢子粉进行测定。结果表明,镉、铬、镍、砷、铅和汞元素在氦气碰撞模式,硒元素在氧气反应模式下,采用内标校正定量,可达到良好的测定效果。在优化的条件下,各元素线性关系良好,检出限均可达μg·kg^(-1)级别;镉、铬、镍、砷、铅及硒元素的加标回收率在90.3%~105.0%,汞的加标回收率在82.1%~92.5%;方法精密度在5%以内。此方法前处理操作简便,检测灵敏度高,稳定性好,给灵芝孢子粉多元素测定提供了良好的技术支撑。

基于不同病原真菌单孢分离方法研究

在植物病理学研究中,通常需要分离和纯化病原真菌,掌握一套简捷又高效的单孢分离技术,有助于研究工作的顺利开展。以葡萄灰霉病菌为试验材料,比较稀释纯化法、挑针转移法、平板稀释画线法和实体镜下转移法4种单孢分离方法。试验发现,实体镜下转移法分离成功率最高,高达93.62%。但各方法各有其优缺点,需结合自身优势和实验条件,总结出一套适宜的、简便可靠的单孢分离方法。

芽孢表面展示系统及其在水产疫苗研发中的应用

水产养殖动物疾病的发生日益频繁,给整个行业造成了巨大的经济损失。口服疫苗可以有效预防疾病的发生,同时不会造成应激反应,更适用于水产动物疾病的预防。芽孢杆菌是水产中常用益生菌,能够形成抗逆性强的芽孢,芽孢能够被用来构建芽孢表面展示系统,进而成为抗原呈递的理想平台。因而,利用芽孢表面展示口服疫苗并将抗原稳定地呈递到肠道,发挥更加高效的免疫性能的研究受到了越来越多的关注。文章综述了芽孢杆菌芽孢和感受态,以及芽孢表面展示系统,此外,还特别概述了芽孢作为口服疫苗载体在预防水产动物细菌病、病毒病和寄生虫病方面的研究与应用,以期为水产养殖动物高效稳定口服疫苗的开发提供参考。

灵芝孢子粉和孢子油脂溶性成分分析

分析不同破壁时间、不同来源灵芝(Ganoderma lucidum)孢子粉,灵芝孢子油加工原料(破壁孢子粉)、中间体(制粒后孢子粉、一级萃取孢子油、二级萃取孢子油)和孢子油成品,不同来源灵芝孢子油,不同植物油的脂溶性成分含量和指纹图谱。结果表明:破壁处理能显著增加灵芝孢子粉中脂溶性成分溶出;不同来源灵芝孢子粉中脂溶性成分含量有差异,但不同来源孢子粉指纹图谱相似度均大于0.90,有18个共有峰;灵芝孢子油加工原料(破壁孢子粉)、制粒后孢子粉、一级萃取孢子油、二级萃取孢子油及孢子油成品脂溶性成分指纹图谱有22个共有峰,不考虑孢子油成品中维生素E峰,孢子油加工原料、中间体和孢子油成品间指纹图谱的相似度均大于0.99;不同来源灵芝孢子油指纹图谱峰组成和峰面积有差异,指纹图谱相似度为0.490~0.925,有23个共有峰;植物油的色谱峰与孢子油相比存在较大差异。研究结果为灵芝孢子粉和孢子油的质量控制提供参考。

不同抑菌剂对枯草芽孢杆菌芽孢动态生长的影响

目的研究不同抑菌剂对枯草芽孢杆菌(Bacillus subtilis)芽孢生长的影响及作用阶段。方法本研究选取枯草芽孢杆菌芽孢为研究对象,考查了茶多酚、Nisin、亚硝酸盐、双乙酸钠、乙二胺四乙酸盐5种抑菌剂对枯草芽孢杆菌芽孢存活量、萌发特性、内容物泄漏量、结构变化的影响。结果5种抑菌剂均能降低枯草芽孢杆菌芽孢的存活率,且不同抑菌剂对枯草芽孢杆菌芽孢生长的主要抑制阶段存在差异。其中乙二胺四乙酸盐、茶多酚在芽孢萌发阶段的作用效果相对较为显著,与芽孢悬浊液共孵育60 min后吸光度分别下降至90.61%、90.74%,2,6-吡啶二羧酸释放量分别为21.18%、21.92%,孵育12 h后仍有部分芽孢保持“相亮”状态。亚硝酸盐、双乙酸钠、Nisin主要在萌发后发挥抑制作用,其中亚硝酸盐、双乙酸钠能使芽孢在后期生长过程中内膜通透性增大,并导致芽孢核内物质发生泄漏。拉曼光谱显示茶多酚、亚硝酸盐能够使得芽孢生长过程中蛋白质、脂质等成分及其结构发生变化,使萌发后的芽孢无法继续生长形成营养体。结论乙二胺四乙酸盐、茶多酚在芽孢萌发阶段发挥主要作用,亚硝酸盐、双乙酸钠、Nisin在萌发后及营养体形成阶段发挥主要抑制作用。本研究为揭示不同抑菌剂对芽孢生长的抑菌机制提供重要信息和参考。

鼠李糖脂抑制芽孢态蜡样芽孢杆菌的活性及机制

以蜡样芽孢杆菌(Bacillus cereus)芽孢为研究对象,从表观、形态和胞膜状态等方面解析鼠李糖脂(rhamnolipids,RLs)对芽孢态B.cereus的抑制活性和作用机制。结果表明,RLs的最低抑菌浓度和最低杀菌浓度分别为80.0 mg/L和160.0 mg/L。两个浓度的RLs均可以引起芽孢表面出现严重的皱缩和凹陷,破坏芽孢细胞膜完整性和通透性,导致胞内电解质、DNA和蛋白质等生物大分子外泄。同时,RLs可以通过降低芽孢的耐热性、产生胞内氧化应激反应、降低表面黏附能力、结合并干扰DNA分子等多种抑菌机制对B.cereus芽孢起到抑制和灭活作用。研究结果有利于推动RLs在食品安全领域的开发和应用。

灵芝孢子粉多糖对APAP肝损伤的保护作用研究

目的:探讨灵芝孢子粉多糖(Ganoderma lucidum spore polysaccharide,GLSP)在对乙酰氨基酚(Aceta-minophen,APAP)肝损伤中的保护作用。方法:将50只小鼠随机分为五组,分别为空白组、模型组、阳性药物组、GLSP低剂量组和GLSP高剂量组,每组10只,各组按相应剂量连续14 d预给药后,使用APAP造模、取材,测定肝脏指数、血清指标(谷草转氨酶(glutamic oxalacetic transaminase,AST)、谷丙转氨酶(glutamic-pyruvic transaminase,ALT))及肝组织匀浆指标(谷胱甘肽(glutathione,GSH)、丙二醛(malonaldehyde,MDA)、超氧化物歧化酶(superoxide dismutase,SOD)、Caspase-3、Bax和Bcl-xl)。结果:与空白组相比,模型组中ALT、AST、MDA及促凋亡基因Caspase-3、Bax均极显著升高(P<0.01),SOD、GSH含量极显著降低(P<0.01),HE染色结果显示APAP处理的小鼠肝脏出现典型的小叶中心性坏死;多糖剂量组与模型组相比ALT、AST极显著降低(P<0.01),多糖低剂量组SOD、GSH显著升高(P<0.05),MDA显著降低(P<0.05),在多糖高剂量组中,SOD、GSH极显著升高(P<0.01),MDA极显著降低(P<0.01),多糖组促凋亡基因Caspase-3、Bax极显著降低(P<0.01),且肝组织病理学观察中可见肝组织坏死面积减小。结论:灵芝孢子粉多糖对APAP肝损伤能够起到预保护作用,其作用机制可能与提高肝脏的抗氧化能力和抑制凋亡的发生有关。