松萝酸研究进展

自从松萝酸于1844年第一次被分离出来,它已经成为研究最广泛的地衣物质之一。对于松萝酸的抗菌功能、化学性质及其在医药、环境监控等各个领域的应用研究,可见于各种外文文献的报道。美国、日本及德国的应用研究较多;而中国、智利、南斯拉夫、印度尼西亚等国仍然在致力于松萝酸的提取、抗菌、抗病毒等基础方面的研究。中文文献不多。目前发现松萝酸只存在于地衣中,在以下种属中较为丰富：树发属、石蕊属、茶渍衣属、松萝属、树花属及扁枝衣。     

新疆北部松萝属地衣生态分布与地理区系成分分析

根据多年的实地调查资料和前人研究资料,对新疆北部松萝属地衣的种类以及它们的分布区、区系特征和垂直分布进行了初步研究。结果表明,分布在新疆北部的松萝属地衣共有22种,主要分布在天山和阿勒泰山,生长在树皮、树枝和朽木上。根据它们对环境的适应特征和选择性,将新疆北部松萝属地衣的主要地理成分分为环极北极及北方成分、北美-欧洲成分、世界广布种、北美成分、环极低北极及北方成分、欧洲成分、东亚—北美成分等7种。研究还发现分布在阿勒泰山和天山的松萝属地衣的垂直分布有明显的差异。阿勒泰山的地衣分布海拔比较高,分布范围比较广泛。     

桦树松萝的石蜡切片方法改良及形态学研究

以传统石蜡切片方法为基础,在固定、软化、包埋、染色等具体方法上进行了适合松萝属植物特点的改良。结果表明:采用改良制片方法获得了染色清晰、组织完整的桦树松萝切片。桦树松萝地衣体横切面结构从外到内依次划分为皮层、藻层、髓层和中轴;皮层是由横向分裂的菌丝交织成类似于高等植物的假厚壁组织,藻层由大量共生藻的藻细胞和菌丝所组成;髓层由疏松的菌丝体组成;中轴由致密的菌丝体组成。     

乔治王岛菲尔德斯半岛地衣研究：I.松萝属石萝亚属

本文扼要回顾了松萝属石萝亚属地衣研究简况,根据形态、化学、分布三者综合的现代地衣物种概念,确认南极乔治王岛菲尔德斯半岛只存在两种石萝即南极石萝和簇花石萝。除形态、化学特征描述外,详述了这两种石萝在菲尔德斯半岛的生境与分布特征。其中,在藓丛生镜中的簇花石萝群体性状分化及其与石生群体性状的比较和讨论是文献中尚未见到的,而生长在木板上的南极石萝则属罕见,其平均生长速率估算为每年增长０．４－１．１ｍｍ。在     

养之于斯——滇金丝猴的食物

在白马雪山,滇金丝猴栖息在3500米—4200米的冷杉林中,以长在冷杉树上的树挂地衣——松萝,当地人称“树胡子”为主要食物,这在非人灵长类中是非常罕见的。     

松萝挂袋法监测氟化盐厂大气氟污染

以长松萝为材料,制成挂袋,与石灰滤纸法（ＬＴＰ）同步对白银市某氟人盐厂内外大气氟进行监测的结果表明：两种方法在监测效果上显著相关。由松萝挂袋法监测结果确定的污染等级范围与实际情况符合,从而证明此法监测大气氟污染的可行性与可靠性。与天然地衣调查法和种子植物污染成分分析法相比,松萝挂袋法具有不受时间、地点限制,可定量反映植物聚焦污染物的数量等优点,对环境质量评价有直接参考价值。     

松萝酸提取工艺的研究

以破茎松萝为材料,分别以碱水或碱醇直接提取、制备松萝酸钠,并对松萝酸钠提取影响因素进行探究。对所得提取物进行分离和定性鉴定,并利用高效液相层析技术测定提取物中松萝酸的含量。通过单因素实验考察了NaOH和Na2CO3浓度对松萝酸提取的影响,用HPLC测定不同浓度碱液提取物中松萝酸的含量。实验结果说明,1.5%NaOH和75%乙醇+4%Na2CO3提取松萝酸效果较好,松萝酸提取得率最高,分别为1.75%和1.99%,破茎松萝材料中松萝酸含量为2.4%。     

耐低温酵母Curvibasidium rogersii菌株在松萝样品中的首次分离鉴定及基于基因组分析的生物特性探究

【目的】对西藏松萝地衣来源的两株非常规酵母进行分离鉴定,并通过基因组序列分析探究其生物学特性和应用潜力。【方法】从西藏来源的松萝地衣样品内部分离得到2株耐低温酵母菌株,通过26S D1/D2和ITS序列比对分析以及生理生化实验进行菌种鉴定;通过全基因组序列分析和验证探究菌株的生物特性。【结果】两株酵母菌株经鉴定均为Curvibasidium rogersii,可以在10℃低温良好生长,在20℃生长最佳,25℃及以上温度生长缓慢或不生长。对其进行基因组测序和基因组挖掘,测序结果发现,其基因组注释出功能的部分与产油脂的低温酵母白冬孢酵母Leucosporidium creatinivorum具有最高相似性,尼罗红染色发现两株酵母都能够生产油脂,另外在基因组序列中还发现了可能参与木糖代谢的相关蛋白编码基因,实验证明两个酵母菌株可以利用木糖生长。【结论】首次分离鉴定了来自西藏松萝的酵母C. rogersii,为充分开发利用松萝和其他地衣来源微生物,以及利用可代谢木糖的新资源酵母生产微生物油脂提供了基础。     

硬枝树花中4个单体化合物的抑菌活性

研究了从硬枝树花中提取得到的4个单体化合物松萝酸(usnic acid)、去甲环萝酸(evernic acid)、巴尔巴地衣酸(barbatic acid)和水杨嗪酸(salazinic acid)对大肠杆菌、沙门氏菌、金黄色葡萄球菌、枯草芽孢杆菌4种细菌及甜瓜根腐病菌、禾谷镰刀病菌、番茄灰霉病菌3种植物病原菌的抑制能力。结果表明,水杨嗪酸对大肠杆菌的抑制能力较强,对枯草芽孢杆菌几乎无抑制作用。松萝酸对大肠杆菌和枯草芽孢杆菌基本无抑制作用。高浓度的去甲环萝酸对大肠杆菌及金黄色葡萄球菌的抑制效果较好。巴尔巴地衣酸对4种细菌的抑制作用不强。水杨嗪酸对3种植物病原菌的抑制效果明显,去甲环萝酸对3种植物病原菌的抑菌效果较好,巴尔巴地衣酸对番茄灰霉病菌的抑制能力较好,而松萝酸对植物病原菌的抑制能力较弱。     

Influences of Nitrogen Sources on Usnic Acid Production in a Cultured Mycobiont of the Lichen Usnea hirta (L.) Wigg.

Effects of the nitrogen sources in the medium for the production of secondary metabolites in lichens were examined. The usnic acid production by a mycobiont of the lichen Usnea hirta was higher in the liquid medium containing ammonium and nitrate ions than in those containing amino acids.     

Identification and quantitation of usnic acid from the lichen Usnea species of Anatolia and antimicrobial activity

Six species of lichens, such as Usnea florida, Usnea barbata, Usnea longissima, Usnea rigida, Usnea hirta and Usnea subflorida, were collected from different areas of Anatolia (district of Antalya, Karabük, Qankiri, Giresun and Trabzon) in Turkey. Their usnic acid amounts in acetone extracts were determined by HPLC. In addition, antimicrobial activities of these extracts were determined against Escherichia coli (ATCC 35218), Enterococcus faecalis (RSKK 508), Proteus mirabilis (Pasteur Ens. 235), Staphylococcus aureus, Bacillus subtilis and Bacillus megaterium. It was shown that with increasing amount of usnic acid, the antimicrobial activity increased. Usnic acid contents of Usnea species varied between 0.22-6.49% of dry weight.     

松萝属的5.8S-ITS2二级结构比较分析

本研究以松萝属为研究对象,构建了该属核糖体5.8S和第二转录区间（ITS2）的二级结构模型,并对种间的结构差异进行了比较。结果显示,松萝属的结构与先前发表的真核生物ITS2二级结构模型非常相似。属内种间的结构差异主要集中在第二转录区间的臂上。核酸序列分析所产生的系统树与结构特征的比较结果相一致,表明ITS2的二级结构信息可以作为一种辅助的分类手段,适用于松萝属的种的鉴定和亲缘关系研究。     

南极地衣提取物抗氧化能力的初步研究

本文讨论4种南极地衣簇花石萝Usnea aurantiacoatra,南极石萝Usnea antarctica,粉球衣Sphaerophorus globosus及一种石蕊Cladonia sp.甲醇提取物的体外抗氧化能力;采用亚油酸氧化体系、二苯代苦味酰自由基体系、还原力实验对其抗氧化活性进行测定,并同维生素C、丁基甲氧基苯酚进行比较。结果显示供试南极地衣均具有较高的抗氧化活性,且呈剂量依赖关系;其中,簇花石萝的脂质过氧化抑制率最高,还原力最大;石蕊的二苯代苦味酰自由基清除能力最大。此外,从簇花石萝中提取的松萝酸具有一定的抗氧化活性,但明显低于簇花石萝粗提物。     

Seasonal Trends in Nitrogen Status of Antarctic Lichens

The thallus nitrogen (N) concentration of two dominant macrolichensof continental Antarctica (Usnea sphacelata and Umbilicariadecussata) was estimated each month for 1 year on a low roundedknoll on Clark Peninsula, Windmill Islands, Wilkes Land, Antarctica.Thallus N was significantly higher in Umbilicaria decussatathan in Usnea sphacelata and varied according to site. Duringthe winter months, when the lichens were metabolically inactive,thalli gradually accumulated N. At the onset of warmer conditions,thallus N content fell dramatically in both species, with thetiming of the decline being related to microclimatic conditions.The strongly seasonal pattern of metabolic activity in thesespecies is reflected in their nitrogen relations. Copyright2000 Annals of Botany Company Lichen, nitrogen, Antarctica, season, Usnea sphacelata, Umbilicaria decussata     

NOTES ON THE GENUSUSNEADILL. EX ADANSON

Usnea quercinaBystrek & Górzyńska, based on heterogeneous type material, is lectotypified and becomes a synonym ofU. wirthiiP. Clerc.Usnea wirthiiis new for South America. A distribution map ofU. madeirensisMotyka (Syn.U. silesiacaMotyka) in Europe is given.Usnea hesperinaMotyka (Syn.U. elongataMotyka,U. schadenbergianaGöpp & Stein,U. subgracilisVain.,U. subplicata(Vain.) Motyka) is new for Africa, Asia and South America.Usnea hirta(L.) F. H. Wigg. (Syn.U. corrugataMotyka,U. foveataVain.,U. leprosaMotyka) is new for Africa.Usnea subscabrosaNyl. ex Motyka (Syn.U. santae-annaeMotyka) is new for South America. The holotype ofU. marocanaMotyka (=U. mutabilisStirt.) was found in LBL.     

五种南极地衣的Co、Cr、Pb和Cu元素富集能力的差异

随着人类活动对全球环境的影响,环境重金属污染负荷日益增加,重金属元素向南极地区的迁移和富集已成为该地区面临的严重问题之一。地衣是研究重金属元素大气沉降特征的良好材料,但对南极地衣的重金属元素大气沉降富集能力的比较研究甚少。作者以网袋法实验比较采自西南极乔治王岛菲尔德斯半岛的5种南极优势地衣,即:王橙衣Caloplaca regalis、夹心果衣Himantormia lugubris、孔树花Ramalina terebrata、球粉衣Sphaerophorus globosus和簇花石萝Usnea aurantiacoatra对钴(Co)、铬(Cr)、铅(Pb)和铜(Cu)的富集能力。2个月的网袋法实验结果表明:1)5种地衣对Pb元素均表现出富集能力,其中夹心果衣富集能力最强,簇花石萝和孔树花次之;2)簇花石萝和夹心果衣对Cu元素的富集能力相近,球粉衣对Cu元素的富集能力较低,其他2种未表现出对Cu的富集作用;3)Co和Cr元素的富集仅分别在夹心果衣和簇花石萝中检测出来。因此,在综合检测Co、Cr、Cu和Pb的大气沉降时,可考虑簇花石萝和夹心果衣的组合;在单独检测Co、Pb和Cu的大气沉降时,夹心果衣均为最佳的物种。     

Nature and bioactivities of endolichenic fungi in Pseudocyphellaria sp., Parmotrema sp. and Usnea sp. at Hakgala montane forest in Sri Lanka

Aim:  The aim of this study was to investigate the nature and bioactivities of endolichenic fungi in three abundant lichens, Pseudocyphellaria sp., Usnea sp. and Parmotrema sp. in the lower elevation of Hakgala montane forest in Sri Lanka.
Methods and Results:  Endolichenic fungal strains, fungi that live asymptomatically in the lichen thallus, much the same way as endophytic fungi live within healthy plant tissues, were isolated from three abundant lichen species, Pseudocyphellaria sp., Usnea sp. and Parmotrema sp., at Hakgala montane forest in Sri Lanka, using the surface sterilization method. Nine endolichenic fungal strains were isolated from Parmotrema sp. and Usnea sp. separately, while 11 endolichenic fungi were recovered from the lichen Pseudocyphellaria sp. Isolation of endolichenic fungus Chrysosporium sp. 2 was common to all three lichen species. Substrate utilization patterns and antifungal activities of eight endolichenic fungal species were evaluated and the results revealed that all the test fungi were able to produce at least one enzyme to utilize the test substrates. Nigrospora sp., Chrysosporium sp. 1 and 2 and Cladosporium sp. showed antifungal activities on growth of some selected plant pathogenic fungi.
Conclusions:  Endolichenic fungal strains (29) were isolated from the lichens Parmotrema sp., Usnea sp. and Pseudocyphellaria sp. in Sri Lanka. Chrysosporium sp. 2 was common in all three lichens. Some of these endolichenic fungal strains showed antifungal activities against common plant pathogenic fungi and they are capable of utilizing the substrates by producing specific enzymes.
Significance and Impact of the Study:  The diversity and prevalence of the endolichenic fungi have not been studied extensively and this is the first report of isolation and identification of endolichenic fungi in lichens available in Sri Lanka.