Notes on the Scottish flora

Background: Abernethy Forest, an area of native Caledonian Scots pine forest, includes areas of open or sparsely forested peatland, largely ombrotrophic, but locally influenced by water from mineral ground.

Aims: To relate vegetation species-composition to the limit of ombrotrophy inferred from water chemistry.

Methods: Species composition was listed in 300 sample quadrats; chemical analyses of water samples were available from 200 of these. The vegetation data were classified using TWINSPAN. Relationships between vegetation and chemical results were analysed statistically using contingency tables.

Results: Eleven ‘vegetation types’ were recognised, five (189 samples) judged as primarily ombrotrophic-bog vegetation. The others showed evidence of flushing, or transition to forest. A previous analysis of major cations in the 200 water samples indicated that a limiting Ca/Mg ratio of 1.0 divided 61 samples showing telluric influence from 139 essentially ombrotrophic samples. Neither division was sharp. Contingency tables showed that the division based on vegetation types was strongly associated with the division of the water samples based on cation ratios.

Conclusions: Large areas of bog south and east of Loch Garten are unequivocally ombrotrophic; the main telluric-influenced sites occupy openings in the forest west of the loch. The limited ‘fen’ flora probably reflects the small size and isolation of the calcium-rich sites and the dominating influence of the ombrotrophic peats.     

柴达木盆地尕斯库勒盐湖区邻近水体对湖泊微生物群落的贡献

【目的】探究尕斯库勒盐湖生态系统中邻近水体对湖泊微生物的贡献。【方法】采集尕斯库勒盐湖区湖水、沉积物以及邻近的泉水、河水和盐田的水样,对其进行地球化学分析;通过16S rRNA基因的Illumina MiSeq高通量测序分析样品的微生物群落组成。【结果】尕斯库勒盐湖区水体和沉积物中的优势门是变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、放线菌门(Actinobacteria)和广古菌门(Euryarchaeota)。盐度和pH是影响尕斯库勒盐湖区群落组成的最主要环境因素。邻近水体对湖泊水体和沉积物的贡献分别为12.94%和7.53%。【结论】邻近水体对尕斯库勒盐湖微生物群落的贡献有限。     

安徽省某酸性矿山废水坑湖中细菌群落的垂向分布特征及其影响因素

【目的】探究酸性矿山废水(acid mine drainage,AMD)坑湖中细菌群落沿垂向不同水深的分布规律及与环境因子之间的相互作用。【方法】采用16SrRNA基因高通量测序技术,对安徽省某AMD坑湖中6条采样垂线不同水深深度的细菌群落进行调查,同时测定水质理化指标,使用统计学软件分析细菌和地化参数间的联系。【结果】AMD坑湖中水质特征及细菌群落结构出现明显分层现象,自上而下溶解氧降低而pH和多种金属离子浓度增加,微生物群落结构发生变化,多样性和部分物种的丰度增大。细菌群落组成上,表层水域以Proteobacteria (Alpha、Gammaproteobacteria)和Acidobacteria占据主导地位;中下层水域则由Firmicutes、Acidobacteria、Actinobacteria、Gammaproteobacteria和Patescibacteria等共同主导。统计分析结果表明,TN、DO、ORP、pH、Fe、Mn、Al和Zn与嗜酸细菌丰度显著相关,是细菌空间分布的主要限制因素。【结论】AMD坑湖中水质理化特征和细菌群落分布在垂向空间上存在显著差异,群落的...     

典型煤层水微生物产甲烷潜力及其群落结构研究

内蒙古自治区二连盆地、海拉尔盆地是我国重要的煤层气产区,其中生物成因煤层气是煤层气的重要来源,但复杂物质转化产甲烷相关微生物群落结构及功能尚不清楚。【目的】研究煤层水中的微生物代谢挥发性脂肪酸产甲烷的生理特征及群落特征。【方法】以内蒙古自治区二连盆地和海拉尔盆地的四口煤层气井水作为接种物,分别添加乙酸钠、丙酸钠和丁酸钠厌氧培养;定期监测挥发性脂肪酸降解过程中甲烷和底物的变化趋势,应用高通量测序技术,分析原始煤层气井水及稳定期产甲烷菌液的微生物群落结构。【结果】除海拉尔盆地H303煤层气井微生物不能代谢丙酸外,其他样品均具备代谢乙酸、丙酸和丁酸产生甲烷的能力,其生理生态参数存在显著差异,产甲烷延滞期依次是乙酸<丁酸<丙酸;最大比产甲烷速率和底物转化效率依次是丙酸<乙酸<丁酸。富集培养后,古菌群落结构与煤层气井水的来源显著相关,二连盆地优势古菌为氢营养型产甲烷古菌Methanocalculus (相对丰度13.5%–63.4%)和复合营养型产甲烷古菌Methanosarcina (7.9%–51.3%),海拉尔盆地的优势古菌为氢营养型产甲烷古菌Methanobact...     

The ‘teflon basin’ myth: hydrology and hydrochemistry of a seasonally snow-covered catchment

Background: Snow and ice melt provide sensitive indicators of climate change and serve as the primary source of stream flow in alpine basins.

Aims: We synthesise the results of hydrological and hydrochemical studies during the period 1995–2014, building on a long history of earlier work focused on snow and water on Niwot Ridge and the adjacent Green Lakes Valley (GLV), which is part of the Niwot Ridge Long Term Ecological Research site (NWT LTER).

Methods: These studies are discussed in the context of how snow, snowmelt and runoff reflect changing local climate. We review recent results of snow, snowmelt, hydrology and hydrochemistry from the plot to the basin scale, utilising new tools such as continuous global positioning system (GPS) measurements of snow depth, along with remotely-sensed measurements of snow-covered area and melt, combined with long-term measurements of snow properties, discharge and solute and isotopic content of water.

Results and Conclusions: Surface–groundwater interactions are important components of water quantity and quality in alpine basins. Some or most snowmelt infiltrates underlying soils and bedrock, transporting soil and bedrock products to surface waters. Infiltrating snowmelt, along with increased melt of stored ice, increases the hydrologic connectivity between the terrestrial and aquatic systems. Alpine basins are being impacted by increases in atmospheric nitrogen deposition, which has caused changes in soil microbial processes such as nitrification. Nitrate, dissolved organic carbon and dissolved organic nitrogen are thus flushed from soils and talus to streams. Our long-term results show that alpine catchments, such as Green Lake 4 at NWT LTER+, have the greatest sensitivity and least resilience to climate warming, with any warming leading to increased water yields.     

Natural diterpenes from <Emphasis Type="Italic">Croton ciliatoglanduliferus</Emphasis> as photosystem II and photosystem I inhibitors in spinach chloroplasts

In our search for new natural photosynthetic inhibitors that could lead to the development of “green herbicides” less toxic to environment, the diterpene labdane-8α,15-diol (1) and its acetyl derivative (2) were isolated for the first time from Croton ciliatoglanduliferus Ort. They inhibited photophosphorylation, electron transport (basal, phosphorylating and uncoupled) and the partial reactions of both photosystems in spinach thylakoids. Compound 1 inhibits the photosystem II (PS II) partial reaction from water to Na⁺ Silicomolibdate (SiMo) and has no effect on partial reaction from diphenylcarbazide (DPC) to 2,6-dichlorophenol indophenol (DCPIP), therefore 1 inhibits at the water splitting enzyme and also inhibits PS I partial reaction from reduced phenylmetasulfate (PMS) to methylviologen (MV). Thus, it also inhibits in the span of P₇₀₀ to Iron sulfur center X (F_X). Compound 2 inhibits both, the PS II partial reactions from water to SiMo and from DPC to DCPIP; besides this, it inhibits the photosystem I (PS I) partial reaction from reduced PMS to MV. With these results, we concluded that the targets of the natural product 2 are located at the water splitting enzyme, and at P₆₈₀ in PS II and at the span of P₇₀₀ to F_X in PS I. The results of compounds 1 and 2 on PS II were corroborated by chlorophyll a fluorescence.     

Children’s book series and associated curricula support elementary education and outreach in water resources

Background: Water resources are of fundamental importance to society, and are better managed by stakeholders who understand resource issues. Gaining such knowledge is a lifelong process best begun at an early age and best supported by educational approaches integrating across science, technology, engineering and mathematics (STEM). Research scientists can bring resource education to young audiences through children’s books and curricula that emphasise and integrate across STEM principals.

Aims: To encourage empathy for the environment in younger students, researchers at the Niwot Ridge Long Term Ecological Research site have developed a children’s book series and methods for training teachers in water science education.

Methods: Children’s books in the My Water series are paired with curricula, hands-on learning kits, teacher development training and dissemination of materials through school districts to further water science education.

Results: Thousands of children and educators have received training through the My Water book series, and a more broadly focused, federally funded Schoolyard Children’s Book Series has grown out of these efforts towards water resource education.

Conclusions: Children’s books and curricula that integrate STEM principals can play a key role in the development of environmental empathy and lifelong learning to support resource management.     

A general enhancement scheme in heteronuclear multidimensional NMR employing pulsed field gradients

Summary General pulse sequence elements that achieve sensitivity-enhanced coherence transfer from a heteronucleus to protons of arbitrary multiplicity are introduced. The building blocks are derived from the sensitivity-enhancement scheme introduced by Cavanagh et al. ((1991) J. Magn. Reson., 91, 429–436), which was used in conjunction with gradient coherence selection by Kay et al. ((1992) J. Am. Chem. Soc., 114, 10663–10665), as well as from a multiple-pulse sequence effecting a heteronuclear planar coupling Hamiltonian. The building blocks are incorporated into heteronuclear correlation experiments, in conjunction with coherence selection by the formation of a heteronuclear gradient echo. This allows for efficient water suppression without the need for water presaturation. The methods are demonstrated in HSQC-type experiments on a sample of a decapeptide in H₂O. The novel pulse sequence elements can be incorporated into multidimensional experiments.     

The Genus Nomocharis

Background: Ziziphus lotus, wild jujube, is a xerophytic shrub of the Rhamnaceae family widely distributed in arid and semi-arid regions of Tunisia, where it occupies most soil types. Phenological patterns of desert plants are strongly affected by the seasonality of water availability and phreatophytes represent a particularly interesting case for studying such relationships.

Aim: This study aims to investigate the relationship between phenological traits and water potential patterns of the wild jujube as a tool for understanding how plants cope with extreme drought.

Methods: Phenophases and predawn (Ψ_pd) and midday (Ψ_md) xylem water potentials of wild jujube were studied monthly (Nov 2007–Oct 2008) at Samaâliate and Oued El Hallouf in southern Tunisia. These sites receive164 mm and 191 mm of annual rainfall, respectively, and differ in slope and soil type.

Results: The Ψ_md decreased progressively and concomitantly with increasing seasonal drought, reaching the lowest values in late summer (down to –3.9 MPa for both sites). Seasonality of Ψ_pd was less pronounced for plants established in Oued El Hallouf (–2.09 MPa) than in Samaâliate (–2.63 MPa) at the end of the dry season. Wild jujube is dormant from October through to March and mature plants flower in May and produce fruits in August.

Conclusions: Our results clearly demonstrate that wild jujube is a drought tolerant species reaching low water potentials during the driest months of summer.     

Effect of turgor pressure on water permeability ofAllium cepa epidermis cell membranes

Summary Using onion epidermis layer a very accurate method for measuring the permeability of epidermis cells to water was standardized. In this method a 1.4 cm diameter epidermis disc was soaked in tritiated water (500 Ci/ml) for about 1 hr. Next the disc was mounted in a specially designed elution chamber where it was held flat and washed on the noncuticular side with ordinary water. A constant flow rate, high enough to minimize unstirred layer effect, was used. Permeability was calculated in the usual way after separating different exponentials from the efflux curve of tritiated water. Turgor pressure of the cell was regulated by soaking the disc in mannitol solutions containing tritiated water and washing it in the chamber with same concentration mannitol solution containing no radioactivity. Water permeability values were found to decrease less than 8% when the turgor pressure was decreased from 8 atm (full turgor) to zero. Turgor pressure had no significant effect on the water permeability of onion epidermal cells. Our results are contradictory to the findings of Zimmerman and Steudle (1974,J. Membrane Biol. 16:331) but are similar to the findings of Tazawa and Kamiya (1966,Aust. J. Biol. Sci. 19:339) and Kiyosawa and Tazawa (1972,Protoplasma 74:257).     

NEW ARRENURUS SPECIES (ACARI,HYDRACHNELLAE, ARRENURIDAE) FROM SOUTHERN AFRICA

SUMMARY

Five new Arrenurus spp, from Southern Africa are described: A. amoenus sp. nov. from Natal, A. agnewi sp. nov., A. curtipalpus sp. nov., A. pedatus sp. nov. and A. cavatus sp. nov. from Botswana. The species from Natal came from an older collection belonging to the National Institute for Water Research. The species from Botswana were collected recently by Dr J.D. Agnew¹

The water mite fauna of South Africa is only partly known. Therefore it is important that collectors should know that alcohol and formalin are not suitable fixatives. Fixing and storing is most successful in the following mixture: 5 parts glycerin, 2 parts glacial acetic acid and 3 parts water.     

Molecular hydrogen alleviates motor deficits and muscle degeneration in mdx mice

Objective: Duchenne muscular dystrophy (DMD) is a devastating muscle disease caused by a mutation in DMD encoding dystrophin. Oxidative stress accounts for dystrophic muscle pathologies in DMD. We examined the effects of molecular hydrogen in mdx mice, a model animal for DMD.

Methods: The pregnant mother started to take supersaturated hydrogen water (>5?ppm) ad libitum from E15.5 up to weaning of the offspring. The mdx mice took supersaturated hydrogen water from weaning until age 10 or 24 weeks when they were sacrificed.

Results: Hydrogen water prevented abnormal body mass gain that is commonly observed in mdx mice. Hydrogen improved the spontaneous running distance that was estimated by a counter-equipped running-wheel, and extended the duration on the rota-rod. Plasma creatine kinase activities were decreased by hydrogen at ages 10 and 24 weeks. Hydrogen also decreased the number of central nuclei of muscle fibers at ages 10 and 24 weeks, and immunostaining for nitrotyrosine in gastrocnemius muscle at age 24 weeks. Additionally, hydrogen tended to increase protein expressions of antioxidant glutathione peroxidase 1, as well as anti-apoptotic Bcl-2, in skeletal muscle at age 10 weeks.

Discussion: Although molecular mechanisms of the diverse effects of hydrogen remain to be elucidated, hydrogen potentially improves muscular dystrophy in DMD patients.     

Production and chitinase-binding ability of lipo-chitopentaose nodulation factor

The penta-N-acetyl-chitopentaose 2 has been prepared by using recombinant E. coli strains harboring the nodC gene (encoding chitooligosaccharide synthase) from Azorhizobium caulinodans. Then, the deacetylase NodB removed the N-acetyl moiety from the nonreducing terminus of 2 to give tetra-N-acetyl-chitopentaose 3. N-Acylation of 3 with stearyl chloride was performed in DMF containing water and provided the corresponding lipo-chitopentaose nodulation factor 4. A binding chitinase assay indicated that 4 was much more stable than 3.     

Identification and probiotic properties of lactobacilli isolated from two different fermented beverages

Purpose

Scientific information regarding the microbial content and functional aspects of fermented beverages traditionally produced in certain parts of Europe are scarce. However, such products are believed to have some health benefits and might contain functional bacterial strains, such as probiotics. The aim of the study was to identify such lactic acid bacteria strains isolated from water kefir and, for the first time, from braga, a Romanian fermented beverage made of cereals.

Methods

Lactic acid bacteria (LAB) were identified to species level based on (GTG)₅-PCR fingerprinting and 16S rRNA gene sequencing. Selected strains were screened for their antibacterial activity and probiotic potential.

Results

Eight isolates belonging to seven Lactobacillus species were recovered from the two drinks. The identification of LAB involved in the fermentation of braga (Lactobacillus plantarum, Lactobacillus fermentum, and Lactobacillus delbrueckii) is firstly reported here. Five of the Lactobacillus isolates showed antibacterial activity against pathogenic bacteria, including Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Salmonella enterica. Moreover, most of them showed a good resistance to pH 2.5 and some survived at high concentrations of bile salts (up to 2%). Two L. plantarum isolates were able to inhibit all the indicator strains, and showed the best viability (about 70%) after a sequential treatment simulating the passage through the gastrointestinal tract.

Conclusion

Based on the results, the most promising candidates for designing new probiotic products are: L. plantarum BR9 from braga and L. plantarum CR1 from water kefir.

     

The Origin and Age of Biogeochemical Trends in Deep Fracture Water of the Witwatersrand Basin,South Africa

Water residing within crustal fractures encountered during mining at depths greater than 500 meters in the Witwatersrand basin of South Africa represents a mixture of paleo-meteoric water and 2.0–2.3 Ga hydrothermal fluid. The hydrothermal fluid is highly saline, contains abiogenic CH ₄ and hydrocarbon, occasionally N ₂ , originally formed at ～ 250–300°C and during cooling isotopically exchanged O and H with minerals and accrued H ₂ , ⁴ He and other radiogenic gases. The paleo-meteoric water ranges in age from ～ 10 Ka to > 1.5 Ma, is of low salinity, falls along the global meteoric water line (GMWL) and is CO ₂ and atmospheric noble gas-rich. The hydrothermal fluid, which should be completely sterile, has probably been mixing with paleo-meteoric water for at least the past ～100 Myr, a process which inoculates previously sterile environments at depths > 2.0 to 2.5 km. Free energy flux calculations suggest that sulfate reduction is the dominant electron acceptor microbial process for the high salinity fracture water and that it is 10 ⁷ times that normally required for cell maintenance in lab cultures. Flux calculations also indicate that the potential bioavailable chemical energy increases with salinity, but because the fluence of bioavailable C, N and P also increase with salinity, the environment remains energy-limited. The ⁴ He concentrations and theoretical calculations indicate that the H ₂ that is sustaining the subsurface microbial communities (e.g. H ₂ -utilizing SRB and methanogens) is produced by water radiolysis at a rate of ～1 nM yr ^?1 . Microbial CH ₄ mixes with abiogenic CH ₄ to produce the observed isotopic signatures and indicates that the rate of methanogenesis diminishes with depth from ～ 100 at < 1 kmbls, to < 0.01 nM yr ^?1 at > 3 kmbls. Microbial Fe(III) reduction is limited due to the elevated pH. The δ¹³C of dissolved inorganic carbon is consistent with heterotrophy rather than autotrophy dominating the deeper, more saline environments. One potential source of the organic carbon may be microfilms present on the mineral surfaces.     

The molluscan genus Cominella (Gastropoda: Buccinidae) at the Three Kings Islands

Abstract

Three endemic taxa of Cominella Gray are recorded from the Three Kings Islands, New Zealand. Cominella (Josepha) regalis n.sp. and C. (Josepha) quoyana griseicalx n.ssp. occur sympatrically in relatively shallow water (to c.50m), whereas C. (Eucominia) mirabilis mirabilis Powell is known only from c.180m. The history of colonisation by these taxa is hypothesised and discussed.     

青藏高原察尔汗盐湖地区可培养中度嗜盐菌的群落结构与多样性

【目的】研究青海察尔汗盐湖地区的可培养中度嗜盐菌的群落结构及多样性。【方法】采用多种选择性培养基进行中度嗜盐菌的分离、培养;通过16S r RNA基因序列扩增、测定,根据序列信息,进行系统进化树构建、群落结构组成分析及多样性指数计算。【结果】从察尔汗盐湖卤水及湖泥中分离到中度嗜盐菌421株,合并重复菌株后共83株中度嗜盐菌。菌株16S rRNA基因序列信息显示,4株中度嗜盐菌为潜在的新分类单元。83株嗜盐细菌分布于3个门的6个科16个属。其中,Bacillus属、Oceanobacillus属和Halomonas属为优势属。多样性结果显示,水样中的菌株多样性高于泥样,而泥样中的菌株优势度高于水样。【结论】察尔汗盐湖中度嗜盐菌具有丰富的遗传多样性,种群种类丰富,优势菌群集中,该盐湖地区存在可分离培养的中度嗜盐菌的疑似新物种。     

海水来源的548株真菌的近海及远海分布模式及其抑菌活性分析

[目的]海洋真菌是新颖天然产物的理想来源.本研究旨在加深对可培养海洋真菌多样性的了解,以及挖掘具有应用潜力的海洋真菌.[方法]采用膜过滤法分离近海和远海海水样品中的真菌,通过菌株分离纯化、ITS基因序列测序,分析浅海带、半深海带和深海带海水样品中可培养真菌的多样性.在此基础上,采用固体平板法筛选具有抑菌活性的菌株.[结...     

接种功能内生细菌Diaphorobacter sp.Phe15减少蔬菜亚细胞菲积累的体外试验研究

[目的]土壤中的多环芳烃(polycyclic aromatic hydrocarbons, PAHs)可被蔬菜根系吸收并在可食部分积累进而通过食物链威胁人群健康。接种功能内生细菌能有效减低蔬菜中PAHs的积累,而关于其对蔬菜亚细胞组分中PAHs积累的影响却鲜有报道。[方法]采用体外实验,研究了接种具有菲降解功能的菌株Diaphorobacter sp. Phe15对空心菜茎叶亚细胞组分中菲积累的影响及PAHs代谢相关酶活性的响应。[结果]接种Phe15可以可加速空心菜茎叶亚细胞中菲的降解,显著削减空心菜亚细胞组分中菲的含量,接菌后空心菜亚细胞组分中菲降解率达90%以上。此外,接种功能菌Phe15可以影响空心菜亚细胞组分中PAHs代谢相关酶系的活性,空心菜亚细胞水平POD、PPO、C230活性整体得到提高,且酶系活性与空心菜体内菲积累呈负相关关系。[结论]接种具有菲降解功能的菌株Phe15增加了空心菜亚细胞水平PAHs代谢相关酶系活性,进而降低空心菜体内菲的积累,研究结果为利用功能内生细菌削减蔬菜中多环芳烃污染提供了一定的参考和理论依据。     

Modified procedures for extraction and analysis of carrageenan applied to the red alga Hypnea musciformis

Dried powder of Hypnea musciformis was extracted with water at pH 7 after an initial short pre-treatment with cold, diluted HCl. Carrageenans were isolated by alcohol precipitation after an amylase treatment and a filtration of the extracts. The yields at 25 and 90 °C were 25 and 75% (w/w) of the dry alga, with molecular weights (M_w) corresponding to 194 000 and 245 000, respectively. The chemical structure was dominated by G4S-DA-(kappa-carrageenan or carrageenose 4-sulphate). A simple fractionation procedure for kappa-carrageenase hydrolysates, based on stirring in different enthanol/water mixtures, is introduced. NMR analysis showed that oligosaccharides with a repeating DA-G4S structure were the main constituents in the enzymic hydrolysates of the carrageenans from Hypnea musciformis. These oligosaccharides were solubilized in an ethanol concentration from 96 to 48% (v/v). In some enzyme resistant fractions D6S-G4S and DA2S-G4S sequences and D2S,6S unites were detected by ¹³C-NMR.Author for correspondence