Pub Date : 2016-09-01DOI: 10.1127/ALGOL_STUD/2016/0274
Sandra Heinrich
Marine macroalgae are key organisms in polar coastal ecosystems. Brown macroalgae dominate rocky shores in both polar hemispheres, where they form huge kelp beds, which are habitat and feeding ground for diverse organisms. To compare physiological response of Arctic vs. Antarctic habitat structuring brown algae to different abiotic factors, Saccharina latissima (Kongsfjorden, Arctic) and Desmarestia anceps (Potter Cove, Antarctic) were exposed for 8h to 12 combinations of photosynthetically active radiation (PAR), UV radiation (UVR) and temperature. The data provide basis information on short abiotic stress in S. latissima and D. anceps. Temperature alone did not cause changes in photosynthetic efficiency, while UVR and high PAR decreased the maximum quantum yield of PS II down to 30% of the initial values. The endemic species D. anceps showed mostly similar responses to the applied stress treatments compared to the generalist S. latissima, indicating a certain tolerance of D. anceps to short periods of UVR and temperature stress. More data are needed to predict biological effects and ecological implications of changing abiotic factors, future studies should include several stress exposure times and gradual changing abiotic factors.
{"title":"Short term physiological response to light, UVR and temperature stress in Antarctic versus Arctic habitat structuring brown algae","authors":"Sandra Heinrich","doi":"10.1127/ALGOL_STUD/2016/0274","DOIUrl":"https://doi.org/10.1127/ALGOL_STUD/2016/0274","url":null,"abstract":"Marine macroalgae are key organisms in polar coastal ecosystems. Brown macroalgae \u0000dominate rocky shores in both polar hemispheres, where they form huge kelp beds, which \u0000are habitat and feeding ground for diverse organisms. To compare physiological response of \u0000Arctic vs. Antarctic habitat structuring brown algae to different abiotic factors, Saccharina \u0000latissima (Kongsfjorden, Arctic) and Desmarestia anceps (Potter Cove, Antarctic) were exposed \u0000for 8h to 12 combinations of photosynthetically active radiation (PAR), UV radiation \u0000(UVR) and temperature. The data provide basis information on short abiotic stress in S. latissima \u0000and D. anceps. Temperature alone did not cause changes in photosynthetic efficiency, \u0000while UVR and high PAR decreased the maximum quantum yield of PS II down to 30% of the \u0000initial values. The endemic species D. anceps showed mostly similar responses to the applied \u0000stress treatments compared to the generalist S. latissima, indicating a certain tolerance of D. \u0000anceps to short periods of UVR and temperature stress. More data are needed to predict biological \u0000effects and ecological implications of changing abiotic factors, future studies should \u0000include several stress exposure times and gradual changing abiotic factors.","PeriodicalId":90782,"journal":{"name":"Algological studies (Stuttgart, Germany : 2007)","volume":"151 1","pages":"151-165"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1127/ALGOL_STUD/2016/0274","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64050671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-09-01DOI: 10.1127/ALGOL_STUD/2016/0252
B. Kutschan, S. Thoms, M. Bayer-Giraldi
The diatom species Fragilariopsis cylindrus produces antifreeze proteins (AFPs) of moderate thermal hysteresis. Two concepts are often used in order to describe a thermal hysteresis, on the one hand the irreversible nucleation growth described by the Gibbs-Thomson relation and on the other hand a nonlinear adsorption kinetics of the ice-binding proteins. We refer to the Landau's phase transition theory and predict a saturation concentration of AFPs for the maximal freezing depression. The derived functional relation between temperature and AFP concentration is more complex than a simple power law as suggested by thermal hysteresis experiments. With the parameter set obtained for Fragilariopsis cylindrus the modelled curve is comparable with the often used square root law.
{"title":"Thermal hysteresis of antifreeze proteins considering Fragilariopsis cylindrus","authors":"B. Kutschan, S. Thoms, M. Bayer-Giraldi","doi":"10.1127/ALGOL_STUD/2016/0252","DOIUrl":"https://doi.org/10.1127/ALGOL_STUD/2016/0252","url":null,"abstract":"The diatom species Fragilariopsis cylindrus produces antifreeze proteins (AFPs) of moderate thermal hysteresis. Two concepts are often used in order to describe a thermal hysteresis, on the one hand the irreversible nucleation growth described by the Gibbs-Thomson relation and on the other hand a nonlinear adsorption kinetics of the ice-binding proteins. We refer to the Landau's phase transition theory and predict a saturation concentration of AFPs for the maximal freezing depression. The derived functional relation between temperature and AFP concentration is more complex than a simple power law as suggested by thermal hysteresis experiments. With the parameter set obtained for Fragilariopsis cylindrus the modelled curve is comparable with the often used square root law.","PeriodicalId":90782,"journal":{"name":"Algological studies (Stuttgart, Germany : 2007)","volume":"151 1","pages":"69-85"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64050016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-09-01DOI: 10.1127/ALGOL_STUD/2016/0256
M. Rippin, Karin Komsic-Buchmann, B. Becker
Biological soil crust (BSC) communities can be found in almost all environments except for the tropics. These microbial mats are especially predominant in ecosystems, which exhibit harsh conditions, in which they play a key role as primary producers. Studying their metatranscriptomic data enables scientists to shed light on taxa composition, the interactions between those organisms and their ability to cope with abiotic stressors in the extreme environments, e.g.the polar regions. The basis of a successful metatranscriptomic analysis is the isolation of pure RNA of high quality and integrity. Nucleic acid extraction from soil samples is challenging due the diverse chemical and physical properties of soil. Humic substances are often co-extracted and, subsequently, contaminate the sample. In this study, different RNA extraction techniques were tested and evaluated for the isolation of high quality RNA from four BSC samples, three isolated in Germany and one polar BSC: a CTAB based protocol, the Spectrum™ Plant Total RNA Kit and the Precellys Plant RNA Kit. The CTAB based method provides high quality RNA at a low yield and with an average degree of contamination for all tested samples. RNA obtained by using the Spectrum™ Plant Total RNA Kit is of high quality with only little contamination but only half of the samples could be processed successfully. A high throughput approach is the Precellys Plant RNA Kit resulting in a fair RNA quality but with the highest level of contamination. Furthermore, only three out of four samples yielded any results. Further purification is often necessary as DNA and humic substances often cannot be easily removed. Using enzymatic digestion DNA can be specifically cleaved while humic substances can be separated from the RNA fraction by using either gel filtration or RNA affinity binding columns.
生物土壤结皮(BSC)群落可以在除热带以外的几乎所有环境中发现。这些微生物席在条件恶劣的生态系统中尤其占优势，它们作为初级生产者在生态系统中发挥着关键作用。研究它们的超转录组学数据使科学家们能够阐明分类群的组成、这些生物之间的相互作用以及它们在极端环境(如极地地区)中应对非生物应激源的能力。成功的亚转录组学分析的基础是高质量和完整性的纯RNA的分离。由于土壤的化学和物理性质不同，从土壤样品中提取核酸具有挑战性。腐殖质经常被共同提取，随后污染样品。在这项研究中，测试和评估了不同的RNA提取技术，以从四个BSC样品中分离出高质量的RNA，三个在德国分离，一个极地BSC:基于CTAB的协议，Spectrum™植物总RNA试剂盒和Precellys植物RNA试剂盒。基于CTAB的方法以低产量和平均污染程度为所有测试样品提供高质量的RNA。使用Spectrum™Plant Total RNA Kit获得的RNA质量高，污染少，但只有一半的样品可以成功处理。Precellys Plant RNA Kit是一种高通量的方法，可以产生公平的RNA质量，但污染程度最高。此外，只有四分之三的样本产生了任何结果。由于DNA和腐殖质往往不容易被去除，因此进一步的净化往往是必要的。利用酶切可以特异性地切割DNA，而腐殖质物质可以通过凝胶过滤或RNA亲和结合柱从RNA部分分离。
{"title":"RNA isolation from biological soil crusts: methodological aspects","authors":"M. Rippin, Karin Komsic-Buchmann, B. Becker","doi":"10.1127/ALGOL_STUD/2016/0256","DOIUrl":"https://doi.org/10.1127/ALGOL_STUD/2016/0256","url":null,"abstract":"Biological soil crust (BSC) communities can be found in almost all environments except for the tropics. These microbial mats are especially predominant in ecosystems, which exhibit harsh conditions, in which they play a key role as primary producers. Studying their metatranscriptomic data enables scientists to shed light on taxa composition, the interactions between those organisms and their ability to cope with abiotic stressors in the extreme environments, e.g.the polar regions. The basis of a successful metatranscriptomic analysis is the isolation of pure RNA of high quality and integrity. Nucleic acid extraction from soil samples is challenging due the diverse chemical and physical properties of soil. Humic substances are often co-extracted and, subsequently, contaminate the sample. In this study, different RNA extraction techniques were tested and evaluated for the isolation of high quality RNA from four BSC samples, three isolated in Germany and one polar BSC: a CTAB based protocol, the Spectrum™ Plant Total RNA Kit and the Precellys Plant RNA Kit. The CTAB based method provides high quality RNA at a low yield and with an average degree of contamination for all tested samples. RNA obtained by using the Spectrum™ Plant Total RNA Kit is of high quality with only little contamination but only half of the samples could be processed successfully. A high throughput approach is the Precellys Plant RNA Kit resulting in a fair RNA quality but with the highest level of contamination. Furthermore, only three out of four samples yielded any results. Further purification is often necessary as DNA and humic substances often cannot be easily removed. Using enzymatic digestion DNA can be specifically cleaved while humic substances can be separated from the RNA fraction by using either gel filtration or RNA affinity binding columns.","PeriodicalId":90782,"journal":{"name":"Algological studies (Stuttgart, Germany : 2007)","volume":"151 1","pages":"21-37"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1127/ALGOL_STUD/2016/0256","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64050191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-09-01DOI: 10.1127/ALGOL_STUD/2016/0260
Sigrid Pfaff, Lydia Gustavs, A. Reichardt, R. Jaskulke, H. Ewald, Gäbler-Schwarz, U. Karsten
The colony forming phytoplankton species Phaeocystis pouchetii plays a key role in nutrient turnover and the fixation of inorganic carbon in the Arctic and sub-Arctic Ocean. In the Fram Strait, salinity is a variable parameter due to freezing and melting processes of sea ice and due to a bidirectional current regime providing the exchange of water masses between the Arctic and Atlantic Ocean. We tested the growth response of seven P. pouchetii strains to six different salinities (7–60) in order to identify ecotypes adapted to specific environmental regimes. The experimental setup was realized by means of a custom-build incubator enabling ecophysiological treatments at low temperatures combined with high irradiances. Salinity tolerance showed a heterogenic, strain specific pattern varying from broad (salinity 60) to relatively narrow ranges (salinity 33–45) indicating an ecophysiological differentiation which is rather dependent on the sampling period than on the geographical origin. In order to confirm these findings it is however necessary to obtain data from strains isolated in the same year or even from the same bloom. The ecotype question can only be solved when methodical constraints concerning molecular taxonomy of P. pouchetii are resolved.
{"title":"Ecophysiological plasticity in the Arctic phytoplankton species Phaeocystis pouchetii (Prymnesiophyceae, Haptophyta)","authors":"Sigrid Pfaff, Lydia Gustavs, A. Reichardt, R. Jaskulke, H. Ewald, Gäbler-Schwarz, U. Karsten","doi":"10.1127/ALGOL_STUD/2016/0260","DOIUrl":"https://doi.org/10.1127/ALGOL_STUD/2016/0260","url":null,"abstract":"The colony forming phytoplankton species Phaeocystis pouchetii plays a key role in nutrient turnover and the fixation of inorganic carbon in the Arctic and sub-Arctic Ocean. In the Fram Strait, salinity is a variable parameter due to freezing and melting processes of sea ice and due to a bidirectional current regime providing the exchange of water masses between the Arctic and Atlantic Ocean. We tested the growth response of seven P. pouchetii strains to six different salinities (7–60) in order to identify ecotypes adapted to specific environmental regimes. The experimental setup was realized by means of a custom-build incubator enabling ecophysiological treatments at low temperatures combined with high irradiances. Salinity tolerance showed a heterogenic, strain specific pattern varying from broad (salinity 60) to relatively narrow ranges (salinity 33–45) indicating an ecophysiological differentiation which is rather dependent on the sampling period than on the geographical origin. In order to confirm these findings it is however necessary to obtain data from strains isolated in the same year or even from the same bloom. The ecotype question can only be solved when methodical constraints concerning molecular taxonomy of P. pouchetii are resolved.","PeriodicalId":90782,"journal":{"name":"Algological studies (Stuttgart, Germany : 2007)","volume":"151 1","pages":"87-102"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64050511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-09-01DOI: 10.1127/ALGOL_STUD/2016/0271
C. Schlie, U. Karsten
The Antarctic continent is separated and isolated by the Antarctic Circumpolar Current from more northern water masses since millions of years, and hence characterised by low and stable temperatures throughout the whole year. Due to this long isolation a large number of endemic marine algae and animals have developed in this southern polar region, which probably might respond negatively to the predicted climate change as already observed around the Antarctic Peninsula. For algae the degree of endemism in the Antarctic flora had been well analysed for macroalgae, while for microalgae such as phytoplankton, sea ice algae or microphytobenthos only few data exist until now. From an ecophysiological standpoint the evaluation and characterisation of the temperature requirements for growth represents a widely used approach to identify algae endemic to Antarctica because of their adaptation to low temperatures. Since such data on polar diatoms are rare, an Antarctic isolate of the genus Navicula was incubated under a range of temperatures (1, 5, 15, 20, 25 °C) and the growth response followed. In addition, since salinity represents also a variable parameter along the ice-edges of Antarctica, growth was measured under various salinities between 5 and 50 S A . Navicula cf. normaloides Cholnoky grew under all salinities between 5 and 50 S A, but with different rates indicating a broad tolerance range. This diatom grew between 1°C and 15 °C with an optimum at 5 °C, but at 20 °C and 25 °C growth was completely inhibited. Hence this Navicula species can be described as a stenothermal/psychrotolerant species, because it has a broader temperature tolerance and prefers higher temperatures compared to other micro- and macroalgae endemic to Antarctica. Navicula cf. normaloides Cholnoky exhibited an unexpectedly broad temperature tolerance, and hence might certainly not be considered as an endemic species, although it can well cope with cold to temperate conditions.
{"title":"Growth of the Antarctic sea ice diatom Navicula cf. normaloides Cholnoky at different temperatures and salinities","authors":"C. Schlie, U. Karsten","doi":"10.1127/ALGOL_STUD/2016/0271","DOIUrl":"https://doi.org/10.1127/ALGOL_STUD/2016/0271","url":null,"abstract":"The Antarctic continent is separated and isolated by the Antarctic Circumpolar Current from more northern water masses since millions of years, and hence characterised by low and stable temperatures throughout the whole year. Due to this long isolation a large number of endemic marine algae and animals have developed in this southern polar region, which probably might respond negatively to the predicted climate change as already observed around the Antarctic Peninsula. For algae the degree of endemism in the Antarctic flora had been well analysed for macroalgae, while for microalgae such as phytoplankton, sea ice algae or microphytobenthos only few data exist until now. From an ecophysiological standpoint the evaluation and characterisation of the temperature requirements for growth represents a widely used approach to identify algae endemic to Antarctica because of their adaptation to low temperatures. Since such data on polar diatoms are rare, an Antarctic isolate of the genus Navicula was incubated under a range of temperatures (1, 5, 15, 20, 25 °C) and the growth response followed. In addition, since salinity represents also a variable parameter along the ice-edges of Antarctica, growth was measured under various salinities between 5 and 50 S A . Navicula cf. normaloides Cholnoky grew under all salinities between 5 and 50 S A, but with different rates indicating a broad tolerance range. This diatom grew between 1°C and 15 °C with an optimum at 5 °C, but at 20 °C and 25 °C growth was completely inhibited. Hence this Navicula species can be described as a stenothermal/psychrotolerant species, because it has a broader temperature tolerance and prefers higher temperatures compared to other micro- and macroalgae endemic to Antarctica. Navicula cf. normaloides Cholnoky exhibited an unexpectedly broad temperature tolerance, and hence might certainly not be considered as an endemic species, although it can well cope with cold to temperate conditions.","PeriodicalId":90782,"journal":{"name":"Algological studies (Stuttgart, Germany : 2007)","volume":"151 1","pages":"39-49"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1127/ALGOL_STUD/2016/0271","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64050664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-05-01DOI: 10.1127/ALGOL_STUD/2016/0233
A. Baloloy, M. A. L. Guzman, Teresita R. Perez, S. Salmo, J. R. Unson, Jason D. Baldesco, Joanaviva C. Plopenio
Phytoplankton were collected from eight sampling stations around Lake Buhi (Camarines Sur, Philippines) in September and November 2013. The eight sites represented varied zonation and resource uses. A total of 29 species were identified belonging to five major taxonomic groups: the diatoms (Heterokontophyta), green algae (Chlorophyta), cyanobacteria (Cyanophyta), eustigmatophytes (Heterokontophyta) and dinoflagellates (Dinophyta). Diatoms were the most abundant group (50%), followed by the green algae (41%). Sampling station with high concentration of fish pens generated high diversity (Shannon-Wiener diversity index 2.65) with dominance of pollution tolerant taxa, while the site near the outlet of the lake has the highest phytoplankton abundance (0.139 cells/ml). Results revealed significant differences in relative abundance of phytoplankton among sampling sites and between sampling months within each site. These differences were attributed to the variation in physico-chemical parameters among the sites. Canonical Correspondence Analysis (CCA) showed that nitrate, depth and turbidity positively influenced phytoplankton abundance. Variation in the abiotic factors, including resource use, affected spatial and temporal distribution of the phytoplankton community. Remediation measures on the lake must be directed towards the primary sources of these variations.
{"title":"Phytoplankton composition and diversity in response to abiotic factors in Lake Buhi, Camarines Sur, Philippines","authors":"A. Baloloy, M. A. L. Guzman, Teresita R. Perez, S. Salmo, J. R. Unson, Jason D. Baldesco, Joanaviva C. Plopenio","doi":"10.1127/ALGOL_STUD/2016/0233","DOIUrl":"https://doi.org/10.1127/ALGOL_STUD/2016/0233","url":null,"abstract":"Phytoplankton were collected from eight sampling stations around Lake Buhi (Camarines \u0000Sur, Philippines) in September and November 2013. The eight sites represented varied \u0000zonation and resource uses. A total of 29 species were identified belonging to five major taxonomic \u0000groups: the diatoms (Heterokontophyta), green algae (Chlorophyta), cyanobacteria (Cyanophyta), \u0000eustigmatophytes (Heterokontophyta) and dinoflagellates (Dinophyta). Diatoms \u0000were the most abundant group (50%), followed by the green algae (41%). Sampling station with \u0000high concentration of fish pens generated high diversity (Shannon-Wiener diversity index 2.65) \u0000with dominance of pollution tolerant taxa, while the site near the outlet of the lake has the highest \u0000phytoplankton abundance (0.139 cells/ml). Results revealed significant differences in relative \u0000abundance of phytoplankton among sampling sites and between sampling months within \u0000each site. These differences were attributed to the variation in physico-chemical parameters \u0000among the sites. Canonical Correspondence Analysis (CCA) showed that nitrate, depth and \u0000turbidity positively influenced phytoplankton abundance. Variation in the abiotic factors, including \u0000resource use, affected spatial and temporal distribution of the phytoplankton community. \u0000Remediation measures on the lake must be directed towards the primary sources of these \u0000variations.","PeriodicalId":90782,"journal":{"name":"Algological studies (Stuttgart, Germany : 2007)","volume":"8 1","pages":"21-38"},"PeriodicalIF":0.0,"publicationDate":"2016-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1127/ALGOL_STUD/2016/0233","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64049800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-05-01DOI: 10.1127/algol_stud/2016/0239
Adil Y. AL-HANDAL, K. Taffs, Dawood S. Abdullah, A. Zawadzki
The Mesopotamian marshlands are one of the most internationally important wetlands in the Middle East as it constitutes a nursing ground for many species of birds migrating from North Europe as well as for its rich biodiversity. These marshlands have undergone significant environmental changes during the last three decades owing to decreasing freshwater discharge which has led to water quality deterioration and a changing hydrological regime. This has had a considerable effect on the fauna and flora of the marshes, diminishing their ecological value and significance. The work presented here is the first attempt to investigate the marshes environmental condition during the past two centuries using paleolimnology, specifically diatoms as bioindicators in a sediment core. 80 species of diatom belonging to 35 genera were identified. The taxa encountered in the core are a mixture of fresh and brackish water forms. These are epiphytic and benthic taxa, no planktonic species were found. The fossil diatom community shows that the marshes have been exposed to different periods of salinization as well as eutrophication. The dominance of pollution tolerant species in the core indicates poor water quality for the past 160 years. Paleolimnology is important to understand past environmental conditions and forms a milestone for successful future restoration process. Further work is required to extend the time scale to identify natural ecological states and thresholds to guide international aid restoration projects.
{"title":"Vertical distribution of diatoms in the sediment of Al-Huwaiza Marsh, Southern Iraq and their use as indicators of environmental changes","authors":"Adil Y. AL-HANDAL, K. Taffs, Dawood S. Abdullah, A. Zawadzki","doi":"10.1127/algol_stud/2016/0239","DOIUrl":"https://doi.org/10.1127/algol_stud/2016/0239","url":null,"abstract":"The Mesopotamian marshlands are one of the most internationally important wetlands \u0000in the Middle East as it constitutes a nursing ground for many species of birds migrating \u0000from North Europe as well as for its rich biodiversity. These marshlands have undergone significant \u0000environmental changes during the last three decades owing to decreasing freshwater \u0000discharge which has led to water quality deterioration and a changing hydrological regime. This \u0000has had a considerable effect on the fauna and flora of the marshes, diminishing their ecological \u0000value and significance. The work presented here is the first attempt to investigate the marshes \u0000environmental condition during the past two centuries using paleolimnology, specifically diatoms \u0000as bioindicators in a sediment core. 80 species of diatom belonging to 35 genera were \u0000identified. The taxa encountered in the core are a mixture of fresh and brackish water forms. \u0000These are epiphytic and benthic taxa, no planktonic species were found. The fossil diatom community \u0000shows that the marshes have been exposed to different periods of salinization as well as \u0000eutrophication. The dominance of pollution tolerant species in the core indicates poor water \u0000quality for the past 160 years. Paleolimnology is important to understand past environmental \u0000conditions and forms a milestone for successful future restoration process. Further work is required \u0000to extend the time scale to identify natural ecological states and thresholds to guide international \u0000aid restoration projects.","PeriodicalId":90782,"journal":{"name":"Algological studies (Stuttgart, Germany : 2007)","volume":"150 1","pages":"53-75"},"PeriodicalIF":0.0,"publicationDate":"2016-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1127/algol_stud/2016/0239","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64049866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-05-01DOI: 10.1127/ALGOL_STUD/2015/0210
Julia Vergalli, C. Bertrand, Andréa Borla, E. Franquet, S. Fayolle
Planktothrix agardhii (P. agardhii), a filamentous cyanobacterium commonly found in freshwater environments, has also been reported in brackish areas. In order to test the hypothesis of an acclimation of P. agardhii to its environmental salinity, we monitored growth and morphometry of P. agardhii brackish and freshwater strains under various salinities (0 to 15 psu). Despite differences in their response under increasing salinities (0–15 psu), the brackish strains show: (i) growth less gradually inhibited by increasing salinities than the freshwater strains; (ii) growth nearly optimal in the salinity of their natural environment (iii) a salt tolerance range wider (0 to [12.5–15 psu]) than that of freshwater P. agardhii (0 to [7.5–10 psu]). Our findings suggest that this tolerance may be due to an acclimation of the strains to their environment by effective salt extrusion and compatible solutes accumulation. This salt acclimation, just as the population response to various salinities, is well reflected by the filaments morphometry. This study highlights the ability of potentially harmful cyanobacteria to acclimate to salinity in a salinization context.
{"title":"Salt tolerance of Planktothrix agardhii (Gomont) Anagnostidis & Komárek (cyanoprokaryota) between freshwater and brackish strains in batch cultures","authors":"Julia Vergalli, C. Bertrand, Andréa Borla, E. Franquet, S. Fayolle","doi":"10.1127/ALGOL_STUD/2015/0210","DOIUrl":"https://doi.org/10.1127/ALGOL_STUD/2015/0210","url":null,"abstract":"Planktothrix agardhii (P. agardhii), a filamentous cyanobacterium commonly found \u0000in freshwater environments, has also been reported in brackish areas. In order to test the hypothesis \u0000of an acclimation of P. agardhii to its environmental salinity, we monitored growth and \u0000morphometry of P. agardhii brackish and freshwater strains under various salinities (0 to \u000015 psu). Despite differences in their response under increasing salinities (0–15 psu), the brackish \u0000strains show: (i) growth less gradually inhibited by increasing salinities than the freshwater \u0000strains; (ii) growth nearly optimal in the salinity of their natural environment (iii) a salt tolerance \u0000range wider (0 to [12.5–15 psu]) than that of freshwater P. agardhii (0 to [7.5–10 psu]). \u0000Our findings suggest that this tolerance may be due to an acclimation of the strains to their environment \u0000by effective salt extrusion and compatible solutes accumulation. This salt acclimation, \u0000just as the population response to various salinities, is well reflected by the filaments \u0000morphometry. This study highlights the ability of potentially harmful cyanobacteria to acclimate \u0000to salinity in a salinization context.","PeriodicalId":90782,"journal":{"name":"Algological studies (Stuttgart, Germany : 2007)","volume":"150 1","pages":"3-19"},"PeriodicalIF":0.0,"publicationDate":"2016-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1127/ALGOL_STUD/2015/0210","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64049032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-01DOI: 10.1127/algol_stud/2015/0225
Karin Komsic-Buchmann, Katja Nagler, B. Becker
Brefeldin A was used to disrupt the contractile vacuoles (CVs) of the streptophyte green flagellate Mesostigma viride. Treatment of M. viride with BFA caused enlarged CVs, as well as a decrease in the number of CVs, and finally the cells burst. In addition, BFA treated cells revealed the typical changes in Golgi structure (decrease in number of cisternae and Golgiassociated COP1 vesicles) observed in other systems. It is well known that treatment with BFA inhibits the formation of COP1-coated vesicles and some types of clathrin-coated vesicles (CCV). Clathrin coated pits (CCPs) and clathrin coated vesicles are associated with the CVs in Mesostigma viride. However, electron microscopically analysis revealed that the number of CCVs did not decrease upon treatment with BFA. We conclude that the molecular cause for BFA effect on the CV must be localized at the Golgi, probably due to the inhibition of transport of proteins from the Golgi to the CV.
{"title":"Brefeldin A affects the system of contractile vacuoles in Mesostigma viride (Streptophyta)","authors":"Karin Komsic-Buchmann, Katja Nagler, B. Becker","doi":"10.1127/algol_stud/2015/0225","DOIUrl":"https://doi.org/10.1127/algol_stud/2015/0225","url":null,"abstract":"Brefeldin A was used to disrupt the contractile vacuoles (CVs) of the streptophyte green flagellate Mesostigma viride. Treatment of M. viride with BFA caused enlarged CVs, as well as a decrease in the number of CVs, and finally the cells burst. In addition, BFA treated cells revealed the typical changes in Golgi structure (decrease in number of cisternae and Golgiassociated COP1 vesicles) observed in other systems. It is well known that treatment with BFA inhibits the formation of COP1-coated vesicles and some types of clathrin-coated vesicles (CCV). Clathrin coated pits (CCPs) and clathrin coated vesicles are associated with the CVs in Mesostigma viride. However, electron microscopically analysis revealed that the number of CCVs did not decrease upon treatment with BFA. We conclude that the molecular cause for BFA effect on the CV must be localized at the Golgi, probably due to the inhibition of transport of proteins from the Golgi to the CV.","PeriodicalId":90782,"journal":{"name":"Algological studies (Stuttgart, Germany : 2007)","volume":"149 1","pages":"79-94"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1127/algol_stud/2015/0225","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64049999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-01DOI: 10.1127/ALGOL_STUD/2015/0247
Christopher F. Carter, Jeannie M. Beadle, D. John, L. Brown
Saturnella saturnus was discovered in March 2014 in open-water pools on blanket peatland at the Moor House – Upper Teesdale National Nature Reserve, straddling Cumbria and County Durham in NE England. This is the first record for the British Isles of a little-known alga recorded previously only from a few peat bog areas, mainly in mainland Europe. The literature is reviewed and new observations presented on its morphology and reproduction based on LM examination of living cells. New observations on the chloroplast structure and cytoplasmic inclusions (especially oil droplets) are discussed in relation to the findings of earlier studies. Doubt attaches as whether it is a chlorophyte or a xanthophyte and the identity of small spherical inclusions been frequently interpreted as autospores. It occurs in Upper Teesdale in pools that are small, relatively newly formed and mostly well-oxygenated. Also discussed is its relationship to Trochiscia, another coloniser of peatland pools. Photographic images are presented for the first time and comments made on its ecology in the context of blanket bog conservation projects and apparent rarity.
{"title":"New observations on Saturnella saturnus (Steinecke) Fott: the first British record of a little-known enigmatic ‘green’ alga","authors":"Christopher F. Carter, Jeannie M. Beadle, D. John, L. Brown","doi":"10.1127/ALGOL_STUD/2015/0247","DOIUrl":"https://doi.org/10.1127/ALGOL_STUD/2015/0247","url":null,"abstract":"Saturnella saturnus was discovered in March 2014 in open-water pools on blanket peatland at the Moor House – Upper Teesdale National Nature Reserve, straddling Cumbria and County Durham in NE England. This is the first record for the British Isles of a little-known alga recorded previously only from a few peat bog areas, mainly in mainland Europe. The literature is reviewed and new observations presented on its morphology and reproduction based on LM examination of living cells. New observations on the chloroplast structure and cytoplasmic inclusions (especially oil droplets) are discussed in relation to the findings of earlier studies. Doubt attaches as whether it is a chlorophyte or a xanthophyte and the identity of small spherical inclusions been frequently interpreted as autospores. It occurs in Upper Teesdale in pools that are small, relatively newly formed and mostly well-oxygenated. Also discussed is its relationship to Trochiscia, another coloniser of peatland pools. Photographic images are presented for the first time and comments made on its ecology in the context of blanket bog conservation projects and apparent rarity.","PeriodicalId":90782,"journal":{"name":"Algological studies (Stuttgart, Germany : 2007)","volume":"149 1","pages":"61-77"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1127/ALGOL_STUD/2015/0247","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64050096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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