Thermophilic Plants Research Articles

Thermophilic lignocellulose deconstruction

Thermophilic microorganisms are attractive candidates for conversion of lignocellulose to biofuels because they produce robust, effective, carbohydrate-degrading enzymes and survive under harsh bioprocessing conditions that reflect their natural biotopes. However, no naturally occurring thermophile is known that can convert plant biomass into a liquid biofuel at rates, yields and titers that meet current bioprocessing and economic targets. Meeting those targets requires either metabolically engineering solventogenic thermophiles with additional biomass-deconstruction enzymes or engineering plant biomass degraders to produce a liquid biofuel. Thermostable enzymes from microorganisms isolated from diverse environments can serve as genetic reservoirs for both efforts. Because of the sheer number of enzymes that are required to hydrolyze plant biomass to fermentable oligosaccharides, the latter strategy appears to be the preferred route and thus has received the most attention to date. Thermophilic plant biomass degraders fall into one of two categories: cellulosomal (i.e. multienzyme complexes) and noncellulosomal (i.e. 'free' enzyme systems). Plant-biomass-deconstructing thermophilic bacteria from the genera Clostridium (cellulosomal) and Caldicellulosiruptor (noncellulosomal), which have potential as metabolic engineering platforms for producing biofuels, are compared and contrasted from a systems biology perspective.

Natural assets in the right-of-way of A-4 Motorway in the Góra Świętej Anny Landscape Park, Opole Region

Construction of the A-4 Motorway section in the Opole Region begun in Summer 1997. Very soon vigorous resistance of ecological NGOs was encountered. The bone of contention was the section of motorway that passes through the Góra Świętej Anny Landscape Park and verges the natural reserve of strict protection Ligota Dolna where rare species of thermophilic plants are sheltered. Between 2011 and 2013 a detailed mycological, geobotanical, floristic and fauna research took place within the right-of-way of the A-4 Motorway section crossing the Góra Świętej Anny Landscape Park in the Opole Region. The survey revealed several rare and protected species of fungi, plants and animals along the road, including the greatest in Poland population of Austrian flax Linum austriacum. The area also harbors the only site of xerothermic grass of Festuco-Brometea class with so many rare and putrefying plant species inside a motorway’s right-of-way in Poland. Given the occurrence of many interesting species of plants and animals in the motorway surrounding it seems justified to establish a system of ecological monitoring, which could provide a range of valuable findings regarding the impact of motorway traffic on surrounding flora and fauna. This knowledge would be very useful for all those involved in construction of next motorways in Poland as well as for a wide circle of interested researchers.

Proučavanje korovske flore u usevu soje na lokalitetu Sremska Mitrovica i mogućnosti njene kontrole primenom herbicida

For the purpose of studying the weed flora in soybeans and possibilities of its containment through an application of herbicides, research has been conducted in various agroecological conditions, over a two-year period (2011 and 2012.), through work on experimental plots and in the laboratory, on location Sremska Mitrovica (Srem). On the aforementioned locations floristic recordings of the weed flora were conducted, followed by a determination of the plant material, data sorting, a design of floristic tables, charts, pictures, etc. Based on the analysis of life forms, a life form classification was established for the flora in the investigated area. The flora of the investigated area shows a dominant presence of therophytes, and to a much lesser extent of geophytes. On localities Sremska Mitrovica all the established species belong to wide-spread floral elements. Apart from cosmopolites, there is a predominant presence of adventive, subcircumpolar, subeuroasian, and pontosubmediteranean geoelements. The pontosubmediteranean floral element is least represented. By way of an analysis of the ecological humidity indexes, of the chemical reaction of the environment (pH), of the contents of biogenic mineral matter (nitro compounds in particular), of light, and of temperature, a domination of neutrophilic plants (K3) was determined, as well as of eutrophic habitat plants (N4), light indicator taxons (S4), and thermophilic plants (T4) (an indicator of warm habitats). The taxonomic analysis of the weed flora in soy crops grown as part of the two-year experiments in a control test variant on the studied localities has shown the presence of vascular macrophyte species, whose genera and families were determined, as well as the belonging classes, Magnolipsida (Dicotyledone) and Liliopsida (Monocotyledones). The class of Magnolipsida is dominated by the representatives of the families Brassicaceae and Asteraceae, while the representatives of other families are fewer. The class of Liliopsida (Monocotyledones) is dominated by a small number of species from the Poaceae family. The total efficacy of the applied herbicides in the investigated areas is high, and was highly dependent upon the type and combination of herbicides, and to a lesser degree on the year of examination.

Pollen and fossil wood's linkage with Mi-1 Glaciation in northeastern Tibetan Plateau, China

A more complete picture of the Cenozoic climate change and its driving mechanisms can only be obtained by an integrated analysis of widely distributed paleoclimate records from both oceanic and terrestrial sediments. However, there are fewer Cenozoic continental paleoclimatic records available when compared with the numerous marine records. Here, we present palynological results from the Xining Basin, northeastern Tibet, covering the Mi-1 Glaciation at around 23Ma. We found that cold-tolerant conifers (such as Picea, Abies, Tsuga, and Larix) thrived while thermophilic plants (Rutaceae, Anacarabiaceae, Euphorbiaceae, Sapindaceae, Myrtaceae, and Podocarpaceae) declined in the Xining Basin during the Mi-1 Glaciation. Both before and after the Mi-1 Glaciation, there were few cold-tolerant conifers but more abundant thermophilic plants in the Xining Basin. Our results clearly show that climate in the northern and southern hemispheres was strongly coupled during the Mi-1 Glaciation and that cooling around 23Ma was not limited to the southern hemisphere. We argue that the most plausible linking mechanism between Antarctic cooling and Asian cooling was the combination of low orbital eccentricity with a protracted node in obliquity.

Changes in air temperature and precipitation and impact on agriculture

Air temperature and precipitation are among the main factors for agricultural production. The aim of the present research work is to analyse changes in air temperature and precipitation in non-mountainous part of Southern Bulgaria in terms of the opportunities for the development of agriculture in the region. The trend in variability of seasonal and annual air temperature and precipitation is determined by the linear regression method. An analysis of the combination between air temperature and precipitation gives a tool to classify the climate according to dry and wet conditions of the territory. For this purpose the Gaussen-Bagnouls classification method is used in the present paper. In terms of air temperature, the investigated area is favourable for growing thermophilic plants. In order to investigate thoroughly the impact of climate change, the quantitative research has been complemented by a qualitative study – case study of farmers from the region of Stara Zagora. Case studies show that farmers are vulnerable to various degrees to the expected annual variability and average changes in yields depending on farm size, crop varieties and availability of irrigation.

New species of thermophilic plants from the Early Oligocene flora of Kraskino (Primorski Region) as evidence of its subtropic type

The transitional Eocene-Oligocene interval of the Primorski Region is briefly reviewed; paleoclimatic features of the formation of the Kraskino Flora during this period are estimated; new species of the thermophilic genera Corylopsis (Hamamelidaceae) and Brucea (Simaroubaceae) are described from the Kraskino Flora.

Pollen and spores from the Tendaguru Beds, Upper Jurassic and Lower Cretaceous of southeast Tanzania: palynostratigraphical and paleoecological implications

Two informal sporomorph assemblage zones can be distinguished in the dinosaur-bearing Tendaguru Beds of southeast Tanzanian. The first zone, the Classopollis–Araucariacites–Shanbeipollenites Assemblage Zone, ranges from the Lower to the Upper Saurian Bed, and a mid-Oxfordian to Tithonian age is suggested based on the presence of Shanbeipollenites quadratus. The second zone, the Classopollis–Cicatricosisporites–Ruffordiaspora Assemblage Zone, is restricted in the Trigonia schwarzi Bed, which overlies the Upper Saurian Bed. The combined ranges of Cicatricosisporites hughesii, Ruffordiaspora australiensis and Trilobosporites obsitus would be consistent with a late Berriasian to Hauterivian age of this zone. This is refined further to late Valanginian to Hauterivian on the basis of already existing evidence from fauna and dinoflagellate cysts. From a phytogeographic point of view the Tendaguru locality belongs to the southern Gondwana Trisaccates Province because of the presence of trisaccate podocarpaceous pollen. The quantitative composition of the palynofloras is characterized by the dominance or abundance of pollen produced by the two conifer families Cheirolepidiaceae (Classopollis) and Araucariaceae (mainly Araucariacites). Pollen of Cheirolepidiaceae, typically xerophytic, drought-resistant, thermophilic plants, is dominant throughout the Tendaguru Beds except in parts of the Middle Saurian Bed where pollen of Araucariaceae, a presumably mesic group, becomes most abundant. Classopollis attains the highest degree of dominance in the shallow marine deposits associated with the saurian beds. This may be related to paleoecological and taphonomic factors, namely abundance of Classopollis-producing plants in low-lying coastal environments close to the lagoon-like depositional sites and transportational sorting of sporomorphs leading to a relative enrichment of small and/or anemophilous pollen. The abundance of Araucariacites in the Middle Saurian Bed suggests that araucarians existed in coastal plain environments that were stable enough to allow the growth of large trees. This open araucarian forest, which may have been a source of food for high-browsing dinosaurs, was situated landward of the cheirolepidiacean belt not far from the depositional sites. Pteridophytes and bryophytes were concentrated at moist places and around water bodies. Podocarpaceous conifers producing bisaccate and trisaccate pollen grew in local uplands, while gnetaleans related to Ephedra and Welwitschia may have been present in dry places. The palynological evidence is consistent with a seasonally dry, tropical to sub-tropical paleoclimate. Three new combinations, Equisetosporites certus (Bolkhovitina), Jugella caichigüensis (Volkheimer and Quattrocchio) and Trichotomosulcites microsaccatus (Couper), are proposed, and Jugella semistriata is described as a new species.

Identification of glacial refugia in south‐eastern North America by phylogeographical analyses of a forest understorey plant, Trillium cuneatum

AbstractAim We examine several hypotheses emerging from biogeographical and fossil records regarding glacial refugia of a southern thermophilic plant species. Specifically, we investigated the glacial history and post‐glacial colonization of a forest understorey species, Trillium cuneatum. We focused on the following questions: (1) Did T. cuneatum survive the Last Glacial Maximum (LGM) in multiple refugia, and (if so) where were they located, and is the modern genetic structure congruent with the fossil record‐based reconstruction of refugia for mesic deciduous forests? (2) What are the post‐glacial colonization patterns in the present geographical range?Location South‐eastern North America.Methods We sampled 45 populations of T. cuneatum throughout its current range. We conducted phylogeographical analyses based on maternally inherited chloroplast DNA (cpDNA haplotypes) and used TCS software to reconstruct intraspecific phylogeny.Results We detected six cpDNA haplotypes, geographically highly structured into non‐overlapping areas. With one exception, none of the populations had mixed haplotype composition. TCS analysis resulted in two intraspecific cpDNA lineages, with one clade subdivided further by shallower diversification.Main conclusions Our investigation revealed that T. cuneatum survived the LGM in multiple refugia, belonging to two (western, eastern) genealogical lineages geographically structured across south‐eastern North America. The western clade is confined to the south‐western corner of T. cuneatum’s modern range along the Lower Mississippi Valley, where fossil records document a major refugium of mesic deciduous forest. For the eastern clade, modern patterns of cpDNA haplotype distribution suggest cryptic vicariance, in the form of forest contractions and subsequent expansions associated with Pleistocene glacial cycles, rather than simple southern survival and subsequent northward colonization. The north–south partitioning of cpDNA haplotypes was unexpected, suggesting that populations of this rather southern thermophilic species may have survived in more northern locations than initially expected based on LGM climate reconstruction, and that the Appalachian Mountains functioned as a barrier to the dispersal of propagules originating in more southern refugia. Furthermore, our results reveal south‐west to north‐east directionality in historical migration through the Valley and Ridge region of north‐west Georgia.

Enhanced biogas recovery by applying post-digestion in large-scale centralized biogas plants

The main objective of this study was to investigate the degradation efficiency of centralized biogas plants and provide guidance for the design of more efficient digester and post-digestion systems. These centralized biogas plants in Denmark digest manure together with organic waste from the food industry to generate biogas, which is used for electricity and thermal energy. A total of 20 such plants are currently active in Denmark, most of which were included in the investigation. From the plants, samples were obtained from various steps of the process. Samples were analysed and the residual biogas potential determined by batch post-digestion at various temperature levels. Results were correlated with plant characteristics and production statistics in order to judge the efficiency of various digestion concepts. A simplified model based on a two-step biogas production process was developed and experimental data were used to determine kinetic constants. Experimental results and analysis combined with model simulations showed that the residual biogas potential in the main digestion step effluent is originating mainly from undegraded particulate matter in the biomass. For thermophilic plants 93% of the residual biogas potential was originating from particulate matter and 88% for the mesophilic biogas plants. This indicates that the residual biogas potential is mainly due to insufficient retention time in the main digestion step for hydrolysis of particulate material and that the hydrolysis step is the methane yield limiting factor, while conversion of soluble material such as VFA is the rate limiting factor critical for achieving a stable process.

Changes in Vascular Plant Biodiversity in the Netherlands in the 20th Century Explained by their Climatic and other Environmental Characteristics

In the Netherlands nation-wide databases are available with about 10 million records of occurrences of vascular plant species in the 20th century on a scale of approximately 1 km2. These data were analysed with a view to identifying relationships between changes in botanical biodiversity and climatic and other environmental factors. Prior to analysis the data were corrected for several major forms of survey bias. The records were broken down into three periods: 1902–1949, 1975–1984 and 1985–1999. Using multiple regression analysis, differences between successive periods were related to plant functional characteristics as explanatory variables. Between the periods 1902–1949 and 1975–1984 there were small but significant increases in the presence of both thermophilic (‘warm’) and psychrophilic (‘cold’) species. However, in the final decades of the 20th century there was a marked increase in thermophilic species only, coinciding with the marked increase in ambient temperature observed during this period, evidence at least of a rapid response of Dutch flora to climate change. Urbanisation was also examined as an alternative explanation for the increase in thermophilic plant species and was found to explain only 50% of the increased presence of such species in the final decades of the 20th century. Besides temperature-related effects, the most important change during the 20th century was a strong decline in oligotrophic and a marked increase in eutrophic plant species.

Status on science and application of thermophilic anaerobic digestion

Thermophilic anaerobic processes are often regarded as less stable than mesophilic processes. In the paper this postulate is examined and disproved based on real operational data from of full-scale mesophilic and thermophilic biogas plants. The start-up procedure for the thermophilic plants was, however, found to be crucial for determining the period needed before full capacity of the thermophilic plant could be achieved. The importance of balanced loading, determined by the concentration of active biomass, is discussed. Finally, data will be shown on the optimal and maximal temperature for thermophilic digestion along with the implications for the methanogenic bacteria active at these temperatures.

Arrhenius plots and the involvement of thermotropic phase transitions of the thylakoid membrane in chilling impairment of photosynthesis in thermophilic higher plants

Arrhenius plots and the involvement of thermotropic phase transitions of the thylakoid membrane in chilling impairment of photosynthesis in thermophilic higher plants

Energy Consumption Relationships for Mesophilic and Thermophilic Digestion of Animal Manures

ABSTRACT THE energy consumption for operation of methane fermentation plants for animal manures is critical to the economics of the system. Energy used in the operation of the plant is not available for use or sale elsewhere. An evaluation of the energy use of these plants when operated at 35 °C and 60 °C has been performed for all four major waste types (beef, swine, dairy and poultry) using systems analysis and a dynamic mathematical model. Studying two options for effluent heat recovery (no heat recovery and 50% heat recovery) and simulation of typical animal operations for a year's period have shown that the thermophilic operation uses a significantly less percentage of the total energy than a comparable mesophilic plant when 50% of the effluent heat is recovered. When effluent heat is not recovered, thermophilic digestion for beef and swine waste uses approximately 3% more energy when compared to mesophilic digestion. Dairy and poultry thermophilic digestion, however, still uses less energy than mesophilic digestion. This is surprising, but the apparent reason for this result is the much smaller-compact size of the thermophilic plant and the heavier loading permitted at the elevated temperature. The net energy output (GJ/YR) of both plants (mesophilic and thermophilic) is approximately the same for each individual waste type. Therefore, based on net energy production alone (economics not considered), mesophilic and thermophilic digestion appear as equals.

Effects of Ca2+ and Temperature on Potassium Uptake along Roots of Wheat, Rice and Cucumber

AbstractThe differences in K+ uptake of different segments of excised roots of two thermophilic plants (rice, Oryza sativa L. cv. Dunghan Shali and cucumber, Cucumis sativus L. cv. Csemege Fürtös) and a non‐thermophilic plant (wheat, Triticum aestivum L. cv. Aurora) were investigated in the presence and absence of Ca2+, at 0 and 25°C, using radiotracer K+(86Rb+) technique. The K+ uptake exhibited different temperature‐ and Ca2+‐dependent distributions along the root axis for the different species studied. In the case of rice and cucumber an extraordinarily large K+ uptake occurred in the apical root portion at 0°C if Ca2+ was omitted. The presence of Ca2+ diminished this anomaly. For wheat normal K+ uptake patterns were observed under similar conditions. At 25°C Ca2+‐stimulated K+ uptake may appear in each root segment, depending upon species and composition of the uptake solution. The results indicate that there may be considerable differences in the compositions of the cell walls and membranes of root cells of thermophilic and non‐thermophilic plants, and in their ion‐exchange properties, especially in the apical region.

Effects of Ca2+ and Temperature on K+ Content Distribution along Roots of Wheat, Rice and Cucumber

AbstractThe effects of Ca2+ and temperature on the K+ contents of root segments of wheat (Triticum aestivum L. cv. Aurora), rice (Oryza sativa L. cv. Dunghan Shali) and cucumber (Cucumis sativus L. cv. Csemege Fürtös) were investigated with special regard to the low‐temperature anomaly of the K+ uptake of thermophilic plants. The anomaly occurred in those root segments where the K+ contents turned out to be highest. The K+ contents of the apical root sections of thermophilic species responded in general to Ca2+ in more pronounced ways than those of wheat, at both 0 and 25°C. The concerted actions of a purely physical process with negative temperature coefficient and of the special thermotropic properties of the membranes are suggested to be responsible for the low‐temperature anomaly. A strict discrimination between the Viets‐effect on the content (classical Viets‐effect) and on the uptake is proposed. The classical Viets‐effect seems to be related to alterations in both active transport and exchange processes.

Effect of temperature and concentration on the anomalous potassium uptake of thermophilic plants

Nachweis, dass in der thermophilen Gurke (Cucumis sativus) ein mehrphasiges K+-Aufnahme-system existiert, welches sich von jenem kalteunempfindlicher Pflanzen unterscheidet. Untersucht wurden abgetrennte Gurkenwurzeln im Temperaturbereich von 0 und 21 °C.

Nachwirkung niedriger Temperaturen auf Stomatabewegung und CO2-Aufnahme thermophiler Pflanzen

Under conditions of water saturation thermophilic plants show as an after-effect of chilling (+ 5 °C, + 2 °C) delayed photo active stomatal opening and reduced CO2-uptake. This inhibition of stomatal movement is also present in isolated epidermal strips in CO2 free air. Therefore the after-effect cannot be due to an increase of intercellular CO2 concentration but to metabolic blocks in the guard cells. A possible mechanism is discussed.