The efficient long-term inhibition of forsterite dissolution by common soil bacteria and fungi at earth surface conditions

San Carlos forsterite was dissolved in initially pure H2O in a batch reactor in contact with the atmosphere for five years. The reactive fluid aqueous pH remained relatively stable at pH 6.7 throughout the experiment. Aqueous Mg concentration maximized after approximately two years time at 3x10-5 mol/kg, whereas aqueous Si concentrations increased continuously with time, reaching 2x10-5 mol/kg after 5 years. Element release rates closely matched those determined on this same forsterite sample during short-term abiotic open system experiments for the first 10 days, then slowed substantially such that the Mg and Si release rates are approximately an order of magnitude slower than that calculated from the short-term abiotic experiments. Post-experiment analysis reveals that secondary hematite, a substantial biotic community, and minor amorphous silica formed on the dissolving forsterite during the experiment. The biotic community included bacteria, dominated by Rhizobiales (Alphaproteobacteria), and fungi, dominated by Trichocomaceae, that grew in a carbon and nutrient-limited media on the dissolving forsterite. The Mg isotope composition of the reactive fluid was near constant after 2 years but 0.25‰ heavier in δ26Mg than the dissolving forsterite. Together these results suggest long-term forsterite dissolution in natural Earth surface systems maybe substantially slower that estimated from short-term abiotic experiments due to the growth of biotic communities on their surfaces

Morfologija i filogenija pikoeukariota i penatnih planktonskih dijatomeja u srednjem i južnom Jadranu

The smallest protists, generally called picoeukaryotes, and planktonic pennate diatoms have received limited attention in world oceans, although they are numerous and important for primary production, biogeochemical cycles and for carbon injection into the deep ocean. In this thesis, represented through seven scientific publications, cultivated planktonic pennate diatoms and picoeukaryotes were investigated with traditional methods (light and electron microscopy, morphometry) and with molecular analyses, including multi-gene phylogenies, and were identified as genera Entomoneis, Pseudo-nitzschia, Haslea and Picochlorum. Detailed investigations of genus Entomoneis resulted with description of seven new species. General picoeukaryotic diversity was addressed by eDNA amplicon sequencing V4 variable region of nuclear 18S rRNA gene. Obtained results identified 95% of the picoeukaryotic community as hetero- or mixotrophic, mostly belonging to parasitic dinoflagellates and radiolarians, while only 5% of the community was represented with photoautotrophic picoeukaryotes belonging to classes of green algae, haptophytes, stramenopiles and cryptophytes. One cultivated Picochlorum sp. strain was subjected to growth rate experiment and pigment and lipid analyses, resulting in interesting and promising data for future biotechnological studies.Najmanji protisti, poznati kao pikoeukarioti i penatne planktonske diatomeje često su zanemareni u istraživanjima svjetskih oceana, iako predstavljaju brojnu i važnu komponentu za primarne proizvodnje, biogeokemijskih ciklusa i značajni su za protok ugljika u duboki ocean. U sklopu ove disertacije kroz sedam znanstvenih publikacija navedene skupine organizama istraživane su tradicionalnim metodama (svjetlosna i elektronska mikroskopija, morfometrija) i molekularnim analizama koje uključuju filogenetske anlize sa više različitih genskih markera te su identificirane kao rodovi Entomoneis, Pseudo-nitzschia, Haslea i Picochlorum. Detaljna analiza roda Entomoneis rezultirala je opisom sedam novih vrsta za znanost. Bioraznolikost ukupne pikoeukariotske zajednice u južnom Jadranu odredila se sekvenciranjem amplikona okolišne DNA i to prema varijabilnoj V4 regiji nuklearnog 18S rRNA gena. Dobiveni rezultati identificirali su 95% pikoeukariotske zajednice kao hetero- ili miksotrofne organizme, većim dijelom pripadajući parazitskim dinoflagelatima i radiolarijama, dok je samo 5% zajednice zastupljeno fotoautotrofnim pikoeukariotima koji pripadaju razredima zelenih algi, haptofita, stramenopila i kriptofita. Jedan kultivirani soj alge Picochlorum sp. istražen je kroz eksperiment određivanja brzine rasta te analizama pigmenta i lipida, što je rezultiralo zanimljivim i obećavajućim rezultatima koji mogu poslužiti kao okosnica za buduće biotehnološke studije

Morfologija i filogenija pikoeukariota i penatnih planktonskih dijatomeja u srednjem i južnom Jadranu

The smallest protists, generally called picoeukaryotes, and planktonic pennate diatoms have received limited attention in world oceans, although they are numerous and important for primary production, biogeochemical cycles and for carbon injection into the deep ocean. In this thesis, represented through seven scientific publications, cultivated planktonic pennate diatoms and picoeukaryotes were investigated with traditional methods (light and electron microscopy, morphometry) and with molecular analyses, including multi-gene phylogenies, and were identified as genera Entomoneis, Pseudo-nitzschia, Haslea and Picochlorum. Detailed investigations of genus Entomoneis resulted with description of seven new species. General picoeukaryotic diversity was addressed by eDNA amplicon sequencing V4 variable region of nuclear 18S rRNA gene. Obtained results identified 95% of the picoeukaryotic community as hetero- or mixotrophic, mostly belonging to parasitic dinoflagellates and radiolarians, while only 5% of the community was represented with photoautotrophic picoeukaryotes belonging to classes of green algae, haptophytes, stramenopiles and cryptophytes. One cultivated Picochlorum sp. strain was subjected to growth rate experiment and pigment and lipid analyses, resulting in interesting and promising data for future biotechnological studies.Najmanji protisti, poznati kao pikoeukarioti i penatne planktonske diatomeje često su zanemareni u istraživanjima svjetskih oceana, iako predstavljaju brojnu i važnu komponentu za primarne proizvodnje, biogeokemijskih ciklusa i značajni su za protok ugljika u duboki ocean. U sklopu ove disertacije kroz sedam znanstvenih publikacija navedene skupine organizama istraživane su tradicionalnim metodama (svjetlosna i elektronska mikroskopija, morfometrija) i molekularnim analizama koje uključuju filogenetske anlize sa više različitih genskih markera te su identificirane kao rodovi Entomoneis, Pseudo-nitzschia, Haslea i Picochlorum. Detaljna analiza roda Entomoneis rezultirala je opisom sedam novih vrsta za znanost. Bioraznolikost ukupne pikoeukariotske zajednice u južnom Jadranu odredila se sekvenciranjem amplikona okolišne DNA i to prema varijabilnoj V4 regiji nuklearnog 18S rRNA gena. Dobiveni rezultati identificirali su 95% pikoeukariotske zajednice kao hetero- ili miksotrofne organizme, većim dijelom pripadajući parazitskim dinoflagelatima i radiolarijama, dok je samo 5% zajednice zastupljeno fotoautotrofnim pikoeukariotima koji pripadaju razredima zelenih algi, haptofita, stramenopila i kriptofita. Jedan kultivirani soj alge Picochlorum sp. istražen je kroz eksperiment određivanja brzine rasta te analizama pigmenta i lipida, što je rezultiralo zanimljivim i obećavajućim rezultatima koji mogu poslužiti kao okosnica za buduće biotehnološke studije

Morfologija i filogenija pikoeukariota i penatnih planktonskih dijatomeja u srednjem i južnom Jadranu

The smallest protists, generally called picoeukaryotes, and planktonic pennate diatoms have received limited attention in world oceans, although they are numerous and important for primary production, biogeochemical cycles and for carbon injection into the deep ocean. In this thesis, represented through seven scientific publications, cultivated planktonic pennate diatoms and picoeukaryotes were investigated with traditional methods (light and electron microscopy, morphometry) and with molecular analyses, including multi-gene phylogenies, and were identified as genera Entomoneis, Pseudo-nitzschia, Haslea and Picochlorum. Detailed investigations of genus Entomoneis resulted with description of seven new species. General picoeukaryotic diversity was addressed by eDNA amplicon sequencing V4 variable region of nuclear 18S rRNA gene. Obtained results identified 95% of the picoeukaryotic community as hetero- or mixotrophic, mostly belonging to parasitic dinoflagellates and radiolarians, while only 5% of the community was represented with photoautotrophic picoeukaryotes belonging to classes of green algae, haptophytes, stramenopiles and cryptophytes. One cultivated Picochlorum sp. strain was subjected to growth rate experiment and pigment and lipid analyses, resulting in interesting and promising data for future biotechnological studies.Najmanji protisti, poznati kao pikoeukarioti i penatne planktonske diatomeje često su zanemareni u istraživanjima svjetskih oceana, iako predstavljaju brojnu i važnu komponentu za primarne proizvodnje, biogeokemijskih ciklusa i značajni su za protok ugljika u duboki ocean. U sklopu ove disertacije kroz sedam znanstvenih publikacija navedene skupine organizama istraživane su tradicionalnim metodama (svjetlosna i elektronska mikroskopija, morfometrija) i molekularnim analizama koje uključuju filogenetske anlize sa više različitih genskih markera te su identificirane kao rodovi Entomoneis, Pseudo-nitzschia, Haslea i Picochlorum. Detaljna analiza roda Entomoneis rezultirala je opisom sedam novih vrsta za znanost. Bioraznolikost ukupne pikoeukariotske zajednice u južnom Jadranu odredila se sekvenciranjem amplikona okolišne DNA i to prema varijabilnoj V4 regiji nuklearnog 18S rRNA gena. Dobiveni rezultati identificirali su 95% pikoeukariotske zajednice kao hetero- ili miksotrofne organizme, većim dijelom pripadajući parazitskim dinoflagelatima i radiolarijama, dok je samo 5% zajednice zastupljeno fotoautotrofnim pikoeukariotima koji pripadaju razredima zelenih algi, haptofita, stramenopila i kriptofita. Jedan kultivirani soj alge Picochlorum sp. istražen je kroz eksperiment određivanja brzine rasta te analizama pigmenta i lipida, što je rezultiralo zanimljivim i obećavajućim rezultatima koji mogu poslužiti kao okosnica za buduće biotehnološke studije

Phytoplankton functional types from Space.

The concept of phytoplankton functional types has emerged as a useful approach to classifying phytoplankton. It finds many applications in addressing some serious contemporary issues facing science and society. Its use is not without challenges, however. As noted earlier, there is no universally-accepted set of functional types, and the types used have to be carefully selected to suit the particular problem being addressed. It is important that the sum total of all functional types matches all phytoplankton under consideration. For example, if in a biogeochemical study, we classify phytoplankton as silicifiers, calcifiers, DMS-producers and nitrogen fix- ers, then there is danger that the study may neglect phytoplankton that do not contribute in any significant way to those functions, but may nevertheless be a significant contributor to, say primary production. Such considerations often lead to the adoption of a category of “other phytoplankton” in models, with no clear defining traits assigned them, but that are nevertheless necessary to close budgets on phytoplankton processes. Since this group is a collection of all phytoplankton that defy classification according to a set of traits, it is difficult to model their physi- ological processes. Our understanding of the diverse functions of phytoplankton is still growing, and as we recognize more functions, there will be a need to balance the desire to incorporate the increasing number of functional types in models against observational challenges of identifying and mapping them adequately. Modelling approaches to dealing with increasing functional diversity have been proposed, for example, using the complex adaptive systems theory and system of infinite diversity, as in the work of Bruggemann and Kooijman (2007). But it is unlikely that remote-sensing approaches might be able to deal with anything but a few prominent functional types. As long as these challenges are explicitly addressed, the functional- type concept should continue to fill a real need to capture, in an economic fashion, the diversity in phytoplankton, and remote sensing should continue to be a useful tool to map them. Remote sensing of phytoplankton functional types is an emerging field, whose potential is not fully realised, nor its limitations clearly established. In this report, we provide an overview of progress to date, examine the advantages and limitations of various methods, and outline suggestions for further development. The overview provided in this chapter is intended to set the stage for detailed considerations of remote-sensing applications in later chapters. In the next chapter, we examine various in situ methods that exist for observing phytoplankton functional types, and how they relate to remote-sensing techniques. In the subsequent chapters, we review the theoretical and empirical bases for the existing and emerging remote-sensing approaches; assess knowledge about the limitations, assumptions, and likely accuracy or predictive skill of the approaches; provide some preliminary comparative analyses; and look towards future prospects with respect to algorithm development, validation studies, and new satellite mis- sions

A Comparative Life Cycle Assessment for Utilising Laminated Veneer Bamboo as a Primary Structural Material in High-Rise Residential Buildings

In a time when construction is ranked as one of the world’s least sustainable industries consuming about half of the world’s non-renewable resources (Hinson, 2012), it is important to develop and advance the methods and means by which we select and use building materials and how we design, engineer and construct our architecture. This research aimed to evaluate a method for utilising laminated veneer bamboo (LVB) as a primary structural material in high-rise residential buildings and evaluate the environmental potential of LVB through a comparative life cycle analysis (LCA). The process of life cycle analysis was completed through the development of a Revit® model and utilising the Tally® life cycle assessment application. A comparative LCA, in particular the global warming potential between laminated veneer bamboo and cross laminated timber, was conducted using a case study model of Stadthaus, Murray Grove, London. This 9-story residential building is constructed using cross laminated timber (CLT) as the primary building material and provides a highly appropriate comparison for this research on the selection of laminated veneer bamboo as an alternative structural material to CLT. The structural aspect of this study aimed to evaluate the mechanical properties of a laminated veneer bamboo sheet product. The capabilities of LVB were reviewed by means of a comparative analysis against timber sheet products (OSB, Plywood). By utilising the strength of engineered bamboo efficiently, a diaphragm panel system was designed and tested as part of the LCA study as an alternative to the CLT panels that were used in the construction of Stadthaus at Murray Grove, London. The literature review and primary research present the environmental value of selecting bamboo as an alternative building material to steel, concrete and engineered timber, three of the most widely used primary structural materials in building projects today. These primary building materials, in particular concrete and steel, are energy intensive in their production1 and application and have a high global warming potential when compared to ‘green’ construction materials, for instance, timber and bamboo. The hypothesis is that engineered bamboo, through its potential to be efficiently designed for use in small and large scale buildings, has the potential to be an alternative, environmentally friendly, primary structural material. Bamboo is, based on its properties, an underutilised resource. Ongoing research and previous studies in Europe and Asia (Chung & Yu, 2002; Li, Zhang, Huang, & Deeks, 2013; C.S. Verma & Chariar, 2012) have shown that engineered bamboo can match the strengths of steel and in some cases far exceed those of engineered timber products. These studies show that there is a potential to utilise engineered bamboo for use as a primary structural material

Zinc limitation and toxicity in crops and effects of Silicon in ameliorating stress response.

Agriculture is the primary food source for human sustainability. The improvement of food provision through agriculture represents a major topic for plant biology. In addition to drought, salinity and starvation, the remediation from soil contaminations by metalloids and heavy metals is important to guarantee food safety. Metalloids are beneficial and necessary elements for higher plants at low concentrations, but high levels of these result severely toxic both for plants and humans. Soil contamination induced by an excess of some metalloids is a widespread problem over the world, causing economic disease and health threatens by human consumption. In addition to metalloids, heavy metal pollution is rapidly increasing and present many environmental problems. Among heavy metals, some metals such as cadmium (Cd), lead (Pb) and chromium (Cr) have no known biological role while others such as copper (Cu), manganese (Mn) and zinc (Zn) are required in small amount for normal plant growth and developments but are extremely toxic to plants and animals slightly larger than the required concentrations. While some metalloids and heavy metals effects are largely identified, a number of potential ameliorative effects of silicon (Si) are actually discussed. In fact, the silicon utilization as fertilizer is a recent suggestion to guarantee a compatible and sustainable agriculture inducing plant growth and to improve biotic and abiotic stress tolerance, such as metalloids deficiency or toxicity. In the present doctoral thesis, we analyzed three horticultural plants of great agronomic importance, exhibiting different tolerance to Zn, Lactuca sativa cv. Phillipus, Brassica oleracea cv. Bronco, and barley (Hordeum vulgare). These species were exposed to Zn toxicity and deficiency in order to evaluate the contribution of compatible osmolytes, in the mechanism(s) of tolerance to Zn stress. As further control, the effects of a heavy metal such as cadmium were tested on barley plants in order to discriminate and confront the damages induced by polluting metals with those caused by limitation or excess of a nutritional microelement as zinc. Furthermore, we studied the possible beneficial effect of Si on ameliorating plant stress conditions in Hordeum vulgare. In conclusion, this project suggests that metals excess and/or deficiency induces in crops substantially similar responses depending on their capability to manage the stress induced by pollutants. Furthermore, stress symptoms induced by metals are clearly mitigated by Si supply, thus improving plant tolerance mechanisms such as photosynthesis and photorespiratory systems