Title Affiliations Abstract "Bio-template silica titania diatoms for gas phase photocatalysis." "Systemic Physiological and Ecotoxicological Research (SPHERE), Sustainable Energy, Air and Water Technology (DuEL)" "Air pollution is of growing social and economical concern in densely populated regions as Flanders. A promising air purification technology is photocatalysis that only uses light to convert harmfull pollutants to harmless components as CO2 and H20. Photocatalysts, frequently based on titanium dioxide, exhibit several drawbacks: (1) environmentally burdening production process, (2) insufficient immobilisation of the nanoparticles, (3) insufficient activity. Immobilisation of titanium dioxide by metabolic incorporation in the diatom silica skeleton can provide a proper solution for the aforementioned problems. In this process titanium dioxide is incorporated in the silica skeleton of the diatom during cell division. Diatoms are single-celled eukaryotic microalgae that form intricate, self-assembled porous silica cell walls, called frustules. These diatom frustules are composed of hydrated silica with specific 3D morphologies, micro- meso or macroporosity and have typically high surface area (10-250 m2/g). In this project two subspecies of diatoms are used, the salt water algae Pinnularia sp.and the acidophilic algae Eunotia sp. This study provides sustainable, well immobilised and highly porous biosilica titania materials that are promising for photocatalytic air purifcation. The expertise on the growing of algae and the incorporation of metal atoms is present in the research group Ecophysiology, Biochemistry and Toxicology (EBT) of the department of Biology. The titanium content of the frustules should be as high as possible in order to obtain photocatalytically active materials. Two new strategies to increase the amount of titanium available for metabolic incorporation are appied. On one hand we will use acidophilic diatoms that can grow at very low pH, on the other hand titanium complexes are studied. The resulting mesoporous biosilica titania complexed are analysed for their titanium dioxide content (ICP-MS) and the location of the titanium dioxide deposition (STEM-EDS). After thermal annealing at high temperatures (400-900°C) the crystallinity (XRD), surface area (BET isotherms), pore distribution (BJH method) and optical properties (UV-VIS spectroscopy) are studied for those materials with sufficient titanium dioxide content. The biotemplate structures are tested for their photocatalytic degradation perfomance towards several common air pollutants (NOx, ethylene, acetaldehyde) in the gas phase. Expertise on real time in-situ study of photocatalysts in operating conditions is present in the research group Sustainable Energy and Air Purification (DuEL) of the department of Bio-science Engineering. This research project results in an optimized bio-template production process for mesoporous silica-titania photocatalysts as a base for an efficient, sustainable, economically and ecologically viable air purification process." "Charting the functional components of the diverse sexual life cycles in diatoms" "Klaas Vandepoele" "Biology, Department of Plant Biotechnology and Bioinformatics, Stazione Zoologica Anton Dohrn" "The most productive clade of eukaryotic algae, the diatoms, demonstrate a remarkable life cycle in which an inevitable cell size decline must be counteracted by sexual reproduction, through differentiation into a unique cell type called the auxospore. During the last 190 million years of evolution, a large range of sexual cell types and reproductive strategies have emerged within diatoms. Yet, the genetic programs controlling these life cycle stages are poorly understood. Moreover, observations of sex in natural samples are notoriously rare. In this project, I will generate a phylum-wide atlas of gene expression during the different stages of sexual development, covering seven different species. Next, I will use comparative genomics to identify and prioritize sexual genes that are either characteristic of a single phylogenetic clade or conserved in all diatoms. Additionally, I aim to distinguish cell fates based on their transcriptional fingerprint by pioneering single-cell RNA sequencing for diatoms. To functionally characterize cell type-specific genes, fluorescent reporter lines will be generated. Finally, I will apply conserved genetic biomarkers to monitor global marine metatranscriptomes and identify the environmental conditions promoting sex. In pursuit of new insights into the diversity of life cycle regulation in unicellular eukaryotes, this project will contribute new techniques and cell type-defining genes that will play a critical role in future studies." "Substrate-mediated interactions between diatoms and bacteria in marine biofilms" "Koen Sabbe" "Biology, University of Essex" "Associations between microalgae and bacteria represent one of the most important ecological relationships in aquatic microbial ecosystems In this proposal, we focus on the largely unknown diatom-bacteria interactions in marine biofilms We forward the general hypothesis that the high diversity observed in diatom-bacteria consortia in these systems is to a great extent mediated by specialized and species-specific interactions related to the production and consumption of diatom exudates, mainly extracellular polymeric substances (EPS) More specifically, we will test the following hypotheses: (1) different diatoms secrete different EPS mixtures, and these select for and enhance the growth of different bacterial taxa specialized in the use of specific EPS components; (2) bacteria stimulate diatom growth and EPS production, and affect its composition, in a species-specific manner; (3) these mutualistic, substrate-mediated interactions enhance the fitness of both diatoms and bacteria and facilitate coexistence and hence diversity in marine biofilms; (4) this EPS-based niche segregation is micro-spatially structured, further facilitating coexistence To unravel these substrate-related interactions in microbial biofilms, we will use a combination of advanced analytical, molecular, stable isotope probing and imaging techniques" "Re-investigation and lectotypification of O. Müller’s diatoms from East Africa: taxa from the genera Rhopalodia, Nitzschia, Sellaphora, Placoneis" "SYNTHESYS, Meise Botanic Garden" "Müller (1903, 1904, 1910) described many new diatom taxa from East Africa based on material collected at the beginning of the 20th century. Original slides were lost during World War II but historic material was rediscovered at the Botanic Garden of Berlin, Dahlem. This makes it possible to designate lectotypes. During a previous SYNTHESYS project (2005) the investigation including lectotypification was undertaken for 32 taxa belonging to the genera Surirella and Cymatopleura, resulting in 7 publications. The study of Rhopalodia was started but not finished. The present project aims to continue this study of the types of East African diatoms. We will focus on the continuation of Rhopalodia taxa and start with taxa belonging to the genera Nitzschia, Sellaphora and Placoneis, the last two were treated by Müller as Navicula s.l. Considering the renewed interest in diatoms from East and Central Africa as well as water quality studies based on diatoms, it is important to understand and typify the diatoms described from this region, and to make them accessible to the scientific community. The present proposal concerns 42 taxa, distributed over the four mentioned genera (Rhopalodia: 17; Nitzschia: 13; Sellaphora + Placoneis: 12). Investigation will be done on newly made light microscopic slides in order to designate a lectotype for each studied taxon. The study will focus on species variability and a large part of our time will go into the investigations of the morphological ultrastructure of the diatom valves using scanning electron microscopy. As done for Surirella and Cymatopleura, the results will be discussed in several papers and send for publication in peer-reviewed international journals." "Development of a forward genetic screen platform for diatoms based on mitotic recombination" "Wim Vyverman" "Biology, Department of Plant Biotechnology and Bioinformatics" "Diatoms are a species-rich group of microalgae with diverse metabolic capabilities and an immense potential for biotechnological application, including the production of biofuels, nutritional compounds and various heterologous molecules. However, the function of a large portion of diatom genes remains unknown. Unraveling the functions of these genes could unlock many novel diatom applications. Recently, we have discovered high mitotic recombination rates between homologous chromosomes in diatoms, resulting in loss-of-heterozygosity. In this project, we aim to use this remarkable phenomenon to develop a forward genetic screen platform, including the establishment and optimization of the best screening conditions, as well as the setup of a bioinformatics pipeline to identify causative mutations. As a proof of concept, we will use the developed platform to identify genes involved in carotenoid biosynthesis." "Biosynthesis of silica-titania photocatalysts using acidophilic diatoms." "Erik Van Eynde" "Sustainable Energy, Air and Water Technology (DuEL)" "Photocatalysis by polycrystalline semiconductor oxides such as TiO2 is a promising technology for the degradation of air pollutants. However, there are some problems with the present generation photocatalysts such as the inadequate immobilization of photocatalyst on a carrier material and the insufficient activity of the photocatalyst. Therefore there is need for novel materials and production methods to overcome these problems. Immobilisation of titanium dioxide by metabolic incorporation in the diatom silica skeleton can provide a proper solution for the aforementioned immobilization problem. A remarkable characteristic of diatoms is their ability to bioaccumulate trace levels of soluble titanium from cell culture medium and incorporate them into their nanostructured frustules. In this way, a sustainable, biological production process for silica-titania materials can be developed. Unfortunately, the low solubility of titanium in aqueous solutions at pH 7 limits the amount of titanium that can be immobilized. The main challenge in this research is to increase the amount of titania immobilized into the porous diatom frustules in order to obtain a photocatalytically active material. In this KP-BOF project an new strategy will be used to increase the amount of titanium, i.e. using acidophilic diatoms that can grow at low pH." "Sex signaling and life cycle evolution in pennate diatoms" "Lieven De Veylder" "Department of Green Chemistry and Technology, Department of Sustainable Organic Chemistry and Technology, Biology, Department of Plant Biotechnology and Bioinformatics" "The goal of the project is to uncover the molecular mechanisms that regulate the life cycle of pennate diatoms. Identification of molecules involved in life cycle regulation that are directly influenced by environmental conditions will help to monitor and predict the consequences of global climate changes on diatom populations" "The nature and evolution of pre- and postzygotic isolation in pennate diatoms" "Wim Vyverman" Biology "Diatoms are the most species-rich group of eukaryotic microalgae and play a pivotal role in global carbon and silica cycles. They have a unique life cycle characterized by gradual vegetative cell size reduction. Sexual reproduction results in cell size restoration and is only possible below a species-specific size threshold, thus allowing diatoms to time their relative investments in asexual propagation and sexual reproduction. Similar to land plants, diatom life cycles are extremely diverse in terms of mating systems and reproductive modes. How the typically obligate nature of sex in diatoms and the diversity in reproductive systems are linked to their speciation potential is currently unknown. In this project we will identify genomic regions and candidate genes responsible for intrinsic reproductive isolation and the switch to asexuality (apomixis) using two well-characterized pennate species complexes, the marine benthic Seminavis robusta and the freshwater epiphytic Eunotia bilunaris. Genotyping by sequencing (GBS) will be used to investigate genome-wide patterns of differences in hybridization potential and apomixis in sympatric and allopatric populations. QTL mapping in combination with Genome-wide association studies will reveal the genetic architecture of these reproductive isolation mechanisms. The identification of candidate genes involved in reproductive isolation will pave the road for comparative and functional studies. Furthermore, these results will contribute to testing the hypothesis that the rapid evolution of reproductive isolation mechanisms contributes to the rapid diversification of this relatively young and highly diverse group of microalgae." "Identification, functional characterization and evolution of genes and molecular-genetic mechanisms involved in mating type determination adn sexual reproduction in diatoms" "Koen Sabbe" Biology "We will use the diatom model Seminavis to study the diatom life cycle and the molecular-genetic mechanisms which regulate mating type determination and sexual reproduction. We will use a suite of molecular tools to identify and functionally characterize the genes involved in these processes. We will then use the available diatom genomic resources to study the evolution of these genes within the diatoms." "The development of public culture collections of diatoms, polar cyanobacteria and mycobacteria and their further integration in the BCCM consortium." "Wim Vyverman" Biology "The development of public culture collections of diatoms, polar cyanobacteria and mycobacteria and their further integration in the BCCM consortium.- BCCM/DCG, diatom collection:The BCCM/DCG public collection is a small but dedicated collection currently containing 195 diatom strains belonging to 23 species, and is the only culture collection worldwide specialized in diatoms, the most species-rich and ecologically important algal group.- BCCM/ITM, mycobacteria collection:The BCCM/ITM public collection currently maintains 150 strains of the Mycobacterium genus, representing 10 species.The collection is hosted by the Mycobacteriology Unit of the Institute of Tropical Medicine. This laboratory has one of the largest and most diverse collections of well documented mycobacteria worldwide. BCCM/ITM will incorporate the most interesting strains from the ITM research collection into the BCCM/ITM public collection.- BCCM/ULC, cyanobacteria collection:The BCCM/ULC public collection has just started in February 2011 and maintains so far 45 Antarctic cyanobacterial strains, assigned to 15 morphospecies. The public collection includes the type strain of the newly described species, Plectolyngbya hodgsonii (Taton et al., Polar Biology, DOI 10.1007/s00300-010-0868-y).The collection is hosted by the Centre for Protein Engineering of the University of Liège.The host laboratory has one of the largest research collection of documented (sub)polar cyanobacteria worldwide, with more than 100 strains characterized by phenotypic (morphology based on microscopic observations) and genotypic (16S rRNA and ITS sequences) tests. The strains are unicyanobacterial, but not axenic. BCCM/ULC aims at incorporating the most interesting strains from the research collection of the host laboratory into the BCCM/ULC public collection."