Predator-Prey Interactions in Ciliated Protists

Protists appeared relatively early in evolution, about 1.8 billion years ago, soon after the first prokaryotic organisms. During this time period, most species developed a variety of behavioral, morphological, and physiological strategies intended to improve the ability to capture prey or to avoid predation. In this scenario, a key role was played by specialized ejectable membrane-bound organelles called extrusomes, which are capable of discharging their content to the outside of the cell in response to various stimuli. The aim of this chapter is to describe the two main strategies adopted in ciliate predator-prey interactions: (a) the first is mediated by mechanical mechanisms and involves, for example, extrusomes called trichocysts and (b) the second is mediated by toxic secondary metabolites and involves different kinds of chemical extrusomes

Blepharismins used for chemical defense in two ciliate species of the genus Blepharisma, B. stoltei and B. undulans (Ciliophora: Heterotrichida)

It is known that the freshwater heterotrich ciliate Blepharisma japonicum uses five pigments called blepharismins, stored in its extrusive pigment granules, for both light perception and chemical defense against predators. In this work we focused our attention on the defensive strategies of two additional pigmented species of Blepharisma, B. stoltei and B. undulans. In particular: (1) we observed the predator\u2013prey interactions of B. stoltei or B. undulans against one multicellular and two unicellular predators; (2) we clarified the nature of B. stoltei and B. undulans pigments by means of High Performance Liquid Chromatography (HPLC) and Liquid Chromatography Mass Spectrometry (LC-MS); and (3) we demonstrated and compared the toxicity of the purified pigments on a panel of ciliated protists, and against one metazoan predator. The results indicate that the chemical defense mechanism present in B. stoltei and B. undulans is mediated by the same five blepharismins previously characterized for B. japonicum, although produced in different proportions

Exploring the Role of Inter-Organizational Information Systems within SMEs Aggregations

Interorganizational Information Systems (IOIS) will play a relevant role in shaping competition in the next years. Even though companies have become extremely efficient in managing information and logistics inside their boundaries, communication and coordination among partners is still far from effective. Both obsolete technologies and very scarce ICT supported interorganizational process are found in practice. In a global market where the entire supply chain is involved in company success, the proper design and implementation of an IOS is becoming mandatory. SMEs, and in particular those inside industrial aggregations, could greatly benefit from IOIS implementation, however a widely accepted IOS adoption theory is still lacking. Focusing on the description of an industrial aggregation this paper proposes a framework, its implementation and a field test on 70 companies belonging to an industrial district, to understand the relationships among aggregation’s main players. The analysis of the results proved that this approach offers useful insight for the comprehension of the aggregation and suggest its use as a pre-design IOIS tool.6-8 June 200

Metabolites from the Euryhaline Ciliate Pseudokeronopsis erythrina

TThree new secondary metabolites (named erythrolactones A2, B2 and C2), that are characterized by a central 4‐hydroxy‐unsaturated δ lactone ring bearing an alkyl saturated chain at C(2) and a butyl‐benzenoid group at C(5), together with their respective sulfate esters (erythrolactones A1, B1 and C1), have been isolated from cell cultures of Pseudokeronopsis erythrina, clone TL‐1. The structures are assigned on the basis of extensive spectroscopic measurements (1D and 2D NMR, UV, IR and HR‐MALDI‐TOF). A plausible biogenetic route for their formation is also suggested. Cold‐shock treatment was performed in order to induce the discharge of the metabolites contained in pigment granules lying on the ciliary organelles of this microorganism. HPLC‐ESI‐MS analysis of this granule discharge reveals that erythrolactones A2–C2 are actually therein contained, strongly suggesting a possible role for these metabolites in the chemical defence strategy of P. erythrina

The non-proteic extrusive secondary metabolites in ciliated protists

The non-proteic extrusive secondary metabolites in ciliated protists F. Buonanno1, A. Anesi2, G. Guella2, E. Marcantoni3, S. Giorgi3, C. Ortenzi1 1Laboratory of Protistology and Biology Education, University of Macerata, 62100 Macerata, Italy 2Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, 38050 Povo, Trento, Italy 3School of Sciences and Technologies, Section of Chemistry, University of Camerino, 62032 Camerino, Macerata, Italy Extrusomes are membrane-bound ejectable organelles widely distributed in protists. They are usually localized in the cell cortex and attached to the cell membrane, and they are able to discharge their contents to the outside of the cell in response to mechanical or chemical stimuli. Notably, cells that discharge their extrusomes remains intact and functional. The chemical nature of protists\u2019 extrusive compounds characterized to date is extremely variable, including proteins, carbohydrates, lipids, and dozens of additional classes of secondary metabolites. However an increasing set of data are now available for particular group of protists, the ciliated protozoa. Many of non-proteic extrusive secondary metabolites in ciliates function for chemical offense or defense in prey-predator interactions against unicellular or/and multicellular organisms. It is worthy of note that at least some of these secondary metabolites have been demonstrated to show antibiotic, anti-cancer and pro-apoptotic properties in addition to their physiological functions. Among these compounds, euplotin C produced by the ciliate Euplotes crassus, and climacostol produced by Climacostomum virens, have been shown to activate programmed cell death by impairing mitochondrial membrane potential and inducing ROS generation in mammalian tumor cell lines. Interestingly, an antimicrobial activity against Gram-positive bacteria and fungal pathogens was also demonstrated for climacostol. Overall, in addition to the understanding of their physiological and ecological functions, the study of non-proteic secondary metabolites of ciliated protozoa may set the basis for the development of a novel series of antitumor and antimicrobial agents

Preliminary Data Related to the Effect of Climacostol Produced by the Freshwater Ciliate Climacostomum virens on Human Adenovirus

The new epidemiological scenario has so far focused on the environmental circulation of human viral pathogens. Owing to the side effects of chemical disinfectants, there is an increasing need for knowledge on the use of virucidal compounds, especially those of a natural origin. Climacostol is a molecule produced by a freshwater ciliate and it exhibits activity against bacterial and fungal pathogens. We thus also speculated that there might be an effect on viral viability, which has never been tested. To evaluate such activity, we chose human adenovirus (HAdV), which is representative of waterborne viruses. We conducted experiments using HAdV serotype 5, whose titer was determined by infecting HeLa cell cultures. HAdV5 was shown to be sensitive to climacostol at a concentration of 0.0002 mg/mL, with an approximate 3 Log(10)reduction when the initial titer of HAdV5 was approximately 10(4)and 10(3)TCID(50)/mL. These preliminary results could be an important starting point for further research aimed at improving the characterization of climacostol activity under different experimental conditions and against various viruses, including enveloped ones (i.e., the coronavirus). The production of climacostol by a protist living in fresh water also suggests a possible application in the activated sludge of wastewater treatment plants

DNA binding and oxidative DNA damage induced by climacostol\u2013copper(II) complexes: Implications for anticancer properties

Climacostol is a natural toxin isolated from the freshwater ciliated protozoan Climacostomum virens and belongs to the group of resorcinolic lipids. Climacostol exerts a potent antimicrobial activity against a panel of bacterial and fungal pathogens. In addition it inhibits the growth of tumor cell lines in a dose-dependent manner by inducing programmed cell death via intrinsic pathway. In this work, we investigated the possibility that climacostol exerts a prooxidant effect, inducing plasmid DNA strand breakage and eukaryotic DNA damage in presence of Cu(II) ions. Inhibition of DNA breakage using SOD, catalase and neocuproine confirmed the involvement of reactive oxygen species and Cu(I) ions in the DNA damage. UV\u2013visible absorption changes and mass spectrometric analysis identified a product of reaction as a deprotonated form of climacostol. Study of the interaction with DNA, using fluorescence spectroscopic techniques, showed that climacostol binds with DNA. Given the structure\u2013activity relationship of this compound and the mechanism of its prooxidant effect, we propose that the Cu(II)-mediated oxidative DNA damage by climacostol could explain its antimicrobial and antiproliferative activity

Ciliate diversity and behavioural observations from the chemoautotrophic cave ecosystem of Frasassi, (Marche region, Italy)

Chemoautotrophic cave organisms require specific adaptations to tolerate the stress of living in extreme environmental conditions, such as darkness, nutrient and energy limitations, low temperatures (12-13°C), highly variable sulphide concentrations (from 0 up to 415 μM H2S) and toxic levels of gases (H2S, CO2, CH4). To date, due to the difficulties in sampling in such harsh environment, very few studies were performed in order to describe the ciliate communities from caves; these have remained largely unexplored. Thus, the main aims of our study were to characterize for the first time, the ciliates from the sulfide-rich Frasassi cave complex (Marche region, Italy) and to observe possible behavioural differences with their non-cave-dwelling counterpart ciliate species. Four main sampling sites within Frasassi caves were selected: Pozzo dei Cristalli, Lago Verde, Ramo Solfureo and Grotta Solfurea. The ciliate diversity from the site Pozzo dei Cristalli was studied in greater detail for its spatio-temporal distribution, since it is highly diversified and includes several microhabitats represented by small sulfidic (H2S-rich) ponds, streams and springs as well as, deep and shallow muddy, stagnant lakes. Periodic sampling was realised from 2009 to 2011 in the form of water-sediments, picked up by scraping the surface. Classical culturing, silver staining methods and 18S rRNA gene (for some selected species) for phylogenetic analysis were employed. A total of 31 species belonging to 9 classes, 15 orders and 23 genera were identified. Fluctuation of the ciliate communities were mainly recorded at the Pozzo dei Cristalli sites during various sampling occasions, this could be due to changing environmental conditions (mainly H2S concentrations and water levels). Interestingly, it was observed that some species e.g. Urocentrum turbo, Coleps hirtus hirtus, Oxytricha sp, Euplotes sp, showed adaptation for the cave environment (photo-sensitivity, sulphur tolerance, feeding behaviour, morphological difference). Overall, these results provide a platform for various in-depth studies of ciliates to understand potential role in aquatic microhabitats, nature of chemical compounds secreted, dispersal pattern, and adaptations to cave environment

Free living ciliated protists from the chemoautotrophic cave ecosystem of Frasassi (Italy)

This study provides the first report on a community of free-living ciliated protists from the chemoautotrophic cave ecosystem of Frasassi, Italy. This subterranean groundwater ecosystem represents a hotspot of biodiversity that still needs to be fully explored with particular reference to microbial eukaryotes such as protist ciliates. A total of 33 taxa of ciliates were identified along with one species each of flagellate, heliozoans and naked amoebae, from four main sampling sites, namely, Grotta Solfurea (GSO), Lago Verde (LVE), Ramo Solfureo (RSO), and Pozzo dei Cristalli (PDC). The last consists of small microhabitats/ponds presenting different chemical–physical and biological parameters, such as sulfur and nutrient contents and the presence of bacterial biofilms. Furthermore, an analysis of the cryptic ciliate species biosphere as a ‘seedbank’ of diversity against cave ecosystem disturbance was also performed. This study also highlights some peculiar adaptations of cave-dwelling ciliates not described in their noncave-dwelling conspecifics, such as the extreme photosensitivity of Urocentrum turbo, the cannibalism of Coleps hirtus, the variable number of thorns in Aspidisca species as a defensive response to predation, and the frequent reorganization of ciliary structures in Euplotes aediculatus. The 18S rDNA sequences were generated for five species and were compared with those of the noncave-dwelling conspecifics. Finally, our results shed light on the still largely unknown ciliate diversity in the chemosynthesis-based sulfidic groundwater ecosystem of Frasassi

Response of the Cardiac Autonomic Control to Exposure to Nanoparticles and Noise: A Cross-Sectional Study of Airport Ground Staff

Airport activity causes the emission of particulate matter and noise, two environmental contaminants and potential health hazards, particularly for the personnel operating nearby taxiways. We explored the association between exposure to fine/ultrafine particles (UFPs) and noise with heart rate variability (HRV), an early indicator of cardiovascular autonomic response, among a sample of airport ground staff. Between May and June 2018, thirty-four male operators (mean age = 43 years and SD = 6.7) underwent personal monitoring of exposure to nanoparticles and noise, and HRV during their work activity. We conducted univariate and multivariate analysis to test the effect of UFP and noise exposure HRV. Total Lung Deposition Surface Area (LDSA) was significantly associated with a decrease in HRV Total Power and Triangular index (beta = -0.038 p = 0.016 and beta = -7.8 x 10(-5), p = 0.042, respectively). Noise peak level showed an opposite effect, which was significant for Total Power (beta = 153.03, p = 0.027), and for Triangular index (beta = 0.362, p = 0.035). Further investigation is warranted to clarify the effect of the concurrent exposure to UFPs and noise on early changes of cardiac autonomic regulation