Terrestrial Microorganisms Research Articles

Rapid colonization of a space‐returned Ryugu sample by terrestrial microorganisms

AbstractThe presence of microorganisms within meteorites has been used as evidence for extraterrestrial life, however, the potential for terrestrial contamination makes their interpretation highly controversial. Here, we report the discovery of rods and filaments of organic matter, which are interpreted as filamentous microorganisms, on a space‐returned sample from 162173 Ryugu recovered by the Hayabusa 2 mission. The observed carbonaceous filaments have sizes and morphologies consistent with microorganisms and are spatially associated with indigenous organic matter. The abundance of filaments changed with time and suggests the growth and decline of a prokaryote population with a generation time of 5.2 days. The population statistics indicate an extant microbial community originating through terrestrial contamination. The discovery emphasizes that terrestrial biota can rapidly colonize extraterrestrial specimens even given contamination control precautions. The colonization of a space‐returned sample emphasizes that extraterrestrial organic matter can provide a suitable source of metabolic energy for heterotrophic organisms on Earth and other planets.

Aeolian Biodispersal of Terrestrial Microorganisms on Mars Through Saltation Bombardment of Spacecraft.

A major unknown in the field of planetary protection is the degree to which natural atmospheric processes remove terrestrial microorganisms from robotic and crewed spacecraft that could potentially contaminate Mars (i.e., forward contamination). We present experiments in which we measured the removal rate of Bacillus subtilis HA101 spores from aluminum surfaces under the bombardment of naturally rounded sand grains. To simulate grain impacts, we constructed a pneumatic sand-feed system and gun to accelerate grains to a desired speed, with independent control of impacting grain mass, flux, and angle. Spore counts of the resulting bombarded surfaces when using scanning electron microscopy indicate that although spores directly impacted by sand grains would likely be killed, those immediately adjacent to grain impacts might be released into the environment intact. The experiments demonstrate a linear relationship between the fractional dislodgement rate of spores and grain impact speed, which can be used to estimate input to microbial transport models (e.g., using numerical models of saltation). Even the slowest grain impacts (∼2.7 m/s) dislodged spores. Such slow events may be common and widespread on Mars, which suggests that microbial dislodgement by slow saltation near the surface is largely unavoidable.

Study on the screening of marine beneficial bacteria and the inhibition of sulfate-reducing bacteria corrosion in marine oil field produced water

PurposeThe purpose of this study is to provide ideas and theoretical guidance for green, environmentally friendly and efficient “bacteriostasis with bacteria” technology.Design/methodology/approachIn this paper, a beneficial strain of bacteria was extracted and purified from marine mud. Weight-loss test, morphological observation and electrochemical test were used to systematically study the effect of sulfate-reducing bacteria (SRB)-induced corrosion inhibition on X65 steel in simulated offshore oil field production water.FindingsThe results showed that a beneficial strain was selected and identified as Vibrio alginolyticus. Under the condition of co-culture of SRB, the average corrosion rate of X65 steel was significantly reduced. In the mixed bacterial system, the surface of X65 steel samples was relatively flat, and the structure of biofilm and corrosion product film was dense. The number of corrosion pits, the average diameter and depth of corrosion pits were significantly reduced. The localized corrosion of X65 steel was significantly inhibited.Originality/valueThe complex and changing marine environment makes the corrosion problem of marine steel increasingly severe, and the microbiologically influenced corrosion (MIC) caused by SRB is particularly serious. The research and development of environmentally friendly corrosion protection technology is a long-term and difficult problem. The use of beneficial microorganisms to control MIC is a green and efficient anticorrosion measure. Compared with terrestrial microorganisms, marine microorganisms can adapt to complex environments, and their metabolites exhibit special biological activities. The use of marine beneficial bacteria can inhibit SRB activity to achieve the corrosion inhibition effect.

Horizon scanning of potential environmental applications of terrestrial animals, fish, algae and microorganisms produced by genetic modification, including the use of new genomic techniques

Horizon scanning of potential environmental applications of terrestrial animals, fish, algae and microorganisms produced by genetic modification, including the use of new genomic techniques

Abiotic formation of alkylsulfonic acids in interstellar analog ices and implications for their detection on Ryugu

For the last century, the source of sulfur in Earth’s very first organisms has remained a fundamental, unsolved enigma. While sulfates and their organic derivatives with sulfur in the S(+VI) oxidation state represent core nutrients in contemporary biochemistry, the limited bioavailability of sulfates during Earth’s early Archean period proposed that more soluble S(+IV) compounds served as the initial source of sulfur for the first terrestrial microorganisms. Here, we reveal via laboratory simulation experiments that the three simplest alkylsulfonic acids—water soluble organic S(+IV) compounds—can be efficiently produced in interstellar, sulfur-doped ices through interaction with galactic cosmic rays. This discovery opens a previously elusive path into the synthesis of vital astrobiological significance and untangles fundamental mechanisms of a facile preparation of sulfur-containing, biorelevant organics in extraterrestrial ices; these molecules can be eventually incorporated into comets and asteroids before their delivery and detection on Earth such as in the Murchison, Tagish Lake, and Allende meteorites along with the carbonaceous asteroid Ryugu.

Metabolic Blockade-Based Genome Mining of Sea Anemone-Associated Streptomyces sp. S1502 Identifies Atypical Angucyclines WS-5995 A-E: Isolation, Identification, Biosynthetic Investigation, and Bioactivities.

Marine symbiotic and epiphyte microorganisms are sources of bioactive or structurally novel natural products. Metabolic blockade-based genome mining has been proven to be an effective strategy to accelerate the discovery of natural products from both terrestrial and marine microorganisms. Here, the metabolic blockade-based genome mining strategy was applied to the discovery of other metabolites in a sea anemone-associated Streptomyces sp. S1502. We constructed a mutant Streptomyces sp. S1502/Δstp1 that switched to producing the atypical angucyclines WS-5995 A-E, among which WS-5995 E is a new compound. A biosynthetic gene cluster (wsm) of the angucyclines was identified through gene knock-out and heterologous expression studies. The biosynthetic pathways of WS-5995 A-E were proposed, the roles of some tailoring and regulatory genes were investigated, and the biological activities of WS-5995 A-E were evaluated. WS-5995 A has significant anti-Eimeria tenell activity with an IC50 value of 2.21 μM. The production of antibacterial streptopyrroles and anticoccidial WS-5995 A-E may play a protective role in the mutual relationship between Streptomyces sp. S1502 and its host.

Blue Biotechnology: Marine Bacteria Bioproducts.

The ocean is the habitat of a great number of organisms with different characteristics. Compared to terrestrial microorganisms, marine microorganisms also represent a vast and largely unexplored reservoir of bioactive compounds with diverse industrial applications like terrestrial microorganisms. This review examines the properties and potential applications of products derived from marine microorganisms, including bacteriocins, enzymes, exopolysaccharides, and pigments, juxtaposing them in some cases against their terrestrial counterparts. We discuss the distinct characteristics that set marine-derived products apart, including enhanced stability and unique structural features such as the amount of uronic acid and sulfate groups in exopolysaccharides. Further, we explore the uses of these marine-derived compounds across various industries, ranging from food and pharmaceuticals to cosmetics and biotechnology. This review also presents a broad description of biotechnologically important compounds produced by bacteria isolated from marine environments, some of them with different qualities compared to their terrestrial counterparts.

Analysis of Mangrove Leaf Litter Decomposition Rate in Mangrove Ecosystem of Muara Pagatan, South Kalimantan

Mangroves are the dominant ecosystem in coastal areas and estuaries and one of the most productive ecosystems in the world. Mangroves are an essential component in a complex food chain and have the potential for the life of various marine and terrestrial biotas, microorganisms, and macroorganisms. The decomposition of mangrove leaf litter by fungal bacteria produces nutrient source that is beneficial for fish, shrimps, and crabs. This study discusses the production and decomposition rate of mangrove leaf litter in the mangrove ecosystem of Muara Pagatan, South Kalimantan. With transect and litter trap methods, litter production during the observation ranged from 218.51 - 858.28 g/m2/45day. Of the four types of mangroves found, the highest litter production was found in Rhizophora mucronata mangrove species at 858.28 g/m2/45day, followed by Bruguiera gymnorrhiza species at 268.52 g/m2/45day, and the lowest litter production was Avicennia marina mangrove species at 222.9 g/m2/45day and Sonneratia alba at 218.51 g/m2/45day. The remaining dry weight during observation ranged from 1.06 g - 2.46 g. In sum, the highest litter productivition and decomposition rate was found in Rhizophora species and litter was not completely decomposed after 45 days.

Extracellular L-asparaginase productive potential of the Priestia megaterium strain GB911 from Khanh Hoa sea of Viet Nam

Currently, L-asparaginase isolated from terrestrial microorganisms has been employed for anticancer industrial production. This enzyme has the function of inhibiting the growth of acute lymphoblastic leukemia, Hodgkin's lymphomas and other cancers. In this study, for the first time, L-asparaginase (ASNase) productive capacity of forty marine bacteria originating from Khanh Hoa sea of Viet Nam was screened and reported. Among those, twenty eight isolates were clarified for their extracellular ASNase activity based on their ability to form a pink zone around colonies on asparagine agar plates. As a result, four strains GB910, GB911, GB976 and GB982 showed high secreted extracellular ASNase activity, ranging from 8.64 to 13.22 IU/mg. Among these four most potential strains, GB911 exhibited better enzyme production capacity and was subjected to taxonomy identification. According to the 16S rRNA gene sequence on the GenBank database, strain GB911 was identified as Priestia megaterium and registered in the GenBank database with accession number MW407014. The purified enzyme obtained from strain GB911 exhibited strong cytotoxic activity against five monolayer and suspension cancerous cell lines with IC50 values ranging from 39 mU/mL to 98 mU/mL. The strain could serve as a promising source for industrial production of ASNase for clinical chemotherapeutic treatment.

Geology defines microbiome structure and composition in nunataks and valleys of the Sør Rondane Mountains, East Antarctica.

Understanding the relation between terrestrial microorganisms and edaphic factors in the Antarctic can provide insights into their potential response to environmental changes. Here we examined the composition of bacterial and micro-eukaryotic communities using amplicon sequencing of rRNA genes in 105 soil samples from the Sør Rondane Mountains (East Antarctica), differing in bedrock or substrate type and associated physicochemical conditions. Although the two most widespread taxa (Acidobacteriota and Chlorophyta) were relatively abundant in each sample, multivariate analysis and co-occurrence networks revealed pronounced differences in community structure depending on substrate type. In moraine substrates, Actinomycetota and Cercozoa were the most abundant bacterial and eukaryotic phyla, whereas on gneiss, granite and marble substrates, Cyanobacteriota and Metazoa were the dominant bacterial and eukaryotic taxa. However, at lower taxonomic level, a distinct differentiation was observed within the Cyanobacteriota phylum depending on substrate type, with granite being dominated by the Nostocaceae family and marble by the Chroococcidiopsaceae family. Surprisingly, metazoans were relatively abundant according to the 18S rRNA dataset, even in samples from the most arid sites, such as moraines in Austkampane and Widerøefjellet ("Dry Valley"). Overall, our study shows that different substrate types support distinct microbial communities, and that mineral soil diversity is a major determinant of terrestrial microbial diversity in inland Antarctic nunataks and valleys.

Biodegradation of Typical Plastics: From Microbial Diversity to Metabolic Mechanisms.

Plastic production has increased dramatically, leading to accumulated plastic waste in the ocean. Marine plastics can be broken down into microplastics (<5 mm) by sunlight, machinery, and pressure. The accumulation of microplastics in organisms and the release of plastic additives can adversely affect the health of marine organisms. Biodegradation is one way to address plastic pollution in an environmentally friendly manner. Marine microorganisms can be more adapted to fluctuating environmental conditions such as salinity, temperature, pH, and pressure compared with terrestrial microorganisms, providing new opportunities to address plastic pollution. Pseudomonadota (Proteobacteria), Bacteroidota (Bacteroidetes), Bacillota (Firmicutes), and Cyanobacteria were frequently found on plastic biofilms and may degrade plastics. Currently, diverse plastic-degrading bacteria are being isolated from marine environments such as offshore and deep oceanic waters, especially Pseudomonas spp. Bacillus spp. Alcanivoras spp. and Actinomycetes. Some marine fungi and algae have also been revealed as plastic degraders. In this review, we focused on the advances in plastic biodegradation by marine microorganisms and their enzymes (esterase, cutinase, laccase, etc.) involved in the process of biodegradation of polyethylene terephthalate (PET), polystyrene (PS), polyethylene (PE), polyvinyl chloride (PVC), and polypropylene (PP) and highlighted the need to study plastic biodegradation in the deep sea.

Biosignature Detection and MinION Sequencing of Antarctic Cryptoendoliths After Exposure to Mars Simulation Conditions.

In the search for life in our Solar System, Mars remains a promising target based on its proximity and similarity to Earth. When Mars transitioned from a warmer, wetter climate to its current dry and freezing conditions, any putative extant life probably retreated into habitable refugia such as the subsurface or the interior of rocks. Terrestrial cryptoendolithic microorganisms (i.e., those inhabiting rock interiors) thus represent possible modern-day Mars analogs, particularly those from the hyperarid McMurdo Dry Valleys in Antarctica. As DNA is a strong definitive biosignature, given that there is no known abiotic chemistry that can polymerize nucleobases, we investigated DNA detection with MinION sequencing in Antarctic cryptoendoliths after an ∼58-sol exposure in MARTE, a Mars environmental chamber capable of simulating martian temperature, pressure, humidity, ultraviolet (UV) radiation, and atmospheric composition, in conjunction with protein and lipid detection. The MARTE conditions resulted in changes in community composition and DNA, proteins, and cell membrane-derived lipids remained detectable postexposure. Of the multitude of extreme environmental conditions on Mars, UV radiation (specifically UVC) is the most destructive to both cells and DNA. As such, we further investigated if a UVC exposure corresponding to ∼278 martian years would impede DNA detection via MinION sequencing. The MinION was able to successfully detect and sequence DNA after this UVC radiation exposure, suggesting its utility for life detection in future astrobiology missions focused on finding relatively recently exposed biomarkers inside possible martian refugia.

Micro/nanoplastics contamination of the terrestrial environment: exposure routes, dose, and co-contaminants complicate the risk calculus

As xenobiotics in the environment, microplastics and nanoplastics have become ever-present in the environment, especially in terrestrial environment. However, a critical issue is that these anthropogenic contaminants are toxic to some terrestrial microorganisms, and the results of that toxic interaction over time can significantly impact microbial community structure and function, with unknown ramifications for ecosystem health. This viewpoint highlights the fact that, considering the diverse array of MPs/NPs, the broad dose range, and the presence of co-contaminants (e.g., retained organic and elemental pollutants, polymer additives) associated with these materials, their risk calculus to microbiome in terrestrial environment is incredibly complex. Short- and long-term dose-response that spans environmentally relevant concentrations and includes appropriate levels of analyte complexity (additives, co-contaminants). This should include microcosm studies that enable assessment of 'omic' parameters over the long term, as well as detailed assessment of impacts on soil microbiome function. We also need to understand impacts on eukaryotic microbes. In conclusion, for both toxicity and benefit, we should focus more on the dynamics of impacts on the microbiome. As some populations are inhibited, others increase. It is not because the plastics are conveying benefit directly but because more sensitive species are decreasing, which frees up resources from less competition. Those changes then have additional consequences, such as shifts in predator species and nutrient cycling and redox conditions.Graphical

Halomonas gemina sp. nov. and Halomonas llamarensis sp. nov., two siderophore-producing organisms isolated from high-altitude salars of the Atacama Desert.

This study aimed to identify and characterize novel siderophore-producing organisms capable of secreting high quantities of the iron-binding compounds. In the course of this, two not yet reported halophilic strains designated ATCHAT and ATCH28T were isolated from hypersaline, alkaline surface waters of Salar de Llamará and Laguna Lejía, respectively. The alkaline environment limits iron bioavailability, suggesting that native organisms produce abundant siderophores to sequester iron. Both strains were characterized by polyphasic approach. Comparative analysis of the 16S rRNA gene sequences revealed their affiliation with the genus Halomonas. ATCHAT showed close similarity to Halomonas salicampi and Halomonas vilamensis, while ATCH28T was related closest to Halomonas ventosae and Halomonas salina. The ability of both strains to secrete siderophores was initially assessed using the chromeazurol S (CAS) liquid assay and subsequently further investigated through genomic analysis and NMR. Furthermore, the effect of various media components on the siderophore secretion by strain ATCH28T was explored. The CAS assay confirmed the ability of both strains to produce iron-binding compounds. Genomic analysis of strain ATCHAT revealed the presence of a not yet reported NRPS-dependant gene cluster responsible for the secretion of siderophore. However, as only small amounts of siderophore were secreted, further investigations did not lie within the scope of this study. Via NMR and genomic analysis, strain ATCH28T has been determined to produce desferrioxamine E (DFOE). Although this siderophore is common in various terrestrial microorganisms, it has not yet been reported to occur within Halomonas, making strain ATCH28T the first member of the genus to produce a non-amphiphilic siderophore. By means of media optimization, the produced quantity of DFOE could be increased to more than 1000 µM. Phenotypic and genotypic characteristics clearly differentiated both strains from other members of the genus Halomonas. Average nucleotide identity (ANI) values and DNA-DNA relatedness indicated that the strains represented two novel species. Therefore, both species should be added as new representatives of the genus Halomonas, for which the designations Halomonas llamarensis sp. nov. (type strain ATCHAT = DSM 114476 = LMG 32709) and Halomonas gemina sp. nov. (type strain ATCH28T = DSM 114418 = LMG 32708) are proposed.

Development of Martian saline seep models and their implications for planetary protection

While life on Mars has not been found, Earth-based microorganisms may contaminate the Red Planet during rover expeditions and human exploration. Due to the survival advantages conferred by the biofilm morphology to microorganisms, such as resistance to UV and osmotic stress, biofilms are particularly concerning from a planetary protection perspective. Modeling and data from the NASA Phoenix mission indicate that temporary liquid water might exist on Mars in the form of high salinity brines. These brines could provide colonization opportunities for terrestrial microorganisms brought by spacecraft or humans. To begin testing for potential establishment of microbes, results are presented from a simplified laboratory model of a Martian saline seep inoculated with sediment from Hailstone Basin, a terrestrial saline seep in Montana (USA). The seep was modeled as a sand-packed drip flow reactor at room temperature fed media with either 1 M MgSO4 or 1 M NaCl. Biofilms were established within the first sampling point of each experiment. Endpoint 16S rRNA gene community analysis showed significant selection of halophilic microorganisms by the media. Additionally, we detected 16S rRNA gene sequences highly similar to microorganisms previously detected in two spacecraft assembly cleanrooms. These experimental models provide an important foundation for identifying microbes that could hitch-hike on spacecraft and may be able to colonize Martian saline seeps. Future model optimization will be vital to informing cleanroom sterilization procedures.

Biodiversity Of Marine Yeasts Isolated From Coral Sand In Truong Sa Archipelago, Khanh Hoa Province, Vietnam

Truong Sa archipelago of Vietnam are very diverse in microorganisms, however, compared to aquatic microorganisms (sea water, sediment, etc) terrestrial microorganisms (soil, coral sand, etc) has received little attention. This study focuses on assessing the biodiversity of marine yeasts in coral sand samples collected at some islands in Truong Sa archipelago. From nine coral sand samples collected at three islands: Song Tu island (three samples), Sinh Ton island (three samples), Truong Sa island (three samples), twenty – four strains of marine yeasts were isolated. The number of marine yeast strains isolated in Truong Sa island was the highest (ten strains). Sample CS9 had the highest number of strains. These strains were grouped into eight groups based on colony and cell morphology and fourteen groups by DNA fingerprinting. The results showed that there are strains in the same group according to morphology but belong to two different groups according to fingerprinting. Otherwise, some strains have different morphology but are grouped according to fingerprinting. The fourteen yeast strains representing groups by DNA fingerprinting were closely related to fourteen different yeast species and belong to ten yeast genera (Yamadazyma, Candida, Trichosporon, Saccharomyces, Kodamaea, Rhodotorula, Rhodosporidium, Aureobasidium, Meyerozyma, Pichia). Among them, the genus Candida accounted for the highest number. This is the first study on marine yeasts in coral sand in Truong Sa archipelago, Vietnam. This study can be a premise for further studies on marine yeast in different fields such as medicine, agriculture, environment, etc.

DNA Polymerization in Icy Moon Abyssal Pressure Conditions.

Evidence of stable liquid water oceans beneath the ice crust of moons within the Solar System is of great interest for astrobiology. In particular, subglacial oceans may present hydrothermal processes in their abysses, similarly to terrestrial hydrothermal vents. Therefore, terrestrial extremophilic deep life can be considered a model for putative icy moon extraterrestrial life. However, the comparison between putative extraterrestrial abysses and their terrestrial counterparts suffers from a potentially determinant difference. Indeed, some icy moons oceans may be so deep that the hydrostatic pressure would exceed the maximal pressure at which hydrothermal vent organisms have been isolated. While terrestrial microorganisms that are able to survive in such conditions are known, the effect of high pressure on fundamental biochemical processes is still unclear. In this study, the effects of high hydrostatic pressure on DNA synthesis catalyzed by DNA polymerases are investigated for the first time. The effect on both strand displacement and primer extension activities is measured, and pressure tolerance is compared between enzymes of various thermophilic organisms isolated at different depths.

Microbiome network in the pelagic and benthic offshore systems of the northern Adriatic Sea (Mediterranean Sea)

Because of their recognized global importance, there is now the urgent need to map diversity and distribution patterns of marine microbial communities. Even if available studies provided some advances in the understanding the biogeographical patterns of marine microbiomes at the global scale, their degree of plasticity at the local scale it is still underexplored, and functional implications still need to be dissected. In this scenario here we provide a synoptical study on the microbiomes of the water column and surface sediments from 19 sites in a 130 km2 area located 13.5 km afar from the coast in the North-Western Adriatic Sea (Italy), providing the finest-scale mapping of marine microbiomes in the Mediterranean Sea. Pelagic and benthic microbiomes in the study area showed sector specific-patterns and distinct assemblage structures, corresponding to specific variations in the microbiome network structure. While maintaining a balanced structure in terms of potential ecosystem services (e.g., hydrocarbon degradation and nutrient cycling), sector-specific patterns of over-abundant modules—and taxa—were defined, with the South sector (the closest to the coast) characterized by microbial groups of terrestrial origins, both in the pelagic and the benthic realms. By the granular assessment of the marine microbiome changes at the local scale, we have been able to describe, to our knowledge at the first time, the integration of terrestrial microorganisms in the marine microbiome networks, as a possible natural process characterizing eutrophic coastal area. This raises the question about the biological threshold for terrestrial microorganisms to be admitted in the marine microbiome networks, without altering the ecological balance.

Organic matter diagenesis and precipitation of Mg-rich carbonate and dolomite in modern hypersaline lagoons linked to climate changes

Lipid-biomarkers have been used to reconstruct environmental changes in lacustrine systems on a range of time scales. Lake sediments are excellent archives to apply these tools due to their rapid and amplified response to environmental pressures. For the past thirty years, the hypersaline lagoons of the Rio de Janeiro coastal plain have been studied as natural laboratories for the observation of the biogeochemical processes involved in modern dolomite precipitation. Here, we apply a multiproxy approach to characterize two depositional stages during the Holocene that may have triggered primary dolomite formation in these lagoonal environments. A first stage, with two sub-stages (1A − 6.1 to 4.2 kyr. BP; 1B − 4.2 to ∼3.6 kyr. BP) was deposited during the sea-level rise, with sediments containing an abundance of long-chain n-alkanes with 2H-depleted (δ2Hn-alk) signatures indicating riverine inputs of terrestrial organic carbon during prevailing wet conditions. A second stage (<∼3.6 kyr. BP), comprising lacustrine facies, was characterized by high amounts of authigenic carbonate precipitates (calcite, Mg-calcite, Ca-dolomite, and dolomite). The carbonates are the result of physico-chemical changes in the water after the isolation of the lagoons from both the Atlantic Ocean and the neighboring Lagoa de Araruama due to a fall in sea level and aridification associated with intensification of the coastal upwelling after 2.2 kyr. BP. The n-alkanes deposited during this phase contain variable proportions of long and short-chain homologues indicating a mixed source of organic matter (terrestrial higher plants and microorganisms), as well as changes in vegetation associated with the driest conditions, inferred from the 2H-enriched n-alkane homologous. These results clearly demonstrate a climatic influence on dolomite formation in coastal hypersaline environments linked to sea-level change and coastal upwelling phenomena. With these observations, we hypothesize that the existence of similar palaeoceanographic and environmental conditions in the geologic past may have triggered the formation of extensive microbial dolomite deposits. This study provides new elements to interpret the formation of massive dolomite deposits in the geological record, for example, along the Late Triassic Tethys margin.

Risk Assessment of the Insecticide Movento 100 SC with the Active Substance Spirotetramat

Movento 100 SC is a new insecticide containing the active substance spirotetramat. The intended use is in stone fruit, pome fruit, vegetables and ornamentals outdoors, and lettuce, tomatoes and cucumbers in greenhouses.&#x0D; VKM was requested by the Norwegian Food Safety Authority to consider possible health risk for operators related to the properties of Movento 100 SC; in particular the relevance of the effects of spirotetramat on thyroid hormones, brain, thymus and body weight observed in dogs, and the reproductive effects of spirotetramat observed in rats. VKM was also asked to consider the fate and behaviour of Movento 100 SC with the active ingredient spirotetramat in the environment, and the ecotoxicological effects and risks related to its use. The risk assessment was finalized in a meeting on May 24. 2013, by VKM’s Scientific Panel on Plant Protection Products.&#x0D; VKM’s conclusions are as follows:&#x0D; Health:&#x0D; VKM concludes that spirotetramat shows toxic effects in dogs and rats that could be relevant for humans. Thyroid and thymus glands are target organs in the oral subchronic toxicity studies of spirotetramat in dogs, and effects are observed from 19 mg/kg bw/day (600 ppm). Decreases in circulating thyroid hormone levels were detected in all three studies carried out with dogs (28-, 90-days and 1-year) and should be considered toxicologically relevant. The opinion of the Panel is that it cannot be excluded that the observed brain dilatation in dogs is treatment-related, and relevant to humans.&#x0D; Furthermore, VKM concludes that the reproductive effect observed in rats could be relevant for humans.&#x0D; VKM proposes a NOAEL of 5 mg/kg bw/day (200 ppm) for spirotetramat based on a 1- year toxicity study in dogs, and a NOAEL of 100 mg/kg bw/day based on the acute neurotoxicity study in rats.&#x0D; VKM supports/proposes:&#x0D; &#x0D; ADI: 0.05 mg/kg bw/day.&#x0D; AOEL: 0.05 mg/kg bw/day.&#x0D; ARfD: 1 mg/kg bw/day.&#x0D; &#x0D; Risk calculations show minimal risk if personal protective equipment is used.&#x0D; Environment:&#x0D; VKM concludes that spirotetramat and its metabolites are not expected to accumulate in soil. It is not expected that spirotetramat or any of its metabolites will reach concentrations in groundwater above the threshold level of 0.1 μg/L when the formulation Movento 100 SC is applied according to the intended use.&#x0D; VKM concludes that use of Movento 100 SC with the active substance spirotetramat according to the proposed application scheme in Norway represents a minimal risk of adverse effects on terrestrial mammals, birds, earthworms, and soil microorganisms. However, in-field effects on sensitive species of predatory mites in the crop cannot be excluded.&#x0D; The risk of adverse effects on bees is minimal providing that spirotetramat is not used on crops during flowering or when bees are actively foraging.&#x0D; For aquatic organisms in surface water, the risk is considered minimal, provided that a 5 m buffer zone to open water is used.