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Nigel W. Tomkins - One of the best experts on this subject based on the ideXlab platform.
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Asparagopsis taxiformis decreases enteric methane production from sheep
Animal Production Science, 2020Co-Authors: Xixi Li, Hayley C. Norman, Robert D. Kinley, M. Laurence, Matt G. Wilmot, Hannah Bender, Nigel W. TomkinsAbstract:Asparagopsis taxiformis concentrates halogenated compounds that are known to inhibit cobamide-dependent methanogenesis in vitro and, therefore, has potential to mitigate enteric methane production. The present study investigated the effect of Asparagopsis on methane (CH4) production from sheep offered a high-fibre pelleted diet (offered at 1.2 × maintenance) at five inclusion levels of Asparagopsis for 72 days (0% (control), 0.5%, 1%, 2% and 3% organic matter basis as offered). Individual animal CH4 measurements were conducted at 21-day intervals using open-circuit respiration chambers. Asparagopsis inclusion resulted in a consistent and dose-dependent reduction in enteric CH4 production over time, with up to 80% CH4 mitigation at the 3% offered rate compared with the group fed no Asparagopsis (P < 0.05). Sheep fed Asparagopsis had a significantly lower concentration of total volatile fatty acids and acetate, but a higher propionate concentration. No changes in liveweight gain were identified. Supplementing Asparagopsis in a high-fibre diet (
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In Vitro Evaluation of the Antimethanogenic Potency and Effects on Fermentation of Individual and Combinations of Marine Macroalgae
American Journal of Plant Sciences, 2016Co-Authors: Robert D. Kinley, Matthew J. Vucko, Lorenna Machado, Nigel W. TomkinsAbstract:Contribution of ruminants to total greenhouse gas emissions in Australia is approximately 10% and likely to increase with demand for livestock products, thus an efficient method of mitigation must be implemented. The red marine macroalgae Asparagopsis taxiformis reduces enteric methane production by up to 99% in vitro. Other macroalgae with less potent antimethanogenic properties may complement inclusion of Asparagopsis in livestock feeds. Adoption of environmental based changes in livestock systems must provide benefits to producers if change in management is to be adopted. This study used 72 h in vitro fermentations with rumen inoculum to characterize and rank seven species of macroalgae at low inclusion that previously demonstrated some degree of antimethanogenesis at higher inclusion concentration. The seven were assessed at 5% inclusion (OM basis) and in combination with Asparagopsis to evaluate beneficial effects on fermentation. When tested individually, improvements in volatile fatty acids were generally observed, however, minimal effect on gas production and no clear justification for a ranking order were demonstrated. When tested in combination with Asparagopsis, the effects on fermentation were dominated by presence of Asparagopsis at 2% and no further benefits demonstrated. Therefore, Asparagopsis remains the only macroalga inducing near elimination of methane in vitro and benefit of combinations with other macroalgae evaluated in this study was not demonstrated. However, combination with high protein macroalgae is proposed to provide productivity enhancement during seasonal lows in grass quality and thus reduce methane emissions intensity providing a stronger conduit for environmental responsibility while increasing productivity.
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dose response effects of Asparagopsis taxiformis and oedogonium sp on in vitro fermentation and methane production
Journal of Applied Phycology, 2016Co-Authors: Lorenna Machado, Robert D. Kinley, Marie Magnusson, Nicholas A Paul, Nigel W. TomkinsAbstract:This study aimed to identify the optimal doses of the macroalgae Asparagopsis taxiformis and Oedogonium sp., individually and in combination, which would decrease the in vitro production of methane while minimizing adverse effects on fermentation, using rumen inoculant from Bos indicus steers. The dose-response experiment evaluated ten doses of Asparagopsis [ranging from 0 to 16.7 % of the organic matter (OM) incubated] and seven doses of Oedogonium (ranging from 0 to 100 % OM) using Rhodes grass hay as a basal substrate. Asparagopsis was highly effective in decreasing the production of methane with a reduction of 99 % at doses as low as 2 % OM basis. However, a dose of 2 % OM also decreased the production of volatile fatty acids (VFA). Oedogonium was less effective with doses ≥50 % OM significantly decreasing the production of methane. A combination of Asparagopsis (2 % OM) and Oedogonium (25 and 50 % OM) continued to suppress the production of methane, independent of the inclusion rate of Oedogonium. The effectiveness of Asparagopsis demonstrates its potential for the mitigation of methane emissions from ruminants at inclusion rates of ≤2 % OM. Oedogonium is a potential feed supplement due to its nutritional value, but supplements ≤25 % OM are recommended to avoid adverse effects on apparent in vitro fermentation.
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identification of bioactives from the red seaweed Asparagopsis taxiformis that promote antimethanogenic activity in vitro
Journal of Applied Phycology, 2016Co-Authors: Lorenna Machado, Robert D. Kinley, Marie Magnusson, Nicholas A Paul, Nigel W. TomkinsAbstract:Asparagopsis taxiformis has potent antimethanogenic activity as a feed supplement at 2 % of organic matter in in vitro bioassays. This study identified the main bioactive natural products and their effects on fermentation using rumen fluid from Bos indicus steers. Polar through to non-polar extracts (water, methanol, dichloromethane and hexane) were tested. The dichloromethane extract was most active, reducing methane production by 79 %. Bromoform was the most abundant natural product in the biomass of Asparagopsis (1723 μg g−1 dry weight [DW] biomass), followed by dibromochloromethane (15.8 μg g−1 DW), bromochloroacetic acid (9.8 μg g−1 DW) and dibromoacetic acid (0.9 μg g−1 DW). Bromoform and dibromochloromethane had the highest activity with concentrations ≥1 μM inhibiting methane production. However, only bromoform was present in sufficient quantities in the biomass at 2 % organic matter to elicit this effect. Importantly, the degradability of organic matter and volatile fatty acids were not affected at effective concentrations.
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the red macroalgae Asparagopsis taxiformis is a potent natural antimethanogenic that reduces methane production during in vitro fermentation with rumen fluid
Animal Production Science, 2016Co-Authors: Robert D. Kinley, Matthew J. Vucko, Lorenna Machado, Nigel W. TomkinsAbstract:Livestock feed modification is a viable method for reducing methane emissions from ruminant livestock. Ruminant enteric methane is responsible approximately to 10% of greenhouse gas emissions in Australia. Some species of macroalgae have antimethanogenic activity on in vitro fermentation. This study used in vitro fermentation with rumen inoculum to characterise increasing inclusion rates of the red macroalga Asparagopsis taxiformis on enteric methane production and digestive efficiency throughout 72-h fermentations. At dose levels ≤1% of substrate organic matter there was minimal effect on gas and methane production. However, inclusion ≥2% reduced gas and eliminated methane production in the fermentations indicating a minimum inhibitory dose level. There was no negative impact on substrate digestibility for macroalgae inclusion ≤5%, however, a significant reduction was observed with 10% inclusion. Total volatile fatty acids were not significantly affected with 2% inclusion and the acetate levels were reduced in favour of increased propionate and, to a lesser extent, butyrate which increased linearly with increasing dose levels. A barrier to commercialisation of Asparagopsis is the mass production of this specific macroalgal biomass at a scale to provide supplementation to livestock. Another area requiring characterisation is the most appropriate method for processing (dehydration) and feeding to livestock in systems with variable feed quality and content. The in vitro assessment method used here clearly demonstrated that Asparagopsis can inhibit methanogenesis at very low inclusion levels whereas the effect in vivo has yet to be confirmed.
Nicholas A Paul - One of the best experts on this subject based on the ideXlab platform.
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Within-species and temperature-related variation in the growth and natural products of the red alga Asparagopsis taxiformis
Journal of Applied Phycology, 2017Co-Authors: Leonardo Mata, Marie Magnusson, Rebecca J. Lawton, Nikos Andreakis, Nicholas A PaulAbstract:The red algal genus Asparagopsis (Bonnemaisoniaceae) is a significant resource for bioactive natural products. However, prior to domestication for commercial production, we need to understand the potential variation in growth and concentration of natural products between isolates of Asparagopsis and, beyond that, how these traits are affected by environmental conditions. Ten isolates of Asparagopsis taxiformis were collected from tropical and warm-temperate regions in Queensland, Australia, and identified by molecular barcoding of the mitochondrial intergenic spacer ( cox 2–3 spacer). The isolates were cultured at three temperatures ranging from the minimum of the warm-temperate region to the maximum of the tropical region. Growth rates and the concentration of natural products varied between the region of origin, between isolates within region and between temperatures. Growth differed by up to 50% between isolates, whereas the concentration of natural products differed more than tenfold. Growth rates were highest at the minimum temperature of 20.2°C, irrespective of region of origin, and were lowest at the maximum temperature of 28.1°C. Natural products were threefold higher in tropical isolates, and this variation was not correlated to growth. Consequently, targeting isolates with high concentrations of natural products should be the primary strategy for the domestication of Asparagopsis for biotechnology applications.
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dose response effects of Asparagopsis taxiformis and oedogonium sp on in vitro fermentation and methane production
Journal of Applied Phycology, 2016Co-Authors: Lorenna Machado, Robert D. Kinley, Marie Magnusson, Nicholas A Paul, Nigel W. TomkinsAbstract:This study aimed to identify the optimal doses of the macroalgae Asparagopsis taxiformis and Oedogonium sp., individually and in combination, which would decrease the in vitro production of methane while minimizing adverse effects on fermentation, using rumen inoculant from Bos indicus steers. The dose-response experiment evaluated ten doses of Asparagopsis [ranging from 0 to 16.7 % of the organic matter (OM) incubated] and seven doses of Oedogonium (ranging from 0 to 100 % OM) using Rhodes grass hay as a basal substrate. Asparagopsis was highly effective in decreasing the production of methane with a reduction of 99 % at doses as low as 2 % OM basis. However, a dose of 2 % OM also decreased the production of volatile fatty acids (VFA). Oedogonium was less effective with doses ≥50 % OM significantly decreasing the production of methane. A combination of Asparagopsis (2 % OM) and Oedogonium (25 and 50 % OM) continued to suppress the production of methane, independent of the inclusion rate of Oedogonium. The effectiveness of Asparagopsis demonstrates its potential for the mitigation of methane emissions from ruminants at inclusion rates of ≤2 % OM. Oedogonium is a potential feed supplement due to its nutritional value, but supplements ≤25 % OM are recommended to avoid adverse effects on apparent in vitro fermentation.
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identification of bioactives from the red seaweed Asparagopsis taxiformis that promote antimethanogenic activity in vitro
Journal of Applied Phycology, 2016Co-Authors: Lorenna Machado, Robert D. Kinley, Marie Magnusson, Nicholas A Paul, Nigel W. TomkinsAbstract:Asparagopsis taxiformis has potent antimethanogenic activity as a feed supplement at 2 % of organic matter in in vitro bioassays. This study identified the main bioactive natural products and their effects on fermentation using rumen fluid from Bos indicus steers. Polar through to non-polar extracts (water, methanol, dichloromethane and hexane) were tested. The dichloromethane extract was most active, reducing methane production by 79 %. Bromoform was the most abundant natural product in the biomass of Asparagopsis (1723 μg g−1 dry weight [DW] biomass), followed by dibromochloromethane (15.8 μg g−1 DW), bromochloroacetic acid (9.8 μg g−1 DW) and dibromoacetic acid (0.9 μg g−1 DW). Bromoform and dibromochloromethane had the highest activity with concentrations ≥1 μM inhibiting methane production. However, only bromoform was present in sufficient quantities in the biomass at 2 % organic matter to elicit this effect. Importantly, the degradability of organic matter and volatile fatty acids were not affected at effective concentrations.
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effects of marine and freshwater macroalgae on in vitro total gas and methane production
PLOS ONE, 2014Co-Authors: Lorenna Machado, Marie Magnusson, Nicholas A Paul, Nigel W. TomkinsAbstract:This study aimed to evaluate the effects of twenty species of tropical macroalgae on in vitro fermentation parameters, total gas production (TGP) and methane (CH4) production when incubated in rumen fluid from cattle fed a low quality roughage diet. Primary biochemical parameters of macroalgae were characterized and included proximate, elemental, and fatty acid (FAME) analysis. Macroalgae and the control, decorticated cottonseed meal (DCS), were incubated in vitro for 72 h, where gas production was continuously monitored. Post-fermentation parameters, including CH4 production, pH, ammonia, apparent organic matter degradability (OMd), and volatile fatty acid (VFA) concentrations were measured. All species of macroalgae had lower TGP and CH4 production than DCS. Dictyota and Asparagopsis had the strongest effects, inhibiting TGP by 53.2% and 61.8%, and CH4 production by 92.2% and 98.9% after 72 h, respectively. Both species also resulted in the lowest total VFA concentration, and the highest molar concentration of propionate among all species analysed, indicating that anaerobic fermentation was affected. Overall, there were no strong relationships between TGP or CH4 production and the >70 biochemical parameters analysed. However, zinc concentrations >0.10 g.kg−1 may potentially interact with other biochemical components to influence TGP and CH4 production. The lack of relationship between the primary biochemistry of species and gas parameters suggests that significant decreases in TGP and CH4 production are associated with secondary metabolites produced by effective macroalgae. The most effective species, Asparagopsis, offers the most promising alternative for mitigation of enteric CH4 emissions.
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ultrastructure of the gland cells of the red alga Asparagopsis armata bonnemaisoniaceae 1
Journal of Phycology, 2006Co-Authors: Nicholas A Paul, Louise Cole, Peter D SteinbergAbstract:Localization of natural products in the gland cells of the tetrasporophyte of Asparagopsis armata Harvey was examined using light microscopy, epifluorescence microscopy, and TEM. A. armata produces a range of halogenated metabolites that deter herbivores and inhibit bacterial fouling. The halogenated metabolites accumulate as a refractile inclusion inside specialized gland cells and this inclusion was no longer produced when the alga was cultured without bromine. Gland cells are formed soon after the apical division and can occupy a large portion of the algal volume, up to 10% of some parts of the filament. TEM was carried out on cryofixed and freeze-substituted samples. Ultrastructure studies revealed that gland cells are positioned inside the pericentral cell, originating from the axial cell wall. The refractile inclusion of these gland cells is comprised of numerous electron-translucent vacuoles enclosed by an electron-opaque matrix. Some contents of the inclusion autofluoresced under UV excitation by epifluorescence microscopy. Light microscopy further revealed that stalk-like structures connected the gland cell to the outer wall of the pericentral cell. These stalk-like structures may provide the mechanism for metabolite transfer to the algal surface. Gland cell walls are relatively thin, which in turn would aid the transfer of metabolites to the stalk-like structure. These features of the gland cells provide essential clues to the production and storage of the halogenated metabolites in A. armata and offer new insights into a possible mechanism for their release.
Lorenna Machado - One of the best experts on this subject based on the ideXlab platform.
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in vitro response of rumen microbiota to the antimethanogenic red macroalga Asparagopsis taxiformis
Microbial Ecology, 2018Co-Authors: Lorenna Machado, Marie Magnusson, Nigel William Tomkins, David J Midgley, Carly P RosewarneAbstract:The red macroalga Asparagopsis taxiformis has been shown to significantly decrease methane production by rumen microbial communities. This has been attributed to the bioaccumulation of halogenated methane analogues produced as algal secondary metabolites. The objective of this study was to evaluate the impact of A. taxiformis supplementation on the relative abundance of methanogens and microbial community structure during in vitro batch fermentation. Addition of A. taxiformis (2% organic matter) or the halogenated methane analogue bromoform (5 μM) reduced methane production by over 99% compared to a basal substrate-only control. Quantitative PCR confirmed that the decrease in methane production was correlated with a decrease in the relative abundance of methanogens. High-throughput 16S ribosomal RNA gene amplicon sequencing showed that both treatments reduced the abundance of the three main orders of methanogens present in ruminants (Methanobacteriales, Methanomassiliicoccales and Methanomicrobiales). Shifts in bacterial community structure due to the addition of A. taxiformis and 5 μM bromoform were similar and concomitant with increases in hydrogen concentration in the headspace of the fermenters. With high potency and broad-spectrum activity against rumen methanogens, A. taxiformis represents a promising natural strategy for reducing enteric methane emissions from ruminant livestock.
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In Vitro Evaluation of the Antimethanogenic Potency and Effects on Fermentation of Individual and Combinations of Marine Macroalgae
American Journal of Plant Sciences, 2016Co-Authors: Robert D. Kinley, Matthew J. Vucko, Lorenna Machado, Nigel W. TomkinsAbstract:Contribution of ruminants to total greenhouse gas emissions in Australia is approximately 10% and likely to increase with demand for livestock products, thus an efficient method of mitigation must be implemented. The red marine macroalgae Asparagopsis taxiformis reduces enteric methane production by up to 99% in vitro. Other macroalgae with less potent antimethanogenic properties may complement inclusion of Asparagopsis in livestock feeds. Adoption of environmental based changes in livestock systems must provide benefits to producers if change in management is to be adopted. This study used 72 h in vitro fermentations with rumen inoculum to characterize and rank seven species of macroalgae at low inclusion that previously demonstrated some degree of antimethanogenesis at higher inclusion concentration. The seven were assessed at 5% inclusion (OM basis) and in combination with Asparagopsis to evaluate beneficial effects on fermentation. When tested individually, improvements in volatile fatty acids were generally observed, however, minimal effect on gas production and no clear justification for a ranking order were demonstrated. When tested in combination with Asparagopsis, the effects on fermentation were dominated by presence of Asparagopsis at 2% and no further benefits demonstrated. Therefore, Asparagopsis remains the only macroalga inducing near elimination of methane in vitro and benefit of combinations with other macroalgae evaluated in this study was not demonstrated. However, combination with high protein macroalgae is proposed to provide productivity enhancement during seasonal lows in grass quality and thus reduce methane emissions intensity providing a stronger conduit for environmental responsibility while increasing productivity.
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dose response effects of Asparagopsis taxiformis and oedogonium sp on in vitro fermentation and methane production
Journal of Applied Phycology, 2016Co-Authors: Lorenna Machado, Robert D. Kinley, Marie Magnusson, Nicholas A Paul, Nigel W. TomkinsAbstract:This study aimed to identify the optimal doses of the macroalgae Asparagopsis taxiformis and Oedogonium sp., individually and in combination, which would decrease the in vitro production of methane while minimizing adverse effects on fermentation, using rumen inoculant from Bos indicus steers. The dose-response experiment evaluated ten doses of Asparagopsis [ranging from 0 to 16.7 % of the organic matter (OM) incubated] and seven doses of Oedogonium (ranging from 0 to 100 % OM) using Rhodes grass hay as a basal substrate. Asparagopsis was highly effective in decreasing the production of methane with a reduction of 99 % at doses as low as 2 % OM basis. However, a dose of 2 % OM also decreased the production of volatile fatty acids (VFA). Oedogonium was less effective with doses ≥50 % OM significantly decreasing the production of methane. A combination of Asparagopsis (2 % OM) and Oedogonium (25 and 50 % OM) continued to suppress the production of methane, independent of the inclusion rate of Oedogonium. The effectiveness of Asparagopsis demonstrates its potential for the mitigation of methane emissions from ruminants at inclusion rates of ≤2 % OM. Oedogonium is a potential feed supplement due to its nutritional value, but supplements ≤25 % OM are recommended to avoid adverse effects on apparent in vitro fermentation.
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identification of bioactives from the red seaweed Asparagopsis taxiformis that promote antimethanogenic activity in vitro
Journal of Applied Phycology, 2016Co-Authors: Lorenna Machado, Robert D. Kinley, Marie Magnusson, Nicholas A Paul, Nigel W. TomkinsAbstract:Asparagopsis taxiformis has potent antimethanogenic activity as a feed supplement at 2 % of organic matter in in vitro bioassays. This study identified the main bioactive natural products and their effects on fermentation using rumen fluid from Bos indicus steers. Polar through to non-polar extracts (water, methanol, dichloromethane and hexane) were tested. The dichloromethane extract was most active, reducing methane production by 79 %. Bromoform was the most abundant natural product in the biomass of Asparagopsis (1723 μg g−1 dry weight [DW] biomass), followed by dibromochloromethane (15.8 μg g−1 DW), bromochloroacetic acid (9.8 μg g−1 DW) and dibromoacetic acid (0.9 μg g−1 DW). Bromoform and dibromochloromethane had the highest activity with concentrations ≥1 μM inhibiting methane production. However, only bromoform was present in sufficient quantities in the biomass at 2 % organic matter to elicit this effect. Importantly, the degradability of organic matter and volatile fatty acids were not affected at effective concentrations.
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the red macroalgae Asparagopsis taxiformis is a potent natural antimethanogenic that reduces methane production during in vitro fermentation with rumen fluid
Animal Production Science, 2016Co-Authors: Robert D. Kinley, Matthew J. Vucko, Lorenna Machado, Nigel W. TomkinsAbstract:Livestock feed modification is a viable method for reducing methane emissions from ruminant livestock. Ruminant enteric methane is responsible approximately to 10% of greenhouse gas emissions in Australia. Some species of macroalgae have antimethanogenic activity on in vitro fermentation. This study used in vitro fermentation with rumen inoculum to characterise increasing inclusion rates of the red macroalga Asparagopsis taxiformis on enteric methane production and digestive efficiency throughout 72-h fermentations. At dose levels ≤1% of substrate organic matter there was minimal effect on gas and methane production. However, inclusion ≥2% reduced gas and eliminated methane production in the fermentations indicating a minimum inhibitory dose level. There was no negative impact on substrate digestibility for macroalgae inclusion ≤5%, however, a significant reduction was observed with 10% inclusion. Total volatile fatty acids were not significantly affected with 2% inclusion and the acetate levels were reduced in favour of increased propionate and, to a lesser extent, butyrate which increased linearly with increasing dose levels. A barrier to commercialisation of Asparagopsis is the mass production of this specific macroalgal biomass at a scale to provide supplementation to livestock. Another area requiring characterisation is the most appropriate method for processing (dehydration) and feeding to livestock in systems with variable feed quality and content. The in vitro assessment method used here clearly demonstrated that Asparagopsis can inhibit methanogenesis at very low inclusion levels whereas the effect in vivo has yet to be confirmed.
Antonio Román Muñoz - One of the best experts on this subject based on the ideXlab platform.
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The invasive species Asparagopsis taxiformis (Bonnemaisoniales, Rhodophyta) on Andalusian coast (Southern Spain): Reproductive stages, new records and invaded communities
Acta Botanica Malacitana, 2020Co-Authors: María Altamirano, Antonio Román Muñoz, Julio De La Rosa, Agustín Barrajón-mínguez, Agustín Barrajón-domenech, Carlos Moreno-robledo, M. Carmen ArroyoAbstract:ABSTRACT. The invasive species Asparagopsis taxiformis (Bonnemaisoniales, Rhodophyta) on Andalusian coasts (Southern Spain): reproductive stages, new records and invaded communities. The present study provides new records from Andalusian coasts of the exotic invasive seaweed Asparagopsis taxiformis (Delile) Trevisan. These records demonstrate that A. taxiformis has rapidly and widely expanded its distribution range in this region, from Almería to Cádiz (Strait of Gibraltar). The latter locality may represent the western geographical limit of the species in the Mediterranean Sea. Spermatangial heads and cystocarps were observed in the collected gametophytes. Additionally, we report the first record of the tetrasporophytic stage, Falkenbergia hillebrandii (Bornet) Falkenberg from the Andalusian coast, although tetraspores were not encountered in these samples. Consequently, information on the affected communities and arguments for considering A. taxiformis as an invasive species in the Andalusian coast are provided.Key words. Asparagopsis taxiformis, Bonnemaisoniales, distribution, Falkenbergia hillebrandii, invasive species, Mediterranean Sea, new record, reproductive stage, RhodophytaRESUMEN. La especie invasora Asparagopsis taxiformis (Bonnemaisoniales, Rhodophyta) en las costas andaluzas (Sur de España): fases reproductivas, nuevas citas y comunidades invadidas. El presente trabajo aporta nuevas citas para las costas andaluzas de la especie exótica invasora de macroalga Asparagopsis taxiformis (Delile) Trevisan. Estas citas muestran que la especie ha aumentado ampliamente su área de distribución de manera rápida en esta región, desde Almería hasta Cádiz (Estrecho de Gibraltar). Esta última localidad representaría el límite occidental de la especie en el mar Mediterráneo. En las muestras recogidas de gametofitos se pudieron observar ramas espermatangiales y cistocarpos. Se aporta la primera cita del estadio tetrasporofítico, Falkenbergia hillebrandii (Bornet) Falkenberg en las costas andaluzas, aunque no se observaron tetrásporas en estas muestras. Se informa sobre las comunidades afectadas y se dan argumentos para considerar a A. taxiformis invasora en las costas andaluzas.Palabras clave. Asparagopsis taxiformis, Bonnemaisoniales, distribución, especie invasora, estadio reproductivo, Falkenbergia hillebrandii, mar Mediterráneo, nueva cita, Rhodophyta
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assessing global range expansion in a cryptic species complex insights from the red seaweed genus Asparagopsis florideophyceae
Journal of Phycology, 2018Co-Authors: Marianela Zanolla, María Altamirano, Antonio Román Muñoz, Julio De La Rosa, Raquel Carmona, Alison R Sherwood, Konstantinos Tsiamis, Ana Márcia Barbosa, Virginia SouzaegipsyAbstract:The mitochondrial genetic diversity, distribution and invasive potential of multiple cryptic operational taxonomic units (OTUs) of the red invasive seaweed Asparagopsis were assessed by studying introduced Mediterranean and Hawaiian populations. Invasive behavior of each Asparagopsis OTU was inferred from phylogeographic reconstructions, past historical demographic dynamics, recent range expansion assessments and future distributional predictions obtained from demographic models. Genealogical networks resolved Asparagopsis gametophytes and tetrasporophytes into four A. taxiformis and one A. armata cryptic OTUs. Falkenbergia isolates of A. taxiformis L3 were recovered for the first time in the western Mediterranean Sea and represent a new introduction for this area. Neutrality statistics supported past range expansion for A. taxiformis L1 and L2 in Hawaii. On the other hand, extreme geographic expansion and an increase in effective population size were found only for A. taxiformis L2 in the western Mediterranean Sea. Distribution models predicted shifts of the climatically suitable areas and population expansion for A. armata L1 and A. taxiformis L1 and L2. Our integrated study confirms a high invasive risk for A. taxiformis L1 and L2 in temperate and tropical areas. Despite the differences in predictions among modelling approaches, a number of regions were identified as zones with high invasion risk for A. taxiformis L2. Since range shifts are likely climate-driven phenomena, future invasive behavior cannot be excluded for the rest of the lineages. This article is protected by copyright. All rights reserved.
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Assessing global range expansion in a cryptic species complex: insights from the red seaweed genus Asparagopsis (Florideophyceae).
Journal of Phycology, 2017Co-Authors: Marianela Zanolla, María Altamirano, Antonio Román Muñoz, Julio De La Rosa, Raquel Carmona, Alison R Sherwood, Virginia Souza-egipsy, Konstantinos Tsiamis, Ana Márcia Barbosa, Nikos AndreakisAbstract:The mitochondrial genetic diversity, distribution and invasive potential of multiple cryptic operational taxonomic units (OTUs) of the red invasive seaweed Asparagopsis were assessed by studying introduced Mediterranean and Hawaiian populations. Invasive behavior of each Asparagopsis OTU was inferred from phylogeographic reconstructions, past historical demographic dynamics, recent range expansion assessments and future distributional predictions obtained from demographic models. Genealogical networks resolved Asparagopsis gametophytes and tetrasporophytes into four A. taxiformis and one A. armata cryptic OTUs. Falkenbergia isolates of A. taxiformis L3 were recovered for the first time in the western Mediterranean Sea and represent a new introduction for this area. Neutrality statistics supported past range expansion for A. taxiformis L1 and L2 in Hawaii. On the other hand, extreme geographic expansion and an increase in effective population size were found only for A. taxiformis L2 in the western Mediterranean Sea. Distribution models predicted shifts of the climatically suitable areas and population expansion for A. armata L1 and A. taxiformis L1 and L2. Our integrated study confirms a high invasive risk for A. taxiformis L1 and L2 in temperate and tropical areas. Despite the differences in predictions among modelling approaches, a number of regions were identified as zones with high invasion risk for A. taxiformis L2. Since range shifts are likely climate-driven phenomena, future invasive behavior cannot be excluded for the rest of the lineages.
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the invasive species Asparagopsis taxiformis bonnemaisoniales rhodophyta on andalusian coasts southern spain reproductive stages new records and invaded communities
Acta Botánica Malacitana (España), 2008Co-Authors: Maria Altamiranojeschke, Antonio Román Muñoz, Julio De La Rosa, Agustin Barrajonminguez, Agustin Barrajonmenech, Carlos Morenorobledo, Carmen M ArroyoAbstract:La especie invasora Asparagopsis taxiformis (Bonnemaisoniales, Rhodophyta) en las costas andaluzas (Sur de Espana): fases reproductivas, nuevas citas y comunidades invadidas. El presente trabajo aporta nuevas citas para las costas andaluzas de la especie exotica invasora de macroalga Asparagopsis taxiformis (Delile) Trevisan. Estas citas muestran que la especie ha aumentado ampliamente su area de distribucion de manera rapida en esta region, desde Almeria hasta Cadiz (Estrecho de Gibraltar). Esta ultima localidad representaria el limite occidental de la especie en el mar Mediterraneo. En las muestras recogidas de gametofitos se pudieron observar ramas espermatangiales y cistocarpos. Se aporta la primera cita del estadio tetrasporofitico, Falkenbergia hillebrandii (Bornet) Falkenberg en las costas andaluzas, aunque no se observaron tetrasporas en estas muestras. Se informa sobre las comunidades afectadas y se dan argumentos para considerar a A. taxiformis invasora en las costas andaluzas.
Nikos Andreakis - One of the best experts on this subject based on the ideXlab platform.
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Assessing global range expansion in a cryptic species complex: insights from the red seaweed genus Asparagopsis (Florideophyceae).
Journal of Phycology, 2017Co-Authors: Marianela Zanolla, María Altamirano, Antonio Román Muñoz, Julio De La Rosa, Raquel Carmona, Alison R Sherwood, Virginia Souza-egipsy, Konstantinos Tsiamis, Ana Márcia Barbosa, Nikos AndreakisAbstract:The mitochondrial genetic diversity, distribution and invasive potential of multiple cryptic operational taxonomic units (OTUs) of the red invasive seaweed Asparagopsis were assessed by studying introduced Mediterranean and Hawaiian populations. Invasive behavior of each Asparagopsis OTU was inferred from phylogeographic reconstructions, past historical demographic dynamics, recent range expansion assessments and future distributional predictions obtained from demographic models. Genealogical networks resolved Asparagopsis gametophytes and tetrasporophytes into four A. taxiformis and one A. armata cryptic OTUs. Falkenbergia isolates of A. taxiformis L3 were recovered for the first time in the western Mediterranean Sea and represent a new introduction for this area. Neutrality statistics supported past range expansion for A. taxiformis L1 and L2 in Hawaii. On the other hand, extreme geographic expansion and an increase in effective population size were found only for A. taxiformis L2 in the western Mediterranean Sea. Distribution models predicted shifts of the climatically suitable areas and population expansion for A. armata L1 and A. taxiformis L1 and L2. Our integrated study confirms a high invasive risk for A. taxiformis L1 and L2 in temperate and tropical areas. Despite the differences in predictions among modelling approaches, a number of regions were identified as zones with high invasion risk for A. taxiformis L2. Since range shifts are likely climate-driven phenomena, future invasive behavior cannot be excluded for the rest of the lineages.
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Within-species and temperature-related variation in the growth and natural products of the red alga Asparagopsis taxiformis
Journal of Applied Phycology, 2017Co-Authors: Leonardo Mata, Marie Magnusson, Rebecca J. Lawton, Nikos Andreakis, Nicholas A PaulAbstract:The red algal genus Asparagopsis (Bonnemaisoniaceae) is a significant resource for bioactive natural products. However, prior to domestication for commercial production, we need to understand the potential variation in growth and concentration of natural products between isolates of Asparagopsis and, beyond that, how these traits are affected by environmental conditions. Ten isolates of Asparagopsis taxiformis were collected from tropical and warm-temperate regions in Queensland, Australia, and identified by molecular barcoding of the mitochondrial intergenic spacer ( cox 2–3 spacer). The isolates were cultured at three temperatures ranging from the minimum of the warm-temperate region to the maximum of the tropical region. Growth rates and the concentration of natural products varied between the region of origin, between isolates within region and between temperatures. Growth differed by up to 50% between isolates, whereas the concentration of natural products differed more than tenfold. Growth rates were highest at the minimum temperature of 20.2°C, irrespective of region of origin, and were lowest at the maximum temperature of 28.1°C. Natural products were threefold higher in tropical isolates, and this variation was not correlated to growth. Consequently, targeting isolates with high concentrations of natural products should be the primary strategy for the domestication of Asparagopsis for biotechnology applications.
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morphological differentiation of cryptic lineages within the invasive genus Asparagopsis bonnemaisoniales rhodophyta
Phycologia, 2014Co-Authors: Marianela Zanolla, Nikos Andreakis, Raquel Carmona, J De La Rosa, N Salvador, Alison R Sherwood, María AltamiranoAbstract:Rapid identification of introduced seaweeds is crucial to support management and conservation decisions, especially when multiple cryptic lineages of high-profile invasive taxa occur sympatrically. The red seaweed genus Asparagopsis (Bonnemaisoniales, Rhodophyta) comprises two recognised morpho-species characterised by heteromorphic life cycles and presumably morphologically identical 'Falkenbergia' tetrasporophyte stages: A. armata and A. taxiformis. Populations of the former were easily identified by the presence of distinctive harpoon-like braches on the gametophyte thalli. Four morphologically cryptic yet genetically distinct mitochondrial lineages of invasive nature were recognised within A. taxiformis. We reported a morphological delineation of tetrasporophytes and gametophytes of Asparagopsis, including cryptic lineages collected from the Mediterranean Sea and the Hawaiian Islands, where multiple Asparagopsis lineages were present. Vegetative anatomical characters of the tetrasporophytes were useful in differentiating A. armata from those of A. taxiformis as well as among tetrasporophyte isolates belonging to the four A. taxiformis lineages. In addition, these characters distinguished lineage 2 native range specimens (Hawaii) from the invasive specimens (Mediterranean Sea), which suggested high levels of morphological plasticity in the invasive taxon. We propose that the taxonomic status of the lineages within A. taxiformis needs to be revised.
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microsatellite markers in an invasive strain of Asparagopsis taxiformis bonnemaisoniales rhodophyta insights in ploidy level and sexual reproduction
Gene, 2007Co-Authors: Nikos Andreakis, Wiebe H C F Kooistra, Gabriele ProcacciniAbstract:Eight polymorphic nuclear microsatellite loci were identified from the invasive Indo-Pacific Mediterranean strain of Asparagopsis taxiformis. Microsatellite markers were tested against a panel of specimens collected along the Italian (Elba, Naples) and Californian (Catalina Island) coasts, all belonging to the same mitochondrial lineage. In addition, we used Hawaiian specimens, belonging to a closely related mitochondrial lineage. The markers amplified in all of the specimens but failed consistently in thalli of two more distantly related mitochondrial lineages of A. taxiformis as well as in specimens belonging to the sister species Asparagopsis armata. Since haploid female individuals among the Mediterranean specimens contained cystocarps, genotyping was performed on supposedly haploid female specimens and supposedly diploid cystocarps separately. As expected, external allelic contribution was detected in the cystocarps. However, even after removal of these reproductive structures, gametophyte thalli exhibited patterns consisting of up to three alleles in all of the tested populations indicating polyploidy. An elevated number of distinct genotypes (up to 85%) were found per population, suggesting high intra-population variation. Results showed high genetic similarity between the two Mediterranean populations screened and lower similarity between these two and the Californian one within the same mitochondrial lineage. Lowest similarity was found between these three and the Hawaiian population belonging to the other related mitochondrial lineage 1.
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phylogeography of the invasive seaweed Asparagopsis bonnemaisoniales rhodophyta reveals cryptic diversity
Molecular Ecology, 2007Co-Authors: Nikos Andreakis, Christine A Maggs, Gabriele Procaccini, Wiebe H C F KooistraAbstract:: The rhodophyte seaweed Asparagopsis armata Harvey is distributed in the northern and southern temperate zones, and its congener Asparagopsis taxiformis (Delile) Trevisan abounds throughout the tropics and subtropics. Here, we determine intraspecific phylogeographic patterns to compare potential causes of the disjunctions in the distributions of both species. We obtained specimens throughout their ranges and inferred phylogenies from the hypervariable domains D1-D3 of the nuclear rDNA LSU, the plastid spacer between the large and small subunits of RuBisCo and the mitochondrial cox 2-3 intergenic spacer. The cox spacer acquired base changes the fastest and the RuBisCo spacer the slowest. Median-joining networks inferred from the sequences revealed the absence of phylogeographic structure in the introduced range of A. armata, corroborating the species' reported recent introduction. A. taxiformis consisted of three nuclear, three plastid and four mitochondrial genetically distinct, lineages (1-4). Mitochondrial lineage 3 is found in the western Atlantic, the Canary Islands and the eastern Mediterranean. Mitochondrial lineages 1, 2, and 4 occur in the Indo-Pacific, but one of them (lineage 2) is also found in the central Mediterranean and southern Portugal. Phylogeographic results suggest separation of Atlantic and Indo-Pacific lineages resulted from the emergence of the Isthmus of Panama, as well as from dispersal events postdating the closure event, such as the invasion of the Mediterranean Sea by mitochondrial lineages 2 and 3. Molecular clock estimates using the Panama closure event as a calibration for the split of lineages 3 and 4 suggest that A. taxiformis diverged into two main cryptic species (1 + 2 and 3 + 4) about 3.2-5.5 million years ago (Ma), and that the separation of the mitochondrial lineages 1 and 2 occurred 1-2.3 Ma.
