Background The red macroalgae Asparagopsis is an effective methanogenesis inhibitor due to the presence of halogenated methane(CH_(4))analogues,primarily bromoform(CHBr_(3)).This study aimed to investigate the degrada...Background The red macroalgae Asparagopsis is an effective methanogenesis inhibitor due to the presence of halogenated methane(CH_(4))analogues,primarily bromoform(CHBr_(3)).This study aimed to investigate the degradation process of CHBr3 from A taxiformis in the rumen and whether this process is diet-dependent.An in vitro batch culture system was used according to a 2×2 factorial design,assessing two A taxiformis inclusion rates[0(CTL)and 2%DM diet(AT)]and two diets[high-concentrate(HC)and high-forage diet(HF)].Incubations lasted for 72 h and samples of headspace and fermentation liquid were taken at 0,0.5,1,3,6,8,12,16,24,48 and 72 h to assess the pattern of degradation of CHBr_(3) into dibromomethane(CH_(2)Br_(2))and fermentation parameters.Additionally,an in vitro experiment with pure cultures of seven methanogens strains(Methanobrevibacter smithii,Methanobrevibacter ruminantium,Methanosphaera stadtmanae,Methanosarcina barkeri,Methanobrevibacter millerae,Methanorhermobacter wolfei and Methanobacterium mobile)was conducted to test the effects of increasing concentrations of CHBr3(0.4,2,10and 50μmol/L).Results The addition of AT significantly decreased CH_(4) production(P=0.002)and the acetate:propionate ratio(P=0.003)during a 72-h incubation.The concentrations of CHBr_(3) showed a rapid decrease with nearly 90%degraded within the first 3 h of incubation.On the contrary,CH_(2)Br_(2) concentration quickly increased during the first 6 h and then gradually decreased towards the end of the incubation.Neither CHBr_(3) degradation nor CH_(2)Br_(2) synthesis were affected by the type of diet used as substrate,suggesting that the fermentation rate is not a driving factor involved in CHBr_(3)degradation.The in vitro culture of methanogens showed a dose-response effect of CHBr3 by inhibiting the growth of M.smithii,M.ruminantium,M.stadtmanae,M.barkeri,M.millerae,M.wolfei,and M.mobile.Conclusions The present work demonstrated that CHBr_(3) from A.taxiformis is quickly degraded to CH_(2)Br_(2)in the rumen and that the fermentation rate promoted by different diets is not a driving factor involved in CHBr_(3)degradation.展开更多
Water and air quality of eight seawater swimming pools using chlorine disinfection was measured during four sampling campaigns, spread on one full-year, and in four thalassotherapy centers located in Southeast of Fran...Water and air quality of eight seawater swimming pools using chlorine disinfection was measured during four sampling campaigns, spread on one full-year, and in four thalassotherapy centers located in Southeast of France. Concentrations of trihalomethanes（THMs） in air and in water as well as concentrations of parameters, including nonpurgeable organic carbon（NPOC）, free residual chlorine（Cl_f）, pH, Kjeldhal Nitrogen（KN）, salinity,conductivity, bromide ions and, water and air temperature, were measured. Water and air samples were collected in triplicates morning — at the opening of the pools —, noon and night — at the closing of the pools —, in summer and winter. Data analysis was performed by Principal Component Analysis（PCA） and rotated component matrix, from both data quality and other parameters such as TOC, aromaticity（UV_（254））, pH, hygrometry, and free residual chlorine（Cl_f）. This statistical analysis demonstrates a high correlation between TOC, Cl_fand UV_（254） and THM levels found in air and water, particularly for the major ones（CHBr_3in water：300.0 μg/L mean, 1029.0 μg/L maximum; CHBr_3 in air： 266.1 μg/m^3 mean,1600.0 μg/m^3 maximum, and CHClBr_2 in water： 18.9 μg/L mean, 81.0 μg/L maximum;CHClBr_2 in air： 13.6 μg/m^3 mean, 150.0 μg/m^3maximum）. These high levels of bromoform（CHBr_3） are particularly worrisome in such health institutions, even these levels do not exceed the Permissible Exposure Limit（PEL） of 5 mg/m^3 as an 8 hour time-weighted average currently fixed by various administrations, such as Occupational Safety and Health Administration（OSHA）.展开更多
Cutting farming-related methane emissions from ruminants is critical in the battle against climate change.Since scientists initially investigated the potential of marine macroalgae to reduce methane emissions,using se...Cutting farming-related methane emissions from ruminants is critical in the battle against climate change.Since scientists initially investigated the potential of marine macroalgae to reduce methane emissions,using seaweeds as an anti-methanogenic feed additive has become prevailing in recent years.Asparagopsis taxiformis is the preferred species because it contains a relatively higher concentration of bromoform.As a type of halogenated methane analogue,bromoform contained in A.taxiformis can specifically inhibit the activity of coenzyme M methyltransferase,thereby blocking the ruminal methanogenesis.However,bromoform is a potential toxin and ozone-depleting substance.In response,current research focuses on the effects of bromoform-enriched seaweed supplementation on ruminant productivity and safety,as well as the impact of large-scale cultivation of seaweeds on the atmospheric environment.The current research on seaweed still needs to be improved,especially in developing more species with low bromoform content,such as Bonnemaisonia hamifera,Dictyota bartayresii,and Cystoseira trinodis.Otherwise,seaweed is rich in bioactive substances and exhibits antibacterial,anti-inflammatory,and other physiological properties,but research on the role of these bioactive compounds in methane emissions is lacking.It is worthy of deeper investigation to identify more potential bioactive compounds.As a new focus of attention,seaweed has attracted the interest of many scientists.Nevertheless,seaweed still faces some challenges as a feed additive to ruminants,such as the residues of heavy metals(iodine and bromine)and bromoform in milk or meat,as well as the establishment of a supply chain for seaweed cultivation,preservation,and processing.We have concluded that the methane-reducing efficacy of seaweed is indisputable.However,its application as a commercial feed additive is still influenced by factors such as safety,costs,policy incentives,and regulations.展开更多
With methane emissions from ruminant agriculture contributing 17%of total methane emissions worldwide,there is increasing urgency to develop strategies to reduce greenhouse gas emissions in this sector.One of the prop...With methane emissions from ruminant agriculture contributing 17%of total methane emissions worldwide,there is increasing urgency to develop strategies to reduce greenhouse gas emissions in this sector.One of the proposed strategies is ruminant feed intervention studies focused on the inclusion of anti-methanogenic compounds which are those capable of interacting with the rumen microbiome,reducing the capacity of ruminal microorganisms to produce methane.Recently,seaweeds have been investigated for their ability to reduce methane in ruminants in vitro and in vivo,with the greatest methane abatement reported when using the red seaweed Asparagopsis taxiformis(attributed to the bromoform content of this species).From the literature analysis in this study,levels of up to 99%reduction in ruminant methane emissions have been reported from inclusion of this seaweed in animal feed,although further in vivo and microbiome studies are required to confirm these results as other reports showed no effect on methane emission resulting from the inclusion of seaweed to basal feed.This review explores the current state of research aiming to integrate seaweeds as anti-methanogenic feed additives,as well as examining the specific bioactive compounds within seaweeds that are likely to be related to these effects.The effects of the inclusion of seaweeds on the ruminal microbiome are also reviewed,as well as the future challenges when considering the largescale inclusion of seaweeds into ruminant diets as anti-methanogenic agents.展开更多
Research using open-circuit respiration chambers has established that Asparagopsis bioactive compounds stabilized in canola oil (Asp-Oil), delivering a range of inclusion between 34 - 51 mg bromoform (CHBr3)/kg dry ma...Research using open-circuit respiration chambers has established that Asparagopsis bioactive compounds stabilized in canola oil (Asp-Oil), delivering a range of inclusion between 34 - 51 mg bromoform (CHBr3)/kg dry matter intake (DMI), inhibits methane (CH4) emissions > 98% in feedlot cattle. In this study, Asp-Oil was fed at 35 mg CHBr3/kg DMI in the feedlot finisher diet under highly replicated and commercially relevant conditions, and adequately powered to confirm differences as low as 3.3% in feed conversion efficiency (FCE). The study also evaluated the effect of Asp-Oil on CH4 production (g/day), carcass and meat-eating qualities, animal health, and food safety. The experiment consisted of 300 Angus-Shorthorn (Bos taurus) steers in 30 pens of 10 and fed a barley-based ration supplemented with canola oil (Control, n = 15), or Asp-Oil (n = 15) for total 81-d, inclusive of 21-d transition to full Asp-Oil and grain inclusion in the finisher ration. Reduction of CH4 was measured using GreenFeed Emissions Monitors (GEM) in a subset of 2 pens in both Control and Asp-Oil. However, 67% of CH4 measurements were recorded below the GEM’s limit of detection. An inhibition range of 58% - 98% was demonstrated by collectively using GEM and preliminary respiration chamber measurements. Asp-Oil improved FCE 7.4% in the finisher diet, and 5.6% across transition and finisher periods. During the transition steps the steers had not yet received their full allocations of grain and Asp-Oil which is responsible for the lower FCE benefits. A 4.1% lower DMI in the finisher period contributed to benefits in FCE with no effect on daily weight gains. Cost of feed and weight gain were reduced $0.35/head/day and $0.23/kg, respectively, in steers receiving Asp-Oil. Residues of Asparagopsis CHBr3 were not detected in any sample and only trace iodide and bromide were detected in livers and kidneys of both Control and Asp-Oil steers at levels safe for human consumption. Steers demonstrated normal rumen development typical of feedlot diets. This study confirms that Asp-Oil safely induces significant productivity benefits and CH4 reductions in feedlot beef production. Commercial adoption of Asparagopsis can benefit feedlot beef production and reduces the climate change contribution of livestock production.展开更多
The use of seawater for industrial cooling is a vital technology that poses some of the most profound environmental impact on the water quality in the Arabian Gulf. Biocide (chlorine) is added to the seawater to contr...The use of seawater for industrial cooling is a vital technology that poses some of the most profound environmental impact on the water quality in the Arabian Gulf. Biocide (chlorine) is added to the seawater to control biofouling of the cooling system. This added chlorine reacts with bromide and other chemicals naturally exist in the water to form a wide range of oxidants. Regrettably, reactions between the residual oxidants and natural organic matter in the water lead to formation of toxic halogenated organic compounds that have detrimental effects on the environment when they are discharged into the Gulf. This paper describes the formation of trihalomethanes (THMs) in seawater cooling systems. Results of kinetic experiments have shown that concentrations of THMs increased rapidly with time during the first half hour. Chlorination of seawater has shown significant increase in total THMs (TTHMs) and in bromoform concentrations. Rapid decrease of UV absorbance at 254 nm was also observed during seawater chlorination which is indicative of natural organic matter degradation into small organic molecules including THMs and other by-products. The increase in chlorine dose was accompanied with an increase in TTHMs and bromoform concentrations. Linear relationships between total chlorine concentration and both final TTHMs and bromoform concentrations were established. First order exponential decay and exponential associate functions were developed to correlate chlorine dose with formed THMs.展开更多
Seaweeds are macroalgae,which can be of many different morphologies,sizes,colors,and chemical profiles.They include brown,red,and green seaweeds.Brown seaweeds have been more investigated and exploited in comparison t...Seaweeds are macroalgae,which can be of many different morphologies,sizes,colors,and chemical profiles.They include brown,red,and green seaweeds.Brown seaweeds have been more investigated and exploited in comparison to other seaweed types for their use in animal feeding studies due to their large sizes and ease of harvesting.Recent in vitro and in vivo studies suggest that plant secondary compound-containing seaweeds(e.g.,halogenated compounds,phlorotannins,etc.)have the potential to mitigate enteric methane(CH_(4))emissions from ruminants when added to the diets of beef and dairy cattle.Red seaweeds including Asparagopsis spp.are rich in crude protein and halogenated compounds compared to brown and green seaweeds.When halogenated-containing red seaweeds are used as the active ingredient in ruminant diets,bromoform concentration can be used as an indicator of antimethanogenic properties.Phlorotannin-containing brown seaweed has also the potential to decrease CH_(4) production.However,numerous studies examined the possible anti-methanogenic effects of marine seaweeds with inconsistent results.This work reviews existing data associated with seaweeds and in vitro and in vivo rumen fermentation,animal performance,and enteric CH4 emissions in ruminants.Increased understanding of the seaweed supplementation related to rumen fermentation and its effect on animal performance and CH_(4) emissions in ruminants may lead to novel strategies aimed at reducing greenhouse gas emissions while improving animal productivity.展开更多
基金funded by Blue Ocean Barns.AB has a Ramón y Cajal research contract(RYC2019-027764-I)funded by the Spanish State Research Agency(AEI)。
文摘Background The red macroalgae Asparagopsis is an effective methanogenesis inhibitor due to the presence of halogenated methane(CH_(4))analogues,primarily bromoform(CHBr_(3)).This study aimed to investigate the degradation process of CHBr3 from A taxiformis in the rumen and whether this process is diet-dependent.An in vitro batch culture system was used according to a 2×2 factorial design,assessing two A taxiformis inclusion rates[0(CTL)and 2%DM diet(AT)]and two diets[high-concentrate(HC)and high-forage diet(HF)].Incubations lasted for 72 h and samples of headspace and fermentation liquid were taken at 0,0.5,1,3,6,8,12,16,24,48 and 72 h to assess the pattern of degradation of CHBr_(3) into dibromomethane(CH_(2)Br_(2))and fermentation parameters.Additionally,an in vitro experiment with pure cultures of seven methanogens strains(Methanobrevibacter smithii,Methanobrevibacter ruminantium,Methanosphaera stadtmanae,Methanosarcina barkeri,Methanobrevibacter millerae,Methanorhermobacter wolfei and Methanobacterium mobile)was conducted to test the effects of increasing concentrations of CHBr3(0.4,2,10and 50μmol/L).Results The addition of AT significantly decreased CH_(4) production(P=0.002)and the acetate:propionate ratio(P=0.003)during a 72-h incubation.The concentrations of CHBr_(3) showed a rapid decrease with nearly 90%degraded within the first 3 h of incubation.On the contrary,CH_(2)Br_(2) concentration quickly increased during the first 6 h and then gradually decreased towards the end of the incubation.Neither CHBr_(3) degradation nor CH_(2)Br_(2) synthesis were affected by the type of diet used as substrate,suggesting that the fermentation rate is not a driving factor involved in CHBr_(3)degradation.The in vitro culture of methanogens showed a dose-response effect of CHBr3 by inhibiting the growth of M.smithii,M.ruminantium,M.stadtmanae,M.barkeri,M.millerae,M.wolfei,and M.mobile.Conclusions The present work demonstrated that CHBr_(3) from A.taxiformis is quickly degraded to CH_(2)Br_(2)in the rumen and that the fermentation rate promoted by different diets is not a driving factor involved in CHBr_(3)degradation.
基金supported by a grant from the French Agency for Food, Environmental and Occupational Health and Safety (Grant 2009-CRD-21)the Doctoral School of “Environmental Sciences” (ED251) at Aix-Marseille Universitythe French Ministry of Higher Education and Research for the doctoral scholarship
文摘Water and air quality of eight seawater swimming pools using chlorine disinfection was measured during four sampling campaigns, spread on one full-year, and in four thalassotherapy centers located in Southeast of France. Concentrations of trihalomethanes（THMs） in air and in water as well as concentrations of parameters, including nonpurgeable organic carbon（NPOC）, free residual chlorine（Cl_f）, pH, Kjeldhal Nitrogen（KN）, salinity,conductivity, bromide ions and, water and air temperature, were measured. Water and air samples were collected in triplicates morning — at the opening of the pools —, noon and night — at the closing of the pools —, in summer and winter. Data analysis was performed by Principal Component Analysis（PCA） and rotated component matrix, from both data quality and other parameters such as TOC, aromaticity（UV_（254））, pH, hygrometry, and free residual chlorine（Cl_f）. This statistical analysis demonstrates a high correlation between TOC, Cl_fand UV_（254） and THM levels found in air and water, particularly for the major ones（CHBr_3in water：300.0 μg/L mean, 1029.0 μg/L maximum; CHBr_3 in air： 266.1 μg/m^3 mean,1600.0 μg/m^3 maximum, and CHClBr_2 in water： 18.9 μg/L mean, 81.0 μg/L maximum;CHClBr_2 in air： 13.6 μg/m^3 mean, 150.0 μg/m^3maximum）. These high levels of bromoform（CHBr_3） are particularly worrisome in such health institutions, even these levels do not exceed the Permissible Exposure Limit（PEL） of 5 mg/m^3 as an 8 hour time-weighted average currently fixed by various administrations, such as Occupational Safety and Health Administration（OSHA）.
基金supported by the Youth Innovation Program of the Chinese Academy of Agricultural Sciences(Y2022QC10)the Agricultural Science and Technology Innovation Program,China(CAAS-ASTIP-2023-IFR-03,CAAS-IFR-ZDRW202302 and CAAS-IFR-ZDRW202404)the Basal Research Fund of the Institute of Feed Research of Chinese Academy of Agricultural Sciences(1610382024009)。
文摘Cutting farming-related methane emissions from ruminants is critical in the battle against climate change.Since scientists initially investigated the potential of marine macroalgae to reduce methane emissions,using seaweeds as an anti-methanogenic feed additive has become prevailing in recent years.Asparagopsis taxiformis is the preferred species because it contains a relatively higher concentration of bromoform.As a type of halogenated methane analogue,bromoform contained in A.taxiformis can specifically inhibit the activity of coenzyme M methyltransferase,thereby blocking the ruminal methanogenesis.However,bromoform is a potential toxin and ozone-depleting substance.In response,current research focuses on the effects of bromoform-enriched seaweed supplementation on ruminant productivity and safety,as well as the impact of large-scale cultivation of seaweeds on the atmospheric environment.The current research on seaweed still needs to be improved,especially in developing more species with low bromoform content,such as Bonnemaisonia hamifera,Dictyota bartayresii,and Cystoseira trinodis.Otherwise,seaweed is rich in bioactive substances and exhibits antibacterial,anti-inflammatory,and other physiological properties,but research on the role of these bioactive compounds in methane emissions is lacking.It is worthy of deeper investigation to identify more potential bioactive compounds.As a new focus of attention,seaweed has attracted the interest of many scientists.Nevertheless,seaweed still faces some challenges as a feed additive to ruminants,such as the residues of heavy metals(iodine and bromine)and bromoform in milk or meat,as well as the establishment of a supply chain for seaweed cultivation,preservation,and processing.We have concluded that the methane-reducing efficacy of seaweed is indisputable.However,its application as a commercial feed additive is still influenced by factors such as safety,costs,policy incentives,and regulations.
基金funding by Irish Research Council Enterprise Partnership Scheme Postgraduate Scholarship(code:EPSPG/2021/154)funding received from AquaTech4Feed(Project No.817992)funded by BlueBio ERA-NET COFUND on the Blue Bioeconomy–Unlocking the Potential of Aquatic Bioresources and The European Commission within the Horizon 2020 programme.
文摘With methane emissions from ruminant agriculture contributing 17%of total methane emissions worldwide,there is increasing urgency to develop strategies to reduce greenhouse gas emissions in this sector.One of the proposed strategies is ruminant feed intervention studies focused on the inclusion of anti-methanogenic compounds which are those capable of interacting with the rumen microbiome,reducing the capacity of ruminal microorganisms to produce methane.Recently,seaweeds have been investigated for their ability to reduce methane in ruminants in vitro and in vivo,with the greatest methane abatement reported when using the red seaweed Asparagopsis taxiformis(attributed to the bromoform content of this species).From the literature analysis in this study,levels of up to 99%reduction in ruminant methane emissions have been reported from inclusion of this seaweed in animal feed,although further in vivo and microbiome studies are required to confirm these results as other reports showed no effect on methane emission resulting from the inclusion of seaweed to basal feed.This review explores the current state of research aiming to integrate seaweeds as anti-methanogenic feed additives,as well as examining the specific bioactive compounds within seaweeds that are likely to be related to these effects.The effects of the inclusion of seaweeds on the ruminal microbiome are also reviewed,as well as the future challenges when considering the largescale inclusion of seaweeds into ruminant diets as anti-methanogenic agents.
文摘Research using open-circuit respiration chambers has established that Asparagopsis bioactive compounds stabilized in canola oil (Asp-Oil), delivering a range of inclusion between 34 - 51 mg bromoform (CHBr3)/kg dry matter intake (DMI), inhibits methane (CH4) emissions > 98% in feedlot cattle. In this study, Asp-Oil was fed at 35 mg CHBr3/kg DMI in the feedlot finisher diet under highly replicated and commercially relevant conditions, and adequately powered to confirm differences as low as 3.3% in feed conversion efficiency (FCE). The study also evaluated the effect of Asp-Oil on CH4 production (g/day), carcass and meat-eating qualities, animal health, and food safety. The experiment consisted of 300 Angus-Shorthorn (Bos taurus) steers in 30 pens of 10 and fed a barley-based ration supplemented with canola oil (Control, n = 15), or Asp-Oil (n = 15) for total 81-d, inclusive of 21-d transition to full Asp-Oil and grain inclusion in the finisher ration. Reduction of CH4 was measured using GreenFeed Emissions Monitors (GEM) in a subset of 2 pens in both Control and Asp-Oil. However, 67% of CH4 measurements were recorded below the GEM’s limit of detection. An inhibition range of 58% - 98% was demonstrated by collectively using GEM and preliminary respiration chamber measurements. Asp-Oil improved FCE 7.4% in the finisher diet, and 5.6% across transition and finisher periods. During the transition steps the steers had not yet received their full allocations of grain and Asp-Oil which is responsible for the lower FCE benefits. A 4.1% lower DMI in the finisher period contributed to benefits in FCE with no effect on daily weight gains. Cost of feed and weight gain were reduced $0.35/head/day and $0.23/kg, respectively, in steers receiving Asp-Oil. Residues of Asparagopsis CHBr3 were not detected in any sample and only trace iodide and bromide were detected in livers and kidneys of both Control and Asp-Oil steers at levels safe for human consumption. Steers demonstrated normal rumen development typical of feedlot diets. This study confirms that Asp-Oil safely induces significant productivity benefits and CH4 reductions in feedlot beef production. Commercial adoption of Asparagopsis can benefit feedlot beef production and reduces the climate change contribution of livestock production.
文摘The use of seawater for industrial cooling is a vital technology that poses some of the most profound environmental impact on the water quality in the Arabian Gulf. Biocide (chlorine) is added to the seawater to control biofouling of the cooling system. This added chlorine reacts with bromide and other chemicals naturally exist in the water to form a wide range of oxidants. Regrettably, reactions between the residual oxidants and natural organic matter in the water lead to formation of toxic halogenated organic compounds that have detrimental effects on the environment when they are discharged into the Gulf. This paper describes the formation of trihalomethanes (THMs) in seawater cooling systems. Results of kinetic experiments have shown that concentrations of THMs increased rapidly with time during the first half hour. Chlorination of seawater has shown significant increase in total THMs (TTHMs) and in bromoform concentrations. Rapid decrease of UV absorbance at 254 nm was also observed during seawater chlorination which is indicative of natural organic matter degradation into small organic molecules including THMs and other by-products. The increase in chlorine dose was accompanied with an increase in TTHMs and bromoform concentrations. Linear relationships between total chlorine concentration and both final TTHMs and bromoform concentrations were established. First order exponential decay and exponential associate functions were developed to correlate chlorine dose with formed THMs.
文摘Seaweeds are macroalgae,which can be of many different morphologies,sizes,colors,and chemical profiles.They include brown,red,and green seaweeds.Brown seaweeds have been more investigated and exploited in comparison to other seaweed types for their use in animal feeding studies due to their large sizes and ease of harvesting.Recent in vitro and in vivo studies suggest that plant secondary compound-containing seaweeds(e.g.,halogenated compounds,phlorotannins,etc.)have the potential to mitigate enteric methane(CH_(4))emissions from ruminants when added to the diets of beef and dairy cattle.Red seaweeds including Asparagopsis spp.are rich in crude protein and halogenated compounds compared to brown and green seaweeds.When halogenated-containing red seaweeds are used as the active ingredient in ruminant diets,bromoform concentration can be used as an indicator of antimethanogenic properties.Phlorotannin-containing brown seaweed has also the potential to decrease CH_(4) production.However,numerous studies examined the possible anti-methanogenic effects of marine seaweeds with inconsistent results.This work reviews existing data associated with seaweeds and in vitro and in vivo rumen fermentation,animal performance,and enteric CH4 emissions in ruminants.Increased understanding of the seaweed supplementation related to rumen fermentation and its effect on animal performance and CH_(4) emissions in ruminants may lead to novel strategies aimed at reducing greenhouse gas emissions while improving animal productivity.
