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1.
Trop Anim Health Prod ; 53(5): 514, 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34643791

RESUMO

Dietary strategies aiming at minimizing enteric methane (CH4) emission in ruminants are of practical interest from nutritional, economical, and environmental point of view. The present study evaluated the effects of supplementing Leucaena leucocephala leaves either alone or in conjunction with malic acid on nutrient utilization, growth performance, and enteric CH4 emission in crossbred cattle fed wheat straw and concentrate-based diet under tropical conditions. Eighteen crossbred (Karan-Fries) calves were randomly allocated into 3 groups: G-I (control)-fed wheat (Triticum aestivum) straw and concentrate mixture in the ratio 50:50; G-II-fed wheat straw, concentrate mixture, and Leucaena leucocephala leaves in the ratio 45:45:10; and (3) G-III-fed similar diet like G-II with an additional supplementation of 1% malic acid on dry matter intake basis. Experimental feeding spanning 90 days included a 7-day metabolism trial and CH4 quantification study by sulfur hexafluoride tracer technique. Results revealed no significant effect of dietary treatments on dry matter intake (DMI) and digestibility of nutrients, except neutral detergent fiber (NDF) digestibility which was 5.5% higher (P < 0.05) in G-III as compared to control. Further, nitrogen (N) metabolism, rumen microbial protein synthesis, and growth performance remained similar among the treatments. No significant effect was also observed for enteric CH4 emission (expressed as g/day and g/kg DMI) in calves supplemented with Leucaena leucocephala leaves and malic acid. Therefore, the present findings depict modest improvement in fiber digestibility with no encouraging effect in mitigating enteric CH4 in growing cattle calves by supplementing Leucaena leucocephala leaves alone or with malic acid within the selected levels.


Assuntos
Digestão , Metano , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Fermentação , Malatos , Metano/metabolismo , Nutrientes , Folhas de Planta , Rúmen/metabolismo , Clima Tropical
2.
J Anim Sci ; 99(11)2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34598276

RESUMO

Residual expressions of enteric emissions favor a more equitable identification of an animal's methanogenic potential compared with traditional measures of enteric emissions. The objective of this study was to investigate the effect of divergently ranking beef cattle for residual methane emissions (RME) on animal productivity, enteric emissions, and rumen fermentation. Dry matter intake (DMI), growth, feed efficiency, carcass output, and enteric emissions (GreenFeed emissions monitoring system) were recorded on 294 crossbred beef cattle (steers = 135 and heifers = 159; mean age 441 d (SD = 49); initial body weight (BW) of 476 kg (SD = 67)) at the Irish national beef cattle performance test center. Animals were offered a total mixed ration (77% concentrate and 23% forage; 12.6 MJ ME/kg of DM and 12% CP) ad libitum with emissions estimated for 21 d over a mean feed intake measurement period of 91 d. Animals had a mean daily methane emissions (DME) of 229.18 g/d (SD = 45.96), methane yield (MY) of 22.07 g/kg of DMI (SD = 4.06), methane intensity (MI) 0.70 g/kg of carcass weight (SD = 0.15), and RME 0.00 g/d (SD = 0.34). RME was computed as the residuals from a multiple regression model regressing DME on DMI and BW (R2 = 0.45). Animals were ranked into three groups namely high RME (>0.5 SD above the mean), medium RME (±0.5 SD above/below the mean), and low RME (>0.5 SD below the mean). Low RME animals produced 17.6% and 30.4% less (P < 0.05) DME compared with medium and high RME animals, respectively. A ~30% reduction in MY and MI was detected in low versus high RME animals. Positive correlations were apparent among all methane traits with RME most highly associated with (r = 0.86) DME. MY and MI were correlated (P < 0.05) with DMI, growth, feed efficiency, and carcass output. High RME had lower (P < 0.05) ruminal propionate compared with low RME animals and increased (P < 0.05) butyrate compared with medium and low RME animals. Propionate was negatively associated (P < 0.05) with all methane traits. Greater acetate:propionate ratio was associated with higher RME (r = 0.18; P < 0.05). Under the ad libitum feeding regime deployed here, RME was the best predictor of DME and only methane trait independent of animal productivity. Ranking animals on RME presents the opportunity to exploit interanimal variation in enteric emissions as well as providing a more equitable index of the methanogenic potential of an animal on which to investigate the underlying biological regulatory mechanisms.


Assuntos
Metano , Rúmen , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Ingestão de Alimentos , Feminino , Fermentação , Metano/metabolismo , Rúmen/metabolismo
3.
Chem Commun (Camb) ; 57(72): 9068-9071, 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34498652

RESUMO

Inspired by the boom of new artificial metalloenzymes, we developed an Fmoc-protected histidinium salt (Hum) as N-heterocyclic carbene precursor. Hum was placed via solid-phase peptide synthesis into short 7-mer peptides. Upon iridation, the metallo-peptidic construct displayed activity in catalytic hydrogenation that outperforms small molecule analogues and which is dependent on the peptide sequence, a typical feature of metalloenzymes.


Assuntos
Aminoácidos/metabolismo , Metano/análogos & derivados , Oxirredutases/metabolismo , Peptídeos/metabolismo , Aminoácidos/química , Metano/química , Metano/metabolismo , Estrutura Molecular , Oxirredutases/química , Peptídeos/química
4.
J Dairy Sci ; 104(12): 12553-12566, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34531049

RESUMO

Metabolome profiling in biological fluids is an interesting approach for exploring markers of methane emissions in ruminants. In this study, a multiplatform metabolomics approach was used for investigating changes in milk metabolic profiles related to methanogenesis in dairy cows. For this purpose, 25 primiparous Holstein cows at similar lactation stage were fed the same diet supplemented with (treated, n = 12) or without (control, n = 13) a specific antimethanogenic additive that reduced enteric methane production by 23% with no changes in intake, milk production, and health status. The study lasted 6 wk, with sampling and measures performed in wk 5 and 6. Milk samples were analyzed using 4 complementary analytical methods, including 2 untargeted (nuclear magnetic resonance and liquid chromatography coupled to a quadrupole-time-of-flight mass spectrometer) and 2 targeted (liquid chromatography-tandem mass spectrometry and gas chromatography coupled to a flame ionization detector) approaches. After filtration, variable selection and normalization data from each analytical platform were then analyzed using multivariate orthogonal partial least square discriminant analysis. All 4 analytical methods were able to differentiate cows from treated and control groups. Overall, 38 discriminant metabolites were identified, which affected 10 metabolic pathways including methane metabolism. Some of these metabolites such as dimethylsulfoxide, dimethylsulfone, and citramalic acid, detected by nuclear magnetic resonance or liquid chromatography-mass spectrometry methods, originated from the rumen microbiota or had a microbial-host animal co-metabolism that could be associated with methanogenesis. Also, discriminant milk fatty acids detected by targeted gas chromatography were mostly of ruminal microbial origin. Other metabolites and metabolic pathways significantly affected were associated with AA metabolism. These findings provide new insight on the potential role of milk metabolites as indicators of enteric methane modifications in dairy cows.


Assuntos
Metano , Leite , Animais , Bovinos , Dieta/veterinária , Feminino , Fermentação , Cromatografia Gasosa-Espectrometria de Massas/veterinária , Lactação , Metaboloma , Metano/metabolismo , Rúmen/metabolismo
5.
BMC Vet Res ; 17(1): 304, 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34503491

RESUMO

BACKGROUND: Total fresh cassava root (FCR) production was 275 million tonnes in 2018 which equals 61.1 % of the total production, and Thailand produced 10.7 % FCR of the total production. FCR is one of the main energy source for ruminant. The limitation of FCR utilization is due to the presence of hydrogen cyanide (HCN). The study aimed to evaluate the effect of sulfur, urea and FCR at various levels on in vitro gas production, ruminal fermentation and in vitro degradability. The study hypothesized that: (1) sulfur, urea and FCR have no interaction effect and (2) effect of FCR and urea is related to sulfur addition. RESULTS: The study aimed to elucidate the optimum level of elemental sulfur, fresh cassava root (FCR) and urea and their effect on in vitro gas production, ruminal fermentation, thiocyanate concentration, and in vitro degradability. A 3 × 2 × 4 in a completely randomized design were conducted. Factor A was level of sulfur at 0 %, 1 and 2 % of concentrate dry matter (DM), factor B was level of urea at 2 and 4 % of concentrate DM, and factor C was level of the FCR at 0, 200, 300 and 400 mg DM of the total substrate. The study found that elemental sulfur, urea and FCR had no interaction effect on the kinetics of in vitro gas, ruminal fermentation, HCN and in vitro degradability. Elemental sulfur supplementation (P < 0.05) significantly increased the in vitro gas produced from an insoluble fraction (b), in vitro DM degradability and either neutral detergent fiber (NDF) or acid detergent fiber (ADF) degradability and propionate (C3) concentration while decreased the ruminal HCN concentration. Urea levels showed a (P < 0.05) significant increase of the potential extent of in vitro gas production, ruminal ammonia nitrogen (NH3-N) and total volatile fatty acid (TVFA). Fresh cassava root supplementation (P < 0.05) significantly increased the in vitro gas produced from an immediate soluble fraction (a), in vitro gas produced from insoluble fraction, in vitro gas production rate constant, total VFA, C3 concentration and HCN while decreased ruminal pH, acetate and butyrate concentration. It could be concluded that 2 % elemental sulfur, 4 % urea and 300 mg FCR showed a greater effect on in vitro gas production, ruminal fermentation and HCN reduction. CONCLUSIONS: The study found that elemental sulfur, urea, and FCR had no interaction effect on the kinetics of in vitro gas, total in vitro gas, ruminal fermentation, and HCN concentration. It could be concluded that 2 % elemental sulfur, 4 % urea, and 300 mg FCR showed a greater effect on in vitro gas production, ruminal fermentation, and HCN reduction.


Assuntos
Ração Animal/análise , Metano/metabolismo , Raízes de Plantas/metabolismo , Rúmen/efeitos dos fármacos , Enxofre/farmacologia , Ureia/farmacologia , Animais , Suplementos Nutricionais/análise , Digestão/efeitos dos fármacos , Digestão/fisiologia , Fermentação/efeitos dos fármacos , Fermentação/fisiologia , Manihot/metabolismo , Metano/análise
6.
Biochemistry ; 60(38): 2845-2850, 2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34510894

RESUMO

Methanobactins (Mbns) are ribosomally produced, post-translationally modified peptidic natural products that bind copper with high affinity. Methanotrophic bacteria use Mbns to acquire copper needed for enzymatic methane oxidation. Despite the presence of Mbn operons in a range of methanotroph and other bacterial genomes, few Mbns have been isolated and structurally characterized. Here we report the isolation of a novel Mbn from the methanotroph Methylosinus (Ms.) sp. LW3. Mass spectrometric and nuclear magnetic resonance spectroscopic data indicate that this Mbn, the largest characterized to date, consists of a 13-amino acid backbone modified to include pyrazinedione/oxazolone rings and neighboring thioamide groups derived from cysteine residues. The pyrazinedione ring is more stable to acid hydrolysis than the oxazolone ring and likely protects the Mbn from degradation. The structure corresponds exactly to that predicted on the basis of the Ms. sp. LW3 Mbn operon content, providing support for the proposed role of an uncharacterized biosynthetic enzyme, MbnF, and expanding the diversity of known Mbns.


Assuntos
Cobre/metabolismo , Methylosinus/enzimologia , Methylosinus/metabolismo , Sequência de Aminoácidos/genética , Proteínas de Bactérias/metabolismo , Produtos Biológicos/metabolismo , Quelantes/química , Cobre/química , Expressão Gênica/genética , Regulação Bacteriana da Expressão Gênica/genética , Genoma Bacteriano/genética , Imidazóis/metabolismo , Metano/metabolismo , Methylosinus/genética , Methylosinus trichosporium/enzimologia , Methylosinus trichosporium/genética , Methylosinus trichosporium/metabolismo , Oligopeptídeos/metabolismo , Óperon/genética , Oxirredução , Peptídeos/metabolismo
7.
Trop Anim Health Prod ; 53(4): 436, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34401959

RESUMO

Ruminal methanogenesis is considered an inefficient process as it can result in the loss of 4 to 12% of the total energy consumed by the ruminant. Recent studies have shown that compounds such as nitroethane, 2-nitroethanol, 2-nitro-1-propanol, and 3-nitro-1-propionic acid are capable of inhibiting methane production during in vitro studies. However, all of these nitrocompounds came from a synthetic origin, which could limit their use. In contrast, some plants of the Astragallus genus produce a natural nitrocompound, although its anti-methanogenic effect has not been evaluated. To determine the anti-methanogenic effect, in vitro cultures of freshly collected mixed populations of ruminal microbes were supplemented with A. mollissimus extracts (MISER). Cultures supplemented with 2-nitroethanol, ethyl 2-nitroacetate, or nitroethane were used as positive controls whereas distilled water was added to the untreated control tubes. After a 24 h incubation period, the methane production was reduced by more than 98% for the samples treated with A. mollissimus extract (P < 0.05) compared to the untreated controls (10.2 ± 0.1 mmol mL-1 incubated liquid). Cultures supplemented with MISER produced a greater (P < 0.05) amount of total VFA, compared to the rest of treated and untreated cultures. Considering that there are significant differences between MISER treatment, positive controls and untreated cultures (P < 0.05) regarding the amounts of total gas, gas composition (CH4 and H2), and the amount of VFA produced, it is concluded that Astragallus mollissimus poses an alternative strategy to reduce ruminal methanogenesis. To further explore such alternative, it is necessary to determine if the metabolization byproducts are safe and/or useful for the animal.


Assuntos
Metano , Extratos Vegetais , Animais , Suplementos Nutricionais , Fermentação , Metano/metabolismo , Extratos Vegetais/metabolismo , Extratos Vegetais/farmacologia , Rúmen/metabolismo , Ruminantes
8.
Nat Commun ; 12(1): 5032, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34413314

RESUMO

Methane, along with other short-chain alkanes from some Archean metasedimentary rocks, has unique isotopic signatures that possibly reflect the generation of atmospheric greenhouse gas on early Earth. We find that alkane gases from the Kidd Creek mines in the Canadian Shield are microbial products in a Neoarchean ecosystem. The widely varied hydrogen and relatively uniform carbon isotopic compositions in the alkanes infer that the alkanes result from the biodegradation of sediment organic matter with serpentinization-derived hydrogen gas. This proposed process is supported by published geochemical data on the Kidd Creek gas, including the distribution of alkane abundances, stable isotope variations in alkanes, and CH2D2 signatures in methane. The recognition of Archean microbial methane in this work reveals a biochemical process of greenhouse gas generation before the Great Oxidation Event and improves the understanding of the carbon and hydrogen geochemical cycles.


Assuntos
Bactérias/metabolismo , Planeta Terra , Gases/química , Sedimentos Geológicos/química , Hidrogênio/química , Hidrogênio/metabolismo , Metano/metabolismo , Fenômenos Microbiológicos , Alcanos/química , Alcanos/metabolismo , Biodegradação Ambiental , Canadá , Isótopos de Carbono/química , Ecossistema , Metano/química , Oxirredução
9.
Anim Sci J ; 92(1): e13614, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34405934

RESUMO

The methane-mitigating potency of cashew nutshell liquid (CNSL) was evaluated by investigating gas production from batch cultures using feces from Thai native ruminants that had been incubated for different periods. Feces was obtained from four Thai native cattle and four swamp buffaloes reared under practical feeding conditions at the Kasetsart University farm, Thailand. Fecal slurry from the same farm was also included in the analysis. CNSL addition successfully suppressed the methane production potential of feces from both ruminants by shifting short chain fatty acid profiles towards propionate production. Methane mitigation continued for almost 150 days, although the degree of mitigation was more apparent from Day 0 to Day 30. Bacterial and archaeal community shifts with CNSL addition were observed in feces from both ruminants; specifically, Bacteroides increased, whereas Lachnospiraceae and Ruminococcaceae decreased in feces to which CNSL was added. Fecal slurry did not show marked changes in gas production with CNSL addition. The findings showed that the addition of CNSL to the feces of ruminants native to the Southeast Asian region can suppress methane emission. Because CNSL can be easily obtained as a byproduct of the local cashew industry in this region, its on-site application might be ideal.


Assuntos
Anacardium/química , Fezes/microbiologia , Gases/metabolismo , Microbioma Gastrointestinal/fisiologia , Metano/metabolismo , Extratos Vegetais/farmacologia , Animais , Búfalos , Bovinos , Ácidos Graxos Voláteis/metabolismo , Fezes/química , Microbiota , Propionatos/metabolismo , Tailândia
10.
Biomolecules ; 11(8)2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34439884

RESUMO

Wastewater treatment plants and other remediation facilities serve important roles, both in public health, but also as dynamic research platforms for acquiring useful resources and biomolecules for various applications. An example of this is methanotrophic bacteria within anaerobic digestion processes in wastewater treatment plants. These bacteria are an important microbial source of many products including ectoine, polyhydroxyalkanoates, and methanobactins, which are invaluable to the fields of biotechnology and biomedicine. Here we provide an overview of the methanotrophs' unique metabolism and the biochemical pathways involved in biomolecule formation. We also discuss the potential biomedical applications of these biomolecules through creation of beneficial biocompatible products including vaccines, prosthetics, electronic devices, drug carriers, and heart stents. We highlight the links between molecular biology, public health, and environmental science in the advancement of biomedical research and industrial applications using methanotrophic bacteria in wastewater treatment systems.


Assuntos
Diamino Aminoácidos/biossíntese , Bactérias Gram-Negativas/metabolismo , Metano/metabolismo , Poli-Hidroxialcanoatos/biossíntese , Purificação da Água/métodos , Reatores Biológicos , Biotecnologia
11.
J Enzyme Inhib Med Chem ; 36(1): 1938-1951, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34459690

RESUMO

In this paper, bis (indol-3-yl) methanes (BIMs) were synthesised and evaluated for their inhibitory activity against α-glucosidase and α-amylase. All synthesised compounds showed potential α-glucosidase and α-amylase inhibitory activities. Compounds 5 g (IC50: 7.54 ± 1.10 µM), 5e (IC50: 9.00 ± 0.97 µM), and 5 h (IC50: 9.57 ± 0.62 µM) presented strongest inhibitory activities against α-glucosidase, that were ∼ 30 times stronger than acarbose. Compounds 5 g (IC50: 32.18 ± 1.66 µM), 5 h (IC50: 31.47 ± 1.42 µM), and 5 s (IC50: 30.91 ± 0.86 µM) showed strongest inhibitory activities towards α-amylase, ∼ 2.5 times stronger than acarbose. The mechanisms and docking simulation of the compounds were also studied. Compounds 5 g and 5 h exhibited bifunctional inhibitory activity against these two enzymes. Furthermore, compounds showed no toxicity against 3T3-L1 cells and HepG2 cells.HighlightsA series of bis (indol-3-yl) methanes (BIMs) were synthesised and evaluated inhibitory activities against α-glucosidase and α-amylase.Compound 5g exhibited promising activity (IC50 = 7.54 ± 1.10 µM) against α-glucosidase.Compound 5s exhibited promising activity (IC50 = 30.91 ± 0.86 µM) against α-amylase.In silico studies were performed to confirm the binding interactions of synthetic compounds with the enzyme active site.


Assuntos
Inibidores de Glicosídeo Hidrolases/síntese química , Indóis/síntese química , Metano/síntese química , alfa-Amilases/metabolismo , alfa-Glucosidases/metabolismo , Células 3T3 , Acarbose/química , Animais , Domínio Catalítico , Inibidores de Glicosídeo Hidrolases/metabolismo , Células Hep G2 , Humanos , Cinética , Metano/metabolismo , Camundongos , Simulação de Acoplamento Molecular , Ligação Proteica , Conformação Proteica , Relação Estrutura-Atividade
12.
Microbes Environ ; 36(3)2021.
Artigo em Inglês | MEDLINE | ID: mdl-34433738

RESUMO

Current challenges in the anaerobic bioremediation of benzene are the lack of capable cultures and limited knowledge on the biodegradation pathway. Under methanogenic conditions, benzene may be mineralized by syntrophic interactions between microorganisms, which are poorly understood. The present study developed an optimized formula for anoxic medium to successfully promote the growth of the putative benzene degrader Deltaproteobacterium Hasda-A and enhance the benzene degradation activity of methanogenic enrichment cultures. Within 70| |d of incubation, the benzene degradation activity and relative abundance of Hasda-A in cultures in the new defined medium increased from 0.5 to >3| |mg L-1 d-1 and from 2.5% to >17%, respectively. Together with Hasda-A, we found a strong positive relationship between the abundances of superphylum OD1 bacteria, three methanogens (Methanoregula, Methanolinea, and Methanosaeta) and benzene degradation activity. The syntrophic relationship between these microbial taxa and Hasda-A was then demonstrated in a correlation analysis of longitudinal data. The involvement of methanogenesis in anaerobic benzene mineralization was confirmed by inhibition experiments. The high benzene degradation activity and growth of Hasda-A were quickly recovered in successive dilutions of enrichment cultures, proving the feasibility of using the medium developed in the present study to produce highly capable cultures. The present results will facilitate practical applications in bioremediation and research on the molecular mechanisms underlying benzene activation and syntrophic interactions in benzene mineralization.


Assuntos
Benzeno/metabolismo , Meios de Cultura/química , Deltaproteobacteria/metabolismo , Metano/metabolismo , Methanosarcinales/metabolismo , Anaerobiose , Biodegradação Ambiental , Crescimento Quimioautotrófico , Técnicas de Cocultura , Meios de Cultura/metabolismo , Deltaproteobacteria/crescimento & desenvolvimento , Methanosarcinales/crescimento & desenvolvimento
13.
J Dairy Sci ; 104(11): 11686-11698, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34389151

RESUMO

This study was conducted to examine the effect of method of diet delivery to dairy cows on enteric CH4 emission, milk production, rumen fermentation, nutrient digestion, N excretion, and manure CH4 production potential. Sixteen lactating cows were used in a crossover design (35-d period) and fed ad libitum twice daily a diet [52:48, forage:concentrate ratio; dry matter (DM) basis] provided as forages and concentrates separately (CF) or as a total mixed ration (TMR). For the CF treatment, concentrates were offered first followed by mixed forages 45 min afterward. Method of diet delivery had no effect on DM intake, but neutral detergent fiber (NDF) intake was greater when the diet was delivered as TMR as compared with CF. Apparent total-tract digestibility of DM, crude protein, and gross energy was slightly (1 percentage unit) lower when the diet was offered as TMR than when offered as CF. In contrast, NDF digestibility was greater when the cows were fed TMR versus CF. Although average daily ruminal pH was not affected by method of diet delivery, daily duration of ruminal pH <5.6 was less when the diet was delivered as TMR as compared with CF (0.9 h/d versus 3.7 h/d). Delivering the diet as TMR increased ruminal total volatile fatty acid and NH3 concentrations, but had no effect on acetate, propionate, or branched-chain volatile fatty acid molar proportions. Yields of milk, milk fat, or milk protein, and milk production efficiency (kg of milk/kg of DM intake or g of N milk/g of N intake) were not affected by the method of diet delivery. Daily production (g/d), yield (% gross energy intake), and emission intensity (g/kg of energy-corrected milk) of enteric CH4 averaged 420 g/d, 4.9%, and 9.6 g/kg and were not affected by diet delivery method. Fecal N output was greater when the diet was delivered as TMR versus CF, whereas urinary N excretion (g/d, % N intake) was not affected. Manure volatile solids excretion and maximal CH4 production potential were not affected by method of diet delivery. Under the conditions of this study, delivering the diet as concentrates and forages separately versus a total mixed ration had no effect on milk production, enteric CH4 energy losses, urinary N, or maximal manure CH4 emission potential. However, feeding the diet as total mixed ration compared with feeding concentrates and forages separately attenuated the extent of postprandial decrease in ruminal pH, which has contributed to improving NDF digestibility.


Assuntos
Esterco , Metano , Animais , Bovinos , Dieta/veterinária , Digestão , Fermentação , Lactação , Metano/metabolismo , Nitrogênio/metabolismo , Nutrientes , Rúmen/metabolismo , Silagem/análise , Zea mays
14.
Angew Chem Int Ed Engl ; 60(41): 22315-22321, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34382314

RESUMO

Hydrogen-bonded organic frameworks (HOFs) are porous materials with great potential for biological applications. The self-assembly of HOFs and biomacromolecules, however, is challenging. We report herein the self-assembly of nanoscale HOFs (nHOFs) to encapsulate protein for intracellular biocatalysis. The self-assembly of tetrakis(4-amidiniumphenyl)methane and azobenzenedicarboxylate can encapsulate protein in situ to form protein@nHOFs under mild conditions. This strategy is applicable to proteins with different surface charge and molecular weight, showing a high protein encapsulation efficiency and minimal effect on protein activity. A cellular delivery study shows that the protein@TA-HOFs can efficiently enter cells and retain enzyme activity for biochemical catalysis in living cells for neuroprotection. Our strategy paves new avenues for interfacing nHOFs with biological settings and sheds light on expanding nHOFs as a platform for biomacromolecule delivery and disease treatment.


Assuntos
Compostos Azo/metabolismo , Ácidos Carboxílicos/metabolismo , Metano/metabolismo , Proteínas/metabolismo , Compostos Azo/química , Biocatálise , Ácidos Carboxílicos/química , Linhagem Celular Tumoral , Sobrevivência Celular , Humanos , Ligação de Hidrogênio , Metano/análogos & derivados , Metano/química , Estrutura Molecular , Tamanho da Partícula , Proteínas/química
15.
J Dairy Sci ; 104(9): 9827-9841, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34253370

RESUMO

This study investigated the effects of an amylase-enabled corn silage on lactational performance, enteric CH4 emission, and rumen fermentation of lactating dairy cows. Following a 2-wk covariate period, 48 Holstein cows were blocked based on parity, days in milk, milk yield (MY), and CH4 emission. Cows were randomly assigned to 1 of 2 treatments in an 8-wk randomized complete block design experiment: (1) control corn silage (CON) from an isogenic corn without α-amylase trait and (2) Enogen hybrid corn (Syngenta Seeds LLC) harvested as silage (ECS) containing a bacterial transgene expressing α-amylase (i.e., amylase-enabled) in the endosperm of the grain. The ECS and CON silages were included at 40% of the dietary dry matter (DM) and contained, on average, 43.3 and 41.8% DM and (% DM) 36.7 and 37.5% neutral detergent fiber, and 36.1 and 33.1% starch, respectively. Rumen samples were collected from a subset of 10 cows using the ororuminal sampling technique on wk 3 of the experimental period. Enteric CH4 emission was measured using the GreenFeed system (C-Lock Inc.). Dry matter intake (DMI) was similar between treatments. Compared with CON, MY (38.8 vs. 40.8 kg/d), feed efficiency (1.47 vs. 1.55 kg of MY/kg of DMI), and milk true protein (1.20 vs. 1.25 kg/d) and lactose yields (1.89 vs. 2.00 kg/d) were increased, whereas milk urea nitrogen (14.0 vs. 12.7 mg/dL) was decreased, with the ECS diet. No effect of treatment on energy-corrected MY (ECM) was observed, but a trend was detected for increased ECM feed efficiency (1.45 vs. 1.50 kg of ECM/kg of DMI) for cows fed ECS compared with CON-fed cows. Daily CH4 emission was not affected by treatment, but emission intensity was decreased with the ECS diet (11.1 vs. 10.3 g/kg of milk, CON and ECS, respectively); CH4 emission intensity on ECM basis was not different between treatments. Rumen fermentation, apart from a reduced molar proportion of butyrate in ECS-fed cows, was not affected by treatment. Apparent total-tract digestibility of nutrients and urinary and fecal nitrogen excretions, apart from a trend for increased DM digestibility by ECS-fed cows, were not affected by treatment. Overall, ECS inclusion at 40% of dietary DM increased milk, milk protein, and lactose yields and feed efficiency, and tended to increase ECM feed efficiency but had no effect on ECM yield in dairy cows. The increased MY with ECS led to a decrease in enteric CH4 emission intensity, compared with the control silage.


Assuntos
Rúmen , Silagem , Amilases/metabolismo , Animais , Bovinos , Dieta/veterinária , Digestão , Feminino , Fermentação , Lactação , Metano/metabolismo , Gravidez , Rúmen/metabolismo , Silagem/análise , Zea mays
16.
Appl Environ Microbiol ; 87(18): e0088121, 2021 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-34288705

RESUMO

The ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) enzyme found in plants, algae, and an array of autotrophic bacteria is also encoded by a subset of methanotrophs, but its role in these microbes has largely remained elusive. In this study, we showed that CO2 was requisite for RubisCO-encoding Methylococcus capsulatus strain Bath growth in a bioreactor with continuous influent and effluent gas flow. RNA sequencing identified active transcription of several carboxylating enzymes, including key enzymes of the Calvin and serine cycles, that could mediate CO2 assimilation during cultivation with both CH4 and CO2 as carbon sources. Marker exchange mutagenesis of M. capsulatus Bath genes encoding key enzymes of potential CO2-assimilating metabolic pathways indicated that a complete serine cycle is not required, whereas RubisCO is essential for growth of this bacterium. 13CO2 tracer analysis showed that CH4 and CO2 enter overlapping anaplerotic pathways and implicated RubisCO as the primary enzyme mediating CO2 assimilation in M. capsulatus Bath. Notably, we quantified the relative abundance of 3-phosphoglycerate and ribulose-1,5-bisphosphate 13C isotopes, which supported that RubisCO-produced 3-phosphoglycerate is primarily converted to ribulose-1-5-bisphosphate via the oxidative pentose phosphate pathway in M. capsulatus Bath. Collectively, our data establish that RubisCO and CO2 play essential roles in M. capsulatus Bath metabolism. This study expands the known capacity of methanotrophs to fix CO2 via RubisCO, which may play a more pivotal role in the Earth's biogeochemical carbon cycling and greenhouse gas regulation than previously recognized. Further, M. capsulatus Bath and other CO2-assimilating methanotrophs represent excellent candidates for use in the bioconversion of biogas waste streams that consist of both CH4 and CO2. IMPORTANCE The importance of RubisCO and CO2 in M. capsulatus Bath metabolism is unclear. In this study, we demonstrated that both CO2 and RubisCO are essential for M. capsulatus Bath growth. 13CO2 tracing experiments supported that RubisCO mediates CO2 fixation and that a noncanonical Calvin cycle is active in this organism. Our study provides insights into the expanding knowledge of methanotroph metabolism and implicates dually CH4/CO2-utilizing bacteria as more important players in the biogeochemical carbon cycle than previously appreciated. In addition, M. capsulatus and other methanotrophs with CO2 assimilation capacity represent candidate organisms for the development of biotechnologies to mitigate the two most abundant greenhouse gases, CH4 and CO2.


Assuntos
Proteínas de Bactérias/metabolismo , Dióxido de Carbono/metabolismo , Metano/metabolismo , Methylococcus capsulatus/enzimologia , Methylococcus capsulatus/crescimento & desenvolvimento , Ribulose-Bifosfato Carboxilase/metabolismo , Reatores Biológicos
17.
Nat Chem Biol ; 17(8): 845-855, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34312558

RESUMO

One-carbon (C1) substrates are preferred feedstocks for the biomanufacturing industry and have recently gained attention owing to their natural abundance, low production cost and availability as industrial by-products. However, native pathways to utilize these substrates are absent in most biotechnologically relevant microorganisms. Recent advances in synthetic biology, genome engineering and laboratory evolution are enabling the first steps towards the creation of synthetic C1-utilizing microorganisms. Here, we briefly review the native metabolism of methane, methanol, CO2, CO and formate, and how these C1-utilizing pathways can be engineered into heterologous hosts. In addition, this review analyses the potential, the challenges and the perspectives of C1-based biomanufacturing.


Assuntos
Bactérias/metabolismo , Fungos/metabolismo , Engenharia Metabólica , Bactérias/citologia , Dióxido de Carbono/metabolismo , Monóxido de Carbono/metabolismo , Formiatos/metabolismo , Fungos/citologia , Metano/metabolismo , Metanol/metabolismo
18.
PLoS One ; 16(7): e0253714, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34260590

RESUMO

Co-digestion of organic biomass mixed with inorganic amendments could have an impact on composting dynamics. Various studies highlighted fertilizers' role as an additive to lesser the nitrogen loss, while some studies focused on the addition of fertilizers to enhance the efficiency. The changes in carbon, nitrogen components, and humic substances during the organic-inorganic co-compost process were seldom studied. Clarifying these changes might help improve the production process and compost nutrients contents. Thus, this study's purpose is to investigate the effects of inorganic amendments on compost characteristics, compost temperature, biochemical methane production (BMP), and nutritional contents. The inorganic phosphorous (P), sulfur (S), and sulfur solubilizing agent (SSA) were added to Farmyard manure (FYM) mixed with biodegradable waste (BW), including wheat straw, corn stalks, and green lawn waste. The P and S amended treatments were carried out into two sets, with and without SSA. The mixed feedstocks were added in the insulated RBC composting pit (15 x 15 x 10 feet). The compost material's moisture content was maintained 50-65% during the entire composting process for optimum waste digestion i.e., the moisture content (MC) of FYM was 82.7% and for BW ranged 8.8-10.2%, while the C/N ratio was found 10.5 for FYM, 74.5 for wheat straw, 83.5 for corn stalks, and 84.8 for lawn waste. At the condition of compost maturity, the inorganic amendments have no significant effect on composted material's moisture content. The maximum organic matter of 69.7% and C/N ratio of 44.6 was measured in T1. On the 6th day of composting, the temperature reached to thermophilic range (>45 oC) in all the treatments due to aeration of compost increased microbial activities and waste decomposition rate and decreased gradually to mesophilic range (35-45 oC) because the supply of high-energy compounds becomes exhausted. The highest temperature was reached in T4 (58 oC) and lowest in CT (47 oC). The significantly maximum methane of 8.95 m3 and biogas burning was 818 minutes in CT, followed by T1 and T4. The results of this study revealed that P enriched compost is a feasible and sustainable way to overcome P deficiency in the soil as well as in plants and best way to use low-grade P and organic waste material.


Assuntos
Biomassa , Compostagem/métodos , Esterco , Carbono/metabolismo , Estudos de Viabilidade , Metano/metabolismo , Nitrogênio/metabolismo , Fosfatos/metabolismo , Enxofre/metabolismo
19.
Sci Rep ; 11(1): 15140, 2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34302023

RESUMO

Interspecies hydrogen transfer (IHT) and direct interspecies electron transfer (DIET) are two syntrophy models for methanogenesis. Their relative importance in methanogenic environments is still unclear. Our recent discovery of a novel species Candidatus Geobacter eutrophica with the genetic potential of IHT and DIET may serve as a model species to address this knowledge gap. To experimentally demonstrate its DIET ability, we performed electrochemical enrichment of Ca. G. eutrophica-dominating communities under 0 and 0.4 V vs. Ag/AgCl based on the presumption that DIET and extracellular electron transfer (EET) share similar metabolic pathways. After three batches of enrichment, Geobacter OTU650, which was phylogenetically close to Ca. G. eutrophica, was outcompeted in the control but remained abundant and active under electrochemical stimulation, indicating Ca. G. eutrophica's EET ability. The high-quality draft genome further showed high phylogenomic similarity with Ca. G. eutrophica, and the genes encoding outer membrane cytochromes and enzymes for hydrogen metabolism were actively expressed. A Bayesian network was trained with the genes encoding enzymes for alcohol metabolism, hydrogen metabolism, EET, and methanogenesis from dominant fermentative bacteria, Geobacter, and Methanobacterium. Methane production could not be accurately predicted when the genes for IHT were in silico knocked out, inferring its more important role in methanogenesis. The genomics-enabled machine learning modeling approach can provide predictive insights into the importance of IHT and DIET.


Assuntos
Transporte de Elétrons/fisiologia , Geobacter/metabolismo , Hidrogênio/metabolismo , Teorema de Bayes , Citocromos/metabolismo , Elétrons , Aprendizado de Máquina , Redes e Vias Metabólicas/fisiologia , Metano/metabolismo , Methanobacterium/metabolismo
20.
Microbes Environ ; 36(2)2021.
Artigo em Inglês | MEDLINE | ID: mdl-34135211

RESUMO

The present study investigated bioelectrical methane production from CO2 without organic substances. Even though microbial methane production has been reported at relatively high electric voltages, the amount of voltage required and the organisms contributing to the process currently remain unknown. Methane production using a biocathode was investigated in a microbial electrolysis cell coupled with an NH4+ oxidative reaction at an anode coated with platinum powder under a wide range of applied voltages and anaerobic conditions. A microbial community analysis revealed that methane production simultaneously occurred with biological denitrification at the biocathode. During denitrification, NO3- was produced by chemical NH4+ oxidation at the anode and was provided to the biocathode chamber. H2 was produced at the biocathode by the hydrogen-producing bacteria Petrimonas through the acceptance of electrons and protons. The H2 produced was biologically consumed by hydrogenotrophic methanogens of Methanobacterium and Methanobrevibacter with CO2 uptake and by hydrogenotrophic denitrifiers of Azonexus. This microbial community suggests that methane is indirectly produced without the use of electrons by methanogens. Furthermore, bioelectrical methane production occurred under experimental conditions even at a very low voltage of 0.05| |V coupled with NH4+ oxidation, which was thermodynamically feasible.


Assuntos
Compostos de Amônio/metabolismo , Bactérias/química , Bactérias/metabolismo , Fontes de Energia Bioelétrica/microbiologia , Metano/metabolismo , Reatores Biológicos/microbiologia , Dióxido de Carbono/metabolismo , Eletricidade , Eletrodos/microbiologia , Hidrogênio/metabolismo , Oxirredução
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