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Nutrients Aug 2020Beta-alanine supplementation (BA) has a positive impact on physical performance. However, evidence showing a benefit of this amino acid in aerobic-anaerobic transition... (Meta-Analysis)
Meta-Analysis
Beta-alanine supplementation (BA) has a positive impact on physical performance. However, evidence showing a benefit of this amino acid in aerobic-anaerobic transition zones is scarce and the results controversial. The aim of this systematic review and meta-analysis is to analyze the effects of BA supplementation on physical performance in aerobic-anaerobic transition zones. At the same time, the effect of different dosages and durations of BA supplementation were identified. The search was designed in accordance with the PRISMA guidelines for systematic reviews and meta-analyses and performed in Web of Science (WOS), Scopus, SPORTDiscus, PubMed, and MEDLINE between 2010 and 2020. The methodological quality and risk of bias were evaluated with the Cochrane Collaboration tool. The main variables were the Time Trial Test (TTT) and Time to Exhaustion (TTE) tests, the latter separated into the Limited Time Test (LTT) and Limited Distance Test (LDT). The analysis was carried out with a pooled standardized mean difference (SMD) through Hedges' g test (95% CI). Nineteen studies were included in the systematic review and meta-analysis, revealing a small effect for time in the TTT (SMD, -0.36; 95% CI, -0.87-0.16; I = 59%; = 0.010), a small effect for LTT (SMD, 0.25; 95% CI, -0.01-0.51; I = 0%; = 0.53), and a large effect for LDT (SMD, 4.27; 95% CI, -0.25-8.79; I = 94%; = 0.00001). BA supplementation showed small effects on physical performance in aerobic-anaerobic transition zones. Evidence on acute supplementation is scarce (one study); therefore, exploration of acute supplementation with different dosages and formats on physical performance in aerobic-anaerobic transition zones is needed.
Topics: Aerobiosis; Anaerobiosis; Dietary Supplements; Humans; Physical Functional Performance; Sports Nutritional Physiological Phenomena; beta-Alanine
PubMed: 32824885
DOI: 10.3390/nu12092490 -
Nutrients May 2020Nitric oxide related ergogenic aids such as arginine (Arg) have shown to impact positively on sport performance through several physiological and metabolic mechanisms.... (Meta-Analysis)
Meta-Analysis
Nitric oxide related ergogenic aids such as arginine (Arg) have shown to impact positively on sport performance through several physiological and metabolic mechanisms. However, research results have shown to be controversial. The great differences regarding required metabolic pathways and physiological demands between aerobic and anaerobic sport disciplines could be the reasons. The aim of this systematic review and meta-analysis was to evaluate the effects of Arg supplementation on aerobic (≤VOmax) and anaerobic (>VOmax) performance. Likewise, to show the effective dose and timing of this supplementation. A structured search was carried out in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement and PICOS guidelines in PubMed/MEDLINE, Web of Science (WOS), and Scopus databases from inception to January 2020. Eighteen studies were included which compare Arg supplementation with placebo in an identical situation and testing its effects on aerobic and anaerobic performance tests. Trials analyzing supplementation with other supplements were removed and there was not athlete's level, gender, ethnicity, or age filters. The performed meta-analysis included 15 studies and random effects model and pooled standardized mean differences (SMD) were used according to Hedges' g. Results revealed that Arg supplementation could improve aerobic (SMD, 0.84; 95% CI, 0.12 to 1.56; magnitude of SMD (MSMD), large; I2, 89%; = 0.02) and anaerobic (SMD, 0.24; 95% CI, 0.05 to 0.43; MSMD, small; I2, 0%; = 0.01) performance tests. In conclusion, acute Arg supplementation protocols to improve aerobic and anaerobic performance should be adjusted to 0.15 g/kg of body weight ingested between 60-90 min before. Moreover, chronic Arg supplementation should include 1.5-2 g/day for 4-7 weeks in order to improve aerobic performance, and 10-12 g/day for 8 weeks to enhance anaerobic performance.
Topics: Aerobiosis; Anaerobiosis; Arginine; Athletic Performance; Body Weight; Dietary Supplements; Energy Metabolism; Female; Humans; Male; Nitric Oxide; Performance-Enhancing Substances
PubMed: 32370176
DOI: 10.3390/nu12051300 -
The ISME Journal Jan 2024Genome-scale metabolic models (GEMs) are valuable tools serving systems biology and metabolic engineering. However, GEMs are still an underestimated tool in informing... (Review)
Review
Genome-scale metabolic models (GEMs) are valuable tools serving systems biology and metabolic engineering. However, GEMs are still an underestimated tool in informing microbial ecology. Since their first application for aerobic gammaproteobacterial methane oxidizers less than a decade ago, GEMs have substantially increased our understanding of the metabolism of methanotrophs, a microbial guild of high relevance for the natural and biotechnological mitigation of methane efflux to the atmosphere. Particularly, GEMs helped to elucidate critical metabolic and regulatory pathways of several methanotrophic strains, predicted microbial responses to environmental perturbations, and were used to model metabolic interactions in cocultures. Here, we conducted a systematic review of GEMs exploring aerobic methanotrophy, summarizing recent advances, pointing out weaknesses, and drawing out probable future uses of GEMs to improve our understanding of the ecology of methane oxidizers. We also focus on their potential to unravel causes and consequences when studying interactions of methane-oxidizing bacteria with other methanotrophs or members of microbial communities in general. This review aims to bridge the gap between applied sciences and microbial ecology research on methane oxidizers as model organisms and to provide an outlook for future studies.
Topics: Methane; Oxidation-Reduction; Aerobiosis; Metabolic Networks and Pathways; Models, Biological
PubMed: 38861460
DOI: 10.1093/ismejo/wrae102 -
Journal of Environmental Management Aug 2021Aerobic Granular Sludge (AGS) is a biological treatment technology that has been extensively studied in the last decade. The possibility of resource recovery has always...
Aerobic Granular Sludge (AGS) is a biological treatment technology that has been extensively studied in the last decade. The possibility of resource recovery has always been highlighted in these systems, but real-scale applications are still scarce. Therefore, this paper aimed to present a systematic review of resources recovery such as water, energy, chemicals, raw materials, and nutrients from AGS systems, also analyzing aspects of engineering and economic viability. In the solid phase, sludge application in agriculture is an interesting possibility. However, the biosolids' metal concentration (the granules have high adsorption capacity due to the high concentration of extracellular polymeric substances, EPS) may be an issue. Another possibility is the recovery of Polyhydroxyalkanoates (PHAs) and Alginate-like exopolymers (bio-ALE) in the solid phase, emphasizing the last one, which has already been made in some Wastewater Treatment Plants (WWTPs), named and patented as Kaumera® process. The Operational Expenditure (OPEX) can be reduced by 50% in the WWTP when recovery of ALE is made. The ALE recovery reduced sludge yield by up to 35%, less CO emissions, and energy saving. Finally, the discharged sludge can also be evaluated to be used for energetic purposes via anaerobic digestion (AD) or combustion. However, the AD route has faced difficulties due to the low biodegradability of aerobic granules.
Topics: Aerobiosis; Bioreactors; Extracellular Polymeric Substance Matrix; Sewage; Waste Disposal, Fluid; Wastewater
PubMed: 33962280
DOI: 10.1016/j.jenvman.2021.112718