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Journal of Clinical Microbiology May 2023
Review
Topics: Humans; Anaerobiosis; Staining and Labeling; Coloring Agents; Bacteria, Anaerobic
PubMed: 37219093
DOI: 10.1128/jcm.00150-22 -
Bioresource Technology Dec 2021Anaerobic digestion (AD) has been widely applied to convert organic solid wastes into biogas, a renewable energy, and digestate, a bio-fertilizer, to sustain waste... (Review)
Review
Anaerobic digestion (AD) has been widely applied to convert organic solid wastes into biogas, a renewable energy, and digestate, a bio-fertilizer, to sustain waste management. Nevertheless, several vexing contaminants in OSWs restrict digestate application in agriculture. Biochar has been evidenced to effectively improve AD by promoting organic biodegradation and alleviating the accumulation of inhibitory substances (e.g. ammonia and volatile fatty acids). Furthermore, biochar could advance contaminant removal in AD given its highly porous, conductive and alkaline features. Thus, this review aims to highlight the role of biochar amendment to advance contaminant removal in AD of OSWs. Key contaminants, such as antibiotics, heavy metals, microplastics, polycyclic aromatic hydrocarbons, furfural and 5-hydroxy methyl furfural (5-HMF) that ubiquitously present in OSWs were demonstrated. The underlying mechanisms of biochar to amend the removal of these contaminants by AD were discussed. Furthermore, future perspectives to the development of biochar-assisted AD for OSWs treatment were provided.
Topics: Anaerobiosis; Charcoal; Plastics; Solid Waste
PubMed: 34455247
DOI: 10.1016/j.biortech.2021.125827 -
International Journal of Environmental... Mar 2021Manure and digestate liquid fractions are nutrient-rich effluents that can be fractionated and concentrated using membranes. However, these membranes tend to foul due to... (Review)
Review
Manure and digestate liquid fractions are nutrient-rich effluents that can be fractionated and concentrated using membranes. However, these membranes tend to foul due to organic matter, solids, colloids, and inorganic compounds including calcium, ammonium, sodium, sulfur, potassium, phosphorus, and magnesium contained in the feed. This review paper is intended as a theoretical and practical tool for the decision-making process during design of membrane-based systems aiming at processing manure liquid fractions. Firstly, this review paper gives an overview of the main physico-chemical characteristics of manure and digestates. Furthermore, solid-liquid separation technologies are described and the complexity of the physico-chemical variables affecting the separation process is discussed. The main factors influencing membrane fouling mechanisms, morphology and characteristics are described, as well as techniques covering membrane inspection and foulant analysis. Secondly, the effects of the feed characteristics, membrane operating conditions (pressure, cross-flow velocity, temperature), pH, flocculation-coagulation and membrane cleaning on fouling and membrane performance are presented. Finally, a summary of techniques for specific recovery of ammonia-nitrogen, phosphorus and removal of heavy metals for farm effluents is also presented.
Topics: Ammonia; Anaerobiosis; Manure; Nitrogen; Phosphorus
PubMed: 33803027
DOI: 10.3390/ijerph18063107 -
Chemosphere Jan 2022Anaerobic digestion (AD) serves as a potential bioconversion process to treat various organic wastes/wastewaters, including sewage sludge, and generate renewable green... (Review)
Review
Anaerobic digestion (AD) serves as a potential bioconversion process to treat various organic wastes/wastewaters, including sewage sludge, and generate renewable green energy. Despite its efficiency, AD has several limitations that need to be overcome to achieve maximum energy recovery from organic materials while regulating inhibitory substances. Hence, bioelectrochemical systems (BESs) have been widely investigated to treat inhibitory compounds including ammonia in AD processes and improve the AD operational efficiency, stability, and economic viability with various integrations. The BES operations as a pretreatment process, inside AD or after the AD process aids in the upgradation of biogas (CO to methane) and residual volatile fatty acids (VFAs) to valuable chemicals and fuels (alcohols) and even directly to electricity generation. This review presents a comprehensive summary of BES technologies and operations for overcoming the limitations of AD in lab-scale applications and suggests upscaling and future opportunities for BES-AD systems.
Topics: Anaerobiosis; Biofuels; Bioreactors; Methane; Sewage
PubMed: 34627010
DOI: 10.1016/j.chemosphere.2021.132299 -
Waste Management (New York, N.Y.) Feb 2021This review focuses on current status of pulsed electric field (PEF) technology and its implementation in biogas production. First, basic principles of PEF and a... (Review)
Review
This review focuses on current status of pulsed electric field (PEF) technology and its implementation in biogas production. First, basic principles of PEF and a schematic overview of typical PEF processing system were provided. Thereafter, lab- and pilot-scale PEF pretreatments of sludge with subsequent anaerobic digestion (AD) were provided. Furthermore, PEF technology, as an emerging technology for the lignocellulose (LC) pretreatment in biogas production which is still predominantly used at lab-scale, was outlined. Eventually, conclusion together with future perspectives and challenges were outlined.
Topics: Anaerobiosis; Biofuels; Sewage; Technology
PubMed: 33139189
DOI: 10.1016/j.wasman.2020.10.009 -
Chemosphere Mar 2022Amongst the most important sustainable waste management strategies, anaerobic biotechnology has had a central role over the past century in the management of... (Review)
Review
Amongst the most important sustainable waste management strategies, anaerobic biotechnology has had a central role over the past century in the management of high-pollution load sources, such as food, agricultural and municipal wastes. During anaerobic digestion (AD), valuable by-products such as digestate and biogas are produced. Biogas (mainly composed of methane) is generated through a series of reactions between bacteria and archaea. Enhancement of AD process with higher methane yield, accelerated methane production rate, and shorter start-up time is possible via tapping into a novel methanogenic pathway discovered a decade ago. This fundamentally new concept that is a substitute to interspecies hydrogen transfer is called direct interspecies electron transfer (DIET). DIET, a thermodynamically more feasible way of electron transfer, has been proven to occur between bacteria and methanogens. It is well-documented that amendment of carbon-based conductive materials (CCMs) can stimulate DIET via serving as an electrical conduit between microorganisms. Therefore, different types of CCMs such as biochar and activated carbon have been amended to a variety of AD reactors and enhancement of process performance was reported. In this review, a comparative analysis is presented for enhancement of AD performance in relation to major CCM related factors; electrical conductivity, redox properties, particle size and dosage. Additionally, the impacts of AD operational conditions such as organic loading rate and temperature on CCM amended reactors were discussed. Further, the changes in microbial communities of CCM amended reactors were reviewed and future perspectives along with challenges for CCM application in AD have been provided.
Topics: Anaerobiosis; Archaea; Bioreactors; Electric Conductivity; Methane
PubMed: 34914946
DOI: 10.1016/j.chemosphere.2021.133247 -
Bioresource Technology Jan 2022Conventional sewage treatment applying activated sludge processes is energy-intensive and requires great financial input, hampering widespread implementation. The... (Review)
Review
Conventional sewage treatment applying activated sludge processes is energy-intensive and requires great financial input, hampering widespread implementation. The introduction of anaerobic membrane bioreactors (AnMBR) followed by an algal reactor growing species of commercial interest, may present an alternative, contributing to the envisaged resource recovery at sewage treatment plants. AnMBRs can be applied for organic matter removal with energy self-sufficiency, provided that effective membrane fouling management is applied. Haematococcus pluvialis, an algal species with commercial value, can be selected for ammonium and phosphate removal. Theoretical analysis showed that good pollutant removal, positive financial output, as well as a significant reduction in the amount of hazardous activated sludge can be achieved by applying the proposed process, showing interesting advantages over current sewage treatment processes. Microbial contamination to H. pluvialis is a challenge, and technologies for preventing the contamination during continuous sewage treatment need to be applied.
Topics: Anaerobiosis; Bioreactors; Sewage; Waste Disposal, Fluid; Wastewater
PubMed: 34655782
DOI: 10.1016/j.biortech.2021.126115 -
Molecular Biology and Evolution May 2021The transition of free-living organisms to parasitic organisms is a mysterious process that occurs in all major eukaryotic lineages. Parasites display seemingly unique... (Comparative Study)
Comparative Study
The transition of free-living organisms to parasitic organisms is a mysterious process that occurs in all major eukaryotic lineages. Parasites display seemingly unique features associated with their pathogenicity; however, it is important to distinguish ancestral preconditions to parasitism from truly new parasite-specific functions. Here, we sequenced the genome and transcriptome of anaerobic free-living Mastigamoeba balamuthi and performed phylogenomic analysis of four related members of the Archamoebae, including Entamoeba histolytica, an important intestinal pathogen of humans. We aimed to trace gene histories throughout the adaptation of the aerobic ancestor of Archamoebae to anaerobiosis and throughout the transition from a free-living to a parasitic lifestyle. These events were associated with massive gene losses that, in parasitic lineages, resulted in a reduction in structural features, complete losses of some metabolic pathways, and a reduction in metabolic complexity. By reconstructing the features of the common ancestor of Archamoebae, we estimated preconditions for the evolution of parasitism in this lineage. The ancestor could apparently form chitinous cysts, possessed proteolytic enzyme machinery, compartmentalized the sulfate activation pathway in mitochondrion-related organelles, and possessed the components for anaerobic energy metabolism. After the split of Entamoebidae, this lineage gained genes encoding surface membrane proteins that are involved in host-parasite interactions. In contrast, gene gains identified in the M. balamuthi lineage were predominantly associated with polysaccharide catabolic processes. A phylogenetic analysis of acquired genes suggested an essential role of lateral gene transfer in parasite evolution (Entamoeba) and in adaptation to anaerobic aquatic sediments (Mastigamoeba).
Topics: Adaptation, Biological; Anaerobiosis; Animals; Archamoebae; Biological Evolution; Entamoeba histolytica; Gene Transfer, Horizontal; Genome Size; Genome, Protozoan; Parasites; Transcriptome
PubMed: 33528570
DOI: 10.1093/molbev/msab020 -
Current Opinion in Biotechnology Oct 2021The lack of real-time reporters in obligate anaerobes has limited studies in gene expression, promoter characterization, library screening, population dynamics, and cell... (Review)
Review
The lack of real-time reporters in obligate anaerobes has limited studies in gene expression, promoter characterization, library screening, population dynamics, and cell biology in these organisms. While the use of enzymatic, colorimetric, and luminescent reporters has been reported, the need for reliable anaerobic fluorescent proteins is widely acknowledged. Recently, the fluorescent proteins HaloTag, SNAP-tag and FAST have been established as reliable reporters in Clostridium spp., thus suggesting that these reporters can be adopted widely for many obligate anaerobes. With a multitude of labeling options, these anaerobic fluorescent proteins hold a great potential for screening promoters, terminators, and RBS sites, tracking population dynamics in complex multi-species co-cultures, such as microbiomes, screening libraries, and in cell biology studies of protein localization and interactions using high-resolution microscopy.
Topics: Anaerobiosis; Genes, Reporter; Genomic Library; High-Throughput Screening Assays; Microbiota
PubMed: 34375813
DOI: 10.1016/j.copbio.2021.07.005 -
Journal of Environmental Management Sep 2022Increased biogas production from increasing numbers of anaerobic digestion (AD) facilities has increased the mass of digestate applied to agricultural land close to AD...
Increased biogas production from increasing numbers of anaerobic digestion (AD) facilities has increased the mass of digestate applied to agricultural land close to AD plants and has led to an oversupply in some regions. This necessitates long distance digestate transportation accompanied by economic, environmental, and social drawbacks. This work assesses the performance of three different digestate management options (MOs); land application of whole digestate (MO1), digestate separation (MO2), and digestate separation and evaporation (MO3), combined with centralised or decentralised digestate storage. All MOs required the same landbank area, whilst MO2 and MO3 reduced digestate management costs by 9% and 37% (if recovered heat is used) respectively. GHG emissions from MO2 were 41% lower than MO1 if renewable electricity was used. MO3 reduced GHG emissions by 63% compared to MO1, if renewable electricity and recovered heat were used. MO2 required the same centralised digestate storage volume as MO1 while MO3 required 44% of the centralised storage volume. Centralised digestate storage required a maximum of 79 days for digestate transportation (33 trucks/day, 20 m capacity) to land for MO1 and MO2, and 35 days for MO3. Decentralised digestate storage required 63 storage tanks and 15 trucks/day for MO1, 69 tanks and 15 trucks/day for MO2, and 68 tanks and 7 trucks/day for MO3. Tank size ranged from 500 m to 20,000 m. MO3 combined with decentralised storage could reduce the cost and GHG emissions (if recovered energy is used), vehicle movements, and the number of storage tanks required for digestate management.
Topics: Agriculture; Anaerobiosis; Biofuels
PubMed: 35751231
DOI: 10.1016/j.jenvman.2022.115312