scholarly journals Syntrophic propionate-oxidizing bacteria in methanogenic systems

2021 ◽  
Author(s):  
Maria Westerholm ◽  
Magdalena Calusinska ◽  
Jan Dolfing
Keyword(s):  
Biogas Production ◽  
Direct Electron Transfer ◽  
Future Research ◽  
Gene Repertoire ◽  
Natural Ecosystems ◽  
Biogenic Methane ◽  
Propionate Metabolism ◽  
Propionate Degradation ◽  
Propionate Oxidation ◽  
Biotechnological Processes

Abstract The mutual nutritional cooperation underpinning syntrophic propionate degradation provides a scant amount of energy for the microorganisms involved, so propionate degradation often acts as a bottleneck in methanogenic systems. Understanding the ecology, physiology, and metabolic capacities of syntrophic propionate-oxidizing bacteria is of interest in both engineered and natural ecosystems, as it offers prospects to guide further development of technologies for biogas production and biomass-derived chemicals, and is important in forecasting contributions by biogenic methane emissions to climate change. Syntrophic propionate-oxidizing bacteria are distributed across different phyla. They can exhibit broad metabolic capabilities in addition to syntrophy (e.g. fermentative, sulfidogenic, and acetogenic metabolism) and demonstrate variations in interplay with cooperating partners, indicating nuances in their syntrophic lifestyle. In this review, we discuss distinctions in gene repertoire and organization for the methylmalonyl-CoA pathway, hydrogenases and formate dehydrogenases, and emerging facets of (formate/hydrogen/direct) electron transfer mechanisms. We also use information from cultivations, thermodynamic calculations, and omic analyses as the basis for identifying environmental conditions governing propionate oxidation in various ecosystems. Overall, this review improves basic and applied understanding of syntrophic propionate-oxidizing bacteria and highlights knowledge gaps, hopefully encouraging future research and engineering on propionate metabolism in biotechnological processes.

Production of Bio Gas from Vegetable and Flowers Wastes Using Anaerobic Digestion

2015 ◽  
Vol 787 ◽  
pp. 803-808 ◽  
Author(s):  
A. Deepanraj ◽  
S. Vijayalakshmi ◽  
J. Ranjitha
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Research Work ◽  
Pressure Gauge ◽  
Pig Manure ◽  
Future Research ◽  
Digital Pressure ◽  
Vegetable Wastes ◽  
Main Component

The present research paper describes about the anaerobic digestion of vegetable (Banana, Cauliflower, potato, and sweet potato) and flower wastes (Rose, sambangi, gulmohar, marigold, golden shower tree, silk tree mimosa) in a 1L capacity of anaerobic digestor using pig manure as an inoculums. The digester was operated in the ratio of 1:1 of substrate to inoculums at RT. The substrate concentrations are varied such as 5%, 7%, and 10% was used and amount of gas produced was analysed using digital pressure gauge. The results obtained showed that, marigold flower had given higher yield of biogas than vegetable wastes and the digestion period was less. The average biogas production potential of withered flowers was observed as 14.36 g/kg in 5 days, where in case of vegetable wastes it was 10.0234 g/kg in 6 days. The study showed that flowers which are available in abundant in India is thrown away within a day, in the environment. These feedstocks are good feed stock for the production of biogas. The generation of biogas from flowers and vegetable waste upholds the concept of waste to wealth in enhancing sustainability of development. The future research work is mainly focused on the characterization of the main component present in the bio-gas using sophisticated instruments.

scholarly journals Plant Phenology and Its Anthropogenic and Natural Influencing Factors in Densely Populated Areas During the Economic Transition Period of China

2022 ◽  
Vol 9 ◽  
Author(s):  
Peijun Ju ◽  
Wenchao Yan ◽  
Jianliang Liu ◽  
Xinwei Liu ◽  
Liangfeng Liu ◽  
...  
Keyword(s):  
Climate Change ◽  
Economic Transition ◽  
Transition Period ◽  
Growing Season ◽  
Plant Phenology ◽  
Future Research ◽  
Urban Management ◽  
Climate Factors ◽  
Natural Ecosystems ◽  
The Impact

As a sensitive, observable, and comprehensive indicator of climate change, plant phenology has become a vital topic of global change. Studies about plant phenology and its responses to climate change in natural ecosystems have drawn attention to the effects of human activities on phenology in/around urban regions. The key factors and mechanisms of phenological and human factors in the process of urbanization are still unclear. In this study, we analyzed variations in xylophyta phenology in densely populated cities during the fast urbanization period of China (from 1963 to 1988). We assessed the length of the growing season affected by the temperature and precipitation. Temperature increased the length of the growing season in most regions, while precipitation had the opposite effect. Moreover, the plant-growing season is more sensitive to preseason climate factors than to annual average climate factors. The increased population reduced the length of the growing season, while the growing GDP increased the length of the growing season in most regions (8 out of 13). By analyzing the impact of the industry ratio, we found that the correlation between the urban management of emerging cities (e.g., Chongqing, Zhejiang, and Guizhou) and the growing season is more significant, and the impact is substantial. In contrast, urban management in most areas with vigorously developed heavy industry (e.g., Heilongjiang, Liaoning, and Beijing) has a weak and insignificant effect on plant phenology. These results indicate that different urban development patterns can influence urban plant phenology. Our results provide some support and new thoughts for future research on urban plant phenology.

scholarly journals A review of anaerobic landfill bioreactor using leachate recirculation to increase methane gas recovery

2021 ◽  
Vol 894 (1) ◽  
pp. 012013
Author(s):  
M A Budihardjo ◽  
B S Ramadan ◽  
E Yohana ◽  
Syafrudin ◽  
F Rahmawati ◽  
...  
Keyword(s):  
Alternative Energy ◽  
Ph Value ◽  
Biogas Production ◽  
Future Research ◽  
Leachate Recirculation ◽  
Methane Gas ◽  
Gas Recovery ◽  
Development Plans ◽  
Waste Degradation ◽  
The Relationship

Abstract Municipal Solid Waste (MSW) treatment with anaerobic landfill bioreactor utilizes landfill as a place of biodegradation and produces methane gas which can be used as renewable alternative energy source. Anaerobic landfill bioreactor technology is a landfill development method that can increase waste degradation and increase biogas production. The increase of biogas and the removal of pollutants from leachate needs to pay attention to the factors that influence the success of anaerobic landfill bioreactor, including pH value, temperature, water content, and COD concentration after recirculation, and methane production. The relationship between these factors was discussed in depth in this paper. The method used is a narrative review where metadata is obtained from Google Scholar and Web of Science. This study explains the development of an anaerobic landfill bioreactor and conducts a synthesis for future research development plans by leachate recirculation.

scholarly journals Two Novel Energy Crops: Sida hermaphrodita (L.) Rusby and Silphium perfoliatum L.—State of Knowledge

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 928
Author(s):  
Laura Cumplido-Marin ◽  
Anil R. Graves ◽  
Paul J. Burgess ◽  
Christopher Morhart ◽  
Pierluigi Paris ◽  
...  
Keyword(s):  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Energy Production ◽  
Biogas Production ◽  
Soil Health ◽  
Farming Systems ◽  
Environmental Benefits ◽  
Bioenergy Crops ◽  
Future Research ◽  
Gas Emissions

Current global temperature increases resulting from human activity threaten many ecosystems and societies, and have led to international and national policy commitments that aim to reduce greenhouse gas emissions. Bioenergy crops provide one means of reducing greenhouse gas emissions from energy production and two novel crops that could be used for this purpose are Sida hermaphrodita (L.) Rusby and Silphium perfoliatum L. This research examined the existing scientific literature available on both crops through a systematic review. The data were collated according to the agronomy, uses, and environmental benefits of each crop. Possible challenges were associated with high initial planting costs, low yields in low rainfall areas, and for Sida hermaphrodita, vulnerability to Sclerotinia sclerotiorum. However, under appropriate environmental conditions, both crops were found to provide large yields over sustained periods of time with relatively low levels of management and could be used to produce large energy surpluses, either through direct combustion or biogas production. Other potential uses included fodder, fibre, and pharmaceutical uses. Environmental benefits included the potential for phytoremediation, and improvements to soil health, biodiversity, and pollination. The review also demonstrated that environmental benefits, such as pollination, soil health, and water quality benefits could be obtained from the use of Sida hermaphrodita and Silphium perfoliatum relative to existing bioenergy crops such as maize, whilst at the same time reducing the greenhouse gas emissions associated with energy production. Future research should examine the long-term implications of using Sida hermaphrodita and Silphium perfoliatum as well as improve knowledge on how to integrate them successfully within existing farming systems and supply chains.

scholarly journals Biogas Production from Rice Husk Waste by using Solid State Anaerobic Digestion (SSAD) Method

2018 ◽  
Vol 31 ◽  
pp. 02007 ◽  
Author(s):  
Hashfi Hawali Abdul Matin ◽  
Hadiyanto
Keyword(s):  
Anaerobic Digestion ◽  
Solid State ◽  
Rice Husk ◽  
Alternative Energy ◽  
Biogas Production ◽  
Lignin Content ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Future Research ◽  
Continuous Systems

An effort to obtain alternative energy is still interesting subject to be studied, especially production of biogas from agriculture waste. This paper was an overview of the latest development of biogas researches from rice husk waste by Solid State Anaerobic Digestion (SSAD). The main obstacle of biogas production from rice husk waste was the lignin content which is very difficult degraded by microbes. Various pretreatments have been conducted, either physically, chemically as well as biologically. The SSAD method was an attractive option because of the low water content of rice husk waste. The biogas yield by SSAD method gave more attractive result compared to Liquid Anaerobic Digestion (LAD) method. Various studies were still conducted in batch mode laboratory scale and also has not found optimum operating conditions. Research on a larger scale such as bench and pilot scale with continuous systems will be an increase trend in the future research.

scholarly journals Understanding ENSO Diversity

2015 ◽  
Vol 96 (6) ◽  
pp. 921-938 ◽  
Author(s):  
Antonietta Capotondi ◽  
Andrew T. Wittenberg ◽  
Matthew Newman ◽  
Emanuele Di Lorenzo ◽  
Jin-Yi Yu ◽  
...  
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Life Cycles ◽  
Future Research ◽  
Natural Ecosystems ◽  
Diverse Range ◽  
Current State ◽  
Global Impacts ◽  
Enso Diversity

Abstract El Niño–Southern Oscillation (ENSO) is a naturally occurring mode of tropical Pacific variability, with global impacts on society and natural ecosystems. While it has long been known that El Niño events display a diverse range of amplitudes, triggers, spatial patterns, and life cycles, the realization that ENSO’s impacts can be highly sensitive to this event-to-event diversity is driving a renewed interest in the subject. This paper surveys our current state of knowledge of ENSO diversity, identifies key gaps in understanding, and outlines some promising future research directions.

scholarly journals Response of methane production via propionate oxidation to carboxylated multiwalled carbon nanotubes in paddy soil enrichments

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4267 ◽  
Author(s):  
Jianchao Zhang ◽  
Xingxuan Xia ◽  
Siliang Li ◽  
Wei Ran
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Paddy Soil ◽  
Archaeal Community ◽  
Major Product ◽  
Natural Environments ◽  
Cell Integrity ◽  
Multiwalled Carbon ◽  
Propionate Degradation ◽  
Propionate Oxidation

Carboxylated multiwalled carbon nanotubes (MWCNTs-COOH) have become a growing concern in terms of their fate and toxicity in aqueous environments. Methane (CH4) is a major product of organic matter degradation in waterlogged environments. In this study, we determined the effect of MWCNTs-COOH on the production of CH4 from propionate oxidation in paddy soil enrichments. The results showed that the methanogenesis from propionate degradation was accelerated in the presence of MWCNTs-COOH. In addition, the rates of CH4 production and propionate degradation increased with increasing concentrations of MWCNTs-COOH. Scanning electron microscopy (SEM) observations showed that the cells were intact and maintained their structure in the presence of MWCNTs-COOH. In addition, SEM and fluorescence in situ hybridization (FISH) images revealed that the cells were in direct contact with the MWCNTs and formed cell-MWCNTs aggregates that contained both bacteria and archaea. On the other hand, nontoxic magnetite nanoparticles (Fe3O4) had similar effects on the CH4 production and cell integrity as the MWCNTs-COOH. Compared with no nanomaterial addition, the relative abundances of Geobacter and Methanosarcina species increased in the presence of MWCNTs-COOH. This study suggests that MWCNTs-COOH exerted positive rather than cytotoxic effects on the syntrophic oxidation of propionate in paddy soil enrichments and affected the bacterial and archaeal community structure at the test concentrations. These findings provide novel insight into the consequences of nanomaterial release into anoxic natural environments.

scholarly journals An ecohydrological sketch of climate change impacts on water and natural ecosystems for The Netherlands: bridging the gap between science and society

2012 ◽  
Vol 9 (5) ◽  
pp. 6311-6344
Author(s):  
J. P. M. Witte ◽  
J. Runhaar ◽  
R. van Ek ◽  
D. C. J. van der Hoek ◽  
R. P. Bartholomeus ◽  
...  
Keyword(s):  
Climate Change ◽  
The Netherlands ◽  
Future Climate ◽  
Plant Performance ◽  
Future Research ◽  
Natural Ecosystems ◽  
Adaptation Measures ◽  
Raised Bogs ◽  
The Future ◽  
Sketch Map

Abstract. For policy making and spatial planning, information is needed about the impacts of climate change on natural ecosystems. To provide this information, commonly hydrological and ecological models are used. We give arguments for our assessment that modelling only is insufficient for determining the impacts of climate changes on natural ecosystems at regional scales. Instead, we proposed a combination of hydrological simulations, a literature review and process-knowledge on climate-hydrology-vegetation interactions, to compile a sketch-map that indicates climate change effects on a number of ecosystems in The Netherlands. Soon after its introduction, copies of our sketch-map appeared in policy documents and in a commercial and popular atlas of The Netherlands. Moreover, the map led to a question in the Dutch parliament about the survivability of bog reserves in the future climate. Apparently, there was an urgent need for the information provided by the map. The map shows that climate change will presumably have the largest influence on ecosystems in The Netherlands that depend on precipitation as the major water source, like heathlands, dry grasslands, rain-fed moorland pools and raised bogs. Also highly susceptible are fens in reserves surrounded by deeply drained polders, because such fens depend on the inlet of surface water, of which quality is likely to deteriorate upon climate change. While the map is indicative for directions of change, in view of the uncertainties of our study no conclusions should be drawn that may have far-reaching consequences, such as giving up certain nature targets that might no longer be feasible in the future climate. Instead, we advise to anticipate on the potential threats from climate change by taking a number of adaptation measures that enhance the robustness of nature reserves. To improve climate change projections on hydrology and ecosystems, future research should especially focus on feedbacks of vegetation on the water balance, on processes that directly influence plant performance and on the ecological effects of weather extremes.

scholarly journals Volatile Fatty Acid Production from Organic Waste with the Emphasis on Membrane-Based Recovery

Fermentation ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 159
Author(s):  
Prawat Sukphun ◽  
Sureewan Sittijunda ◽  
Alissara Reungsang
Keyword(s):  
Organic Waste ◽  
Volatile Fatty Acids ◽  
Low Cost ◽  
Cost Effective ◽  
Future Research ◽  
Fatty Acid Production ◽  
Factors Affecting ◽  
Acidogenic Fermentation ◽  
Recovery Techniques ◽  
Biotechnological Processes

In recent years, interest in the biorefinery concept has emerged in the utilization of volatile fatty acids (VFAs) produced by acidogenic fermentation as precursors for various biotechnological processes. This has attracted substantial attention to VFA production from low-cost substrates such as organic waste and membrane based VFA recovery techniques to achieve cost-effective and environmentally friendly processes. However, there are few reviews which emphasize the acidogenic fermentation of organic waste into VFAs, and VFA recovery. Therefore, this article comprehensively summarizes VFA production, the factors affecting VFA production, and VFA recovery strategies using membrane-based techniques. Additionally, the outlook for future research on VFA production is discussed.

scholarly journals The Effects of Hot Water and Ultrasonication Pretreatment of Microalgae (Nannochloropsis oculata) on Biogas Production in Anaerobic Co-Digestion with Cow Manure

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1558
Author(s):  
Muhammad Saleem ◽  
Muhammad Usman Hanif ◽  
Ali Bahadar ◽  
Hamid Iqbal ◽  
Sergio C. Capareda ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Suspended Solids ◽  
Biogas Production ◽  
Gas Production ◽  
Nannochloropsis Oculata ◽  
Hot Water ◽  
Cow Manure ◽  
Biogenic Methane ◽  
Promising Solution

Anaerobic co-digestion provides a promising solution for converting inexpensive carbon from wastes to biogenic methane. We used microalgae (Nannochloropsis oculata) with cow manure and sludge to produce a better quantity and quality of biogas. To further improve the gas production, microalgae were pretreated with ultrasonication, hot water, and a combination of both. Interestingly, the results showed that the pretreatment of microalgae decreased biogas production by 5 to 30%. The no-pretreatment runs produced a maximum of 118 L of biogas. The relative content of biogenic methane was higher in the pretreated feedstock (48 to 52%) in comparison with the no-pretreatment runs (44%). The conversion of volatile suspended solids present in the feedstock to total biogenic methane production was highest in hot-water-treated runs. The carbon content in the gas produced by the pretreated microalgae peaked (38%) in the middle of the experiment (i.e., at 45 days), whereas for no-pretreatment runs, the content remained constant from the start to the middle and declined (from 36 to 34%) at the end of the experiment (i.e., at 90 days). We also report the chemical structure of microalgae with and without pretreatments.

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