scholarly journals The Enrichment And Characterization Of Compost And Wastewater-Derived Microbial Cellulolytic Consortia For Biofuel Production

Author(s):  
Augustyna Dobosz

Over the last decade, a rise in energy demand and diminishing fuel resources have created a challenge for finding an alternative solution that could supplement our current energy sources. This study demonstrated that ethanol and other useful end-products can be produced from the fermentative activity of microbial consortia derived from cellulose-rich waste environments. Compost and wastewater were used as inoculum sources to enrich cellulolytic cultures at incubation temperatures 50 ºC and 60ºC. A chemically defined medium was used without complex nutrients such as yeast extract. Four cellulolytic cultures were obtained and their end-products were monitored over an active cellulose degrading period. The compost culture incubated at 50ºC produced the highest concentration of butyrate while the wastewater-derived culture incubated at 60ºC produced the highest ethanol concentration. Optimization of DNA extraction and purification from complex environmental samples such as the compost and wastewater cultures used in this study was also discussed.

2021 ◽  
Author(s):  
Augustyna Dobosz

Over the last decade, a rise in energy demand and diminishing fuel resources have created a challenge for finding an alternative solution that could supplement our current energy sources. This study demonstrated that ethanol and other useful end-products can be produced from the fermentative activity of microbial consortia derived from cellulose-rich waste environments. Compost and wastewater were used as inoculum sources to enrich cellulolytic cultures at incubation temperatures 50 ºC and 60ºC. A chemically defined medium was used without complex nutrients such as yeast extract. Four cellulolytic cultures were obtained and their end-products were monitored over an active cellulose degrading period. The compost culture incubated at 50ºC produced the highest concentration of butyrate while the wastewater-derived culture incubated at 60ºC produced the highest ethanol concentration. Optimization of DNA extraction and purification from complex environmental samples such as the compost and wastewater cultures used in this study was also discussed.


Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 504
Author(s):  
Yane Ansanay ◽  
Praveen Kolar ◽  
Ratna Sharma-Shivappa ◽  
Jay Cheng ◽  
Consuelo Arellano

In the present research, activated carbon-supported sulfonic acid catalysts were synthesized and tested as pretreatment agents for the conversion of switchgrass into glucose. The catalysts were synthesized by reacting sulfuric acid, methanesulfonic acid, and p-toluenesulfonic acid with activated carbon. The characterization of catalysts suggested an increase in surface acidities, while surface area and pore volumes decreased because of sulfonation. Batch experiments were performed in 125 mL serum bottles to investigate the effects of temperature (30, 60, and 90 °C), reaction time (90 and 120 min) on the yields of glucose. Enzymatic hydrolysis of pretreated switchgrass using Ctec2 yielded up to 57.13% glucose. Durability tests indicated that sulfonic solid-impregnated carbon catalysts were able to maintain activity even after three cycles. From the results obtained, the solid acid catalysts appear to serve as effective pretreatment agents and can potentially reduce the use of conventional liquid acids and bases in biomass-into-biofuel production.


Author(s):  
Ahmed I. Osman ◽  
Neha Mehta ◽  
Ahmed M. Elgarahy ◽  
Amer Al-Hinai ◽  
Ala’a H. Al-Muhtaseb ◽  
...  

AbstractThe global energy demand is projected to rise by almost 28% by 2040 compared to current levels. Biomass is a promising energy source for producing either solid or liquid fuels. Biofuels are alternatives to fossil fuels to reduce anthropogenic greenhouse gas emissions. Nonetheless, policy decisions for biofuels should be based on evidence that biofuels are produced in a sustainable manner. To this end, life cycle assessment (LCA) provides information on environmental impacts associated with biofuel production chains. Here, we review advances in biomass conversion to biofuels and their environmental impact by life cycle assessment. Processes are gasification, combustion, pyrolysis, enzymatic hydrolysis routes and fermentation. Thermochemical processes are classified into low temperature, below 300 °C, and high temperature, higher than 300 °C, i.e. gasification, combustion and pyrolysis. Pyrolysis is promising because it operates at a relatively lower temperature of up to 500 °C, compared to gasification, which operates at 800–1300 °C. We focus on 1) the drawbacks and advantages of the thermochemical and biochemical conversion routes of biomass into various fuels and the possibility of integrating these routes for better process efficiency; 2) methodological approaches and key findings from 40 LCA studies on biomass to biofuel conversion pathways published from 2019 to 2021; and 3) bibliometric trends and knowledge gaps in biomass conversion into biofuels using thermochemical and biochemical routes. The integration of hydrothermal and biochemical routes is promising for the circular economy.


2009 ◽  
Vol 191 (7) ◽  
pp. 2033-2041 ◽  
Author(s):  
Meriyem Aktas ◽  
Franz Narberhaus

ABSTRACT Agrobacterium tumefaciens requires phosphatidylcholine (PC) in its membranes for plant infection. The phospholipid N-methyltransferase PmtA catalyzes all three transmethylation reactions of phosphatidylethanolamine (PE) to PC via the intermediates monomethylphosphatidylethanolamine (MMPE) and dimethylphosphatidylethanolamine (DMPE). The enzyme uses S-adenosylmethionine (SAM) as the methyl donor, converting it to S-adenosylhomocysteine (SAH). Little is known about the activity of bacterial Pmt enzymes, since PC biosynthesis in prokaryotes is rare. In this article, we present the purification and in vitro characterization of A. tumefaciens PmtA, which is a monomeric protein. It binds to PE, the intermediates MMPE and DMPE, the end product PC, and phosphatidylglycerol (PG) and phosphatidylinositol. Binding of the phospholipid substrates precedes binding of SAM. We used a coupled in vitro assay system to demonstrate the enzymatic activity of PmtA and to show that PmtA is inhibited by the end products PC and SAH and the antibiotic sinefungin. The presence of PG stimulates PmtA activity. Our study provides insights into the catalysis and control of a bacterial phospholipid N-methyltransferase.


2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Maria Thereza Bazzo Martins ◽  
Wagner Rodrigo de Souza ◽  
Bárbara Andrade Dias Brito da Cunha ◽  
Marcos Fernando Basso ◽  
Nelson Geraldo de Oliveira ◽  
...  

RSC Advances ◽  
2016 ◽  
Vol 6 (81) ◽  
pp. 78161-78169 ◽  
Author(s):  
Jiajun Hu ◽  
Yiyun Xue ◽  
Jixiang Li ◽  
Lei Wang ◽  
Shiping Zhang ◽  
...  

CO2 fixation efficiency of the devised synthetic microbial consortia with both autotrophic–autotrophic and autotrophic–heterotrophic microbial interactions were higher than the sum of theoretical CO2 fixation efficiency of the microbial components.


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