Genomics Perspectives of Bioethanol Producing Zymomonas Mobilis

2013 ◽  
pp. 1354-1377
Author(s):  
S. Sheik Asraf ◽  
K.N. Rajnish ◽  
P. Gunasekaran
Keyword(s):  
Functional Properties ◽  
Zymomonas Mobilis ◽  
Fossil Fuels ◽  
Ethanol Yield ◽  
Genomic Data ◽  
Continuous Increase ◽  
Renewable Source ◽  
Gram Negative ◽  
High Interest ◽  
High Ethanol

In recent years, there has been continuous increase in demand for fossil fuels that has led to the need for new potential fuel sources. Biofuels, in particular ethanol, are of high interest because of dwindling fossil fuels. Among the ethanol producers, Zymomonas mobilis has acquired greater interest because it is a renewable source of bioethanol. Zymomonas mobilis is an aerotolerant, gram-negative, ethanol producing bacterium that shows high ethanol yield, tolerance, and greater productivity. This chapter focuses on recent efforts made to engineer Z. mobilis, transcriptomic, genome-based metabolomic studies, and bioinformatics exploitation of the available genomic data for the production of bioethanol. Recently, several bioinformatics tools have been used to predict the functional properties of the carbohydrate active ethanologenic enzymes in Z. mobilis. A number of processes were used to study the functional properties of the ethanologenic enzymes of Z. mobilis. Thus, functional genomics seeks to apply technologies that would help to improve the production of bioethanol by Z. mobilis.

Genomics Perspectives of Bioethanol Producing Zymomonas Mobilis

2012 ◽  
pp. 209-233
Author(s):  
S. Sheik Asraf ◽  
K.N. Rajnish ◽  
P. Gunasekaran
Keyword(s):  
Functional Properties ◽  
Zymomonas Mobilis ◽  
Fossil Fuels ◽  
Ethanol Yield ◽  
Genomic Data ◽  
Continuous Increase ◽  
Renewable Source ◽  
Gram Negative ◽  
High Interest ◽  
High Ethanol

In recent years, there has been continuous increase in demand for fossil fuels that has led to the need for new potential fuel sources. Biofuels, in particular ethanol, are of high interest because of dwindling fossil fuels. Among the ethanol producers, Zymomonas mobilis has acquired greater interest because it is a renewable source of bioethanol. Zymomonas mobilis is an aerotolerant, gram-negative, ethanol producing bacterium that shows high ethanol yield, tolerance, and greater productivity. This chapter focuses on recent efforts made to engineer Z. mobilis, transcriptomic, genome-based metabolomic studies, and bioinformatics exploitation of the available genomic data for the production of bioethanol. Recently, several bioinformatics tools have been used to predict the functional properties of the carbohydrate active ethanologenic enzymes in Z. mobilis. A number of processes were used to study the functional properties of the ethanologenic enzymes of Z. mobilis. Thus, functional genomics seeks to apply technologies that would help to improve the production of bioethanol by Z. mobilis.

scholarly journals Production of Bioethanol from Cassava using Zymomonas mobilis: Effect of Temperature and Substrate concentration

2019 ◽  
Vol 1 ◽  
pp. 153-160
Author(s):  
I J Ona ◽  
H O Agogo ◽  
M S Iorungwa
Keyword(s):  
Zymomonas Mobilis ◽  
Simultaneous Saccharification And Fermentation ◽  
Ethanol Yield ◽  
Effect Of Temperature ◽  
Cassava Flour ◽  
Gram Negative ◽  
Theoretical Yield ◽  
Ethanol Yields ◽  
Theoretical Ethanol Yield ◽  
Simultaneous Saccharification

The production of ethanol from cassava flour using Zymomonas mobilis a gram negative bacterium was conducted at 30oC, 33oC, 35oC and 37oC. The fermentation reaction was also carried out at different substrate concentrations; 5% W/V, 7% W/V and 10% W/V. The microorganism Zymomonas mobilis was detected in palm wine, isolated and identified. It was found to be gram negative, oxidase negative, catalase positive, anaerobic and plump rods with an unusual width. Results obtained from the simultaneous saccharification and fermentation reactions carried out with Zymomonas mobilis showed that maximum theoretical ethanol yield of 63% was obtained for 7% W/V cassava flour at 35oC. This was followed by a theoretical yield of 56.23 and 54.12 for 5% W/V and 10% W/V cassava flour, respectively. Fermentations at 30oC and 33 oC gave similar results with 7% W/V cassava producing higher ethanol yield when compared to 5% W/V and 10% W/V. Fermentation reactions at 37oC gave the lowest ethanol yields. The optimum pH for the simultaneous saccharification and fermentation of cassava was found to be pH of 6.

scholarly journals The Quorum Sensing Auto-Inducer 2 (AI-2) Stimulates Nitrogen Fixation and Favors Ethanol Production over Biomass Accumulation in Zymomonas mobilis

2021 ◽  
Vol 22 (11) ◽  
pp. 5628
Author(s):  
Valquíria Campos Alencar ◽  
Juliana de Fátima dos Santos Silva ◽  
Renata Ozelami Vilas Boas ◽  
Vinícius Manganaro Farnézio ◽  
Yara N. L. F. de Maria ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Quorum Sensing ◽  
Ethanol Production ◽  
N2 Fixation ◽  
Energy Demand ◽  
Zymomonas Mobilis ◽  
Biomass Accumulation ◽  
High Energy ◽  
Gram Negative ◽  
Expression Of Genes

Autoinducer 2 (or AI-2) is one of the molecules used by bacteria to trigger the Quorum Sensing (QS) response, which activates expression of genes involved in a series of alternative mechanisms, when cells reach high population densities (including bioluminescence, motility, biofilm formation, stress resistance, and production of public goods, or pathogenicity factors, among others). Contrary to most autoinducers, AI-2 can induce QS responses in both Gram-negative and Gram-positive bacteria, and has been suggested to constitute a trans-specific system of bacterial communication, capable of affecting even bacteria that cannot produce this autoinducer. In this work, we demonstrate that the ethanologenic Gram-negative bacterium Zymomonas mobilis (a non-AI-2 producer) responds to exogenous AI-2 by modulating expression of genes involved in mechanisms typically associated with QS in other bacteria, such as motility, DNA repair, and nitrogen fixation. Interestingly, the metabolism of AI-2-induced Z. mobilis cells seems to favor ethanol production over biomass accumulation, probably as an adaptation to the high-energy demand of N2 fixation. This opens the possibility of employing AI-2 during the industrial production of second-generation ethanol, as a way to boost N2 fixation by these bacteria, which could reduce costs associated with the use of nitrogen-based fertilizers, without compromising ethanol production in industrial plants.

scholarly journals Hemicellulosic Bioethanol Production from Fast-Growing Paulownia Biomass

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 173
Author(s):  
Elena Domínguez ◽  
Pablo G. del Río ◽  
Aloia Romaní ◽  
Gil Garrote ◽  
Lucília Domingues
Keyword(s):  
Ethanol Production ◽  
Ethanol Concentration ◽  
Ethanol Yield ◽  
Xylose Reductase ◽  
Energy Crop ◽  
Scheffersomyces Stipitis ◽  
Fractionation Process ◽  
Renewable Source ◽  
Fast Growing ◽  
Engineered Strain

In order to exploit a fast-growing Paulownia hardwood as an energy crop, a xylose-enriched hydrolysate was obtained in this work to increase the ethanol concentration using the hemicellulosic fraction, besides the already widely studied cellulosic fraction. For that, Paulownia elongata x fortunei was submitted to autohydrolysis treatment (210 °C or S0 of 4.08) for the xylan solubilization, mainly as xylooligosaccharides. Afterwards, sequential stages of acid hydrolysis, concentration, and detoxification were evaluated to obtain fermentable sugars. Thus, detoxified and non-detoxified hydrolysates (diluted or not) were fermented for ethanol production using a natural xylose-consuming yeast, Scheffersomyces stipitis CECT 1922, and an industrial Saccharomyces cerevisiae MEC1133 strain, metabolic engineered strain with the xylose reductase/xylitol dehydrogenase pathway. Results from fermentation assays showed that the engineered S. cerevisiae strain produced up to 14.2 g/L of ethanol (corresponding to 0.33 g/g of ethanol yield) using the non-detoxified hydrolysate. Nevertheless, the yeast S. stipitis reached similar values of ethanol, but only in the detoxified hydrolysate. Hence, the fermentation data prove the suitability and robustness of the engineered strain to ferment non-detoxified liquor, and the appropriateness of detoxification of liquor for the use of less robust yeast. In addition, the success of hemicellulose-to-ethanol production obtained in this work shows the Paulownia biomass as a suitable renewable source for ethanol production following a suitable fractionation process within a biorefinery approach.

scholarly journals Food Grade Ethanol Production Process of Sorghum Stem Juice Using Immobilized Cells Technique

2015 ◽  
Vol 9 (7) ◽  
pp. 8 ◽  
Author(s):  
Tri Widjaja ◽  
Ali Altway ◽  
Arief Widjaja ◽  
Umi Rofiqah ◽  
Rr Whiny Hardiyati Erlian
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Sieve ◽  
Zymomonas Mobilis ◽  
Immobilized Cells ◽  
Ethanol Yield ◽  
Continuous Fermentation ◽  
Continuous Process ◽  
Pichia Stipitis ◽  
Batch Process ◽  
Food Grade

One form of economic development efforts for waste utilization in rural communities is to utilize stem sorghum to produce food grade ethanol. Sorghum stem juice with 150 g/L of sugar concentration was fermented using conventional batch process and cell immobilization continuous process with K-carrageenan as a supporting matrix. The microorganism used was Mutated Zymomonas Mobilis to be compared with a mixture of Saccharomyces Cerevisiae and Pichia Stipitis, and a mixture of Mutated Zymomonas Mobilis and Pichia Stipitis. Ethanol in the broth, result of fermentation process, was separated in packed distillation column. Distilate of the column, still contain water and other impurities, was flown into molecular sieve for dehydration and activated carbon adsorption column to remove the other impurities to meet food grade ethanol specification. The packing used in distillation process was steel wool. For batch fermentation, the fermentation using a combination of Saccharomyces Cerevisiae and Pichia Stipitis produced the best ethanol with 12.07% of concentration, where the yield and the productivity were 63.49%, and 1.06 g/L.h, respectively. And for continuous fermentation, the best ethanol with 9.02% of concentration, where the yield and the productivity were 47.42% and 174.27 g/L.h, respectively, is obtained from fermentation using a combination of Saccharomyces Cerevisiae and Pichia Stipitis also. Fermentation using combination microorganism of Saccharomyces Cerevisiae and Pichia Stipitis produced higher concentration of ethanol, yield, and productivity than other microorganisms. Distillation, molecular sieve dehydration and adsorption process is quite successful in generating sufficient levels of ethanol with relatively low amount of impurities.

scholarly journals Combining Ability Studies for Identifying High Sugar Yielding Sweet Sorghum [Sorghum bicolor (L.) Moench] Genotypes

2020 ◽  
pp. 43-49
Author(s):  
B. C. Nandeshwar ◽  
Beka Biri ◽  
Alemayehu Dugassa
Keyword(s):  
Combining Ability ◽  
Sweet Sorghum ◽  
Gene Action ◽  
Ethanol Yield ◽  
Breeding Programme ◽  
Combining Ability Analysis ◽  
Half Diallel ◽  
High Ethanol ◽  
Sorghum Bicolor L ◽  
Pedigree Breeding

Combining ability analysis provides information about the gene action involved in the expression of a trait and facilitates breeding of superior cultivars. Hence, 45 hybrids evolved from 10 parent half-diallel were evaluated for combining ability to identify good general combiners and superior cross combinations for high ethanol yield from sweet sorghum. RSSV-21-2 has been identified as the best general combiner. It can be used in pedigree breeding programme for the incorporation of desired traits for enhancing ethanol yield. ARS-SS-35-1 × NSS-218 and ARS-SS-83 × NSS-221-2 have been identified as the best specific combinations. These could be exploited in heterosis breeding programme.

High ethanol productivities using small Ca-alginate beads of immobilized cells of Zymomonas mobilis

1981 ◽  
Vol 3 (11) ◽  
pp. 613-618 ◽  
Author(s):  
Argyrios Margaritis ◽  
Pramod K. Bajpai ◽  
J. Blair Wallace
Keyword(s):  
Zymomonas Mobilis ◽  
Immobilized Cells ◽  
Alginate Beads ◽  
High Ethanol ◽  
Ca Alginate

scholarly journals Influence of Lactose Concentration in Bioethanol Production from Cheese Whey

2017 ◽  
Vol 39 (5) ◽  
pp. 533
Author(s):  
Cleidiane Samara Murari ◽  
Débora Cristina Moraes Niz da Silva ◽  
Bruna Lima da Silva ◽  
Vanildo Luiz Del Bianchi
Keyword(s):  
Alcoholic Fermentation ◽  
Cheese Whey ◽  
Ethanol Yield ◽  
Oxygen Demand ◽  
Bioethanol Production ◽  
Organic Substances ◽  
Promising Alternative ◽  
Renewable Source ◽  
Initial Concentration ◽  
Lactose Concentration

The present study aimed the utilization of the cheese whey as substrate for ethanol production by Kluyveromyces marxianus.  Was studied the effect of the initial concentration of cheese whey (M1 57,6 g L-1; M2 45,6 g L-1; M3 32,5 g L-1 e M4 18,8 g L-1) on the alcoholic fermentation. After sterilization, the medium were incubated at 30ºC for 48 hours, performing analysis of lactose, proteins, ethanol, cell growth and chemical oxygen demand. According to the results, the medium M1 (the highest concentration) showed a higher production and productivity of ethanol 16.9 g L-1 and 1.26 g L.h-1, respectively, and also obtained the highest production and productivity of cell of 5.8 g L-1 and 0.40 g L.h-1, respectively. However, in terms of ethanol yield, the most satisfactory result was obtained with the M3 medium with 82.30% in 12 hours of fermentation. The organic substances content has been reduced in relation to COD in the medium M4 in 82.28%, representing a promising alternative for valorization of cheese whey as an effective alternative to obtain a renewable source of biofuel.

scholarly journals Catalytic Production of Jet Fuels from Biomass

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 802 ◽  
Author(s):  
Manuel Antonio Díaz-Pérez ◽  
Juan Carlos Serrano-Ruiz
Keyword(s):  
Molecular Weight ◽  
Global Warming ◽  
Natural Gas ◽  
Heterogeneous Catalysts ◽  
Fossil Fuels ◽  
Fossil Fuel ◽  
Liquid Hydrocarbon ◽  
Jet Fuels ◽  
Renewable Source ◽  
The World

Concerns about depleting fossil fuels and global warming effects are pushing our society to search for new renewable sources of energy with the potential to substitute coal, natural gas, and petroleum. In this sense, biomass, the only renewable source of carbon available on Earth, is the perfect replacement for petroleum in producing renewable fuels. The aviation sector is responsible for a significant fraction of greenhouse gas emissions, and two billion barrels of petroleum are being consumed annually to produce the jet fuels required to transport people and goods around the world. Governments are pushing directives to replace fossil fuel-derived jet fuels with those derived from biomass. The present mini review is aimed to summarize the main technologies available today for converting biomass into liquid hydrocarbon fuels with a molecular weight and structure suitable for being used as aviation fuels. Particular emphasis will be placed on those routes involving heterogeneous catalysts.

Comparison of Bacterial and Yeast Ethanol Fermentation Yield from Rice Straw

2011 ◽  
Vol 347-353 ◽  
pp. 2541-2544
Author(s):  
Benjarat Laobussararak ◽  
Warawut Chulalaksananukul ◽  
Orathai Chavalparit
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Enzymatic Hydrolysis ◽  
Rice Straw ◽  
Zymomonas Mobilis ◽  
Ethanol Yield ◽  
Sugar Content ◽  
Alkali Pretreatment ◽  
Yeast Saccharomyces Cerevisiae ◽  
Pretreatment Condition ◽  
Theoretical Yield

This study was to investigate the fermentation of rice straw using various microorganisms, i.e., the bacterium Zymomonas mobilis, a distillery yeast Saccharomyces cerevisiae and a co-culture of Zymomonas mobilis and Saccharomyces cerevisiae. Rice straw was pretreated with alkaline and followed by enzymatic hydrolysis using cellulase before fermentation by the bacterium and a distillery yeast. Results show that alkali pretreatment is appropriate for rice straw since this pretreatment condition can produce the maximum cellulose of 88.96% and reducing sugar content of 9.18 g/l. Furthermore, the ethanol yield after enzymatic hydrolysis (expressed as % theoretical yield) was 15.94-19.73% for the bacterium, 20.48-35.70% for yeast and 21.56-29.89% for co-culture. Therefore, the distillery yeast was a suitable microorganism for ethanol production from rice straw.

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