Bioethanol is mainly produced from fermentation of sugar containing materials such as molasses, sugarcane (cane juice or cane syrup), serial crops, sugar beet and sweet sorghum. Recent biotechnological developments have led to an increased focus on utilization of lignocellulosic biomass as a resource for the production of liquid fuels and other chemicals. Multiple biomass substrates have been identified to hold a great potential due to their high content of cellulose and hemicellulose, combined with an abundant annual production (Wiselogel et al. 1996). The main challenge in the conversion of biomass into ethanol is the pretreatment step. Due to the structure of the ligocellulosic complex, the pretreatment is required for its degradation, the removal of lignin, the partial or total hydrolysis of the hemicellulose, and the decrease in the fraction of crystalline cellulose related to the amorphous cellulose, the most suitable form for the subsequent hydrolysis step. In this step, the cellulose undergoes enzymatic hydrolysis in order to obtain glucose that is transformed into ethanol by process microorganisms. Eventually, the sugars released during the hydrolysis of hemicellulose can be converted into ethanol as well. Industrially, the pretreated material is mainly thought to be hydrolyzed and fermented in two different steps: separate hydrolysis and fermentation (SHF); or in one single step: simultaneous saccharification and fermentation (SSF). A few microbial species such as Neurospora, Monilia, Paecilomyces and Fusarium sp. have been reported to hold the ability to ferment cellulose directly to ethanol (Singh et al. 1992). Consequently, the involved technologies are more complex leading to higher ethanol production costs compared to cane, beet or corn. However, the fact that
urgent need for increased security in the world’s energy sector and most importantly Africa’s. Some fuels which can be gotten from solid biomass include ethanol, methanol, biodiesel, and hydrogen and methane also known as gaseous fuels. Research and development in biofuel production is made up of three basic areas: production of the fuels, uses and applications of the fuels, and distribution of infrastructure . Primarily biofuels are used to power vehicles, but can also be used to fuel engines or fuel cells for generation of electricity. Some of such fuels include biodiesel, bioethanol, and many other liquid fuels derived from lignocellulosic biomass . Ethanol, butanol and propanol are classified as alcohols that can be produced biologically by microorganism and enzymatic action on starches, sugars and cellulose; this biological process is called fermentation. Of all the biofuels, the one which is most acceptable and readily produced worldwide is ethanol fuel, particularly in Brazil and USA . Fermentation of sugars derived from wheat, sugar beets, corn, cane, bagasse and molasses leads to the production of alcohols. The stages involved in ethanol production are, enzyme digestion (to release sugars stored in starch crops), fermentation of the sugars, distillation and lastly drying. Cellulosic ethanol production involves the use of inedible or non- food crops, waste products and does not cause food shortage for humans and animals alike . Bagasse which is the dry, fibrous reminant after the juice has been extracted from the crushed sugarcane, has recently become a source of bioethanol. The recent research and development is focused on the potential of energy crops with lignocellulosic residues for bioethanolproduction . Conversion of this feedstock into biofuel is an important choice for the study of sources of alternative energy and hence, reducing polluting gases which are contained in fossil fuels. Furthermore, the use of biofuels has important economic and social effects. For instance, as pointed out by Kuchler and Linner,  that the diversification of fuel research would stabilize America’s economy by bringing money and jobs back into the economy.
Raw materials used for bioethanolproductionBioethanolproduction is mainly based on the fermentation of products containing mono- saccharides. The theoretical maximum yield of the ethanol productionfrom such sugars is about 0.5 kg/kg. An example of a good raw material for the production of bioethanol is, among oth- ers, molasses, which is a by-product of the sugar production process. It contains about 40–55% su- crose. It comes in the form of a dark-brown alka- line syrup. Depending on the raw material from which it is made, cane and beet molasses, among others, are distinguished. Taking into account the fact that about 0.31 tonne of molasses is produced from 1 tonne of sugar, in 2018/2019 it was possi- ble to produce about 650 000 kg in Poland, which in turn corresponds to about 195 000 m 3 of bioeth-
We consider the combined use of strains tolerant to or- ganic acids, including acetate and lactate, to be suitable for industrial ethanol productionfrommolasses, because or- ganic acids are safe and inexpensive reagents for inhibiting bacterial growth. By making antibiotics unnecessary, our proposed ethanol production system offers several advan- tages. One of the most important is that the waste gener- ated during antibiotic-free bioethanolproduction can be used safely as forage or fertilizer. In the future, inexpensive methods for preparing organic acids, such as recycling, need to be investigated for industrial application. However, ER HAA1-OP clearly has the ability to produce ethanol in molasses medium containing 0.5% acetate.
ISSUE 4 JULY – AUGUST ISSN: 2581-7876 Abstract – Bioethanol fuel is mainly produced by the sugar fermentation process. Ethanol or ethyl alcohol (C2H5OH) is a clear, colourless biodegradable liquid and is less toxic and causes less environmental pollution. It is a high-octane fuel and has replaced lead as octane enhancer in petrol. Mango peel waste collection and disposal creates a range of environmental problems in our environment. A considerable amount of waste ends up in open dumps or drainage system, threatening both surface water and ground water quality and causing flooding, which provides a breeding ground for diseases-carrying pests. Open air burning of waste, spontaneous combustion in landfills and incinerating plants that lack effective treatment for gas emissions are causing air pollution. Waste disposal has become one of the major concerns for our city juice house, Ambo, Addis Ababa etc. The objective of this study Production of bioethanolfrom mango peels using Saccharomyces cerevisiae and to determine the properties of bioethanol. The mango peels were crushed in to 3-5 cm sizes for easy drying and grinding. Sample drying was carried out in oven (600C for 72hr) to obtain easily crushable material. After drying, each of the samples was milled separately. The maximum particle sizes of the ground mixed sample were 2 mm. Laboratory experiments of 16 run were conducted to produce bio-ethanol mango peel wastes. The mill samples of 100gm sample were taken and mixed, then passed through steam pretreatment, hydrolysis, and fermentation and distillation process respectively to produce bio-ethanol. The present study was done with objectives to produce bioethanolfrom mango peel which solves the waste disposal problem. In a country like Ethiopia, it is very hard to do proper disposal of wastes and thus generation of infectious diseases is rapid here. So, using these wastes not only provide a use of those wastes but also help to be beneficial economically. We recommended that government or other investor’s to recover this very valuable product as well as to contribute to the country in reducing the highly rising quantity of wastes. To conclude the recommendation, there is an urgent need for proper collection, documentation and assessment of fruit peel yields of mango well as their seasonal variation in our country.
The aim is to study the characterize fig molasses to enable marketing and to standardize the production in order to increase the product efficiency. To assess the physicochemical properties, water activities, pH ash content for the 70 degrees brix molasses for both molasses produced with and without the addition of the citric acid (Kuchi, Gupta, & Tamang, 2014) (Cevrimli, Kariptas, & Ciftci, 2009) of the three cultivars are identified in this study. In addition, the most important indicator for the efficiency of production, namely the Kg figs to Kg fig molasses produced is calculated and accordingly it can be used in future feasibility studies concerning this product. Furthermore, to assess the overall acceptability of the fig molasses produced a sensory evaluation was conducted.
These seven yeasts were further used for identification studies. Colonies formed by yeast isolates were round, smooth and cream, white to whitish cream colored. Colony size ranged from 3.8 x 16.0 to 6.0 x 13.0 as shown in Table-2. Individual cells were oval, elongate, ovoid to spherical when young and hexagonal when aged. Cells showed oval, globose, spherical and ellipsoidal budding. S3, TA, C2, K2 and MTCC 170 strains were sensitive to cycloheximide which was indicated by formation of a clear inhibitory zone
enhancement of gas production through processes such as co- digestion or blending of organic wastes (Parawira et al., 2004; Uzodinma et al., 2007; Mshandete and Parawira, 2009), reduction of size of organic wastes, addition of chemicals, etc. (Ofoefule and Uzodinma, 2008). Co-production of bioethanol and biogas would allow all the components of both plant biomass and animal manure to be used. An earlier study on the pure wastes alone frombioethanol process which constituted the waste from starch processing and that from fermentation wort showed that their biogas production profile needed optimization, even though the biogas production of the variant from starch processing was better in terms of cumulative and average yield, onset of gas flammability and microbial load (Ofoefule et al., 2012). The study was therefore undertaken to; determine the effect of co-digesting the pure wastes frombioethanol process with some animal and plant wastes on the biogas production. The wastes constituted: (i) process wastes from starch extraction (ET) and (ii) fermentation worth (ETP). They were studied alone (ET-A) and (ETP-A) and in combination with some animal wastes (cow dung (CD) and swine dung (SD) and plant wastes (field grass (FG) and glycerol (GL). The combinations were done in a 1:1 ratio thus giving ET–CD, ET–SD, ETP–FG, and ETP– FG-GL. The biogas production capabilities of the wastes were in terms of (i) biogas yields (ii) onset of gas flammability and (iii) effective retention time.
Flask cultivations of EMY-01, EMY-68, EMY-69, and EMY-70 were conducted with 80 g/L of three differ- ent carbon sources (fructose, glucose, and sucrose) for 10 h to confirm the effect of cra deletion on sugar utili- zation (Fig. 2; Additional file 2). The removal of scrR, a transcriptional repressor of the scr regulon for sucrose catabolism, caused considerable enhancement of sucrose utilization, but did not affect the utilization of fructose and glucose, in accordance with a previous report . The disruption of cra did not affect the consumption of glucose, while significantly increasing fructose utiliza- tion by 32.9 and 39.0% in EMY-69 and EMY-70, respec- tively (Fig. 2a, b). The improvement in fructose utilization increased 2,3-butanediol production by 32.5 and 35.1%, respectively. Interestingly, the removal of cra repressed the utilization of sucrose significantly. The sucrose con- sumption of EMY-69 and EMY-70 was reduced by 58.2 and 24.6%, respectively, compared to that of their parent strains (Fig. 2c).
Second generation bioethanolproduction is an encouraging solution to solve the energy and environmental crisis. The flexibility it offers, which is seen from the various possible routes of the production and various existing production technologies, endorses more development to obtain the better efficient production, feasible cost production and lesser national emission. Moreover, second generation bioethanol is beneficial from the perspective of industry since agricultural wastes practically have zero value for the industry as well as for the food, which helps to decrease the feedstock cost in the total production cost. We are running out of fuel and we must face it sooner or later so we should start now and think of other energy sources specially those which are renewable and cheap. Government must display the strong level of support, willingness and consistency for the program. The policies should aid the R&D of production of bioethanol, as well as trying to invite the shareholders to put their shares into production of renewable source. Bioethanol as a fuel is promising that more attention must be drawn to it, if this is done, success and efficiency will be guaranteed. That project not only solve an energy problem but also solve one of the greatest problems in some countries like Egypt as burning of rice straw accounts for 42% of air pollution in Egypt. If the project could be implemented in
Barley spent grain (BSG) which remains after the mashing and lautoring process was obtained from the Heineken brewery industry, Addis Ababa, Ethiopia. This Sample transported to Addis Ababa institute technology (AAiT), School of chemical and bioengineering laboratory and it was packed in polyethylene bags. The Samples used for this study were prepared in the biochemical engineering laboratory. 180 g of BSG was washed in order to remove unwanted matter and dried at 70 ºC for 24hrs until 10.8 % of moisture content remains. Followed by dried sample was milled and sieved into appropriate particle size which is less than 0.5 mm. The milled sample was sterilized at 120 ºC for 16 min and stored at less than 4 º C refrigerators.
A. cellulolyticus C-1 and S. cerevisiae were co-cultured in a single reactor. Cellulase producing-medium supplemented with 2.5 g/l of yeast extract was used for productions of both cellulase and ethanol. Cellulase production was achieved by A. cellulolyticus C-1 using Solka-Floc (SF) as a cellulase-inducing substrate. Subsequently, ethanol was produced with addition of both 10%(v/v) of S. cerevisiae inoculum and SF at the culture time of 60 h. Dissolved oxygen levels were adjusted at higher than 20% during cellulase producing phase and at lower than 10% during ethanol producing phase. Cellulase activity remained 8 – 12 FPU/ml throughout the one-pot process. When 50 – 300 g SF/l was used in 500 ml Erlenmeyer flask scale, the ethanol concentration and yield based on initial SF were as 8.7 – 46.3 g/l and 0.15 – 0.18 (g ethanol/g SF), respectively. In 3-l fermentor with 50 – 300 g SF/l, the ethanol concentration and yield were 9.5 – 35.1 g/l with their yields of 0.12 – 0.19 (g/g) respectively, demonstrating that the one-pot bioethanolproduction is a reproducible process in a scale-up bioconversion of cellulose to ethanol. Conclusion: A. cellulolyticus cells produce cellulase using SF. Subsequently, the produced cellulase saccharifies the SF, and then liberated reducing sugars are converted to ethanol by S. cerevisiae. These reactions were carried out in the one-pot process with two different microorganisms in a single reactor, which does require neither an addition of extraneous cellulase nor any pretreatment of cellulose. Collectively, the one-pot bioethanolproduction process with two different microorganisms could be an alternative strategy for a practical bioethanolproduction using biomass.
The vast majority of research into producing a CBP candidate has however followed the recombinant strategy of heterologous expression of cellulase genes in natural ethanologens. In order to achieve complete hydrolysis of cellulose, at least one copy of each of the three classes of cellulase genes must be expressed in the host cell. The most commonly used host for heterologous expres- sion of cellulase genes for CBP is the baker’s yeast, S. cerevisiae (Fujita et al., 2004; Den Haan et al., 2007a; Tsai et al., 2010; Wen et al., 2010; Yamada et al., 2011; Fan et al., 2012; Nakatani et al., 2013), although the three classes of cellulase genes have also been expressed in other Saccharomyces species such as S. pastorianus (Fitzpatrick et al., 2014) as well as in bacterial species such as Escherichia coli (Ryu and Karim, 2011) (Table 1). Since the native promoters of cellulase genes are repressed by glucose, strategies of using inducible or constitutive promoters of the host have been pursued. Inducible promoters such as S. cerevisiae GAL1 or CUP1 promoters are extremely efficient but require the addition of an inducer, galactose or copper, respectively. The requirement for such inducers can be expensive and often incompatible with fer- mentation conditions for ethanol production. Moreover, the GAL promoters are repressed in the presence of glucose and there- fore not suited for industrial CBP. Partow et al. (2010) tested the performance of several constitutive and inducible promoters for heterologous gene expression in S. cerevisiae. Their findings indi- cated that the constitutive promoters TEF1 and PGK1 produced the most constant expression profiles. These promoters have been used for heterologous cellulase gene expression in S. cerevisiae (Den Haan et al., 2007b; Yamada et al., 2011), however no more than a 2-fold difference in expression was observed in genes driven by these two promoters, with TEF1 generating the highest levels (Fitzpatrick et al., 2014).
Leather industry is one of the oldest cottage industries in India. Although tanning has been in existence for a long time, the problem of environment pollution received serious consideration only in recent years. The leather industry produces a significant amount of chromium bearing hazardous waste. This work has two aspects one is the management of such huge generation and another is the production of energy in terms of Bioethanol. On production of biofuel in the form of ethanol from tannery solid wastes was made using selective anaerobic microorganism isolated form rumen. Chromium is present at the chemical composition of solid wastes and the protein concentration was at higher percentage (79%) followed by fat (7.57%). The screened microorganism was subjected for zymogram and the different bands were found on SDS-PAGE and on compared with standard collagenase bands, it was confirmed the production of collagenase enzyme from anaerobic microorganism. In the Anaerobic digestion of formic, acetic and propionic acid, production of ethanol was observed only with the acetic acid and with not formic and propionic acid. Volatile fatty acids production determines the rate of ethanol production; it was found that after 48 hours of incubation, more than 75 % of substrate reduced. The maximum yield of ethanol was observed after 48 hours of incubation. It was found that maximum ethanol was produced with digestion of 0.30gram of substrate and concentration of ethanol is 3.53 g/lit. This work can solve the problems of leather waste management as well as bring the fulfillment of energy requirement in terms of Bioethanol.
Ionic liquids (ILs) are ionic, salt-like materials that are liquid below 100°C. ILs have ambient temperature and possess many attractive properties such as negligible volatility, non-flammability, high thermal stability, and controllable hydrophobicity, (Kojiro Shimojo et al., 2006). ILs has solvent properties and is miscible with organic solvents and water. Their non-flammability and negligible vapour pressure make them not readily lost to the environment. In recent years, ILs has been extensively studied as an alternative to organic solvent. They have been widely examined as extracting phases in liquid-liquid extraction systems and show good extraction performance and separation ability for metal ions when compare with organic solvents, (Kojiro Shimojo et al., 2006). Dai et al., (1999) studied the extraction of alkaline and alkaline metal in ILs and achieved high extraction efficiency compared to that of ordinary organic solvent. The extraction behaviour of strontium into imidazolium cation based ILs was also examined by Dai et al. (1999), and obtained a high distribution coefficient compared to that of ordinary organic solvent. From these studies, it can be deduced that apart from being environmentally benign, ILs also show high extraction performance compared to conventional organic solvents.
farming, no genetically altered organisms, enzymes or chemicals produced by genetically altered organisms are used in this process set up. By steeping and germinating the grain, natural enzymes (amylases) are produced, enough to hydrolyze the starch material in the grain which, in turn, facilitates ethanol production. This method was first examined at the laboratory in a small scale (100g), and based on promising results (not yet published) the process model was built. What justifies the usage of starch material for ethanol production is the significant amount of grains on the farms which very often cannot be used either for human or animal consumption (bad quality, rotting, etc.). It is hard to estimate their amount, as it differs from year to year, but what remains constant is the fact that their use in ethanol production would be a good alternative to discharging them. In the future the lignocellulosic biomass should be primary source for on- farm bioethanol, using grain as the only additional carbon source. However, at the moment, the 2 nd generation bioethanol technologies do not seem to be suitable for small scale production, due to their high cost of production and high energy usage, especially in organic farming as they require high pressure, temperature and chemical additives.
Among the all transportation fuel, the importance of ethanol is a clean and safe transportation fuel which has increased with the anticipated shortage of fossil fuel reserves and create less The continuous depletion of the fossil fuel reserves and consequent hike in their price has stimulated an extensive evaluation of alternative technologies to find out different substrates to meet the global energy demand (Cazetta Ethanol can be readily produced from agriculture based renewable materials like sugarcane juice, molasses,
Currently most commercial cellulases are produced from Trichoderma reesei ,  usually used to describe a mixture of cellulolytic enzymes action is required for effective breakdown of substrate to its monomeric units. The action of cellulases involves the concerted action of (i) endoglucanases (endo-1, 4- β -glucanases, EGs) can hydrolyze internal bonds preferably in cellulose amorphous regions releasing new terminal ends, which randomly attacks the internal, β1,4-linkages (ii) cellobiohydrolase, (exo-1, 4 β --glucanases, CBHs) act on the existing or endoglucanase generated chain ends (iii) β 3-glucosidase, which hydrolyzes cellobiose to glucose.
NCYC 3312 gave only a slightly higher ethanol yield than NCYC 2826. Under these conditions, the ethanol con- centration achieved from sorghum was 45.8 g/L (5.81% v/v; Fig. 5a) which is in the order of the level required for industrial distillation (≥50 g/L [21, 22]). Use of high torque reactors, slightly higher substrate concentra- tions and optimisation of SSF conditions to increase the yield (which was in the region of 65–70% for Sorghum) might be expected to achieve this. Nevertheless, vari- ability in the levels of cellulose in the different samples of sorghum-derived mushroom compost will need to be addressed. This and other properties of the spent com- post may be related to the mushroom yield. Restricting the time of Pleurotus cultivation can minimise the loss of cellulose . Thus, taking the compost after 2 flushes may be better than after three, although this would be likely to have a negative impact on the economics of mushroom production.
Water and energy both drive and constrain human development, and water is a major input to bioethanolproduction that must be considered . The water footprint (WF), introduced by Hoekstra , is indicator could measure water use in relation to production or consumption and tool for calculating. The research on WF has been deepened in order to solve the problem of water shortage in China [22,23]. WF computations are used to provide detailed process-based evaluations of water requirements of various food and non-food feedstock for bioethanol [24,25]. These evaluations are helpful for selecting the most water-efficient crops and the best regions in which to produce bioenergy [26,27] and more comprehensively analyze all links associated with the consumption of water. It is important to consider the different regions’ level of development, as well as the impact of bioethanolproduction upon competition for water; this article focuses on Chinese mainland, which consists of 31 provinces, autonomous regions and municipal cities, and assesses water consumption in bioethanolproductionfrom crop residues in China.