Improve Bioethanol Production Research Articles

Harnessing artificial intelligence for enhanced bioethanol productions: a cutting-edge approach towards sustainable energy solution

Abstract The adoption of biofuels as an energy source has experienced a substantial increase, exceeding the consumption of fossil fuels. The shift can be ascribed to the availability of renewable resources for energy production and the ecological advantages linked to their utilisation. Nevertheless, due to its intricate characteristics, the process of producing ethanol fuel from biomass poses difficulties in terms of administration, enhancement, and forecasting future results. To tackle these difficulties, it is crucial to utilise modelling techniques like artificial intelligence (AI) to create, oversee, and improve bioethanol production procedures. Artificial Neural Networks (ANN) is a prominent AI technique that offers significant advantages for modelling bioethanol production systems’ pretreatment, fermentation, and conversion stages. They are highly flexible and accurate, making them particularly well-suited. This study thoroughly examines several artificial intelligence techniques used in bioethanol production, specifically focusing on research published in the past ten years. The analysis emphasises the importance of using AI methods to address the complexities of bioethanol production and shows their role in enhancing efficiency and sustainability in the biofuel industry.

Role of microbial laccases in valorization of lignocellulosic biomass to bioethanol.

The persistent expansion in world energy and synthetic compounds requires the improvement of renewable alternatives in contrast to non-sustainable energy wellsprings. Lignocellulose is an encouraging feedstock to be utilized in biorefineries for its conversion into value-added products, including biomaterials, biofuels and several bio-based synthetic compounds. Aside from all categories, biofuel, particularly bioethanol is the most substantial fuel derived from lignocellulosic biomass and can be obtained through microbial fermentation. Generally, extreme settings are required for lignocellulosic pretreatment which results in the formation of inhibitors during biomassdegradation. Occasionally, lignin polymers also act as inhibitors and are left untreated during the pretreatment, engendering inefficient hydrolysis. The valorization of lignocellulosic biomass by laccases can be viewed as a fundamental trend for improving bioethanol production. However, one of the main obstacles for developing commercially viable biofuel industries is the cost of enzymes, which can be resolved by utilizing laccases derived from microbial sources. Microbial laccases have been considered an exceptionally integral asset for delignification and detoxification of pretreated LCB, which amplify the resultant fermentation and saccharification processes. This review provides a summary of microbial laccases and their role in valorizing LCB to bioethanol, compelling enthralling applications in bio-refining industries all across the globe.

Short-term adaptation as a tool to improve bioethanol production using grass press-juice as fermentation medium

Grass raw materials collected from grasslands cover more than 30% of Europe’s agricultural area. They are considered very attractive for the production of different biochemicals and biofuels due to their high availability and renewability. In this study, a perennial ryegrass (Lolium perenne) was exploited for second-generation bioethanol production. Grass press–cake and grass press-juice were separated using mechanical pretreatment, and the obtained juice was used as a fermentation medium. In this work, Saccharomyces cerevisiae was utilized for bioethanol production using the grass press-juice as the sole fermentation medium. The yeast was able to release about 11 g/L of ethanol in 72 h, with a total production yield of 0.38 ± 0.2 gEthanol/gsugars. It was assessed to improve the fermentation ability of Saccharomyces cerevisiae by using the short-term adaptation. For this purpose, the yeast was initially propagated in increasing the concentration of press-juice. Then, the yeast cells were re-cultivated in 100%(v/v) fresh juice to verify if it had improved the fermentation efficiency. The fructose conversion increased from 79 to 90%, and the ethanol titers reached 18 g/L resulting in a final yield of 0.50 ± 0.06 gEthanol/gsugars with a volumetric productivity of 0.44 ± 0.00 g/Lh. The overall results proved that short-term adaptation was successfully used to improve bioethanol production with S. cerevisiae using grass press-juice as fermentation medium.Key points• Mechanical pretreatment of grass raw materials• Production of bioethanol using grass press-juice as fermentation medium• Short-term adaptation as a tool to improve the bioethanol production

Bioethanol production from sugarcane molasses by co-fermentation of Saccharomyces cerevisiae isolate TA2 and Wickerhamomyces anomalus isolate HCJ2F-19

PurposeCo-culturing is a widely used method to improve bioethanol production from biomass enriched in fermentable sugars. This study aims to produce bioethanol from sugarcane molasses by simultaneous co-fermentation of S. cerevisiae isolate TA2 and W. anomalus isolate HCJ2F-19.MethodsResponse surface methodology (RSM) based on the central composite design (CCD) was employed to optimize fermentation conditions, including mixing rate (110–150 rpm), temperature (25–35 °C), molasses concentration (25–35 obrix), and incubation time (36–72 h). The ethanol concentration was analyzed using HPLC equipped with a UV detector.ResultsThe monocultureS. cerevisiae isolate TA2 produced 17.2 g.L−1 of ethanol, 0.33 g.g−1 of ethanol yield, and 0.36 g.L−1.h−1 of productivity compared to W. anomalus isolate HCJ2F that produced 14.5 g.L−1, 0.30 g.g−1 and 0.28 g.L−1.h−1 ethanol, ethanol yield, and productivity under laboratory conditions, respectively. In comparison to single cultures of S. cerevisiae TA2 and W. anomalus HCJ2F, the co-fermentation using both isolates showed an increased ethanol yield of 29% and 53% compared to the single species fermentations, respectively. The results showed that the growth of W. anomalus HCJ2F-19 and S. cerevisiae TA2 was not influenced by each other during the co-fermentation process. The one variable at a time optimization (OVAT) analysis resulted in an ethanol concentration of 26.5 g.L−1 with a specific yield and productivity of 0.46 g.g−1, 0.55 g.L−1.h−1, respectively, at pH 5.5, 25 obrix, 48 h, 150 rpm, 30 °C, 60:40 inoculum ratio, and 10% overall inoculum size. The maximum ethanol concentration of 35.5 g.L−1 was obtained by co-fermentation using the RSM-CCD tool at 30 obrix, 30 °C, 54 h, and 130 rpm.ConclusionThe results suggested that the co-fermentation of S. cerevisiae isolate TA2 and W. anomalus isolate HCJ2F improves bioethanol production from sugar cane molasses under optimum fermentation conditions.

Detoxification of fermentation inhibitors using a waste biomass-based adsorbent of AEPA250 to enhance bioethanol production: The adsorption analysis and microbial mechanism

Environmental pollution and energy scarcity have promoted the development of renewable alternative energy of rice straw-based bioethanol. However, the production of main fermentation inhibitors from the pretreatment of rice straw raw material reduces the bioethanol yield. In order to improve bioethanol production, a waste biomass-based adsorbent (AEPA250) was used to adsorb three main inhibitors of ferulic acid, vanillin, and furfural from the rice straw hydrolysate in this study. The adsorption percentages were calculated using the high-performance liquid chromatography method. The results showed that the adsorption percentages of three inhibitors were all above 70% in 10 min, demonstrating the efficient detoxification of AEPA250 on rice straw hydrolysate. The adsorption contributions related to the attribute features of three inhibitors and AEPA250 were evaluated for the first time. The density functional theory calculations and AEPA250 characterizations were used to obtain these attribute parameters. Analysis of the correlation heat map between adsorption efficiencies and attribute features of AEPA250 (or fermentation inhibitors) indicated that AEPA250 possessed the lower activation energy (Ea) and pre-exponential factor (A) when it was prepared, as well as fermentation inhibitors had the higher ionization constant (pKa) and lower electrophilicity index (ω), resulting in the enhancement of bioethanol production. The contribution of pKa was greater than A followed by Ea and ω for adsorption process. Meanwhile, the key metabolic pathways involved in central carbon metabolism were analyzed for AEPA250 detoxification using proteomics method. The results indicated that the up-regulation of SDH3, ACO1, CIT2 and MLS1 (or down-regulation of SCT1) genes contributed to inhibitors detoxification using AEPA250, which effectively provided more nicotinamide adenine dinucleotide (NADH) for the reduction of these inhibitors. This study explores the detoxification mechanisms at the molecular level for boosting bioethanol production in the future, which lays the foundation for the development of efficient adsorbents and resistant engineering strains.

From Saccharomyces cerevisiae to Ethanol: Unlocking the Power of Evolutionary Engineering in Metabolic Engineering Applications.

Increased human population and the rapid decline of fossil fuels resulted in a global tendency to look for alternative fuel sources. Environmental concerns about fossil fuel combustion led to a sharp move towards renewable and environmentally friendly biofuels. Ethanol has been the primary fossil fuel alternative due to its low carbon emission rates, high octane content and comparatively facile microbial production processes. In parallel to the increased use of bioethanol in various fields such as transportation, heating and power generation, improvements in ethanol production processes turned out to be a global hot topic. Ethanol is by far the leading yeast output amongst a broad spectrum of bio-based industries. Thus, as a well-known platform microorganism and native ethanol producer, baker's yeast Saccharomyces cerevisiae has been the primary subject of interest for both academic and industrial perspectives in terms of enhanced ethanol production processes. Metabolic engineering strategies have been primarily adopted for direct manipulation of genes of interest responsible in mainstreams of ethanol metabolism. To overcome limitations of rational metabolic engineering, an alternative bottom-up strategy called inverse metabolic engineering has been widely used. In this context, evolutionary engineering, also known as adaptive laboratory evolution (ALE), which is based on random mutagenesis and systematic selection, is a powerful strategy to improve bioethanol production of S. cerevisiae. In this review, we focus on key examples of metabolic and evolutionary engineering for improved first- and second-generation S. cerevisiae bioethanol production processes. We delve into the current state of the field and show that metabolic and evolutionary engineering strategies are intertwined and many metabolically engineered strains for bioethanol production can be further improved by powerful evolutionary engineering strategies. We also discuss potential future directions that involve recent advancements in directed genome evolution, including CRISPR-Cas9 technology.

Elucidation and engineering mitochondrial respiratory-related genes for improving bioethanol production at high temperature in Saccharomyces cerevisiae

Industrial manufacturing of bioproducts, especially bioethanol, can benefit from high-temperature fermentation, which requires the use of thermotolerant yeast strains. Mitochondrial activity in yeast is closely related to its overall metabolism. However, the mitochondrial respiratory changes in response to adaptive thermotolerance are still poorly understood and have been rarely utilized for developing thermotolerant yeast cell factories. Here, adaptive evolution and transcriptional sequencing, as well as whole-genome-level gene knockout, were used to obtain a thermotolerant strain of Saccharomyces cerevisiae. Furthermore, thermotolerance and bioethanol production efficiency of the engineered strain were examined. Physiological evaluation showed the boosted fermentation capacity and suppressed mitochondrial respiratory activity in the thermotolerant strain. The improved fermentation produced an increased supply of adenosine triphosphate required for more active energy-consuming pathways. Transcriptome analysis revealed significant changes in the expression of the genes involved in the mitochondrial respiratory chain. Evaluation of mitochondria-associated gene knockout confirmed that ADK1, DOC1, or MET7 were the key factors for the adaptive evolution of thermotolerance in the engineered yeast strain. Intriguingly, overexpression of DOC1 with TEF1 promoter regulation led to a 10.1% increase in ethanol production at 42 °C. The relationships between thermotolerance, mitochondrial activity, and respiration were explored, and a thermotolerant yeast strain was developed by altering the expression of mitochondrial respiration-related genes. This study provides a better understanding on the physiological mechanism of adaptive evolution of thermotolerance in yeast.

Development of yeast aerobic granules for long-term continuous bioethanol production from rice straw hydrolysate

For the first time application of aerobic granulation technology has been demonstrated for bioethanol production. A reactor was fabricated for ethanol production from rice straw hydrolysate (RSH) using Saccharomyces cerevisiae aerobic granules. The yeast granules were developed within 4–6 days by alternate aerobic mixing phase and settling phase without airflow of 8 h and 4 h, respectively. These yeast granules were found to produce ethanol (34.42 g/L) from pure glucose (80 g/L). A column filter was designed using activated charcoal, silica, cotton, and concrete aggregate to eliminate toxic impurities from RSH. Compared to unfiltered RSH, the filtered one was found to be more effective in ethanol production. A maximum of 16.18 g/L ethanol was produced from filtered RSH containing 10 g/L reducing sugar supplemented with pure glucose (40 g/L). It was possible to continuously run the process for more than 60 days. This study for the first time demonstrates continuous bioethanol production for an extended period by repeated use of yeast in the form of novel aerobic granules. This new concept has the potential to improve bioethanol production efficiencies of existing biorefineries.

Improved bioethanol production from oil palm empty fruit bunch using different fermentation strategies

Improved bioethanol production from oil palm empty fruit bunch using different fermentation strategies

Statistical screening of process variables for improving bioethanol production using alkali-pretreated of some environmental wastes

Statistical screening of process variables for improving bioethanol production using alkali-pretreated of some environmental wastes

Improvement of bioethanol production from waste chestnut shells via evaluation of mass balance-based pretreatment and glucose recovery process

Chestnut shells (CSs), an organic waste generated from food processing, have the potential to be useful feedstock for biorefinery. In this study, to improve the availability of bioresource, KOH pretreatment of CSs was statistically optimized by response surface methodology. Optimal conditions based on the model of biomass to glucose conversion (BtGC) were derived with a CSs loading of 92.7 g/L for 2.5 h at 38.6 °C. In the predictions and experiments, BtGC was 15.3% and 15.7%, respectively, about 2.5-fold improvement compared to the control group (6.3%). In addition, to achieve maximum enzymatic digestibility, effective enzyme loading was investigated. Finally, CSs hydrolysate was utilized as a medium for Saccharomyces cerevisiae K35 and had no inhibitory effect during fermentation. In conclusion, bioethanol production was estimated to be 150 g according to the mass balance based on 1,000 g CSs. This research provides a useful direction for the development of a sustainable society through the valorization of food waste as a resource for biofuel production. • Chestnut Shells (CSs), food processing residue, can be usefully applied as a resource for biorefinery. • The goal of maximizing CSs to glucose conversion (BtGC) was successfully achieved. • The CS pretreatment was performed at a relatively low temperature (38.6 °C). • BtGC was improved 4.7-fold by pretreatment optimization and saccharification profiling. • The bioethanol yield was estimated to be 150 g/kg-CS under the designed processes.

Lignocellulosic biomass for bioethanol: Insight into the advanced pretreatment and fermentation approaches

The global energy demand and need for sustainable sources are expected to rise in the coming years. The second-generation bioethanol production from lignocellulosic biomass (LB) can sustain the energy demand. Thus, this review comprehensively discussed the suitable feedstock selection and different pretreatment progress (including mechanical/thermal, biological, chemical, and physical-chemical) for LB in recent years. The effect of engineered and immobilized microbial strains on biomass conversion to bioethanol is also elaborated. The sugarcane bagasse , switchgrass , cheery wood, and corn cobs (>40 % cellulose content) are considered to be potential and promising LB for bioethanol generation. The application of pretreatments (such as extrusion, steam explosion combined with mild acids, mild thermo-alkaline, green liquor, and surfactants combined with a steam explosion) increased sugar conversion and bioethanol production. The use of genetically engineered yeast along with microbial immobilization offered a full utilization of pentoses and hexoses that enhanced the bioethanol yield. Bioethanol production is comparatively effective at a laboratory scale. However, extensive research is still required to develop a cost-effective process and complete biomass utilization. • Lignocellulosic feedstocks are a potential source for bioethanol production. • Pretreatment efficiency depends on the structural composition of the feedstocks. • Ammonia pretreatment can remove up to 75 %–85 % lignin. • Integrated pretreatments and hydrolysis can improve bioethanol production. • Yeast immobilization is a suitable approach to facilitate bioethanol productivity.

Statistical optimization of bioethanol production from giant reed hydrolysate by Candida tropicalis using Taguchi design

The economic production of bioethanol as a sustainable liquid fuel is particularly needed and attractive. Giant reed as a low-cost and renewable biomass can be utilized as a sustainable feedstock for bioethanol development. The current research focuses on optimizing the fermentation parameters to increase ethanol concentration while lowering production costs. In this work, the giant reed was hydrolyzed thermochemically using HCl; cellulose and hemicellulose fractions were maximally converted at optimized hydrolysis conditions (5% HCl, 30 min, and 120 °C), resulting in a high sugar concentration (≈ 55 g/L), which were fermented by Candida tropicalis Y-26 for bioethanol production (≈ 15 g/L). Taguchi design was used to optimize the fermentation parameters (temperatures, pH, incubation period, and nitrogen sources). Under optimum fermentation conditions (25 °C; 24 h.; pH 5.5; and ammonium nitrate as a nitrogen source), the ethanol concentration at flask level accomplished ≈ 21 g/L, while its scale-up to bioreactor level contributed ≈ 25 g/L (equivalent to 250 kg ethanol/ton biomass) with ≈ 67% increase than the fermentation under unoptimized conditions. Overall, these findings proved that optimizing the fermentation parameters by Taguchi design and scaling up at a bioreactor could improve bioethanol production from giant reed biomass.

The characterisation of Wickerhamomyces anomalus M15, a highly tolerant yeast for bioethanol production using seaweed derived medium.

Advanced generation biofuels have potential for replacing fossil fuels as society moves forward into a net-zero carbon future. Marine biomass is a promising source of fermentable sugars for fermentative bioethanol production; however the medium derived from seaweed hydrolysis contains various inhibitors, such as salts that affected ethanol fermentation efficiency. In this study the stress tolerance of a marine yeast, Wickerhamomyces anomalus M15 was characterised. Specific growth rate analysis results showed that Wickerhamomyces anomalus M15 could tolerate up to 600 g/L glucose, 150 g/L xylose and 250 g/L ethanol, respectively. Using simulated concentrated seaweed hydrolysates, W. anomalus M15’s bioethanol production potential using macroalgae derived feedstocks was assessed, in which 5.8, 45.0, and 19.9 g/L ethanol was produced from brown (Laminaria digitata), green (Ulva linza) and red seaweed (Porphyra umbilicalis) based media. The fermentation of actual Ulva spp. hydrolysate harvested from United Kingdom shores resulted in a relatively low ethanol concentration (15.5 g/L) due to challenges that arose from concentrating the seaweed hydrolysate. However, fed-batch fermentation using simulated concentrated green seaweed hydrolysate achieved a concentration of 73 g/L ethanol in fermentations using both seawater and reverse osmosis water. Further fermentations conducted with an adaptive strain W. anomalus M15-500A showed improved bioethanol production of 92.7 g/L ethanol from 200 g/L glucose and reduced lag time from 93 h to 24 h in fermentation with an initial glucose concentration of 500 g/L. The results indicated that strains W. anomalus M15 and W. anomalus M15-500A have great potential for industrial bioethanol production using marine biomass derived feedstocks. It also suggested that if a concentrated high sugar content seaweed hydrolysate could be obtained, the bioethanol concentration could achieve 90 g/L or above, exceeding the minimum industrial production threshold.

Understanding HMF inhibition on yeast growth coupled with ethanol production for the improvement of bio-based industrial processes

Inhibitory compounds generated from biomass hydrolysis affect the production of biofuels. HMF is a furan derivative inhibitor and influences the ethanol yield by inhibiting enzymes such as alcohol dehydrogenase, aldehyde dehydrogenase and glycolysis. The most striking effect of HMF on the organisms is that it interferes with the microbial growth and is considered as the most potent inhibitor in bioethanol production. In this study, HMF inhibition within yeast cells is investigated by both computational (COBRA) and experimental approaches. The active subsystems in the medium with and without HMF and the coupling types of the reactions are determined to get an insight on how to improve bioethanol production by strain engineering techniques. While extracellular transport subsystem is prominent in term of flexibility, post transcriptional regulation is outstanding among transcriptional to metabolic regulation types. The strategies to increase biomass and ethanol simultaneously with gene/reaction deletion methods are discussed, and ethanol production can be increased by 17% up to 33.35 mmol gDW−1hr−1 with several reaction deletions. The genome scale metabolic model and the complementary experiment given here shed light on the biofuel management in the bio-based industry for future.

The ability of Pichia kudriavzevii to tolerate multiple stresses makes it promising for developing improved bioethanol production processes.

Thermotolerant ethanol fermenting yeasts have been extensively used in industrial bioethanol production. However, little is known about yeast physiology under stress during bioethanol processing. This study investigated the physiological characteristics of the thermotolerant yeast Pichia kudriavzevii, strains NUNS-4, NUNS-5 and NUNS-6, under the multiple stresses of heat, ethanol and sodium chloride. Results showed that NUNS-4, NUNS-5 and NUNS-6 displayed higher growth rates under each stress condition than the reference strain, Saccharomyces cerevisiae TISTR5606. Maximum specific growth rates under stresses of heat (45°C), 15% v/v ethanol and 1·0 M sodium chloride were 0·23 ± 0·04 (NUNS-4), 0·11 ± 0·01 (NUNS-5) and 0·15 ± 0·01 h-1 (NUNS-5), respectively. Morphological features of all yeast studied changed distinctly with the production of granules and vacuoles when exposed to ethanol, and cells were elongated under increased sodium chloride concentration. This study suggests that the three P. kudriavzevii strains are potential candidates to use in industrial-scale fermentation due to a high specific growth rate under multiple stress conditions. Multiple stress-tolerant P. kudriavzevii NUNS strains have received much attention not only for improving large-scale fuel ethanol production, but also for utilizing these strains in other biotechnological industries.

Improvement of bioethanol production using a new fermentation system: The process analysis and micro-mechanisms study

Rice straw based bioethanol is a clean alternative energy source to alleviate the energy crisis and greenhouse gases emission. However, the efficient alkali pretreatment of rice straw for bioethanol production will generate several fermentation inhibitors, such as ferulic acid, which could inhibit bioethanol fermentation. Therefore, an adsorbent called Air Environment-Prepared Adsorbent at 250 ℃ (AEPA250) was prepared using the enzymatically hydrolyzed residue of rice straw to detoxify ferulic acid in this study for enhancing the subsequent bioethanol production. Analysis of the mass balance showed that ferulic acid detoxification by AEPA250 had a high removal efficiency of 94.393% with a low glucose and xylose loss of 2.532% and 8.219%, respectively. A higher 277.551 mg/L bioethanol concentration and 76.005% glucose consumption rate in the SSBP system were obtained compared to non-detoxified sample. Furthermore, proteomics analysis indicated that certain metabolic pathways of TCA cycle and ribosome pathway as well as various coded proteins of ACO1, MRP2, RPL24B, MRPL33, RPL32, RPL39, RPS17B, RPS19A, RPS26A and ATP5 contributed to ferulic acid detoxification in the SSBP system. The findings of this study may help develop efficient pretreatment methods, detoxification strategies and engineering yeast strains for improving bioethanol production in the future.

Saccharomyces cerevisiae and newly isolated Candida boidinii co-fermentation of industrial tea waste for improved bioethanol production

ABSTRACT Although bioethanol is a suitable alternative to fossil-based fuels, limited technologies or lack of microorganisms with a broad substrate spectrum are serious bottlenecks for lignocellulosic ethanol production. In this context, the current study aimed to optimize bioethanol production from industrial tea waste by applying co-fermentation strategy for the first time. For this purpose, newly isolated xylose fermenter Candida boidinii and Saccharomyces cerevisiae produced 12.1 g/L and 14.1 g/L bioethanol, respectively, when the yeasts were cultivated alone in 20% (w/v) dilute acid pretreated and enzymatically hydrolyzed industrial tea waste. Bioethanol production increased to 21.9 g/L, and 70% improvement was achieved when the co-fermentation strategy was applied under the same conditions. This study shows that co-fermentation of industrial tea waste is an economically viable choice for value-added bioethanol production.

Environmental comparison of banana waste valorisation strategies under a biorefinery approach

Banana wastes can be valorised in bioethanol due to its high content in cellulose (more than 30% of total on a dry basis) and hemicelluloses (25% of total). Large amount of these wastes is generated during the banana cultivation and harvesting stage. This study proposes the use of, beside conventional acid sulphuric, different organic acids (tartaric, oxalic and citric) during acid pretreatment step, to suppress the unwanted compounds formation and improve bioethanol production. Instead, bioethanol production generates a solid waste flow that is managed in an anaerobic digestion plant, obtaining biogas, to be converted into energy, and digestate, considered as a potential biofertiliser. Life cycle assessment methodology is used to analyse the environmental profiles of four valorisation scenarios to produce bioethanol from banana peel waste. According to the results, reported per kilogram of bioethanol, the citric acid-based scenario has the worst environmental profile due to the background processes involved in the acid production (around 55% for most impact categories). Conversely, the oxalic acid-based scenario has the best environmental profile, with a decrease of around 20% and 35%, depending on the impact category, compared to the citric acid scenario. The energy requirements production (mostly thermal energy) is the main hotspot in numerous subsystems regardless of the scenario (ranging from 30% to 50% depending on the impact category). Therefore, the use of renewable energy sources to satisfy energy requirements combined with an energy optimisation of the valorisation strategies through the reuse of some internal steams, is proposed as improvement activities.

Biotechnological tools to improve ethanol production from plant biomass

Increasing concerns for security of the fossil fuel supply emphasizes the need to complement fossil fuel-based energy sources with renewable energy sources. Plant biomass represents an abundant renewable resource for the production of bioenergy and biomaterials. This review summarizes the last advancements in the use of biotechnological tools to improve bioethanol production from plant biomass through genetic engineering the starch content and composition and lignocellulosic matter characteristics, and increasing the capacity of plants to produce harvestable yield and ameliorating the negative abiotic stresses on plants so as to increase yield.