Bioethanol Production from Concentrated Ripe Pear Fruit Waste Juice Using Sorghum as an Additional Fermentable Sugar

Lignocellulosic substances such as agricultural wastes are attractive feed stocks for bioethanol production. Indica IR.64 rice straw is one of abundant agricultural wastes in Indonesia and could be used to bioethanol production. It has several characteristics such as high content of cellulose and hemicelluloses that can be readily hydrolyzed into fermentable sugars. A simple process (the direct saccharification and fermentation process) to produce ethanol from rice straw was developed in order to establish an efficient bioethanol production. In this work, no harsh pre-treatment steps were applied and also use a simple one-vat reactor without the risk of losing liberated carbohydrate. The first step in using rice straw for bioethanol production is size reduction through milling and sieving process prior to enzymatic hydrolysis. Direct saccharification and fermentation (DSF) of Indica IR.64 rice straw was examined and compared with two type of control (systems devoid of yeast and enzyme). The experiment were carried out under anaerobic condition, where the cellulase crude enzyme and cellulosic substrates (rice straw) produced glucose from the cellulose and Saccharomyces cerevisiae directly assimilated the glucose to bioethanol. The faster rate of bioethanol production during DSF by S accharomyces cerevisiae was obtained within the first 12h. The maximum ethanol concentration, ethanol yield, and theoretical ethanol yield of untreated rice straw were 0.25 g/L, 10 and 14.88%, respectively. Nevertheless, the direct saccharification and fermentation shows the potential for lower cost and higher efficiency for bioethanol production.

With the rising demands for renewable fuels, there is growing interest in utilizing abundant and sustainable non-edible biomass as a feedstock for bioethanol production. Macroalgal biomass contains a high content of carbohydrates in the form of special polysaccharides like alginate, agar, and carrageenan that can be converted to fermentable sugars. In addition, using seagrass as a feedstock for bioethanol production can provide a sustainable and renewable energy source while addressing environmental concerns. It is a resource-rich plant that offers several advantages for bioethanol production, including its high cellulose content, rapid growth rates, and abundance in coastal regions. To reduce sugar content and support efficient microbial fermentation, co-fermentation of macroalgae with seagrass (marine biomass) can provide complementary sugars and nutrients to improve process yields and economics. This review comprehensively covers the current status and future potential of fermenting macroalgal biomass and seagrass, as well as possible combinations for maximizing bioethanol production from non-edible energy crops. An overview is provided on the biochemical composition of macroalgae and seagrass, pretreatment methods, hydrolysis, and fermentation processes. Key technical challenges and strategies to achieve balanced co-substrate fermentation are discussed. The feasibility of consolidated bioprocessing to directly convert mixed feedstocks to ethanol is also evaluated. Based on current research, macroalgae-seagrass co-fermentation shows good potential to improve the bioethanol yields, lower the cost, and enable more optimal utilization of diverse marine biomass resources compared to individual substrates.

Aim. Main aim of this research was the evaluation of theoretical bioethanol yield (per ha) from hexaploid giant miscanthus (Miscanthus х giganteus) and further comparison with conventional triploid form as well as with other bioethanol crops. Methods. Several mathematic functions were determined that describe yearly yield dynamics and equations, which were used in calculations of theoretical bioethanol yield. Results. The theoretical bioethanol yield was evaluated for different hexaploid miscanthus lines. The most productive in terms of ethanol yield were lines 108 and 202, from which potential bioethanol yield was found to be higher than in control line (6451 L/ha) by 10.7 % and 14.2% respectively and can reach 7144 L/ha and 7684 L/ha. Conclusions. It was determined that the most productive lines of polyploid miscanthus (lines 108 and 202) are able to compete with other plant cellulosic feedstocks for second-generation bioethanol production in Ukraine. However, these lines show bioethanol productivity than sweet sorghum, in the case when sweet sorghum is processed for obtainment of both first- and second-generation bioethanol. Keywords: bioenergy crops, biofuels, giant miscanthus, Miscanthus, polyploidy, second-generation bioethanol.

The development of non-dairy fermented juices based on fruits and vegetables is favoured by multiple factors, such as greater consumer awareness of health-related properties of fermented foods, a growing number of lactose intolerance cases, and an increasing popularity of food trends like veganism. Therefore, the scientific community’s interest in the design of lactic acid fermented juices and determining their functional features has increased over the past 10 years. The aim of this study was to review the latest reports concerning the influence of lactic acid bacteria on fermented fruit and vegetable juices, using the SALSA (search, appraisal, synthesis, analysis) systematic literature review framework. This approach allowed for gathering 42 most essential publications, which have undergone detailed analysis. Most studies focused on the functional properties of fruit juices (e.g. cashew apple or pomegranate juice), while vegetable (e.g. tomato or carrot juice) and mixed juices (e.g. apple–carrot juice) were studied in a lesser extent. Recent studies indicate a great commercialization potential of non-dairy fermented juices due to their adequate probiotic delivery; strong antimicrobial and antioxidant properties; high content of vitamins, total phenols, amino acids, exopolysaccharides; unique sensory characteristics as well as their anticancer, antidiabetic, and anti-inflammatory activities. All these advantages are strictly associated with the use of particular bacterial strain (mostly strains of L. plantarum) and plant matrices.

Bioethanol plays a crucial role in Indonesia’s development, given its wide application across various industries, such as food, chemicals, pharmaceuticals, cosmetics, and alternative fuel. The diversity of feedstocks available for bioethanol production ranging from food crops, lignocellulose, food waste, to microalgae reflects positive advancements in production technologies. This study examines several aspects of bioethanol, including its historical development, the specifications applied in Indonesia, feedstock types, and the current demand for bioethanol in the country. The primary aim of this research is to identify the most promising feedstocks for large-scale bioethanol production in Indonesia. The methodology employed is a narrative literature review, drawing from 37 journal articles, 8 thesis documents, 7 web articles, and 2 publications from Badan Statistik Nasional. The analysis identifies the best feedstocks for bioethanol production in Indonesia, highlighting macroalgae, microalgae, and food waste as having significant potential to support the sustainable growth of the bioethanol industry in the future.

Bioethanol production using carbohydrate-rich microalgae biomass as feedstock

BackgroundRice straw is one of the abundant lignocellulosic biomass with potential as a feedstock for bioethanol production. To produce ethanol from the biomass biologically, enzymatic hydrolysis is necessary that can effectively degrade rice straw into fermentable sugars such as glucose and xylose. Many researches utilized many kinds of commercial cellulase reagents on the hydrolysis of cellulose. Since these have different enzyme activities, enzyme reagents suitable for each biomass must be selected. In this study, three appropriate cellulase reagents were selected by multivariate analysis technique and then optimized by design of experiments method for efficient hydrolysis of alkali-pretreated rice straw. Moreover, an ethanol production from the treated straw was performed by simultaneous saccharification and fermentation (SSF) with the optimized enzyme cocktail and xylose-fermenting fungus of Mucor circinelloides.ResultsPretreatment by alkali solution of rice straw resulted in the increase of fermentable sugar content from 56.3 to 80.0%. The desirable commercial enzyme reagents for saccharification of the straw were determined as a combination of “Cellulase Onozuka 3S”, “Cellulase T Amano 4”, and “Pectinase G Amano” by a multivariate analysis based on various cellulolytic activities of each reagent. The optimum mixing ratio was calculated by response surface method based on design of experiment method. The optimized cocktail successfully achieved 75.3 g/L in production of the total fermentable sugar by hydrolysis of alkali-treated rice straw that agreed with the hydrolysis efficiency of 94.1%. SSF of 100 g/L treated rice straw with the optimal cocktail and M. circinelloides under aerobic condition resulted in 30.5 g/L ethanol concentration for 36 h.ConclusionThe construction of cellulase cocktail by the proposed statistical method enabled efficient hydrolysis of alkali-treated rice straw. SSF process combining the optimized cocktail and a xylose-fermenting fungus could be expected as a promising system for ethanol production from various lignocellulosic biomasses.

Effects of metabolite changes during lacto-fermentation on the biological activity and consumer acceptability for dragon fruit juice

Bioethanol production from bamboo (Dendrocalamus sp.) process waste

Cellulose II as bioethanol feedstock and its advantages over native cellulose

Triticale and sorghum as feedstock for bioethanol production via consolidated bioprocessing

Resource use efficiency of rice production upon single cropping and ratooning agro-systems in terms of bioethanol feedstock production

Global warming, urban pollution and depletion of fossil fuels have been driving for looking alternative energy sources, especially those derived from biomass. Production of bio-ethanol from lingocellulosic materials is providing a long-term sustainable for fuel supply. <i>Striga hermonthica</i>, a parasitic weed plant is one of cheap source of lignocellosic materials to serve as feedstock for bio-ethanol production. With the objective of evaluating its potential for bio-ethanol production, different concentrations (10g, 20g, 30g, and 40g) of <i>Striga hermonthica</i> treated with 1% diluted sulfuric acid and untreated were subjected to batch fermentation for 16 days with 0.5% and 1% yeast inoculums. Percent of bio-ethanol production, cell density and reducing sugars were measured at an interval of 4 days starting from the beginning. Results of these study showed that ethanol production was observed starting from the 4^th day of fermentation, but its amount peaked 28.05% from 40g substrate with 1% inoculum on the 12^th day of fermentation, and declined on 16^th days (20.24%) from the same substrate concentration. Pretreated substrate showed significantly higher ethanol production than untreated. In agreement with ethanol production, cell density and reduction in reducing sugar were observed in the same pattern. Compared ethanol production between untreated substrates yield of 21.31%, and treated substrates yielded of 28.05%. Overall, this study showed that acid pre-treatment, inoculum concentration, fermentation period and substrate concentration affect the amount of bio-ethanol production. Finally, it can be concluded that the production of bioethanol from <i>Striga hermonthica</i> is economically and environmentally viable. Extensive use of this harmful weed for bioethanol production may have twofold advantages, viz. reduction of its negative impact on crop productivity and generation of bio-ethanol.

Genetic modification of cereal plants: A strategy to enhance bioethanol yields from agricultural waste

Fermented fruit juices are considered functional beverages because they contain bioactive compounds derived from plant materials and produced by the microorganisms involved in fermentation. The composition of these beverages can vary depending on the strain used. This study aimed to determine the effect of different microorganisms conducting lactic acid fermentation on the chemical composition and bioactive component content of naturally cloudy fermented pear and plum juices. The process used Lactiplantibacillus plantarum K7 bacteria, which were isolated during sauerkraut fermentation, as well as Lachancea thermotolerans PYCC6375 and Lachancea fermentati PYCC5883 yeast cultures, which have poor ethanol fermentation capabilities. The pH, acidity, sugars (HPLC), free amino nitrogen, selected organic acids (HPLC), color (CIELAB), polyphenols (HPLC), volatiles (GC-MS), aroma-active volatiles (GC-MS-O), and sensory characteristics were analyzed. The fermented juices obtained were rich in organic acids (of plant and microbial origin), polyphenols, and had a reduced sugar content (with polyols replacing glucose and fructose), as well as a low alcohol content (<0.2%). At the same time, all three microorganisms significantly enhanced the fruity aroma of the juices. Lachancea yeasts proved to be a viable alternative to lactic acid bacteria for producing fermented juices and were significantly better suited to fermenting plum juices. The highest polyphenol content and highest consumer preference rating were obtained with plum juices fermented with L. fermentati yeast.