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Design and Engineering Parameters of Bioreactors for Production of Bioethanol
Published in Ayerim Y. Hernández Almanza, Nagamani Balagurusamy, Héctor Ruiz Leza, Cristóbal N. Aguilar, Bioethanol, 2023
David Francisco Lafuente-Rincón, Inty Omar Hernández-De Lira, Héctor Hernández-Escoto, María Alejandra Sánchez-Muñoz, Héctor Hugo Molina Correa, Cristian Emanuel Gámez-Alvarado, Perla Araceli Meléndez-Hernández, Javier Ulises Hernández-Beltrán
On the other hand, enzymatic hydrolysis can be influenced by the concentrations of substrate and final product, the enzymatic activity, and the reaction conditions [33]. Recently, one of the main strategies to reach a high concentration of reducing sugars is by using a high concentration of substrate, however, this aspect affects directly to the mixing of the reaction and simultaneously to the process conditions such as pH and temperature cannot be constant along the time, even the adjustment of these parameters is difficult [34]. Thus, there is no possible to ensure the best performance considering that the mixing trouble begin from 7% w v–1 of substrate concentration [14]. Therefore, the research activities in enzymatic hydrolysis have been focused to reach high solids concentration of substrate between 20–40% w v–1 using engineering strategies as fed-batch or semi-continuous configurations for the reaction instead of a batch one and to deeply study the relationship of the several parameters which affect the enzymatic hydrolysis process to increase the profitability of fermentable sugars production [35].
Sustainable Production of Biofuels—A Green Spark: Technology, Economics, and Environmental Issues
Published in V. Sivasubramanian, Bioprocess Engineering for a Green Environment, 2018
Rajarathinam Ravikumar, Muthuvelu Kirupa Sankar, Manickam Nareshkumar, Moorthy Ranjithkumar
Though enzymatic hydrolysis has advantages over chemical hydrolysis methods, key concerns should be considered with enzymatic hydrolysis of the biomass. Enzymatic hydrolysis can be affected by two different factors: enzyme-related factors and substrate-related factors (Binod et al., 2011). The enzyme-related factors are incubation temperature, the effect of surfactants, and inhibitors. These factors critically impact reduction of enzymatic activity on cellulose and hemicellulose sugars. The substrate-related factors are cellulose crystallinity, degree of polymerization, accessible surface area of cellulose and hemicellulose, structural organization of carbohydrate polymers (Fan et al., 1981), and substrate concentration (Penner and Liaw, 1994) during enzymatic hydrolysis. Both these types of factors significantly influence the enzymatic hydrolysis process by affecting enzymatic activity, which leads to the lower reducing sugar yield. Frequent monitoring of these factors is necessary for the hydrolysis process; otherwise, optimization of these factors is advisable prior to the enzymatic hydrolysis process.
Bioethanol Production from Lignocellulosic Biomass: An Overview of Pretreatment, Hydrolysis, and Fermentation
Published in Prasenjit Mondal, Ajay K. Dalai, Sustainable Utilization of Natural Resources, 2017
Zabed Hossain, J. N. Sahu, Akter Suely
A further research efforts should be kept continue on the following aspects as attempts to overcome these challenges: Implementation of the process integration on pilot, demonstration, and commercial scales incorporating pretreatment, enzymatic hydrolysis, and fermentation (Hahn-Hägerdal et al. 2006).Improvement in enzymatic hydrolysis through developing potential enzyme systems, which will require low production costs and have potential for working in high solid load (Galbe and Zacchi 2002; Hahn-Hägerdal et al. 2006).Screening for naturally occurring microorganisms having the ability to ferment all kinds of sugars (polymers, oligosaccharides, and monosaccharides), efficient fermentation, and tolerance to inhibitors (Gírio et al. 2010).Development of promising recombinant microorganisms, strain improvement, and successful exploitation of these microorganisms into commercial ethanol production.
Efficient enzymatic hydrolysis of Protogracillin for clean preparation of Prosapogenin A by response surface methodology optimization
Published in Green Chemistry Letters and Reviews, 2022
Haicheng Xie, Le Zhang, Shunli Jing, Jinwei Zhou, Qing Wu, Yaya Yang, Yufei Chen, Chengyu Yang, Guohua Xia, Yuping Shen, Huan Yang
The new strategy of this study was validated by comparison with other conventional methods of obtaining Prosapogenin A, and the results are summarized in Table 4. Acid hydrolysis of TSS can only obtain aglycone diosgenin but not Prosapogenin A (5). By chromatographic separation, only 45 mg of Prosapogenin A was isolated from 10 kg of dry rhizomes of DZW (yield = 0.00045%) (16) and 3.4 mg from 400 g of dry rhizomes of Dioscorea villosa (yield = 0.00085%) (17). In addition, 82 mg Prosapogenin A was obtained from 15 g TSS by fermentation, and the final yield was about 0.0226% (18). In this study, the abundant primary glycoside Protogracillin was enzymatically hydrolyzed to obtain the rare bioactive secondary glycoside Prosapogenin A, the yield was greatly increased to 0.294%, while the product was of high purity, which did not require subsequent complicated purification. Therefore, our results indicate that enzymatic hydrolysis is more efficient and eco-friendly than conventional methods.
Novel freeze drying based technologies for production and development of healthy snacks and meal replacement products with special nutrition and function: A review
Published in Drying Technology, 2022
Kai Chen, Min Zhang, Bhesh Bhandari, Jincai Sun, Jingjing Chen
According to the previous studies, enzymatic hydrolysis and fermentation were the most common biological pretreatments prior to FD with the main aims of improving the taste, flavor, and nutritional value of products or obtaining desired ingredients. Technically, enzymatic hydrolysis relies on the hydrolytic actions of enzymes such as protease, amylase, and cellulase, to degrade the macromolecular substances to small molecules,[30] while fermentation mainly depends on yeasts and probiotics like acetic acid and lactic acid bacteria.[31] In a previous study, a mixture of Lactobacillus acidophilus, bifidobacterium, Lactobacillus plantarum, Bacillus bulgaricus, and yeast was used as leavening agent to ferment rice paste containing millet, whole wheat flour, fresh egg, and milk powder before FD. After the integration process consisting of fermentation and FD, a meal replacement rice paste high in nutritional value and good in health-promoting performance was obtained.[32] Besides, alfalfa dietary fibers obtained from alfalfa by enzymatic hydrolysis was also mixed with green tea powder, lotus leaf powder, shrimp meat powder, peanut powder, and soybean powder to get a meal replacement powder. Due to the optimized preparation method consisting of enzymatic hydrolysis and FD, this meal replacement powder was reported to have good color and smell.[33]
Biogas potential determination and production optimisation through optimal substrate ratio feeding in co-digestion of water hyacinth, municipal solid waste and cow dung
Published in Biofuels, 2022
Tawanda Kunatsa, Lijun Zhang, Xiaohua Xia
Complex biomass materials are broken down into simple monomers with the aid of enzymes in the hydrolysis stage. Starch hydrolysis is catalysed by a combination of amylase enzymes while cellulose hydrolysis is catalysed by cellulases such as exo-glucanases, endo-glucanases and cellobiases. Enzymatic hydrolysis of proteins is aided by protease and peptidases collectively known as proteinases. Lipid hydrolysis is facilitated by triglyceride lipases [41,42]. In acidogenesis, the monomers produced in hydrolysis (amino acids, simple sugars and fatty acids) are fermented and anaerobically oxidised by acidogenic bacteria. Intermediate products such as volatile fatty acids are anaerobically oxidised by acetogenic bacteria in the acetogenesis stage. In methanogenesis, methane is produced from the products of acidogenesis and acetogenesis with the aid of methanogenic bacteria. These biochemical reactions are interrelated and depend on each other as depicted in Table 1.