Enzymatic saccharification of agar waste from Gracilaria verrucosa and Gelidium latifolium for bioethanol production

2017 ◽  
Vol 29 (6) ◽  
pp. 3201-3209 ◽  
Author(s):  
Maria Dyah Nur Meinita ◽  
Bintang Marhaeni ◽  
Yong-Ki Hong ◽  
Gwi-Taek Jeong
Keyword(s):  
Enzymatic Saccharification ◽  
Gracilaria Verrucosa ◽  
Bioethanol Production ◽  
Gelidium Latifolium

scholarly journals Diverse Banana Pseudostems and Rachis Are Distinctive for Edible Carbohydrates and Lignocellulose Saccharification towards High Bioethanol Production under Chemical and Liquid Hot Water Pretreatments

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3870
Author(s):  
Jingyang Li ◽  
Fei Liu ◽  
Hua Yu ◽  
Yuqi Li ◽  
Shiguang Zhou ◽  
...  
Keyword(s):  
Soluble Sugars ◽  
Enzymatic Saccharification ◽  
Hot Water ◽  
Biofuel Production ◽  
Bioenergy Crops ◽  
Bioethanol Production ◽  
Factors Affecting ◽  
Liquid Hot Water ◽  
Biomass Processing ◽  
Banana Crops

Banana is a major fruit crop throughout the world with abundant lignocellulose in the pseudostem and rachis residues for biofuel production. In this study, we collected a total of 11 pseudostems and rachis samples that were originally derived from different genetic types and ecological locations of banana crops and then examined largely varied edible carbohydrates (soluble sugars, starch) and lignocellulose compositions. By performing chemical (H2SO4, NaOH) and liquid hot water (LHW) pretreatments, we also found a remarkable variation in biomass enzymatic saccharification and bioethanol production among all banana samples examined. Consequently, this study identified a desirable banana (Refen1, subgroup Pisang Awak) crop containing large amounts of edible carbohydrates and completely digestible lignocellulose, which could be combined to achieve the highest bioethanol yields of 31–38% (% dry matter), compared with previously reported ones in other bioenergy crops. Chemical analysis further indicated that the cellulose CrI and lignin G-monomer should be two major recalcitrant factors affecting biomass enzymatic saccharification in banana pseudostems and rachis. Therefore, this study not only examined rich edible carbohydrates for food in the banana pseudostems but also detected digestible lignocellulose for bioethanol production in rachis tissue, providing a strategy applicable for genetic breeding and biomass processing in banana crops.

Bioethanol production by enzymatic saccharification ofSalix viminalisvar.giganteabiomass

2014 ◽  
Vol 10 (2) ◽  
pp. 67-72
Author(s):  
Hak-Gon Kim ◽  
Hyun-Jin Song ◽  
Mi-Jin Jeong ◽  
Young-Long Seo ◽  
Jae-Kyung Yang ◽  
...  
Keyword(s):  
Enzymatic Saccharification ◽  
Bioethanol Production

Enzymatic saccharification and liquid state fermentation of hydrothermal pretreated Tunisian Luffa cylindrica (L.) fibers for cellulosic bioethanol production

2017 ◽  
Vol 114 ◽  
pp. 1209-1213 ◽  
Author(s):  
Kaouther Zaafouri ◽  
Manel Ziadi ◽  
Aida ben Hassen-Trabelsi ◽  
Sabrine Mekni ◽  
Balkiss Aïssi ◽  
...  
Keyword(s):  
Liquid State ◽  
Enzymatic Saccharification ◽  
Bioethanol Production ◽  
Luffa Cylindrica

Comparison of bioethanol production from cultivated versus wild Gracilaria verrucosa and Gracilaria gigas

2017 ◽  
Vol 30 (1) ◽  
pp. 143-147 ◽  
Author(s):  
Maria Dyah Nur Meinita ◽  
Bintang Marhaeni ◽  
Diyah Fatimah Oktaviani ◽  
Gwi-Taek Jeong ◽  
Yong-Ki Hong
Keyword(s):  
Gracilaria Verrucosa ◽  
Bioethanol Production

Bioethanol Production from Rice Straw in the MAFF Research Project, Japan

2009 ◽  
Vol 1219 ◽  
Author(s):  
Ken Tokuyasu
Keyword(s):  
Heat Treatment ◽  
Saccharomyces Cerevisiae ◽  
Rice Straw ◽  
Enzymatic Saccharification ◽  
Bioethanol Production ◽  
Chemical Pretreatment ◽  
Simple Method ◽  
Herbaceous Biomass ◽  
Free Glucose ◽  
Simultaneous Saccharification

AbstractRice straw is among the most abundant herbaceous biomass, and regarded as the central feedstock for bioethanol production in Japan. We found that significant amounts of soft carbohydrates (SCs), defined as carbohydrates readily recoverable by mere extraction from the biomass or brief enzymatic saccharification, exist in rice straw in the form of free glucose, free fructose, sucrose, starch, and β-1,3-1,4-glucan. Based on the finding, we proposed a simple method for bioethanol production from rice straw samples with SCs, by a heat treatment for sterilization and starch gelatinization, followed by simultaneous saccharification/fermentation with Saccharomyces cerevisiae. This method would offer an efficient process for bioethanol production without the aid of harsh thermo/chemical pretreatment step.

scholarly journals Evaluation of Alkali-Pretreated Soybean Straw for Lignocellulosic Bioethanol Production

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Seonghun Kim
Keyword(s):  
Sodium Hydroxide ◽  
Enzymatic Saccharification ◽  
Renewable Resource ◽  
Bioethanol Production ◽  
Yield Efficiency ◽  
Lignocellulosic Bioethanol ◽  
Acid Metabolites ◽  
Soybean Straw ◽  
Pretreated Biomass ◽  
Simultaneous Saccharification

Soybean straw is a renewable resource in agricultural residues that can be used for lignocellulosic bioethanol production. To enhance enzymatic digestibility and fermentability, the biomass was prepared with an alkali-thermal pretreatment (sodium hydroxide, 121°C, 60 min). The delignification yield was 34.1~53%, in proportion to the amount of sodium hydroxide, from 0.5 to 3.0 M. The lignin and hemicellulose contents of the pretreated biomass were reduced by the pretreatment process, whereas the proportion of cellulose was increased. Under optimal condition, the pretreated biomass consisted of 74.0±0.1% cellulose, 10.3±0.1% hemicellulose, and 10.1±0.6% lignin. During enzymatic saccharification using Cellic® CTec2 cellulase, 10% (w/v) of pretreated soybean straw was hydrolyzed completely and converted to 67.3±2.1 g/L glucose and 9.4±0.5 g/L xylose with a 90.9% yield efficiency. Simultaneous saccharification and fermentation of the pretreated biomass by Saccharomyces cerevisiae W303-1A produced 30.5±1.2 g/L ethanol in 0.5 L fermented medium containing 10% (w/v) pretreated biomass after 72 h. The ethanol productivity was 0.305 g ethanol/g dry biomass and 0.45 g ethanol/g glucose after fermentation, with a low concentration of organic acid metabolites. Also, 82% of fermentable sugar was used by the yeast for ethanol fermentation. These results show that the combination of alkaline pretreatment and biomass hydrolysate is useful for enhancing bioethanol productivity using delignified soybean straw.

scholarly journals Recent advances in bioethanol production from lignocelluloses: a comprehensive review with a focus on enzyme engineering and designer biocatalysts

2020 ◽  
Vol 7 (4) ◽  
pp. 1267-1295
Author(s):  
Yogita Lugani ◽  
Rohit Rai ◽  
Ashish A. Prabhu ◽  
Poonam Maan ◽  
Meenu Hans ◽  
...  
Keyword(s):  
Enzymatic Saccharification ◽  
Strain Improvement ◽  
Deep Eutectic Solvents ◽  
Enzyme Engineering ◽  
Bioethanol Production ◽  
Green Solvents ◽  
Promising Alternative ◽  
Biofuel Policy ◽  
Recent Advances ◽  
Ethanol Yields

Many countries have their biofuel policy programs in place as part of their overall strategy to achieve sustainable development. Among biofuels, bioethanol as a promising alternative to gasoline is of substantial interest. However, there is limited availability of a sufficient quantity of bioethanol to meet demands due to bottlenecks in the present technologies to convert non-edible feedstocks, including lignocelluloses. This review article presents and critically discusses the recent advances in the pretreatment of lignocellulosic biomass, with a focus on the use of green solvents, including ionic liquids and deep eutectic solvents, followed by enzymatic saccharification using auxiliary proteins for the efficient saccharification of pretreated biomass. Different techniques used in strain improvement strategies to develop hyper-producing deregulated lignocellulolytic strains are also compared and discussed. The advanced techniques employed for fermentation of mixed sugars contained in lignocellulosic hydrolysates for maximizing bioethanol production are summarized with an emphasis on pathway and transporters engineering for xylose assimilation. Further, the integration of different steps is suggested and discussed for efficient biomass utilization and improved ethanol yields and productivity.

scholarly journals Valorisation of bambara and cowpea haulms for bioethanol production

2020 ◽  
Author(s):  
◽  
Somiame Itseme Okuofu
Keyword(s):  
Ethanol Yield ◽  
Promising Result ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Enzymatic Saccharification ◽  
Deep Eutectic Solvents ◽  
Sugar Yield ◽  
Dilute Acid Pretreatment ◽  
Bioethanol Production ◽  
Dilute Acid

Bambara and cowpea are important pulses grown in semi-arid South Africa due to their balanced nutrient profile and drought resilient capacity. The haulm is the lignocellulosic residue obtained after grain harvest and are rich in carbohydrates. However, these haulms are underutilised and under researched. The aim of the study, therefore, was to investigate the potential to valorise bambara haulms (BGH) and cowpea haulms (CH) to bioethanol which is the most promising biofuel with commercial prospects currently. The structural and chemical composition of BGH and CH was elucidated using techniques such as compositional analysis, XRD, FTIR, ICP-AES, and SEM. Results indicated a volatile matter and fixed carbon mass fraction of 77.70% and 13.15% (w/w) in BGH and 76.16% and 16.26% (w/w) in CH respectively. The polysaccharides make up the largest fraction (51%), followed by extractives (> 20%), while the lignin in BGH (12%) and CH (10%) was low. X-ray diffraction pattern showed a higher percentage of amorphous regions in BGH (78%) than CH (56%). CH was then subjected to dilute acid pretreatment (DAP) to enhance biosugar production for bioethanol fermentation. The effects of operational factors for DAP including temperature, time, and acid concentration on sugar yield and inhibitor formation was investigated and optimised using response surface methodology (RSM). The solid recovered after DAP was subjected to prehydrolysis with simultaneous saccharification and fermentation (PSSF). In addition, the pretreatment hydrolysate was detoxified and fermented to ethanol using cocultures of Saccharomyces cerevisiae BY4743 and Scheffersomyces stipitis wild type (PsY633). A total ethanol titre of 15.67 g/L was obtained corresponding to 75% conversion efficiency. On the other hand, BGH was subjected to deep eutectic solvent (DES) pretreatment. Five deep eutectic solvents were prepared and screened for their effectiveness in improving enzymatic sugar yield. This was achieved by pretreating BGH with each DES followed by a 48 h enzymatic saccharification. Choline chloride – lactic acid (ChCl-LA) treatment provided the most promising result and was further optimised by investigating the effect of different temperatures and time on cellulose loss and enzymatic sugar yield. ChCl-LA pretreatment at 100°C for 1 h was observed to be the best condition for maximum sugar recovery. The hydrolysate thus obtained was concentrated and fermented for 72 h with S. cerevisiae BY4743. A maximum ethanol yield of 11.57 g/L was obtained. From the results, it is evident that bambara and cowpea haulm are promising substrates for bioethanol production. Dilute acid hydrolysis was shown to be effective in the pretreatment of CH with over 85% of the theoretical sugar recoverable for conversion to bioethanol. In addition, deep eutectic solvents are effective media for breaking the recalcitrance in BGH to achieve high sugar yield for conversion to bioethanol. However, further studies are required to reduce cellulose loss during pretreatment to improve bioethanol yield.

Improvement of bioethanol production by Saccharomyces cerevisiae through the deletion of GLK1, MIG1 and MIG2 and overexpression of PGM2 using the red seaweed Gracilaria verrucosa

2020 ◽  
Vol 89 ◽  
pp. 134-145 ◽  
Author(s):  
Pailin Sukwong ◽  
In Yung Sunwoo ◽  
Deok Yeol Jeong ◽  
Soo Rin Kim ◽  
Gwi-Taek Jeong ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gracilaria Verrucosa ◽  
Red Seaweed ◽  
Bioethanol Production
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