scholarly journals Comparison of performances of different fungal laccases in delignification and detoxification of alkali-pretreated corncob for bioethanol production

2021 ◽  
Author(s):  
Shenglong Liu ◽  
Huan Liu ◽  
Chen Shen ◽  
Wei Fang ◽  
Yazhong Xiao ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Ethanol Concentration ◽  
Ethanol Productivity ◽  
Phenol Concentration ◽  
Control Treatment ◽  
Bioethanol Production ◽  
Fungal Laccases ◽  
Fermentation Time ◽  
Ph Adjustment ◽  
Fungal Laccase

Abstract The performance of the alkaline fungal laccase PIE5 (pH 8.5) in the delignification and detoxification of alkali-pretreated corncob to produce bioethanol was evaluated and compared with that of the neutral counterpart (rLcc9, 6.5), with the acidic laccase rLacA (4.0) was used as an independent control. Treatment with the three laccases facilitated bioethanol production compared with their respective controls. The lignin contents of alkali-pretreated corncob reduced from 4.06 per cent, 5.06 per cent, and 7.80 per cent to 3.44 per cent, 3.95 per cent, and 5.03 per cent, after PIE5, rLcc9, and rLacA treatment, respectively. However, the performances of the laccases were in the order rLacA > rLcc9 > PIE5 in terms of decreasing total phenol concentration (0.18, 0.36, and 0.67 g/L), boosting ethanol concentration (8.02, 7.51, and 7.31 g/L), and volumetric ethanol productivity (1.34, 0.94, and 0.91 g/L·h), and shortening overall fermentation time. Our results would inform future attempts to improve laccases for ethanol production. Furthermore, based on our data and the fact that additional procedures, such as pH adjustment, are needed during neutral/alkaline fungal laccase treatment, we suggest acidic fungal laccases may be a better choice than neutral/alkaline fungal laccases in bioethanol production.

scholarly journals Evaluating crude whey for bioethanol production using non-Saccharomyces yeast, Kluyveromyces marxianus

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Asmamaw Tesfaw ◽  
Ebru Toksoy Oner ◽  
Fassil Assefa
Keyword(s):  
Ethanol Production ◽  
Ammonium Sulfate ◽  
Yeast Extract ◽  
Food Production ◽  
Ethanol Productivity ◽  
Bioethanol Production ◽  
Ph Adjustment ◽  
Saccharomyces Yeast ◽  
Food Substrate ◽  
High Ethanol

AbstractEthanol production from non-food substrate is strongly recommended to avoid competition with food production. Whey, which is rich in nutrients, is one of the non-food substrate for ethanol production by Kluyveromyces spp. The purpose of this study was to optimize ethanol from different crude (non-deproteinized, non-pH adjusted, and non-diluted) whey using K. marxianus ETP87 which was isolated from traditional yoghurt. The sterilized and non-sterilized whey were employed for K. marxianus ETP87 substrate to evaluate the yeast competition potential with lactic acid and other microflora in whey. The effect of pH and temperature on ethanol productivity from whey was also investigated. Peptone, yeast extract, ammonium sulfate ((NH4)2SO4), and urea were supplemented to whey in order to investigate the requirement of additional nutrient for ethanol optimization. The ethanol obtained from non-sterilized whey was slightly and statistically lower than sterilized whey. The whey storage at 4 °C didn’t guarantee the constant lactose presence at longer preservation time. Significantly high amount of ethanol was attained from whey without pH adjustment (3.9) even if it was lower than pH controlled (5.0) whey. The thermophilic yeast, K. marxianus ETP87, yielded high ethanol between 30 and 35 °C, and the yeast was able to produce high ethanol until 45 °C, and significantly lower ethanol was recorded at 50 °C. The ammonium sulfate and peptone enhanced ethanol productivity, whereas yeast extract and urea depressed the yeast ethanol fermentation capability. The K. marxianus ETP87, the yeast isolated from traditional yoghurt, is capable of producing ethanol from non-sterilized and non-deproteinized substrates.

Bioethanol Production from Pineapple Peel Juice Using Saccharomyces cerevisiae

2014 ◽  
Vol 875-877 ◽  
pp. 242-245
Author(s):  
Jutarut Pornpunyapat ◽  
Wilaiwan Chotigeat ◽  
Pakamas Chetpattananondh
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ethanol Production ◽  
Ethanol Concentration ◽  
Renewable Resource ◽  
Reducing Sugar ◽  
Total Sugar ◽  
Bioethanol Production ◽  
Pineapple Peel ◽  
Initial Ph ◽  
Production Characteristics

Bioethanol is widely used as renewable resource due to its safe to produce and environmentally friendly. However, knowledge on ethanol production from pineapple peel juice (Pattawia spp) is far from sufficient. In this work, pineapple peel juice (initial pH at 5) was fermented at various yeast contents (1, 3 and 5% by wt.) and fermentation times (3, 5 and 7 days) in order to investigate ethanol production characteristics. Yeast, Sacchromyces cerevisiae was grown on pineapple peel juice. The squeezed juice contained 11% of total sugar and 5% of reducing sugar. The results indicated that the optimum ethanol production was yeast contents of 5% by wt. and fermentation times of 5 days which gave the ethanol production of 9.08g/l. The ethanol at a higher yeast content also had a higher ethanol concentration.

scholarly journals Bioethanol Production by Using Detoxified Sugarcane Bagasse Hydrolysate and Adapted Culture of Candida tropicalis

2016 ◽  
Vol 2 (1) ◽  
pp. 1-12
Author(s):  
Inda Setyawati ◽  
Laksmi Ambarsari ◽  
Siti Nur'aeni ◽  
Suryani Suryani ◽  
Puspa Julistia Puspita ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Sugarcane Bagasse ◽  
Ethanol Yield ◽  
Renewable Resource ◽  
Bioethanol Production ◽  
Fermentation Inhibitors ◽  
Renewable Materials ◽  
Promising Alternative ◽  
Fermentation Time ◽  
Sugarcane Bagasse Hydrolysate

Ethanol is considered as the most promising alternative fuel, since it can be produced from a variety of agriculturally-based renewable materials, such as sugarcane bagasse. Lignocellulose as a major component of sugarcane bagasse is considered as an attractive renewable resource for ethanol production due to its great availability and relatively low cost. The major problem of lignocellulose is caused by its need for treatment to be hydrolyzed to simple sugar before being used for bioethanol production. However, pretreatment using acid as hydrolyzing agent creates some inhibitor compounds that reduce ethanol production because these compounds are potential fermentation inhibitors and affect the growth rate of the yeast. Reduction of these by-products requires a conditioning (detoxification and culture starter adaptation). Thus, the aim of this study was to evaluate bioethanol production by fermentation with and without detoxified sugarcane bagasse acid hydrolysate using adapted and non-adapted culture of C. tropicalis. According to this study, the highest ethanol amount was obtained about 0.43 % (v/v) with an ethanol yield of 2.51 % and theoretical yield of 4.92 % by fermentation of sugarcane bagasse hydrolysate with detoxification using the adapted strain of C. tropicalis at 72 hours fermentation time. Furthermore, the addition of 3 % glucose as co-substrate on detoxified-hydrolysate media only achieved the highest ethanol concentration 0.21 % after 24 hours fermentation with the ethanol yield 0.69 % and theoretical ethanol yield 1.35 %, thus it can be concluded that the addition of glucose could not increase the ethanol production.

Screening and Characterization of Ethanol-Producing Yeasts from Sewage Sludge, Soil and Rotten Fruits

2020 ◽  
Vol 14 (2) ◽  
pp. 287-293
Author(s):  
Chunming Wang ◽  
Xiaobing Chen ◽  
Jialang Lao
Keyword(s):  
Sewage Sludge ◽  
Ethanol Production ◽  
Food Waste ◽  
Specific Growth ◽  
Waste Recycling ◽  
Ethanol Productivity ◽  
Fermentation Time ◽  
Oxygen Conditions ◽  
Food Waste Recycling

Food waste recycling attracts people's attention recently. Fiber such as vegetable stem vegetable is main ingredient of food waste. How to use this resource becomes an important topic. In this manuscript, six ethanol-producing yeasts were isolated from sewage sludge, soil and rotten fruits, then examined using PDA medium, TTC screening, and Duchenne tube fermentation experiments. After screeing on D-xylose medium, an ethanol-producing yeast Y9, Saccharomyces cerevisiae, was isolated. Ethanol production over time by strain Y9 indicated that 12 days is the screened strain's optimal fermentation time. The screened strain's specific growth rate is 0.12 h–1, and its ethanol productivity is higher than that of store-bought Angel Yeast or its co-culture, which indicated inhibition existing among the strains. Moreover, the ethanol productivity in shaken samples was higher than that in static samples, indicating that slight oxygen conditions benefited the screened strain's ethanol production. The results may have implications in ethanol production and the treatment of sewage sludge and food waste.

scholarly journals Ethanol Production from Gmelina arborea Wood Wastes by Saccharomyces cerevisiae using Submerged Fermentation

2021 ◽  
Vol 37 (2) ◽  
pp. 144-151
Author(s):  
M.R Adedayo ◽  
A.E Ajiboye ◽  
O.A Yahaya
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Specific Gravity ◽  
Ethanol Production ◽  
Submerged Fermentation ◽  
Ethanol Concentration ◽  
Sugar Content ◽  
Reducing Sugar ◽  
Gmelina Arborea ◽  
Fermentation Time ◽  
Standard Curve

Lignocellulose wastes are the most abundant residues on the surface of the earth. This project studies the possibility of ethanol production from a forestry waste. Wood wastes from Gmelina arborea were treated with dillute sulfuric acid to break down the lignin component. Fermentation for ethanol production was done using baker’s yeast (Saccharomyces cerevisiae ATCC 204508/S288c) for 120 hours using submerged fermentation, and the pH, reducing sugar, specific gravity and lignin content were determined using standard techniques. Ethanol concentration and yield were measured via vinometer and ethanol standard curve techniques. From the results, the highest pH was obtained at 72 hours of the fermentation period. The reducing sugar content and specific gravity decreased over the fermentation time . The acid-pretreated wood wastes gave a maximum ethanol concentration of 3.84 % and a yield of 7.60 ml/g as measured from the vinometer and ethanol standard curve methods at 72 and 96 hours of fermentation, respectively. About 13.6% v/v of ethanol was recovered from the distillation process employed to separate the components of the product generated after fermentation. The observations in this research reveal the possibility of producing ethanol from G. arborea wood wastes and under optimized culture conditions. This could serve as an alternate means of biofuel generation and hence value addition to the wastes. Keywords: Gmelina arborea, Saccharomyces cerevisiae, Ethanol, Submerged fermentation

scholarly journals A microwave-assisted liquefaction as a pretreatment for the bioethanol production by the simultaneous saccharification and fermentation of corn meal

2008 ◽  
Vol 14 (4) ◽  
pp. 231-234 ◽  
Author(s):  
Svetlana Nikolic ◽  
Ljiljana Mojovic ◽  
Marica Rakin ◽  
Dusanka Pejin ◽  
Dragisa Savic
Keyword(s):  
Simultaneous Saccharification And Fermentation ◽  
Ethanol Concentration ◽  
Microwave Treatment ◽  
Ethanol Productivity ◽  
Bioethanol Production ◽  
Corn Meal ◽  
Microwave Assisted ◽  
Batch System ◽  
Ssf Process ◽  
Simultaneous Saccharification

A microwave-assisted liquefaction as a pretreatment for the bioethanol production by the simultaneous saccharification and fermentation (SSF) of corn meal using Saccharomyces cerevisiae var. ellipsoideus yeast in a batch system was studied. An optimal power of microwaves of 80 W and the 5-min duration of the microwave treatment were selected by following the concentration of glucose released from the corn meal suspensions at hidromodul of 1:3 (corn meal to water ratio) in the liquefaction step. The results indicated that the microwave pretreatment could increase the maximum ethanol concentration produced in the SSF process for 13.4 %. Consequently, a significant increase of the ethanol productivity on substrate (YP/S), as well as the volumetric ethanol productivity (P) in this process, could be achieved.

scholarly journals Renewable Sources and their Applications in Biotechnological Processes

2020 ◽  
Vol 9 (2) ◽  
pp. 155-170
Author(s):  
Maria do Socorro Mascarenhas Santos ◽  
Margareth Batistote
Keyword(s):  
Gas Chromatography ◽  
Liquid Medium ◽  
Ethanol Production ◽  
Ethanol Concentration ◽  
Bioethanol Production ◽  
Technological Parameters ◽  
Renewable Sources ◽  
Fermentative Capacity ◽  
Biotechnological Processes ◽  
Metabolites Production

Brazil has edaphoclimatic conditions to produce a diversity of crops with energetic potential. Thus, the study aims to correlate the technological parameters of biomasses suitable for fermentation, quantify metabolites produced by yeast FT-858, as well as assess the yield and fermentative efficiency for bioethanol production. It was performed studies of technological qualities of the biomasses and fermentative capacity test. For metabolites production, the yeast FT-858 was pre-grown in liquid medium (YPD 2%), recovered and inoculated in the substrates, and aliquots were collected for analysis of ethanol concentration by gas chromatography and glycerol accumulation by enzymatic kit of triglycerides. The yield and fermentative efficiency were assessed by consumption of sugar using DNS method, and ethanol density using digital densimeter. According to the results, the yeast presented better performance in saccharine sorghum, which also presented more expressive values of fermentative efficiency and yield. Saccharine sorghum has great bioenergetic potential and can be used as complement to sugarcane to increase ethanol production.

scholarly journals Bioethanol Production from Cellulose-Rich Corncob Residue by the Thermotolerant Saccharomyces cerevisiae TC-5

2021 ◽  
Vol 7 (7) ◽  
pp. 547
Author(s):  
Pinpanit Boonchuay ◽  
Charin Techapun ◽  
Noppol Leksawasdi ◽  
Phisit Seesuriyachan ◽  
Prasert Hanmoungjai ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Elevated Temperatures ◽  
Ethanol Concentration ◽  
Ethanol Productivity ◽  
Solid Loading ◽  
Bioethanol Production ◽  
Fed Batch ◽  
Separate Hydrolysis And Fermentation ◽  
Ssf Process ◽  
Simultaneous Saccharification

This study aimed to select thermotolerant yeast for bioethanol production from cellulose-rich corncob (CRC) residue. An effective yeast strain was identified as Saccharomyces cerevisiae TC-5. Bioethanol production from CRC residue via separate hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF), and prehydrolysis-SSF (pre-SSF) using this strain were examined at 35–42 °C compared with the use of commercial S. cerevisiae. Temperatures up to 40 °C did not affect ethanol production by TC-5. The ethanol concentration obtained via the commercial S. cerevisiae decreased with increasing temperatures. The highest bioethanol concentrations obtained via SHF, SSF, and pre-SSF at 35–40 °C of strain TC-5 were not significantly different (20.13–21.64 g/L). The SSF process, with the highest ethanol productivity (0.291 g/L/h), was chosen to study the effect of solid loading at 40 °C. A CRC level of 12.5% (w/v) via fed-batch SSF resulted in the highest ethanol concentrations of 38.23 g/L. Thereafter, bioethanol production via fed-batch SSF with 12.5% (w/v) CRC was performed in 5-L bioreactor. The maximum ethanol concentration and ethanol productivity values were 31.96 g/L and 0.222 g/L/h, respectively. The thermotolerant S. cerevisiae TC-5 is promising yeast for bioethanol production under elevated temperatures via SSF and the use of second-generation substrates.

scholarly journals Hemicellulosic Bioethanol Production from Fast-Growing Paulownia Biomass

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 173
Author(s):  
Elena Domínguez ◽  
Pablo G. del Río ◽  
Aloia Romaní ◽  
Gil Garrote ◽  
Lucília Domingues
Keyword(s):  
Ethanol Production ◽  
Ethanol Concentration ◽  
Ethanol Yield ◽  
Xylose Reductase ◽  
Energy Crop ◽  
Scheffersomyces Stipitis ◽  
Fractionation Process ◽  
Renewable Source ◽  
Fast Growing ◽  
Engineered Strain

In order to exploit a fast-growing Paulownia hardwood as an energy crop, a xylose-enriched hydrolysate was obtained in this work to increase the ethanol concentration using the hemicellulosic fraction, besides the already widely studied cellulosic fraction. For that, Paulownia elongata x fortunei was submitted to autohydrolysis treatment (210 °C or S0 of 4.08) for the xylan solubilization, mainly as xylooligosaccharides. Afterwards, sequential stages of acid hydrolysis, concentration, and detoxification were evaluated to obtain fermentable sugars. Thus, detoxified and non-detoxified hydrolysates (diluted or not) were fermented for ethanol production using a natural xylose-consuming yeast, Scheffersomyces stipitis CECT 1922, and an industrial Saccharomyces cerevisiae MEC1133 strain, metabolic engineered strain with the xylose reductase/xylitol dehydrogenase pathway. Results from fermentation assays showed that the engineered S. cerevisiae strain produced up to 14.2 g/L of ethanol (corresponding to 0.33 g/g of ethanol yield) using the non-detoxified hydrolysate. Nevertheless, the yeast S. stipitis reached similar values of ethanol, but only in the detoxified hydrolysate. Hence, the fermentation data prove the suitability and robustness of the engineered strain to ferment non-detoxified liquor, and the appropriateness of detoxification of liquor for the use of less robust yeast. In addition, the success of hemicellulose-to-ethanol production obtained in this work shows the Paulownia biomass as a suitable renewable source for ethanol production following a suitable fractionation process within a biorefinery approach.

scholarly journals Single-step ethanol production from raw cassava starch using a combination of raw starch hydrolysis and fermentation, scale-up from 5-L laboratory and 200-L pilot plant to 3000-L industrial fermenters

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Morakot Krajang ◽  
Kwanruthai Malairuang ◽  
Jatuporn Sukna ◽  
Krongchan Rattanapradit ◽  
Saethawat Chamsart
Keyword(s):  
Ethanol Production ◽  
Ethanol Concentration ◽  
Consolidated Bioprocessing ◽  
Scale Up ◽  
Cassava Starch ◽  
Single Step ◽  
Starch Hydrolysis ◽  
Yield Coefficient ◽  
Raw Starch ◽  
Raw Starch Hydrolysis

Abstract Background A single-step ethanol production is the combination of raw cassava starch hydrolysis and fermentation. For the development of raw starch consolidated bioprocessing technologies, this research was to investigate the optimum conditions and technical procedures for the production of ethanol from raw cassava starch in a single step. It successfully resulted in high yields and productivities of all the experiments from the laboratory, the pilot, through the industrial scales. Yields of ethanol concentration are comparable with those in the commercial industries that use molasses and hydrolyzed starch as the raw materials. Results Before single-step ethanol production, studies of raw cassava starch hydrolysis by a granular starch hydrolyzing enzyme, StargenTM002, were carefully conducted. It successfully converted 80.19% (w/v) of raw cassava starch to glucose at a concentration of 176.41 g/L with a productivity at 2.45 g/L/h when it was pretreated at 60 °C for 1 h with 0.10% (v/w dry starch basis) of Distillase ASP before hydrolysis. The single-step ethanol production at 34 °C in a 5-L fermenter showed that Saccharomyces cerevisiae (Fali, active dry yeast) produced the maximum ethanol concentration, pmax at 81.86 g/L (10.37% v/v) with a yield coefficient, Yp/s of 0.43 g/g, a productivity or production rate, rp at 1.14 g/L/h and an efficiency, Ef of 75.29%. Scale-up experiments of the single-step ethanol production using this method, from the 5-L fermenter to the 200-L fermenter and further to the 3000-L industrial fermenter were successfully achieved with essentially good results. The values of pmax,Yp/s, rp, and Ef of the 200-L scale were at 80.85 g/L (10.25% v/v), 0.42 g/g, 1.12 g/L/h and 74.40%, respectively, and those of the 3000-L scale were at 70.74 g/L (8.97% v/v), 0.38 g/g, 0.98 g/L/h and 67.56%, respectively. Because of using raw starch, major by-products, i.e., glycerol, lactic acid, and acetic acid of all three scales were very low, in ranges of 0.940–1.140, 0.046–0.052, 0.000–0.059 (% w/v), respectively, where are less than those values in the industries. Conclusion The single-step ethanol production using the combination of raw cassava starch hydrolysis and fermentation of three fermentation scales in this study is practicable and feasible for the scale-up of industrial production of ethanol from raw starch.

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