Renewable Plant Waste As Substrates for Enzyme Production, Saccharification and Direct Bioethanol Production by Indigenous Yeast Strain Pichia Exigua

2021 ◽  
Vol 47 (2) ◽  
pp. 306-316
Author(s):  
O.C. Amadi ◽  
C.C. Mbaeke ◽  
T.N. Nwagu ◽  
C.I. Nnamchi ◽  
I.A. Ndubuisi ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Nitrogen Source ◽  
Substrate Concentration ◽  
Yeast Strain ◽  
Enzyme Production ◽  
Culture Conditions ◽  
Single Step ◽  
Total Carbohydrate ◽  
Plant Waste ◽  
Indigenous Yeast

Renewable plant wastes constitute environmental nuisance. Their conversion by enzymes into bioethanol can be beneficial. We investigated the use of renewable plant waste as substrate for enzyme production and hydrolysis of the plant waste for ethanol production using an indigenous yeast strain. Five yeast strains; MCC-1, MCC-2, MCC-3, MCC-4 and MCC-5 were evaluated for production of sugars, α-amylase, glucoamylase and bioethanol using soluble starch. Phylogenetic analysis using partial sequence of the ITS gene classified MCC-4 as Pichia exigua. Proximate composition of plant wastes – cassava, wild yam, mango seed, udara seed and breadfruit were determined. Results showed total carbohydrate of (83.9%) for cassava flour. The ability of yeast to utilize these substrates and the effect of culture conditions (inoculum, pH, nitrogen source and substrate concentration) were also determined. Cassava pulp flour was the best substrate producing reducing sugar (1.471 ± 0.056mg/mL), α-amylase (0.573 ± 0.019U/mL), glucoamylase (1.605 ± 0.119U/mL), and ethanol (4.440 ± 0.014g/L). Culture conditions revealed optimum for inoculum concentration as (1mL), pH (4), nitrogen source (soya bean, 3g/L) and substrate concentration of (8%). Pichia exigua (MCC-4) a natural yeast strain isolated from the soil has the potential for both enzyme and ethanol production in a single step process.

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.

Application of low-cost algal nitrogen source feeding in fuel ethanol production using high gravity sweet potato medium

2012 ◽  
Vol 160 (3-4) ◽  
pp. 229-235 ◽  
Author(s):  
Yu Shen ◽  
Jin-Song Guo ◽  
You-Peng Chen ◽  
Hai-Dong Zhang ◽  
Xu-Xu Zheng ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Nitrogen Source ◽  
Sweet Potato ◽  
Low Cost ◽  
Fuel Ethanol ◽  
High Gravity

Yeast Strain Selection for Fuel Ethanol Production

2020 ◽  
pp. 225-243
Author(s):  
Chandra J. Panchal ◽  
Flavio Cesar Almeida Tavares
Keyword(s):  
Ethanol Production ◽  
Yeast Strain ◽  
Fuel Ethanol ◽  
Strain Selection ◽  
Selection For

scholarly journals Effect of Various Pretreatment Methods on Bioethanol Production from Cotton Stalks

Fermentation ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 5 ◽  
Author(s):  
Konstantinos Dimos ◽  
Thomas Paschos ◽  
Argiro Louloudi ◽  
Konstantinos G. Kalogiannis ◽  
Angelos A. Lappas ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Substrate Concentration ◽  
Ethanol Yield ◽  
Direct Conversion ◽  
Hydrothermal Pretreatment ◽  
Solid Loading ◽  
Hydrolysis Time ◽  
Cotton Stalks ◽  
Sequential Combination ◽  
Simultaneous Saccharification

Cotton stalks (CS) are considered a good candidate for fuel-ethanol production due to its abundance and high carbohydrate content, but the direct conversion without pretreatment always results in extremely low yields due to the recalcitrant nature of lignocelluloses. The present study was undertaken to investigate the effect of various chemical and physicochemical pretreatment methods, i.e., alkali, microwave-assisted acid, organosolv, hydrothermal treatment, and sequentially organosolv and hydrothermal pretreatment, on chemical composition of CS and subsequent ethanol production applying pre-hydrolysis and simultaneous saccharification and fermentation (PSSF) at high solid loading. The best results in terms of ethanol production were achieved by the sequential combination of organosolv and hydrothermal pretreatment (32.3 g/L, using 15% w/v substrate concentration and 6 h pre-hydrolysis) with an improvement of 32% to 50% in ethanol production compared to the other pretreatments. Extending pre-hydrolysis time to 14 h and increasing substrate concentration to 20% w/v, ethanol production reached 47.0 g/L (corresponding to an ethanol yield of 52%) after 30 h of fermentation.

scholarly journals Statistical optimization of simple culture conditions to produce biomass of an ochratoxigenic mould biocontrol yeast strain

2012 ◽  
Vol 54 (5) ◽  
pp. 377-382 ◽  
Author(s):  
R. Pelinski ◽  
P. Cerrutti ◽  
M.L. Ponsone ◽  
S. Chulze ◽  
M. Galvagno
Keyword(s):  
Yeast Strain ◽  
Culture Conditions ◽  
Statistical Optimization

Stimulation of dextranase production by oxidized dextran

1970 ◽  
Vol 16 (9) ◽  
pp. 841-844 ◽  
Author(s):  
Robert G. Brown
Keyword(s):  
Carbon Source ◽  
Nitrogen Source ◽  
Enzyme Production ◽  
Inorganic Nitrogen ◽  
Penicillium Funiculosum ◽  
Inorganic Nitrogen Source ◽  
Oxidized Dextran ◽  
Excess Glucose ◽  
Stimulation Of

Penicillium funiculosum, Penicillium lilacinum, and Spicaria violacea produced excellent yields of dextranase if ketodextran replaced dextran as a carbon source. Ketodextrans I and II having degrees of substitution of 2 and 20% respectively were used in this study. P. funiculosum grew equally well on dextran and ketodextran I but less well on ketodextran II. Addition of a readily metabolizable carbohydrate such as glucose, sucrose, or galactose stimulated growth on ketodextran II, resulting in better dextranase production. However, excess glucose reversed this increase in enzyme production. Replacement of an inorganic nitrogen source with an organic one further stimulated dextranase production during growth of P. funiculosum on ketodextran II.

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