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

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.

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 3,000-L Industrial Fermenters

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 3,000-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 3,000-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.

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 3,000-L Industrial Fermenters

Background: A single-step ethanol production is the combination of raw cassava starch hydrolysis and fermentation. For the development of raw starch consolidated bioprocessing (CBP) technologies, this research work was to investigate the optimum conditions and technical procedures for the production of ethanol from raw cassava starch in a single step. This resulted high yields and productivities of all the experiments from the laboratory, the pilot, through the industrial scales. The 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, the 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 of 2.45 g/L/h when the raw starch was pretreated at 60 °C for 1 h with 0.10% (v/w dry starch basis) of Distillase ASP before hydrolysis. A single-step ethanol production at 34 °C in a 5-L fermenter showed that S. cerevisiae (Fali, active dry yeast) produced the maximum ethanol concentration, p of 81.86 g/L (10.43% v/v) with a yield coefficient, Y p/s of 0.41 g/g, a productivity or production rate, r p of 1.14 g/L/h with an efficiency, Ef of 71.44%. The 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 3,000-L industrial fermenter were successfully achieved with essentially good results. The p, Y p/s , r p , and Ef values of the 200-L scale were 80.85 g/L (10.23% v/v), 0.41 g/g, 1.12 g/L/h and 72.47% , respectively ; of the 3,000-L scale were 70.74 g/L (9.01% v/v), 0.34 g/g, 0.98 g/L/h and 59.82% , respectively. Because of using raw starch, the major by-products of all the three scales were very low; glycerol lactic acid and acetic acid, in ranges of 0.94-1.14%, 0.046-0.052%, 0-0.059% (w/v), respectively, where are less than those values in the industries. Conclusions: This single-step ethanol production using a combination of raw cassava starch hydrolysis and fermentation of the three fermentation scales here is practicable and feasible for the scale-up of industrial production of ethanol from raw starch.

Highly efficient production of Aspergillus niger amylase cocktail by solid-state fermentation using triticale grains as a well-balanced substrate

Triticale (Triticosecale, Wittmak) an important industrial crop, with high grain yield, containing high amounts of starch, proteins and also major and minor mineral elements, is not sufficiently utilized yet. The simultaneous production of ?-amylase and glucoamylase isoforms by Aspergillus niger on triticale grains, without any nutritive supplements, has been developed, optimized and scaled up 10 fold for the first time. The specific combination of examined effects led to the production of a novel glucoamylase isoform. Reduction of particle size, increase of oxygen availability and substrate height lead to increase of amylases production of 30%. Reduction of relative humidity from 65% to 30% increased glucoamylase production 2 times and ?-amylase production for 30%. Peak production of ?-amylase (158 U/g) and glucoamylase (170 U/g) were obtained in erlenmayers and in scaled-up trays. The obtained A. niger amylase cocktail was more efficient in raw starch hydrolysis from wheat flour, 29% more efficient in glucose formation and 10% more efficient in total reducing sugar formation, than commercially available amylase cocktail SAN Super 240L widely used in industry.

A thin layer chromatographic comparison of raw and soluble starch hydrolysis patterns of some α-amylases from Bacillus sp. isolated in Serbia

Several natural isolates of Bacillus strains namely 5B, 12B, 16B, 18 and 24B were grown on two different temperatures in submerged fermentation for the raw-starch-digesting a-amylases production. All strains except Bacillus sp. 18 produced more ?-amylase on 37?C. The hydrolysis of raw corn starch followed same pattern. Efficient hydrolysis was obtained with ?-amylases from Bacillus sp. 5B, 12B, 16B and 24B grown on 37?C and Bacillus sp. 18 grown on 50?C. Zymography after isoelectric focusing shown that ?-amylases were produced in multiple forms, from 2 to 6, depending on the strain when they were growing at 37 ?C, while growing at 50?C induced only 1 or 2 isoforms. TLC analysis of hydrolysis products of raw corn and soluble starch by ?-amylases revealed production of various mixtures of oligosaccharides. In most cases G3 was the most dominant product from soluble starch while G2, G3 and G5 were the main products of raw starch hydrolysis. This indicates that obtained a-amylases can be used for starch liquefying or short-chain-oligosaccharide forming, depending on what type of starch (raw or soluble) was used for the hydrolysis.