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Two-step fermentation of cooked rice with Aspergillus oryzae and Clostridium acetobutylicum YM1 for biobutanol production

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Abstract

In Asia, uneaten cooked rice is the highest portion amongst many forms of food wastes that are thrown away. In order to make use of the thrown-away rice and potentially use it for liquid fuels, steamed Japanese rice was evaluated on biobutanol production through a two-step fermentation by amylase-producing Aspergillus oryzae, and solvent-producing Clostridium acetobutylicum YM1. The effects of sterilization and providing anaerobic conditions on solvent production in acetone-butanol-ethanol (ABE) fermentation cannot be underestimated. Several conditions, including aerobic, anaerobic, sterile, and non-sterile were investigated concerning the solvent production capability of Clostridium acetobutylicum YM1. The maximum solvent production was 11.02 ± 0.22 g/l butanol and 18.03 ± 0.34 g/l total ABE from 75 g/l dried rice. The results confirmed that the solvent production performance of the YM1 strain was not affected by the sterilization conditions. In particular, 10.91 ± 0.16 g/l butanol and 16.68 ± 0.22 g/l ABE were produced under non-sterile and aerobic conditions, which can reduce industrial-scale production costs.

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... Joanna Kawarygielska et al. reported A. oryzae final product yields ranging from 0.29 to 0.32 g EtOH/g and 0.20 to 0.22 g biomass/g bread waste, on the second fermentation [112]. Abdullah Bilal Ozturk et al. conducted experiments to test the production of bio-butanol through fermentation of Japanese steamed rice using A. oryzae and Clostridium acetobutylicum, and the output was (10.91 ± 0.16) g/L [113]. ...
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Present investigation explores the use of pineapple peel, a food industry waste, for acetone-butanol-ethanol (ABE) production using Clostridium acetobutylicum B 527. Proximate analysis of pineapple peel shows that it contains 35% cellulose, 19% hemicellulose, and 16% lignin on dry basis. Drying experiments on pineapple peel waste were carried out in the temperature range of 60-120 °C and experimental drying data was modeled using moisture diffusion control model to study its effect on ABE production. The production of ABE was further accomplished via acid hydrolysis, detoxification, and fermentation process. Maximum total sugar release obtained by using acid hydrolysis was 97 g/L with 95-97% and 10-50% removal of phenolics and acetic acid respectively during detoxification process. The maximum ABE titer obtained was 5.23 g/L with 55.6% substrate consumption when samples dried at 120 °C were used as a substrate (after detoxification).
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Acetone-butanol-ethanol (ABE) production from cassava starch was enhanced by a syntrophic co-culture of Clostridium butylicum TISTR 1032 and high amylase producing Bacillus subtilis WD 161 without anaerobic pretreatment. The production of amylase and ABE using this co-culture were respectively 16 and 6 times higher than those using the pure culture of C. butylicum TISTR 1032. The effect of the medium components on the performance of the co-culture was investigated using response surface methodology (RSM). Among the investigated components, cassava starch and ammonium nitrate contributed a significant effect on the production of amylase and ABE, while yeast extract had less effect. Based on the optimum strategy using RSM, the ABE production by the co-culture was improved 2.2-fold compared with that obtained from the initial condition and with a minimum requirement of nitrogen source. © 2011 by Maejo University, San Sai, Chiang Mai, 50290 Thailand.
Article
In this study, the techno-economic evaluation of a combined bioprocess based on solid state fermentation for fermentative hydrogen production from food waste was carried out. The hydrogen production plant was assumed to be built in Hangzhou and designed for converting 3 ton food waste per day into hydrogen. The total capital cost (TCC) and the annual production cost (APC) were US583092andUS583092 and US88298.1/year, respectively. The overall revenue after the tax was US$146473.6/year. The return on investment (ROI), payback period (PBP) and internal rate of return (IRR) of the plant were 26.75%, 5years and 24.07%, respectively. The results exhibited that the combined bioprocess for hydrogen production from food waste was feasible. This is an important study for attracting investment and industrialization interest for hydrogen production from food waste in the industrial scale.
Article
Improvement in the butanol production selectivity or enhanced butanol: acetone ratio (B:A) is desirable in acetone-butanol-ethanol (ABE) fermentation by Clostridium strains. In this study, artificial electron carriers were added to the fermentation medium of a new isolate of Clostridium acetobutylicum YM1 in order to improve the butanol yield and B:A ratio. The results revealed that medium supplementation with electron carriers changed the metabolism flux of electron and carbon in ABE fermentation by YM1. A decrease in acetone production, which subsequently improved the B:A ratio, was observed. Further improvement in the butanol production and B:A ratios were obtained when the fermentation medium was supplemented with butyric acid. The maximum butanol production (18.20±1.38 g/L) was gained when a combination of methyl red and butyric acid was added. Although the addition of benzyl viologen (0.1 mM) and butyric acid resulted in high a B:A ratio of 16:1 (800% increment compared with the conventional 2:1 ratio), the addition of benzyl viologen to the culture after 4 h resulted in the production of 18.05 g/L butanol. Manipulating the metabolic flux to butanol through the addition of electron carriers could become an alternative strategy to achieve higher butanol productivity and improve the B:A ratio.
Article
Recently, lignocellulosic biomass as the most abundant renewable resource has been widely considered for bioalcohols production. However, the complex structure of lignocelluloses requires a multi-step process which is costly and time consuming. Although, several bioprocessing approaches have been developed for pretreatment, saccharification and fermentation, bioalcohols production from lignocelluloses is still limited because of the economic infeasibility of these technologies. This cost constraint could be overcome by designing and constructing robust cellulolytic and bioalcohols producing microbes and by using them in a consolidated bioprocessing (CBP) system. This paper comprehensively reviews potentials, recent advances and challenges faced in CBP systems for efficient bioalcohols (ethanol and butanol) production from lignocellulosic and starchy biomass. The CBP strategies include using native single strains with cellulytic and alcohol production activities, microbial co-cultures containing both cellulytic and ethanologenic microorganisms, and genetic engineering of cellulytic microorganisms to be alcohol-producing or alcohol producing microorganisms to be cellulytic. Moreover, high-throughput techniques, such as metagenomics, metatranscriptomics, next generation sequencing and synthetic biology developed to explore novel microorganisms and powerful enzymes with high activity, thermostability and pH stability are also discussed. Currently, the CBP technology is in its infant stage, and ideal microorganisms and/or conditions at industrial scale are yet to be introduced. So, it is essential to bring into attention all barriers faced and take advantage of all the experiences gained to achieve a high-yield and low-cost CBP process.
Article
In this study, we attempted to increase butanol/acetone ratio and total solvent productivity in ABE fermentations with corn- and cassava-based media, by consecutively feeding a small amount of butyrate/acetate during solventogenic phase to weaken the metabolic strengths in butyrate/acetate closed-loops. Consecutively feeding a small amount of butyrate (a total of 3.0 g/L-broth) is most effective in improving performance of corn-based ABE fermentations, as it simultaneously increased average butanol/acetone ratio by 23 % (1.92-2.36) and total solvent productivity by 16 % (0.355-0.410 g/L/h) as compared with those of control. However, the butyrate feeding strategy could not improve butanol/acetone ratio and total solvent productivity in cassava-based ABE fermentations, where the metabolic strength of butyrate closed-loop had already been very low.
Article
This study aimed to quantitatively evaluate the correlations between butanol (BtOH) tolerance of solvent-producing bacteria (SPB) and the performance of fermentative butanol production. The toxicity potency of BtOH was revealed to suggest the feasibility of butanol formation with a Clostridial species-dominated bacterial consortium. When the mixed culture was grown on the optimal medium comprising 60 g/L glucose, 0.5 g/L FeSO4·7H2O and 5.13 g/L yeast extract, the maximal tolerant butanol concentration, butanol production, hydrogen production and glucose consumption were ca. 16 g/L, 10.64 ± 0.60 g/L, 4153 ± 815 mL/L and 54.99 ± 1.92 g/L, respectively. Moreover, almost all the dose–response curves representing toxicity potency of butanol on microbial characteristics was nearly identical in order of magnitude. Thus, although generations of by-products during butanol fermentation are interactive, the maintenance of microbial growth capability still plays a crucial role to control the performance of butanol production. The quantitative findings in toxicological terms directly suggest that the BtOH toxicity seemed to be inevitable during BtOH production. In addition, butanol inhibition could be reversibly attenuated by removal of butanol to make it below the critical level (ca. 7.83–9.52 g/L or EC50).
Article
Biobutanol can become the replacement of petroleum gasoline in near future. However, economic feasibility of biobutanol production from ABE fermentation is suffering due to the unavailability of cheap feedstocks, production inhibition and inefficient product recovery processes. Here, economic analysis of ABE fermentation has been performed based on cellulosic (bagasse, barley straw, wheat straw, corn stover, and switchgrass) and non-cellulosic (glucose, sugarcane, corn, and sago) feedstocks, which are widely and cheaply available in agriculture based countries. Analysis shows that utilization of glucose required 37% lesser total fixed capital cost than the other cellulosic and non-cellulosic feedstocks for the per year production of 10,000 tonnes of butanol. However, the production cost of butanol from glucose was fourfold higher than sugarcane and cellulosic materials because of its (glucose) high cost. The cost of sago also affected threefold production cost of butanol comparative to other feedstocks. Therefore, these two substrates turned the biobutanol production far from being economically feasible. Interestingly, sugarcane and cellulosic materials showed suitability for economically feasible production of butanol with the production cost range of 0.590.59-0.75 per kg butanol. Consequently, quantitative variation in the design and process parameters namely fermentor size, plant capacity, production yield using sugarcane and cellulosic materials as raw materials, trigger significant reduction in unitary cost of butanol up to 53%, 19%, and 31% respectively. Therefore, these parameters will play significant role in making the butanol production economical from cheaper feedstocks (sugarcane and cellulosic materials). Further, high sensitivity of production cost from the product yield postulates significant manipulation in genome of butanol producing bacteria for improving the yield of ABE fermentation. (c) 2012 Elsevier Ltd. All rights reserved.
Article
Statistically and causally meaningful relationships are established between starch molecular structures (obtained by size-exclusion chromatography, proton NMR and multiple-angle laser light scattering) and digestibility of cooked rice grains (measured by in vitro digestion). Significant correlations are observed between starch digestion rate and molecular structural characteristics, including fine structures of the distributions of branch (chain) lengths in both amylose and amylopectin. The in vitro digestion rate tends to increase with longer amylose branches and smaller ratios of long amylopectin and long amylose branches to short amylopectin branches, although the statistical analyses show that further data are needed to establish this unambiguously. These new relationships between fine starch structural features and digestibility of cooked rice grains are mechanistically reasonable, but suggestive rather than statistically definitive.
Article
Rochelle salt, normally present in the dinitrosalicylic acid reagent for reducing sugar, interferes with the protective action of the sulfite, but is essential to color stability. The difficulty may be resolved either by eliminating Rochelle salt from the reagent and adding it to the mixture of reducing sugar and reagent after the color is developed, or by adding known amounts of glucose to the samples of reducing sugar to compensate for the losses sustained in the presence of the Rochelle salt. The optimal composition of a modified dinitrosalicylic acid reagent is given.
Article
In Japan, a revised Food Recycling Law went into effect in 2007 to promote a "recycling loop" that requires food industries to purchase farm products that are grown using food waste-derived compost/animal feed. To realize and expand food recycling, it is necessary to evaluate how the recycling facilities work in the recycling loop. The purpose of this study is to assess the environmental and economic efficiency of the food recycling facilities that are involved in the recycling loop, which are also known as looped facilities. The global warming potential and running cost of five looped facilities were evaluated by LCA (life cycle assessment) and LCC (life cycle cost) approaches: machine integrated compost, windrow compost, liquid feed, dry feed, and bio-gasification. The LCA results showed low total GHG (greenhouse gas) emissions of -126 and -49 kg-CO(2)/t-waste, respectively, for dry feed and bio-gasification facilities, due to a high substitution effect. The LCC study showed a low running cost for composting facilities of -15,648 and -18,955 yen/t-waste, respectively, due to high revenue from the food waste collection. It was found that the mandatory reporting of food waste emitters to the government increased collection fees; however, the collection fee in animal feed facilities was relatively low because food waste was collected at a low price or nutritious food waste was purchased to produce quality feed. In the characterisation survey of various treatment methods, the composting facilities showed a relatively low environmental impact and a high economic efficiency. Animal feed facilities had a wide distribution of the total GHG emissions, depending on both the energy usage during the drying process and the substitution effect, which were related to the water content of the food waste and the number of recycled products. In comparison with incineration, the majority of the food recycling facilities showed low GHG emissions and economic effectiveness. This paper also reported on the effects of recycling loops by comparing looped and non-looped animal feed facilities, and confirmed that the looped facilities were economically effective, due to an increased amount of food waste collection.
Article
A high amylase producing Bacillus subtilis WD 161 was used in a co-culture with Clostridium butylicum TISTR 1032 to enhance acetone–butanol–ethanol (ABE) production from starch. The mixed culture of C. butylicum TISTR 1032 and B. subtilis WD 161 without anaerobic pretreatment by reducing agent and N2 flushing increased amylase activity 10 folds and enhanced ABE production 5.4 and 6.5 folds from soluble starch and cassava starch, respectively, compared to those of the pure culture of Clostridium itself. The medium optimization for ABE production by the mixed culture without anaerobic pretreatment found that cassava starch concentration of 40 g/L, C/N ratio of 4.35 and the mixed nitrogen sources of 265 mM yeast extract and 100 mM NH4NO3 gave the highest ABE production in terms of final concentration and productivity. The benefits of using this high amylase producing aerobic Bacillus in a co-culture with anaerobic Clostridium were not only increasing substrate utilization and ABE production but there was also no requirement to add any costly reducing agent to the medium or flushing with N2 to ensure anaerobic condition. This thus makes the anaerobic fermentation more economical and cost effective. This co-culture system may contribute greatly to developing industrialized ABE production.
Article
The production of extracellular amylase by the thermophilic fungus Thermomyces lanuginosus was studied in solid state fermentation (SSF). Solid substrates such as wheat bran, molasses bran, rice bran, maize meal, millet cereal, wheat flakes, barley bran, crushed maize, corncobs and crushed wheat were studied for enzyme production. Growth on wheat bran gave the highest amylase activity. The maximum enzyme activity obtained was 534 U/g of wheat bran under optimum conditions of an incubation period of 120 h, an incubation temperature of 50 degrees C, an initial moisture content of 90%, a pH of 6.0, an inoculum level of 10% (v/w), a salt solution concentration of 1.5:10 (v/w) and a ratio of substrate weight to flask volume of 1:100 with soluble starch (1% w/w) and peptone (1% w/w) as supplements.
  • S B Bankar
  • P R Nimbalkar
  • M A Khedkar
Bankar SB, Nimbalkar PR, Khedkar MA, et al. Biobutanol: Research Breakthrough for its Commercial Interest. In: Liquid Biofuel Production. Hoboken (NJ): John Wiley & Sons; 2019. p. 237-283.