Optimization of Simultaneous Saccharification and Fermentation for the Production of Ethanol from Lignocellulosic Biomass

2000 ◽  
Vol 48 (5) ◽  
pp. 1971-1976 ◽  
Author(s):  
S. Hari Krishna ◽  
G. V. Chowdary
2012 ◽  
Vol 06 ◽  
pp. 715-720
Author(s):  
Maki Takano ◽  
Kazuhiro Hoshino

To develop biofuel production from waste lignocellulosic biomass materials the rice straw was selected one of renewable material and the degradation condition about pretreatment and enzymatic hydrolysis to obtain effectively fermentable sugars was investigated. Rice straw was pretreated by five kinds of methods and then the components ratio of rice straw was examined. First, the steam explosion was selected based on the degradability and the requirement energy. In addition, the best suitable combination of two cellulases to effective and economical hydrolyze was determined from the degradability of these pretreated rice straws. In the simultaneous saccharification and fermentation of the steam explosion rice straw by combining cellulase cocktail and a novel fermenting fungus, 13.2 g/L ethanol was able to product for 96 h.


2014 ◽  
Vol 917 ◽  
pp. 80-86
Author(s):  
Mohd Saman Siti Aisyah ◽  
Pacharakamol Petchpradab ◽  
Yoshimitsu Uemura ◽  
Suzana Yusup ◽  
Machi Kanna ◽  
...  

Separate hydrolysis and fermentation (SHF) is the common process in producing ethanol from lignocellulosic biomass. Nowadays, simultaneous saccharification and fermentation (SSF) process has been seen as potential process for producing ethanol with shortens process time with higher yield of ethanol. Hence, in the current work, the utilization of empty fruit bunches (EFB) in SSF process was studied. In order to improve saccharification reactivity of EFB, hydrothermal pretreatment at 180 and 220 °C was used to pretreat EFB. The findings showed that SSF has the potential in producing ethanol from EFB.


2020 ◽  
Author(s):  
Vishnu Prasad J. ◽  
Tridweep K. Sahoo ◽  
Naveen S. ◽  
Guhan Jayaraman

Abstract BackgroundSimultaneous saccharification and fermentation (SSF) of pre-treated lignocellulosics to biofuels and other platform chemicals has long been a promising alternative to separate hydrolysis and fermentation processes. However, the disparity between the optimum conditions (temperature, pH) for fermentation and enzyme hydrolysis leads to execution of the SSF process at sub-optimal conditions, which can affect the rate of hydrolysis and cellulose conversion. The fermentation conditions could be synchronized with hydrolysis optima by carrying out the SSF at a higher temperature, but this would require a thermo-tolerant organism. Economically viable production of platform chemicals from lignocellulosic biomass has long been stymied because of the significantly higher cost of hydrolytic enzymes. The major objective of this work is to develop an SSF strategy for D- lactic acid production by a thermo-tolerant organism, in which the enzyme loading could significantly be reduced without compromising on the overall conversion. ResultsA thermo-tolerant strain of Lactobacillus bulgaricuswas developed by adaptive laboratory evolution (ALE) which enabled the SSF to be performed at 45 °C with reduced enzyme usage.Despite the reduction of enzyme loading from 15 FPU/gbiomass to 5 FPU/gbiomass, we could still achieve ~8% higher cellulose to D-LA conversion in batch SSF, in comparison to the conversion by separate enzymatic hydrolysis and fermentation processes at 45 °C and pH 5.5. Extending the batch SSF to an SSF with pulse-feeding of 5% pre-treated biomass and 5 FPU/g-biomass, at12-hour intervals (36th h – 96th h), resulted in a titer of 108 g/L D-LA and 60% conversion of cellulose to D-LA.This is one among the highest reported D-LA titers achieved from lignocellulosic biomass.ConclusionsWe have demonstrated that the SSF strategy, in conjunction with evolutionary engineering, could drastically reduce enzyme requirement and be the way forward for economical production of platform chemicals from lignocellulosics. We have shown that fed-batch SSF processes, designed with multiple pulse-feedings of the pre-treated biomass and enzyme, can be an effective way of enhancing the product concentrations.


2016 ◽  
Vol 6 (1) ◽  
pp. 773-779
Author(s):  
Leonard Guimarães Carvalho ◽  
Luiz Felipe A. Modesto ◽  
Donato A. Gomes Aranda ◽  
Nei Pereira Jr

Brazil presents the world's largest potential for the production of palm oil due to nearly 75 million hectares of land suitable for palm culture and advantageous soil and climate. The biomass generated in the production of palm oil (palm pressed fiber, PPF) is mainly composed of lignocellulosic material that can be hydrolyzed into fermentable sugars for further conversion to ethanol. This work evaluated alkaline pretreatment of this palm oil residue and subsequent Simultaneous Saccharification and Fermentation (SSF), achieving a conversion of glucose to ethanol higher than 90% and a concentration equivalent to 22.40 g/L of the alcohol.  


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