Integrating sugarcane molasses into sequential cellulosic biofuel production based on SSF process of high solid loading

Abstract

BackgroundSugarcane bagasse (SCB) is one of the most promising lignocellulosic biomasses for use in the production of biofuels. However, bioethanol production from pure SCB fermentation is still limited by its high process cost and low fermentation efficiency. Sugarcane molasses, as a carbohydrate-rich biomass, can provide fermentable sugars for ethanol production. Herein, to reduce high processing costs, molasses was integrated into lignocellulosic ethanol production in batch modes to improve the fermentation system and to boost the final ethanol concentration and yield.ResultsThe co-fermentation of pretreated SCB and molasses at ratios of 3:1 (mixture A) and 1:1 (mixture B) were conducted at solid loadings of 12% to 32%, and the fermentation of pretreated SCB alone at the same solid loading was also compared. At a solid loading of 32%, the ethanol concentrations of 64.10 g/L, 74.69 g/L, and 75.64 g/L were obtained from pure SCB, mixture A, and mixture B, respectively. To further boost the ethanol concentration, the fermentation of mixture B (1:1), with higher solid loading from 36 to 48%, was also implemented. The highest ethanol concentration of 94.20 g/L was generated at a high solid loading of 44%, with an ethanol yield of 72.37%. In addition, after evaporation, the wastewater could be converted to biogas by anaerobic digestion. The final methane production of 312.14 mL/g volatile solids (VS) was obtained, and the final chemical oxygen demand removal and VS degradation efficiency was 85.9% and 95.9%, respectively.ConclusionsMolasses could provide a good environment for the growth of yeast and inoculum. Integrating sugarcane molasses into sequential cellulosic biofuel production could improve the utilization of biomass resources.

Bioconversion of poly-γ-glutamic acid (γ-PGA) from fulvic acid powder produced from the wastewater of yeast molasses fermentation

“…Detecting compatibility of GJ11 to FA powder GJ11 was cultured in LB medium overnight, then inoculated in 50 mL of concentration -gradient FA powder medium (1,5,10,20,40, 60 and 100 g/L, respectively) in a 250 mL ask at a ratio of 3% (v/v), for further culture at 37 o C and 180 rpm for 24 h. After the incubation, the samples in different broths were collected for counting the colony-forming unit (cfu) of GJ11.…”

“…Molasses is one of the main raw materials for producing bioethanol through yeast fermentation [2][3][4], because molasses contains many easily-fermentable sugars (e.g. primarily sucrose, glucose, and fructose), and is abundant, low-cost and highly available for the fermentation industry [5][6][7]. Thereby, molasses is widely used for microbial conversion into different value-added products, such as bioethanol, baker's yeast, amino acids, butanol, organic acids, single cell proteins, etc [8][9][10][11].…”

Microbial synthesis of poly-γ-glutamic acid (γ-PGA) with fulvic acid powder, the waste from yeast molasses fermentation

“…Due to the petroleum crisis, renewable sources, such as bioethanol, have been explored and used as alternative energy in recent years [ 1 ]. Molasses is one of the main raw materials for producing bioethanol through yeast fermentation [ 2 – 4 ], because it contains many easily fermentable sugars (e.g., primarily sucrose, glucose, and fructose), and is abundant, low cost, and highly available for the fermentation industry [ 5 – 7 ]. Thereby, molasses is widely used for microbial conversion of different value-added products, such as bioethanol, baker’s yeast, amino acids, butanol, organic acids, single-cell proteins, etc.…”

Microbial synthesis of poly- γ -glutamic acid ( γ -PGA) with fulvic acid powder, the waste from yeast molasses fermentation

“…Molasses is one of the main raw materials for producing bioethanol through yeast fermentation [2][3][4], because it contains many easily fermentable sugars (e.g. primarily sucrose, glucose, and fructose), and is abundant, low-cost and highly available for the fermentation industry [5][6][7]. Thereby, molasses is widely used for microbial conversion of different value-added products, such as bioethanol, baker's yeast, amino acids, butanol, organic acids, single cell proteins, etc [8][9][10][11].…”