Second Generation Ethanol Production from Brewers’ Spent Grain

Abstract

Ethanol production from lignocellulosic biomasses raises a global interest because it represents a good alternative to petroleum-derived energies and reduces the food versus fuel conflict generated by first generation ethanol. In this study, alkaline-acid pretreated brewers' spent grain (BSG) was evaluated for ethanol production after enzymatic hydrolysis with commercial enzymes. The obtained hydrolysate containing a glucose concentration of 75 g/L was adopted, after dilution up to 50 g/L, for fermentation by the strain Saccharomyces cerevisiae NRRL YB 2293 selected as the best producer among five ethanologenic microorganims. When the hydrolysate was supplemented with yeast extract, 12.79 g/L of ethanol, corresponding to 0.28 g of ethanol per grams of glucose consumed (55% efficiency), was obtained within 24 h, while in the non-supplemented hydrolysate, a similar concentration was reached within 48 h. The volumetric productivity increased from 0.25 g/L·h in the un-supplemented hydrolysate to 0.53 g/L h in the yeast extract supplemented hydrolysate. In conclusion, the strain S. cerevisiae NRRL YB 2293 was shown able to produce ethanol from BSG. Although an equal amount of ethanol was reached in both BSG hydrolysate media, the nitrogen source supplementation reduced the ethanol fermentation time and promoted glucose uptake and cell growth. OPEN ACCESSEnergies 2015, 8 2576

An Assessment of the Sustainability of Lignocellulosic Bioethanol Production from Wastes in Iceland

“…Dioxin levels in the fly-ash from the nearby incinerator were more than 20 times the EU limits [17]. Moreover, soil and incinerator emissions measurements at several sites in Iceland such as Kirkjubaejarklaustur revealed that emissions were 85 times the EU limits [6,18]. These problematic findings resulted in the widespread testing of soil across Iceland [17], shutdown of several incinerators [18], withdrawal of some Icelandic meat and milk from the markets and culling of all the livestock on the farms impacted [17].…”

“…Lignocellulosic materials, a third group of feedstocks, represents the most viable option for bioethanol production. Increasing food demand and the need to feed an increasing global population could make conventional agricultural crops less competitive and more costly sources compared to lignocellulosic materials [4][5][6].…”

Integrated biorefinery fromArthrospira platensisbiomass as feedstock for bioethanol and lactic acid production

“…The yeast strain adopted for ethanol fermentation was S. cerevisiae LPB-287 selected in our previous work (Liguori et al, 2015a). The yeast was inoculated in three 250 mL flasks containing 100 mL of YM broth whose composition in (g/L -1 ) is as follows: glucose (10), peptone (5), malt extract (3), yeast extract (3).…”

“…Based on this, the aim of this work was to analyze the strains Saccharomyces cerevisiae LPB-287 (Liguori et al, 2015a) and Lactobacillus acidophilus ATCC 43121 (Liguori et al, 2015b) for their ability to grow on the A. platensis residual biomass after high value metabolites extraction by either supercritical fluid extraction (SFE) or microwave-assisted extraction (MAE) and produce ethanol and lactic acid, respectively.…”

Optimization of Reducing Sugar Production from Manihot glaziovii Starch Using Response Surface Methodology

“…Currently, the predominant bioethanol is generally used blended with gasoline to push down the usage of conventional fuel and can be used in existing motor engines [1]. Bioethanol is a liquid resulting from fermentation of sugar and it is sourced from plants containing carbohydrates (starch) [2].…”