Production of Lactic Acid from Carob, Banana and Sugarcane Lignocellulose Biomass.

Lignocellulosic biomass from agricultural residues is a promising feedstock for lactic acid (LA) production. The aim of the current study was to investigate the production of LA from different lignocellulosic biomass. The LA production from banana peduncles using strain Bacillus coagulans with yeast extract resulted in 26.6 g LA·L-1, and yield of 0.90 g LA·g-1 sugars. The sugarcane fermentation with yeast extract resulted in 46.5 g LA·L-1, and yield of 0.88 g LA·g-1 sugars. Carob showed that addition of yeast extract resulted in higher productivity of 3.2 g LA·L-1·h-1 compared to without yeast extract where1.95 g LA·L-1·h-1 was obtained. Interestingly, similar LA production was obtained by the end where 54.8 and 51.4 g·L-1 were obtained with and without yeast extract, respectively. A pilot scale of 35 L using carob biomass fermentation without yeast extract resulted in yield of 0.84 g LA·g-1 sugars, and productivity of 2.30 g LA·L-1·h-1 which indicate a very promising process for future industrial production of LA.

Circular economy in olive oil production - Olive mill solid waste to ethanol and heavy metal sorbent using microwave pretreatment.

Olive mill solid waste (OMSW) is an abundant agricultural waste without viable solution. The effects of OMSW different pretreatments (microwave or autoclave), different additives (water, formic, or sulfuric acid), and utilization of different saccharification enzymes (Cellic® CTec2 or Accellerase® 1500) were tested on saccharification process and sugar release, and on fermentation inhibitors formation and ethanol production. Microwave treatment with formic acid resulted in highest saccharification rates (90% of cellulose fraction) and fermentation yields (15.9 g/L ethanol), although loss of sugars and fermentation inhibitors production was notable. Microwave with water treatment resulted in less saccharification and ethanol (9.6 g/L). To facilitate economical process and to extract maximum value, solid remnants after saccharification were tested as heavy metal sorbent. Microwave with water resulted in the best sorbent, followed by microwave with formic acid. Addition of sulfuric acid, to either microwave or autoclave, resulted in very poor saccharification and absorbance capacity. Therefore, combination of ethanol and sorbent production from OMSW are suggested.