Bioreactor

About: Bioreactor is a research topic. Over the lifetime, 9980 publications have been published within this topic receiving 192690 citations. The topic is also known as: bioreactors.

Enzymatic hydrolysis of food waste and methane production using uasb bioreactor

Abstract: Complex carbohydrates of food waste (FW) can be converted to biogas, methane. In this article, enzymatic solubilization of FW and methane production potential using an upflow anaerobic sludge blanket (UASB) reactor of FW liquor enzymatically hydrolyzed were investigated. The optimum conditions of FW hydrolysis were enzyme mixture ratio of 1:2:1 with carbohydrase: protease: lipase, respectively, 0.2% (w/w FW) of mixture dose, and 10-h hydrolysis reaction. More than 95% of high soluble chemical oxygen demand (SCOD) removal efficiency and 0.35 L-CH4/g-SCOD of high methane yield were observed at 9.1 g-SCOD/L/d of organic loading rate. Our results revealed that methane production via a UASB reactor in conjunction with enzymatic hydrolysis of FW could be a novel anaerobic digestion process to obtain high-value biogas.

Simultaneous lipid production and dairy wastewater treatment using Rhodococcus opacus in a batch bioreactor for potential biodiesel application

Abstract: This study examined the valorization of dairy wastewater in the production of lipids by Rhodococcus opacus for biodiesel application. Using synthetic media based on dextrose and ammonium nitrate as the carbon and nitrogen source, respectively, the bacterium accumulated 71% (w/w) of lipids. Using only the raw dairy wastewater, the bacterium accumulated 14.28% w/w lipid and reduced the initial wastewater chemical oxygen demand (COD) by 30%. These values were, however, enhanced to 30–33% w/w and 62%, respectively, by supplementing the dairy wastewater with mineral salt media in the ratio 1:3. Bioreactor experiments were further performed using raw dairy wastewater and mineral salt medium in 1:3 ratio under both uncontrolled and controlled temperature and pH conditions. Interestingly biomass growth, lipid accumulation in the bioreactor experiments were found to be lower as compared to those in the shake flask experiments, whereas the wastewater COD removal was much higher in the bioreactor study. 1H nuclear magnetic resonance (NMR) spectroscopy of the fatty acids accumulated by the bacteria using dairy wastewater based media revealed that it contained more saturated fatty acids than unsaturated fatty acids. Gas chromatography (GC) analysis of the biodiesel produced by either ex-situ or in-situ transesterification of the bacterial lipids further revealed the presence of methyl palmitate (34.90%), methyl stearate (35.48%) methyl myristate (29.79%), methyl linoleate (27.87%), and methyl palmitate (25.85) as the main esters. The estimated properties of the transesterified product indicated its potential for biodiesel applications.

Continuous acetone–ethanol–butanol fermentation by immobilized cells of Clostridium acetobutylicum

Abstract: Eight Clostridium acetobutylicum strains were examined for α-amylase and strains B-591, B-594 and P-262 had the highest activities. Defibered-sweet-potato-slurry (DSPS), containing 39.7 g starch l−1, supplemented with potassium phosphate (1.0 g l −1 ) , cysteine-HCl (5.0 g l −1 ), the antifoam (polypropylene glycol, 0.1 mg ml −1 ), was used as continuous feedstock (FS) to a multistage bioreactor system for acetone–ethanol–butanol (AEB) fermentation. The system consisted of four columns (three vertical and one near horizontal) packed with beads containing immobilized cells of C. acetobutylicum P-262. When DSPS was pumped into the bioreactor system, at a flow rate of 2.36 ml min −1 , the effluent had 7.73 g solvents l−1 (1.56, acetone; 0.65, ethanol; 5.52 g, butanol) and no starch. Productivity of total solvents synthesized during continuous operation were 1.0 g l −1 h −1 and 19.5% yield compared to 0.12 g l −1 h −1 with 29% yield using the batch system. We propose using DSPS for AEB fermentation in a continuous mode with immobilized P-262 cells that are active amylase producers which will lead to cost reduction compared to the batch system.