Recovery of acids from anaerobic acidification broth by liquid-liquid extraction

Alkaya, Emrah
Kaptan, Serkan
Ozkan, Leyla
Uludag-Demirer, Sibel
Demirer, Göksel Niyazi
In this study, anaerobic acidification of sugar beet processing wastes and subsequent liquid-liquid extraction of produced fermentation metabolites were investigated. The aim of extraction experiments was to asses the influence of pH and extractant (trioctylphosphine oxide (TOPO) in kerosene) concentrations on the recovery of volatile fatty acids (VFAs) from fermentation broth. The effect of TOPO in kerosene concentration was as crucial as the effect of pH on the recovery of VFAs via extraction. Consequently, pH 2.5 was determined as optimum. At this pH, percent recoveries of VFAs were changed from 43% to 98%, depending on the type of the acid extracted (acetic, butyric, propionic and valeric acids) and the concentration of TOPO in kerosene (5-20%). As the concentration of TOPO in kerosene was increased, efficiency of extraction was increased. As a result, highest VFA recoveries (61-98%) were observed at 20% TOPO in kerosene with distribution ratio values ranging between 1.54 and 40.79. At pH 2.5, the increase in TOPO concentration directly increased the chemical oxygen demand (COD) removal efficiencies, as it does for total VFA recovery. Up to 72% COD removals were achieved, at 20% TOPO in kerosene at pH 2.5, while the removal efficiencies remained between 19% and 22% at pH 5.5.


Separation of the protease enzymes of Bacillus licheniformis from the fermentation medium by crossflow ultrafiltration
Takac, S; Elmas, S; Çalık, Pınar; Ozdamar, TH (2000-06-01)
The separation from fermentation medium of extracellular serine alkaline protease (SAP) enzyme produced by Bacillus licheniformis was investigated using a crossflow ultrafiltration system. SAP was separated from the high molecular weight neutral protease (NP) and amylase (AMY) enzymes and from the low molecular weight organic acids and amino acids in a crossflow ultrafiltration system with 30000 Da and 10000 Da MWCO polysulfone membranes, respectively. The effects of transmembrane pressure (TMP), recirculat...
Production of thermophylic α-amylase from aspergillus sp. and its utilization for various applications
Gazaloğlu, Mehmet; Hamamcı, Haluk; Department of Biotechnology (2017)
The objective of this study was to scale up the production of thermophilic α-amylase and its use to obtain fermentable sugar as the main carbon source for microorganisms such as baker’s yeast and Lactobacillus casei. Aspergillus niger N402 was the strain used for determining the fermentation parameters (carbon and nitrogen source, fermentation volume/total flask volume ratio (FV/TFV), pH & temperature of the fermentation and spore inoculum level.) Different strains (Am13, AmC18, and AmC28) were also tested ...
Preventing sluggish or stuck fermentations which may be caused by sugar uptake deficiency in saccharomyces cerevisiae wine yeast strains by using glucose isomerase
Ünal, Nahide Seray; Hamamcı, Haluk; Department of Food Engineering (2019)
The objective of this study was to prevent stuck fermentation, which may be caused by sugar uptake deficiency in yeast by using glucose isomerase, whose activity was tested in different media. The unfermented grape juice contains almost equal amounts of glucose and fructose. After fermentation, amount of residual fructose is higher than that of glucose and the glucose/fructose discrepancy (GFD) occurs. One of the main reasons of GFD is that affinity of hexose transporters of yeast towards fructose decreases...
Optimization of Ethanol Production From Microfluidized Wheat Straw by Response Surface Methodology
Turhan, Ozge; Isci, Asli; Mert, Behiç; Sakiyan, Ozge; Donmez, Sedat (2015-11-17)
In this study, wheat straw was pretreated with a microfluidizer to improve its enzymatic hydrolysis and ethanol yields. The pretreatment was performed at various pressures (500, 1000, and 1500bar) and solid loadings (1, 2, and 3%). The microfluidized biomass was then subjected to hydrolysis and simultaneous saccharification and co-fermentation (SSCF) experiments at different enzyme loadings (5, 10, and 15 FPU/g dry wheat straw) using a mutant yeast. The results indicated that the microfluidization method al...
Removal and recovery of nutrients as struvite from anaerobic digestion/co-digestion residues of poultry manure
Yılmazel, Yasemin Dilşad; Demirer, Göksel Niyazi; Department of Environmental Engineering (2009)
The main objective of this study was to investigate the removal and recovery of nutrients from anaerobic digestion residues of poultry manure through struvite (MgNH4PO4.6H2O, MAP) precipitation. To this purpose, three sets of laboratory experiments were conducted. In the first set, separate and co-digestion of poultry manure and sewage sludge were studied in laboratory-scale mesophilic anaerobic batch reactors and subsequent struvite precipitation experiments were conducted with the reactors effluents. The ...
Citation Formats
E. Alkaya, S. Kaptan, L. Ozkan, S. Uludag-Demirer, and G. N. Demirer, “Recovery of acids from anaerobic acidification broth by liquid-liquid extraction,” CHEMOSPHERE, pp. 1137–1142, 2009, Accessed: 00, 2020. [Online]. Available: