scholarly journals Two-Stage Polyhydroxyalkanoates (PHA) Production from Cheese Whey Using Acetobacter Pasteurianus C1 and Bacillus sp. CYR1

2021 ◽  
Vol 8 (11) ◽  
pp. 157
Author(s):  
Young-Cheol Chang ◽  
M. Venkateswar Reddy ◽  
Kazuma Imura ◽  
Rui Onodera ◽  
Natsumi Kamada ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Carbon Source ◽  
Cheese Whey ◽  
Bacillus Sp ◽  
Two Stage ◽  
Acetobacter Pasteurianus ◽  
13C Nuclear Magnetic Resonance ◽  
Ft Ir ◽  
Stage Process ◽  
Pha Production

Cheese whey (CW) can be an excellent carbon source for polyhydroxyalkanoates (PHA)-producing bacteria. Most studies have used CW, which contains high amounts of lactose, however, there are no reports using raw CW, which has a relatively low amount of lactose. Therefore, in the present study, PHA production was evaluated in a two-stage process using the CW that contains low amounts of lactose. In first stage, the carbon source existing in CW was converted into acetic acid using the bacteria, Acetobacter pasteurianus C1, which was isolated from food waste. In the second stage, acetic acid produced in the first stage was converted into PHA using the bacteria, Bacillus sp. CYR-1. Under the condition of without the pretreatment of CW, acetic acid produced from CW was diluted at different folds and used for the production of PHA. Strain CYR-1 incubated with 10-fold diluted CW containing 5.7 g/L of acetic acid showed the higher PHA production (240.6 mg/L), whereas strain CYR-1 incubated with four-fold diluted CW containing 12.3 g/L of acetic acid showed 126 mg/L of PHA. After removing the excess protein present in CW, PHA production was further enhanced by 3.26 times (411 mg/L) at a four-fold dilution containing 11.3 g/L of acetic acid. Based on Fourier transform infrared spectroscopy (FT-IR), and 1H and 13C nuclear magnetic resonance (NMR) analyses, it was confirmed that the PHA produced from the two-stage process is poly-β-hydroxybutyrate (PHB). All bands appearing in the FT-IR spectrum and the chemical shifts of NMR nearly matched with those of standard PHB. Based on these studies, we concluded that a two-stage process using Acetobacter pasteurianus C1 and Bacillus sp. CYR-1 would be applicable for the production of PHB using CW containing a low amount of lactose.

scholarly journals Effect of Corrosive Media on the Chemical and Mechanical Resistance of IPS e.max® CAD Based Li2Si2O5 Glass-Ceramics

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 365
Author(s):  
Anna Švančárková ◽  
Dagmar Galusková ◽  
Aleksandra Ewa Nowicka ◽  
Helena Pálková ◽  
Dušan Galusek
Keyword(s):  
Wear Resistance ◽  
Acetic Acid ◽  
Prolonged Exposure ◽  
Glass Ceramics ◽  
Mechanical Resistance ◽  
Two Stage ◽  
Lithium Metasilicate ◽  
Dynamic Conditions ◽  
One Stage ◽  
Stage Process

The influence of 4% acetic acid (pH~2.4) and an alkaline solution of NaOH (pH~10) on the corrosion resistance and micromechanical properties of disilicate crystals containing glass-ceramics (LS2-GC’s) is studied. Partially crystallized lithium metasilicate crystal containing glass-ceramics (LS-GC’s) are annealed to fully LS2-GC’s using a one stage and a two-stage heating to induce nucleation. Materials with various chemical and wear resistance are prepared. The content of the crystalline phase in the material annealed in the two-stage process A is 60.0% and increases to 72.2% for the material heated in the one-stage process B. The main elements leached in the acidic medium are lithium and phosphorus, while lithium, silicon, and phosphorus leached into the alkaline environment. Material B exhibits better chemical resistance to the corrosive influence of 4% acetic acid under quasi-dynamic conditions. In the alkaline corrosion medium, silicon is leached from material A faster compared to the material B. After prolonged exposure to acidic or basic environments, both materials show evidence of surface structural changes. A decrease of the sliding wear resistance is observed after corrosion in the acidic environment under dynamic conditions. In both materials, the wear rate increases after corrosion.

Continuous hydrogen and methane production in a two-stage cheese whey fermentation system

2011 ◽  
Vol 64 (2) ◽  
pp. 367-374 ◽  
Author(s):  
C. B. Cota-Navarro ◽  
J. Carrillo-Reyes ◽  
G. Davila-Vazquez ◽  
F. Alatriste-Mondragón ◽  
E. Razo-Flores
Keyword(s):  
Methane Production ◽  
Cheese Whey ◽  
Continuous Production ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Stable Operation ◽  
Operational Parameters ◽  
Two Stage ◽  
Production Of Hydrogen ◽  
Stage Process

The feasibility of integrating biological hydrogen and methane production in a two-stage process using mixed cultures and cheese whey powder (CWP) as substrate was studied. The effect of operational parameters such as hydraulic retention time (HRT) and organic loading rate (OLR) on the volumetric hydrogen (VHPR) and methane (VMPR) production rates was assessed. The highest VHPR was 28 L H2/L/d, obtained during stable operation in a CSTR at HRT and OLR of 6 h and 142 g lactose/L/d, respectively. Moreover, hydrogen (13 L/L/d) was produced even at HRT as low as 3.5 h and OLR of 163 g lactose/L/d, nonetheless, the reactor operation was not stable. Regarding methane production in an UASB reactor, the acidified effluent from the hydrogen-producing bioreactor was efficiently treated obtaining COD removals above 90% at OLR and HRT of 20 g COD/L/d and 6 h, respectively. The two-stage process for continuous production of hydrogen and methane recovered over 70% of the energy present in the substrate. This study demonstrated that hydrogen production can be efficiently coupled to methane production in a two-stage system and that CWP is an adequate substrate for energy production.

scholarly journals Assessment of Single- vs. Two-Stage Process for the Anaerobic Digestion of Liquid Cow Manure and Cheese Whey

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5423
Author(s):  
Margarita Andreas Dareioti ◽  
Aikaterini Ioannis Vavouraki ◽  
Konstantina Tsigkou ◽  
Michael Kornaros
Keyword(s):  
Anaerobic Digestion ◽  
Production Rate ◽  
Methane Production ◽  
Cheese Whey ◽  
Biogas Production ◽  
Single Stage ◽  
Cow Manure ◽  
Two Stage ◽  
Methane Production Rate ◽  
Stage Process

The growing interest in processes that involve biomass conversion to renewable energy, such as anaerobic digestion, has stimulated research in this field in order to assess the optimum conditions for biogas production from abundant feedstocks, like agro-industrial wastes. Anaerobic digestion is an attractive process for the decomposition of organic wastes via a complex microbial consortium and subsequent conversion of metabolic intermediates to hydrogen and methane. The present study focused on the exploitation of liquid cow manure (LCM) and cheese whey (CW) as noneasily and easily biodegradable sources, respectively, using continuous stirred-tank reactors for biogas production, and a comparison was presented between single- and two-stage anaerobic digestion systems. No significant differences were found concerning LCM treatment, in a two-stage system compared to a single one, concluding that LCM can be treated by implementing a single-stage process, as a recalcitrant substrate, with the greatest methane production rate of 0.67 L CH4/(LR·d) at an HRT of 16 d. On the other hand, using the easily biodegradable CW as a monosubstrate, the two-stage process was considered a better treatment system compared to a single one. During the single-stage process, operational problems were observed due to the limited buffering capacity of CW. However, the two-stage anaerobic digestion of CW produced a stable methane production rate of 0.68 L CH4/(LR·d) or 13.7 L CH4/Lfeed, while the total COD was removed by 76%.

Evaluation of a two-stage hydrothermal process for enhancing acetic acid production using municipal biosolids

2012 ◽  
Vol 65 (1) ◽  
pp. 149-155 ◽  
Author(s):  
Anderson Aggrey ◽  
Peter Dare ◽  
Robert Lei ◽  
Daniel Gapes
Keyword(s):  
Acetic Acid ◽  
Acid Production ◽  
Oxidation Process ◽  
Hydrothermal Process ◽  
Wet Oxidation ◽  
Thermal Hydrolysis ◽  
Two Stage ◽  
Acetic Acid Production ◽  
Stage Process ◽  
Municipal Biosolids

A two-stage hydrothermal process aimed at improving acetic acid production using municipal biosolids was evaluated against thermal hydrolysis and conventional wet oxidation process in a 600 ml Parr batch reactor. Thermal hydrolysis was conducted at 140 °C, wet oxidation at 220 °C and the two-stage process, which acted as a series combination of thermal hydrolysis and wet oxidation, at 220 °C. Initial pressure of 1 MPa was maintained in all the three processes. The results indicated that the highest acetic acid production of up to 58 mg/g dry solids feed was achieved in the wet oxidation process followed by the two-stage process with 36 mg/g dry solids feed and 1.8 mg/g dry solids feed for thermal hydrolysis. The acetic acid yield obtained by the thermal processes increased from 0.4% in the thermal hydrolysis process to 12% during the single stage wet oxidation, with the two-stage process achieving 8%. The purity of the acetic acid improved from 1% in thermal hydrolysis to 38% in the wet oxidation process. The two-stage process achieved acetic acid purity of 25%. This work demonstrated no enhancement of acetic acid production by the two-stage concept compared with the single stage wet oxidation process. This is in contrast to similar work by other researchers, investigated on carbohydrate biomass and vegetable wastes using hydrogen peroxide as the oxidant. However, the data obtained revealed that substrate specificity, reaction severity or oxidant type is clearly important in promoting reaction mechanisms which support enhanced acetic acid production using municipal biosolids.

Extracting value-added products before pulping: Hemicellulosic ethanol from Eucalyptus globulus wood

Holzforschung ◽  
2012 ◽  
Vol 66 (5) ◽  
pp. 591-599 ◽  
Author(s):  
Julio Rodríguez-López ◽  
Aloia Romaní ◽  
María J. González-Muñoz ◽  
Gil Garrote ◽  
Juan C. Parajó
Keyword(s):  
Acetic Acid ◽  
Eucalyptus Globulus ◽  
Value Added ◽  
Pichia Stipitis ◽  
Two Stage ◽  
Stage Process ◽  
Hot Compressed Water ◽  
Fermentation Media ◽  
Value Added Products ◽  
Membrane Concentration

Abstract Xylose solutions have been produced from Eucalyptus globulus wood by autohydrolysis (with hot, compressed water) and post-hydrolysis (in presence of sulfuric acid). This two-stage process led to solids enriched in cellulose and lignin (suitable as a substrate for pulping) and liquors containing xylose as the major component. The liquid phase from post-hydrolysis also contained other sugars (glucose, arabinose) and acetic acid. Neutralized liquors (as obtained, or after membrane concentration), were employed (directly or after detoxification by ion exchange) as fermentation media for the production of hemicelluosic bioethanol with the yeast Pichia stipitis CECT 1922T. Under the best conditions assayed (fermentation of neutralized, concentrated and detoxified two-stage hydrolysis liquors), bioconversion took place at nearly stoichiometric yield, with a volumetric productivity of 0.37 g l-1·h-1.

scholarly journals Enhancement of Biogas Production by Using a Two-Stage Process for the Anaerobic Digestion of Cheese Whey

2017 ◽  
pp. 130 ◽  
Author(s):  
Margarita A. Dareioti ◽  
Spyros N. Dokianakis ◽  
Constantina Zafiri ◽  
Michael Kornaros
Keyword(s):  
Anaerobic Digestion ◽  
Cheese Whey ◽  
Biogas Production ◽  
Organic Content ◽  
Single Stage ◽  
Total Carbon ◽  
Municipal Sewage ◽  
Two Stage ◽  
Specific Product ◽  
Stage Process

Cheese making companies have a specific product that is seasonally produced and, like most other agro-industries, generate wastewaters characterized by a high organic loading. Cheese whey is the most important waste stream produced having a high organic content (up to 70 g COD/L), which is highly biodegradable, and low alkalinity (50 meq/L). Cheese production industries worldwide generate more than 145 million tones of liquid whey per year. Because of these characteristics, cheese whey may cause serious environmental problems on the local municipal sewage treatment systems or water receptors if disposed untreated. Anaerobic digestion is a particularly attractive treatment solution for high strength wastewaters due to the operational economy and generation of biogas and therefore is considered as a promising solution for energy production from cheese whey, in this case. In this work, a comparative study between single and two-stage anaerobic treatment of cheese whey was conducted in order to enhance biogas production. Our experiments were carried out using one reactor for the single-stage process (operated at a HRT of 20 d), and two reactors connected in series, from which the first one was used for acidogenesis (operated at a HRT of 3 d) and the other for methanogenesis (operated at a HRT of 20 d). The single-stage process presented many operational problems, as a result of little or no buffering capacity of whey, which caused the pH of the anaerobic digester to drop drastically and the process being inhibited. This kind of inhibition proved to be irreversible and the digester was not able to recover even though it was operated batchwise and the value of the pH was restored to 7.0. On the contrary, the two-stage process exhibited a stable biogas production rate of 1.57 L/Lreactor/d with the composition of methane in the biogas reaching 54.3%. The dissolved COD and total carbon concentration removal was 70.5% and 77.2% respectively.

scholarly journals Two-Stage Biodiesel Synthesis from Used Cooking Oil with a High Acid Value via an Ultrasound-Assisted Method

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3703
Author(s):  
Ming-Chien Hsiao ◽  
Wei-Ting Lin ◽  
Wei-Cheng Chiu ◽  
Shuhn-Shyurng Hou
Keyword(s):  
Acid Value ◽  
Molar Ratio ◽  
Optimal Conditions ◽  
Two Stage ◽  
Cooking Oil ◽  
High Acid ◽  
Used Cooking Oil ◽  
Biodiesel Synthesis ◽  
Stage Process ◽  
Ultrasound Assisted

In this study, ultrasound was used to accelerate two-stage (esterification–transesterification) catalytic synthesis of biodiesel from used cooking oil, which originally had a high acid value (4.35 mg KOH/g). In the first stage, acid-catalyzed esterification reaction conditions were developed with a 9:1 methanol/oil molar ratio, sulfuric acid dosage at 2 wt %, and a reaction temperature of 60 °C. Under ultrasound irradiation for 40 min, the acid value was effectively decreased from 4.35 to 1.67 mg KOH/g, which was decreased to a sufficient level (<2 mg KOH/g) to avoid the saponification problem for the subsequent transesterification reaction. In the following stage, base-catalyzed transesterification reactions were carried out with a 12:1 methanol/oil molar ratio, a sodium hydroxide dosage of 1 wt %, and a reaction temperature of 65 °C. Under ultrasound-assisted transesterification for 40 min, the conversion rate of biodiesel reached 97.05%, which met the requirement of EN 14214 standard, i.e., 96.5% minimum. In order to evaluate and explore the improvement of the ultrasound-assisted two-stage (esterification–transesterification) process in shortening the reaction time, additional two-stage biodiesel synthesis experiments using the traditional mechanical stirring method under the optimal conditions were further carried out in this study. It was found that, under the same optimal conditions, using the ultrasound-assisted two-stage process, the total reaction time was significantly reduced to only 80 min, which was much shorter than the total time required by the conventional method of 140 min. It is worth noting that compared with the traditional method without ultrasound, the intensification of the ultrasound-assisted two-stage process significantly shortened the total time from 140 min to 80 min, which is a reduction of 42.9%. It was concluded that the ultrasound-assisted two-stage (esterification–transesterification) catalytic process is an effective and time-saving method for synthesizing biodiesel from used cooking oil with a high acid value.

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