Composition control of poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) copolymerization by oxygen transfer rate ( OTR ) in Azotobacter vinelandii OPNA

2021 ◽  
Author(s):  
Angie Johanna Torres‐Pedraza ◽  
Holjes Salgado‐Lugo ◽  
Daniel Segura ◽  
Alvaro Díaz‐Barrera ◽  
Carlos Peña
Keyword(s):  
Oxygen Transfer ◽  
Transfer Rate ◽  
Azotobacter Vinelandii ◽  
Oxygen Transfer Rate ◽  
Composition Control

Copolymerization of poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) produced by Azotobacter vinelandii OPNA is determined by the oxygen transfer rate of the culture

2021 ◽  
Author(s):  
Angie Johanna Torres Pedraza ◽  
Holjes Salgado-Lugo ◽  
Daniel Segura ◽  
Carlos Pena
Keyword(s):  
Mutant Strain ◽  
Oxygen Transfer ◽  
Transfer Rate ◽  
Azotobacter Vinelandii ◽  
Molar Fraction ◽  
Oxygen Transfer Rate ◽  
Agitation Rate ◽  
Industrial Level ◽  
Maximum Content

Abstract The aim of this study was to evaluate the changes in the composition of poly-3-hydoxybutyrate-co-3-hydroxyvalerate (PHBV) by an OPNA mutant strain of Azotobacter vinelandii cultured under different conditions. In shaken flasks, the oxygen transfer rate (OTR) significantly affected the PHBV composition, the highest content of 3-hydroxyvalerate (3HV) (28%) was achieved from the cultures developed at high OTR max (5.87 mmol L -1 h -1 ). In the bioreactor, the cultures were grown under oxygen limited conditions and different OTRs, varying the agitation rate. The highest PHBV accumulation (85%) was achieved at low OTR max (4.96 mmol L -1 h -1 ), whereas, the maximum content of 3HV (8.5 mol%) was obtained at higher OTR max (20.3 mmol L -1 h -1 ). Our results reveal that increasing the OTR rises the molar fraction of 3HV in the PHBV copolymer. Therefore, the manipulation of OTR could be a feasible strategy to produce PHBV copolymers with different monomeric compositions at industrial level.

DISTRIBUTION OF OXYGEN TRANSFER RATE IN STIRRED BIOREACTORS WITH SIMULATED BROTHS

2008 ◽  
Vol 7 (3) ◽  
pp. 199-211 ◽  
Author(s):  
Dan Cascaval ◽  
Anca-Irina Galaction ◽  
Stefanica Camarut ◽  
Radu Z. Tudose
Keyword(s):  
Oxygen Transfer ◽  
Transfer Rate ◽  
Oxygen Transfer Rate ◽  
Stirred Bioreactors

Estimation of oxygen transfer rate in sequencing batch reactor

1996 ◽  
Vol 34 (3-4) ◽  
pp. 413-420
Author(s):  
Y. C. Liao ◽  
D. J. Lee
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Transfer ◽  
Transfer Rate ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Oxygen Transfer Rate ◽  
Intermittent Aeration ◽  
Transient Effects ◽  
Operational Parameters ◽  
Transient Model

Transient model of oxygen transfer rate in a sequencing batch reactor is derived and solved numerically. The dissolved oxygen response under several conditions is analyzed. Effects of operational parameters and liquid bath height are studied. When with short, intermittent aeration periods, the transient effects on oxygen transfer rate may be substantial and should be taken into considerations. An example considering bioreaction is also given.

scholarly journals Two-Phase Flow Mass Transfer Analysis of Airlift Pump for Aquaculture Applications

Fluids ◽  
2021 ◽  
Vol 6 (6) ◽  
pp. 226
Author(s):  
Rashal Abed ◽  
Mohamed M. Hussein ◽  
Wael H. Ahmed ◽  
Sherif Abdou
Keyword(s):  
Mass Transfer ◽  
Oxygen Transfer ◽  
Transfer Rate ◽  
Two Phase Flow ◽  
Oxygen Transfer Rate ◽  
Flow Patterns ◽  
Oxygen Mass Transfer ◽  
Phase Flow ◽  
Two Phase ◽  
Airlift Pump

Airlift pumps can be used in the aquaculture industry to provide aeration while concurrently moving water utilizing the dynamics of two-phase flow in the pump riser. The oxygen mass transfer that occurs from the injected compressed air to the water in the aquaculture systems can be experimentally investigated to determine the pump aeration capabilities. The objective of this study is to evaluate the effects of various airflow rates as well as the injection methods on the oxygen transfer rate within a dual injector airlift pump system. Experiments were conducted using an airlift pump connected to a vertical pump riser within a recirculating system. Both two-phase flow patterns and the void fraction measurements were used to evaluate the dissolved oxygen mass transfer mechanism through the airlift pump. A dissolved oxygen (DO) sensor was used to determine the DO levels within the airlift pumping system at different operating conditions required by the pump. Flow visualization imaging and particle image velocimetry (PIV) measurements were performed in order to better understand the effects of the two-phase flow patterns on the aeration performance. It was found that the radial injection method reached the saturation point faster at lower airflow rates, whereas the axial method performed better as the airflow rates were increased. The standard oxygen transfer rate (SOTR) and standard aeration efficiency (SAE) were calculated and were found to strongly depend on the injection method as well as the two-phase flow patterns in the pump riser.

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