scholarly journals Phenol Degradation Kinetics by Free and Immobilized Pseudomonas putida BCRC 14365 in Batch and Continuous-Flow Bioreactors

Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 721
Author(s):  
Yen-Hui Lin ◽  
Yu-Siang Cheng

Phenol degradation by Pseudomonas putida BCRC 14365 was investigated at 30 °C and a pH of 5.0–9.0 in the batch tests. Experimental results for both free and immobilized cells demonstrated that a maximum phenol degradation rate occurred at an initial pH of 7. The peak value of phenol degradation rates by the free and immobilized cells were 2.84 and 2.64 mg/L-h, respectively. Considering the culture at 20 °C, there was a lag period of approximately 44 h prior to the start of the phenol degradation for both free and immobilized cells. At the temperatures ranging from 25 to 40 °C, the immobilized cells had a higher rate of phenol degradation compared to the free cells. Moreover, the removal efficiencies of phenol degradation at the final stage were 59.3–92% and 87.5–92%, for the free and immobilized cells, respectively. The optimal temperature was 30 °C for free and immobilized cells. In the batch experiments with various initial phenol concentrations of 68.3–563.4 mg/L, the lag phase was practically negligible, and a logarithmic growth phase of a particular duration was observed from the beginning of the culture. The specific growth rate (μ) in the exponential growth phase was 0.085–0.192 h−1 at various initial phenol concentrations between 68.3 and 563.4 mg/L. Comparing experimental data with the Haldane kinetics, the biokinetic parameters, namely, maximum specific growth rate (μmax), the phenol half-saturation constant (Ks) and the phenol inhibition constant (KI), were determined to equal 0.31 h−1, 26.2 mg/L and 255.0 mg/L, respectively. The growth yield and decay coefficient of P. putida cells were 0.592 ± 4.995 × 10−3 mg cell/mg phenol and 5.70 × 10−2 ± 1.122 × 10−3 day−1, respectively. A completely mixed and continuous-flow bioreactor with immobilized cells was set up to conduct the verification of the kinetic model system. The removal efficiency for phenol in the continuous-flow bioreactor was approximately 97.7% at a steady-state condition. The experimental and simulated methodology used in this work can be applied, in the design of an immobilized cell process, by various industries for phenol-containing wastewater treatment.

2019 ◽  
pp. 12-16
Author(s):  
M. S. Firsova ◽  
V. A. Yevgrafova ◽  
A. V. Potekhin

Different liquid nutrient media supplemented with growth factors intended for Avibacterium paragallinarum strain No. 5111 cultivation were com­pared. The highest specific growth rate (μ = 0.787 ± 0.041 h-1) and the maximal accumulation of the agent’s biomass (Х = 9.52 ± 0.04 lg CFU/ cm3) were reported when cultured in casein soybean broth. Herewith, the mean time of the live microbial cell concentration doubling was minimal (td = 0.88 h), and the exponential growth phase lasted for 6 hours. The optimal method for Avibacterium paragallinarum cultivation in casein soy­bean broth in laboratory bioreactor Biotron LiFlus GX was determined through the measurements and adjustment of basic physical and chemical parameters. The time period until the culture reached the stationary growth phase was maximal with aeration at 1.0 l/min; herewith, the O2 partial pressure in the nutrient medium did not exceed 25%. The period of the intense decrease of medium’s pH was accompanied with the exponential phase of the bacterial growth. The nutrient medium’s pH ranging from 7.30 ± 0.02 to 7.90 ± 0.06 had no significant impact on the specific growth rate of the strain and the lag phase duration was minimal – 0.36–0.45 h. The strain cultivation in the nutrient medium with pH 7.90 ± 0.06 demonstrated maximal aggregation of the bacteria (9.76 ± 0.04 lg CFU/cm3). 40% glucose solution added at 0.6-0.8 g/l during cultivation facilitated the decrease of the suspension’s pH. Minimal redox value (–75 mV) was indicative of the completion of the exponential phase of the strain growth.  


2002 ◽  
Vol 30 (4) ◽  
pp. 696-698 ◽  
Author(s):  
M. G. Wiebe

Fusarium venenatum A3/5 was grown in iron-restricted batch cultures and iron-limited chemostat cultures to determine how environmental conditions affected siderophore production. The specific growth rate in iron-restricted batch cultures was 0.22 h−1, which was reduced to 0.12 h−1 when no iron was added to the culture. Derit in iron-limited chemostat culture was 0.1 h−1. Siderophore production was correlated with specific growth rate, with the highest siderophore production occurring at D = 0.08 h−1 and the lowest at D = 0.03 h−1. Siderophore production was greatest at pH 4.7 and was significantly reduced at pHs above 6.0. Siderophore production could be enhanced by providing insoluble iron instead of soluble iron in continuous flow cultures.


1995 ◽  
Vol 126 (2) ◽  
pp. 151-157 ◽  
Author(s):  
Duncan R. Simpson ◽  
Marilyn G. Wiebe ◽  
Geoffrey D. Robson ◽  
Anthony P.J. Trinci

2013 ◽  
Vol 724-725 ◽  
pp. 369-372
Author(s):  
Jin Hua Wang ◽  
Feng Huang ◽  
Xiao Zhao ◽  
Jin Fang Zhao ◽  
Yong Ze Wang ◽  
...  

Hydrolysis of the aquatic vegetables waste would lead to the generation of some toxic components and by-products, such as weak acids, aldehydes and phenols. They might do harm to sequent fermentation process to some extent. The toxic effect of acetic acid on ethanol fermentation by ethanologenic Escherichia coli SZ470 was investigated. The growth curves of Escherichia coli SZ470, specific growth rate (μ), the ethanol yield and consumption of glucose were compared with different concentrations of acetic acid addition in the fermentation medium. When concentrations of acetic acid exceed 0.8 g/L, the exponential growth phase of Escherichia coli SZ470 was significantly expanded from 10 h to above 12 h, moreover, the ethanol yield and consumption of glucose drastically decreased. Specific growth rate increased as acetic acid concentrations below 0.6 g/L, but fell as acetic acid concentrations exceeded 0.6 g/L, the result indicated that minor amount of acetic acid might be helpful with growth of Escherichia coli SZ470.


Aquaculture ◽  
2008 ◽  
Vol 274 (1) ◽  
pp. 87-95 ◽  
Author(s):  
S. Millot ◽  
M.-L. Bégout ◽  
J. Person-Le Ruyet ◽  
G. Breuil ◽  
C. Di-Poï ◽  
...  

2010 ◽  
Vol 45 (11) ◽  
pp. 1800-1807 ◽  
Author(s):  
S. Chenikher ◽  
J.S. Guez ◽  
F. Coutte ◽  
M. Pekpe ◽  
P. Jacques ◽  
...  

2012 ◽  
Vol 48 (2) ◽  
pp. 382-386 ◽  
Author(s):  
Juan Aguirre ◽  
Mª Rosa Rodríguez ◽  
Rodrigo González ◽  
Gonzalo García de Fernando

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