The comparison of trichloroethylene removal rates by methane- and aromatic-utilizing microorganisms

1998 ◽  
Vol 38 (7) ◽  
pp. 19-24 ◽  
Author(s):  
C.-J. Lu ◽  
C. M. Lee ◽  
M.-S. Chung
Keyword(s):  
Cell Concentration ◽  
Removal Rate ◽  
Carbon Sources ◽  
Batch Reactors ◽  
Initial Cell Concentration ◽  
Removal Rates ◽  
Initial Cell ◽  
Toluene Concentration ◽  
Cell Source ◽  
Removal Efficiencies

The comparison of TCE cometabolic removal by methane, toluene, and phenol utilizers was conducted with a series of batch reactors. Methane, toluene, or phenol enriched microorganisms were used as cell source. The initial cell concentration was about 107 cfu/mL. Methane, toluene, and phenol could be readily biodegraded resulting in the cometabolic removal of TCE. Among the three primary carbon sources studied, the presence of phenol provided the best cometabolic removal of TCE. When the concentration of carbon source was 3 mg-C/L, the initial TCE removal rates initiated by methane, toluene, and phenol utilizers were 1.5, 30, and 100 μg/L-hr, respectively. During the incubation period of 80 hours, TCE removal efficiencies were 26% and 96% with the presence of methane and toluene, respectively. However, it was 100% within 20 hours with the presence of phenol. For phenol utilizers, the initial TCE removal rates were about the same, when the phenol concentrations were 1.35, 2.7, and 4.5 mg/L. However, TCE removal was not proportional to the concentrations of phenol. TCE removal was hindered when the phenol concentration was higher than 4.5 mg/L because of the rapid depletion of dissolved oxygen. The presence of toluene also initiated cometabolic removal of TCE. The presence of toluene at 3 and 5 mg/L resulted in similar TCE removal. The initial TCE removal rate was about 95 μg/L-hr at toluene concentrations of 3 and 5 mg/L compared to 20 μg/L-hr at toluene concentration of 1 mg/L.

scholarly journals THE EFFECT OF THE INITIAL CELL CONCENTRATION UPON SURVIVAL OF BACTERIA AT −22 C

1955 ◽  
Vol 69 (3) ◽  
pp. 244-249 ◽  
Author(s):  
Cecil P. Major ◽  
John D. McDougal ◽  
Arthur P. Harrison
Keyword(s):  
Cell Concentration ◽  
Initial Cell Concentration ◽  
Initial Cell

The Effect of Initial Cell Concentration on Xylose Fermentation by Pichia stipitis

2007 ◽  
pp. 653-662 ◽  
Author(s):  
Frank K. Agbogbo ◽  
Guillermo Coward-Kelly ◽  
Mads Torry-Smith ◽  
Kevin Wenger ◽  
Thomas W. Jeffries
Keyword(s):  
Xylose Fermentation ◽  
Cell Concentration ◽  
Pichia Stipitis ◽  
Initial Cell Concentration ◽  
Initial Cell

scholarly journals The Growth ofMonoraphidiumsp. andScenedesmussp. Cells in the Presence of Thorium

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Juliana Cristina de Queiroz ◽  
Ana Cristina de Melo Ferreira ◽  
Antonio Carlos Augusto da Costa
Keyword(s):  
Cell Concentration ◽  
Direct Count ◽  
Initial Cell Concentration ◽  
Initial Cell ◽  
Count Method ◽  
Low Concentrations ◽  
Direct Counting ◽  
Presence And Absence ◽  
Positive Effect

Toxicity of thorium byMonoraphidiumsp. andScenedesmussp. was studied. Microalgal cultures were inoculated in ASM-1 medium in presence and absence of thorium. Its effect was monitored by direct counting on Fuchs-Rosenthal chamber and with software. The toxicity of thorium over the species was observed for concentrations over 50.0 mg/L. After 30 days,Monoraphidiumcells decreased their concentration from4.23×106to4.27×105and8.57×105 cells/mL, in the presence of 50.0 and 100.0 mg/L of thorium, respectively.Scenedesmussp. cells were more resistant to thorium: for an initial cell concentration of7.65×104 cells/mL it was observed a change to5.25×105and5.12×105 cells/mL, in the presence of thorium at 50.0 and 100.0 mg/L, respectively. This is an indication that low concentrations of the radionuclide favored the growth, and thatScenedesmuscells are more resistant to thorium thanMonoraphidiumcells. The software used for comparison with direct count method proved to be useful for the improvement of accuracy of the results obtained, a decrease in the uncertainty and allowed recording of the data. The presence of thorium suggests that low concentrations have a positive effect on the growth, due to the presence of the nitrate, indicating its potential for ecotoxicological studies.

The effect of initial cell concentration on xylose fermentation by Pichia stipitis

2007 ◽  
Vol 137-140 (1-12) ◽  
pp. 653-662 ◽  
Author(s):  
Frank K. Agbogbo ◽  
Guillermo Coward-Kelly ◽  
Mads Torry-Smith ◽  
Kevin Wenger ◽  
Thomas W. Jeffries
Keyword(s):  
Xylose Fermentation ◽  
Cell Concentration ◽  
Pichia Stipitis ◽  
Initial Cell Concentration ◽  
Initial Cell

Modeling the effect of initial cell concentration and soluble solids on the plasma inactivation of yeast in apple juices

LWT ◽  
2021 ◽  
pp. 112227
Author(s):  
Xiaowei Bao ◽  
Zirong Wang ◽  
Wenle Zhang ◽  
Haiyan Yang ◽  
Xuan Zhu ◽  
...  
Keyword(s):  
Cell Concentration ◽  
Soluble Solids ◽  
Initial Cell Concentration ◽  
Initial Cell

Effects of initial cell concentration, growth phase, and process parameters on the viability of Lactobacillus rhamnosus GG after spray drying

2019 ◽  
Vol 38 (11) ◽  
pp. 1474-1492 ◽  
Author(s):  
Géraldine Broeckx ◽  
Shari Kiekens ◽  
Katarina Jokicevic ◽  
Eline Byl ◽  
Tim Henkens ◽  
...  
Keyword(s):  
Spray Drying ◽  
Process Parameters ◽  
Growth Phase ◽  
Cell Concentration ◽  
Lactobacillus Rhamnosus ◽  
Lactobacillus Rhamnosus Gg ◽  
Initial Cell Concentration ◽  
Initial Cell

scholarly journals L-asparaginase Production by Leucosporidium scottii in a Bench-Scale Bioreactor With Co-production of Lipids

2020 ◽  
Vol 8 ◽  
Author(s):  
Ignacio S. Moguel ◽  
Celina K. Yamakawa ◽  
Adalberto Pessoa ◽  
Solange I. Mussatto
Keyword(s):  
Carbon Source ◽  
Production Process ◽  
Enzyme Production ◽  
Cell Concentration ◽  
Economic Feasibility ◽  
Process Conditions ◽  
Initial Cell Concentration ◽  
Initial Cell ◽  
Bench Scale ◽  
Accumulation Of Lipids

L-asparaginase (ASNase) is a therapeutical enzyme used for treatment of acute lymphoblastic leukemia. ASNase products available in the market are produced by bacteria and usually present allergic response and important toxicity effects to the patients. Production of ASNase by yeasts could be an alternative to overcome these problems since yeasts have better compatibility with the human system. Recently, it was found that Leucosporidium scottii, a psychrotolerant yeast, produces ASNase. In order to advance the production of ASNase by this yeast, the present study aimed to select suitable process conditions able to maximize the production of this enzyme in a bench-scale bioreactor. Additionally, the accumulation of lipids during the enzyme production process was also determined and quantified. Experiments were carried out with the aim of selecting the most appropriate conditions of initial cell concentration (1.0, 3.5, and 5.6 g L–1), carbon source (sucrose and glycerol, individually or in mixture) and oxygen transfer rate (kLa in the range of 1.42–123 h–1) to be used on the production of ASNase by this yeast. Results revealed that the enzyme production increased when using an initial cell concentration of 5.6 g L–1, mixture of sucrose and glycerol as carbon source, and kLa of 91.72 h–1. Under these conditions, the enzyme productivity was maximized, reaching 35.11 U L–1 h–1, which is already suitable for the development of scale-up studies. Additionally, accumulation of lipids was observed in all the cultivations, corresponding to 2–7 g L–1 (32–40% of the cell dry mass), with oleic acid (C18:1) being the predominant compound (50.15%). Since the L-asparaginase biopharmaceuticals on the market are highly priced, the co-production of lipids as a secondary high-value product during the ASNase production, as observed in the present study, is an interesting finding that opens up perspectives to increase the economic feasibility of the enzyme production process.

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