Effect of acids produced from carbohydrate metabolism in cryoprotectants on the viability of freeze-dried Lactobacillus and prediction of optimal initial cell concentration

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.

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Effect of protective agents, rehydration media and initial cell concentration on viability of Pantoea agglomerans strain CPA-2 subjected to freeze-drying

Journal of Applied Microbiology ◽

10.1046/j.1365-2672.2000.01182.x ◽

2000 ◽

Vol 89 (5) ◽

pp. 793-800 ◽

Cited By ~ 118

Author(s):

E. Costa ◽

J. Usall ◽

N. Teixido ◽

N. Garcia ◽

I. Vinas

Keyword(s):

Freeze Drying ◽

Cell Concentration ◽

Pantoea Agglomerans ◽

Initial Cell Concentration ◽

Initial Cell ◽

Protective Agents

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Studies of the recovery of frozen Salmonella gallinarum: the roles of cooling rate, initial cell concentration and plating medium*

International Journal of Food Science & Technology ◽

10.1111/j.1365-2621.1973.tb01708.x ◽

2007 ◽

Vol 8 (2) ◽

pp. 211-216 ◽

Cited By ~ 7

Author(s):

M. RACCACH ◽

B. JUVEN

Keyword(s):

Cooling Rate ◽

Cell Concentration ◽

Initial Cell Concentration ◽

Salmonella Gallinarum ◽

Initial Cell

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

Journal of Bacteriology ◽

10.1128/jb.69.3.244-249.1955 ◽

1955 ◽

Vol 69 (3) ◽

pp. 244-249 ◽

Cited By ~ 19

Author(s):

Cecil P. Major ◽

John D. McDougal ◽

Arthur P. Harrison

Keyword(s):

Cell Concentration ◽

Initial Cell Concentration ◽

Initial Cell

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Effect of culture age, protectants, and initial cell concentration on viability of freeze-dried cells ofMetschnikowia pulcherrima

Canadian Journal of Microbiology ◽

10.1139/w10-068 ◽

2010 ◽

Vol 56 (10) ◽

pp. 809-815 ◽

Cited By ~ 11

Author(s):

Davide Spadaro ◽

Annalisa Alessandra Ciavorella ◽

Jorge Giovanny Lopez-Reyes ◽

Angelo Garibaldi ◽

Maria Lodovica Gullino

Keyword(s):

Freeze Drying ◽

Cell Concentration ◽

Yeast Cells ◽

Initial Cell Concentration ◽

Commercial Development ◽

Culture Age ◽

Biocontrol Efficacy ◽

High Viability ◽

Freeze Dried ◽

Drying Conditions

The effect of freeze-drying using different lyoprotectants at different concentrations on the viability and biocontrol efficacy of Metschnikowia pulcherrima was evaluated. The effects of initial yeast cell concentration and culture age on viability were also considered. Yeast cells grown for 36 h were more resistant to freeze-drying than were 48 h cells. An initial concentration of 108cells·mL–1favoured the highest survival after freeze-drying. When maltose (25%, m/v) was used as protectant, a high cell viability was obtained (64.2%). Cells maintained a high viability after 6 months of storage at 4 °C. The biocontrol efficacy of freeze-dried cells was similar to the activity of fresh cells on ‘Gala’ apples and was slightly lower on ‘Golden Delicious’ apples. After optimizing freeze-drying conditions, the viability of M. pulcherrima cells was similar to that obtained in other studies. The results constitute a first step towards the commercial development of M. pulcherrima as a biocontrol agent.

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

Applied Biochemistry and Biotecnology ◽

10.1007/978-1-60327-181-3_53 ◽

2007 ◽

pp. 653-662 ◽

Cited By ~ 1

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

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

The Scientific World JOURNAL ◽

10.1100/2012/592721 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 1

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.

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