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A Small-Volume, Low-Cost, and Versatile Continuous Culture Device.

Matteau D, Baby V, Pelletier S, Rodrigue S - PLoS ONE (2015)

Bottom Line: However, commercially available instruments are expensive, were not designed to handle small volumes in the milliliter range, and can lack the flexibility required for the diverse experimental needs found in several laboratories.Furthermore, the selected light-emitting diode and photodetector enable the use of phenol red as a pH indicator, which can be used to indirectly monitor the bulk metabolic activity of a cell population rather than the turbidity.This affordable and customizable system will constitute a useful tool in many areas of biology such as microbial ecology as well as systems and synthetic biology.

View Article: PubMed Central - PubMed

Affiliation: Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada.

ABSTRACT

Background: Continuous culture devices can be used for various purposes such as establishing reproducible growth conditions or maintaining cell populations under a constant environment for long periods. However, commercially available instruments are expensive, were not designed to handle small volumes in the milliliter range, and can lack the flexibility required for the diverse experimental needs found in several laboratories.

Methodology/principal findings: We developed a versatile continuous culture system and provide detailed instructions as well as a graphical user interface software for potential users to assemble and operate their own instrument. Three culture chambers can be controlled simultaneously with the proposed configuration, and all components are readily available from various sources. We demonstrate that our continuous culture device can be used under different modes, and can easily be programmed to behave either as a turbidostat or chemostat. Addition of fresh medium to the culture vessel can be controlled by a real-time feedback loop or simply calibrated to deliver a defined volume. Furthermore, the selected light-emitting diode and photodetector enable the use of phenol red as a pH indicator, which can be used to indirectly monitor the bulk metabolic activity of a cell population rather than the turbidity.

Conclusions/significance: This affordable and customizable system will constitute a useful tool in many areas of biology such as microbial ecology as well as systems and synthetic biology.

No MeSH data available.


Related in: MedlinePlus

Illustration of available continuous culture modes used to maintain cell growth.(A) Under its present software configuration, the versatile continuous cultivation device (VCCD) can behave like a turbidostat or a chemostat, or simply be used to measure the transmittance of a batch culture without performing any culture refresh. In the turbidostat mode, the culture is refreshed when a desired transmittance value is detected until: 1) a second value is reached [Real-time feedback loop] or 2) a specified refresh time has elapsed [Threshold-activated]. Alternatively, the chemostat behavior uses a Time interval mode to refresh the culture with a constant specified dilution rate. (B) In the Time interval mode, additional options are available to choose if the interval timer starts at a specified value or at a specified time, and to decide if refreshes are stopped in a time-dependent manner or using a transmittance threshold.
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pone.0133384.g004: Illustration of available continuous culture modes used to maintain cell growth.(A) Under its present software configuration, the versatile continuous cultivation device (VCCD) can behave like a turbidostat or a chemostat, or simply be used to measure the transmittance of a batch culture without performing any culture refresh. In the turbidostat mode, the culture is refreshed when a desired transmittance value is detected until: 1) a second value is reached [Real-time feedback loop] or 2) a specified refresh time has elapsed [Threshold-activated]. Alternatively, the chemostat behavior uses a Time interval mode to refresh the culture with a constant specified dilution rate. (B) In the Time interval mode, additional options are available to choose if the interval timer starts at a specified value or at a specified time, and to decide if refreshes are stopped in a time-dependent manner or using a transmittance threshold.

Mentions: In order to establish continuous cultures, we included different options and parameters in the VCCD software to accommodate various experimental parameters. Among those, one major setting that has to be considered before executing a continuous culture experiment is the desired general behavior of the system, which is defined according to the selected culture refresh mode (Fig 4A). For example, the Real-time feedback loop mode makes the VCCD behave like a turbidostat, in which the culture is diluted by fresh medium in response to a specific transmittance threshold until a second threshold is reached. In that mode, a maximum culture refresh time (pinch time) can be set to avoid culture overflow during a refresh cycle, thus forcing the system to execute multiple dilution cycles to obtain the desired transmittance value (see S1 Manual). If a chemostat behavior is more convenient for a specific experiment, the Time interval mode can be chosen to refresh the culture with a constant dilution rate. In that context, different options must be selected to specify whether the interval timer starts at a specified transmittance value or at a specified time, and if culture refreshing is stopped according to a defined pinch time or a transmittance threshold (Fig 4B).


A Small-Volume, Low-Cost, and Versatile Continuous Culture Device.

Matteau D, Baby V, Pelletier S, Rodrigue S - PLoS ONE (2015)

Illustration of available continuous culture modes used to maintain cell growth.(A) Under its present software configuration, the versatile continuous cultivation device (VCCD) can behave like a turbidostat or a chemostat, or simply be used to measure the transmittance of a batch culture without performing any culture refresh. In the turbidostat mode, the culture is refreshed when a desired transmittance value is detected until: 1) a second value is reached [Real-time feedback loop] or 2) a specified refresh time has elapsed [Threshold-activated]. Alternatively, the chemostat behavior uses a Time interval mode to refresh the culture with a constant specified dilution rate. (B) In the Time interval mode, additional options are available to choose if the interval timer starts at a specified value or at a specified time, and to decide if refreshes are stopped in a time-dependent manner or using a transmittance threshold.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4510131&req=5

pone.0133384.g004: Illustration of available continuous culture modes used to maintain cell growth.(A) Under its present software configuration, the versatile continuous cultivation device (VCCD) can behave like a turbidostat or a chemostat, or simply be used to measure the transmittance of a batch culture without performing any culture refresh. In the turbidostat mode, the culture is refreshed when a desired transmittance value is detected until: 1) a second value is reached [Real-time feedback loop] or 2) a specified refresh time has elapsed [Threshold-activated]. Alternatively, the chemostat behavior uses a Time interval mode to refresh the culture with a constant specified dilution rate. (B) In the Time interval mode, additional options are available to choose if the interval timer starts at a specified value or at a specified time, and to decide if refreshes are stopped in a time-dependent manner or using a transmittance threshold.
Mentions: In order to establish continuous cultures, we included different options and parameters in the VCCD software to accommodate various experimental parameters. Among those, one major setting that has to be considered before executing a continuous culture experiment is the desired general behavior of the system, which is defined according to the selected culture refresh mode (Fig 4A). For example, the Real-time feedback loop mode makes the VCCD behave like a turbidostat, in which the culture is diluted by fresh medium in response to a specific transmittance threshold until a second threshold is reached. In that mode, a maximum culture refresh time (pinch time) can be set to avoid culture overflow during a refresh cycle, thus forcing the system to execute multiple dilution cycles to obtain the desired transmittance value (see S1 Manual). If a chemostat behavior is more convenient for a specific experiment, the Time interval mode can be chosen to refresh the culture with a constant dilution rate. In that context, different options must be selected to specify whether the interval timer starts at a specified transmittance value or at a specified time, and if culture refreshing is stopped according to a defined pinch time or a transmittance threshold (Fig 4B).

Bottom Line: However, commercially available instruments are expensive, were not designed to handle small volumes in the milliliter range, and can lack the flexibility required for the diverse experimental needs found in several laboratories.Furthermore, the selected light-emitting diode and photodetector enable the use of phenol red as a pH indicator, which can be used to indirectly monitor the bulk metabolic activity of a cell population rather than the turbidity.This affordable and customizable system will constitute a useful tool in many areas of biology such as microbial ecology as well as systems and synthetic biology.

View Article: PubMed Central - PubMed

Affiliation: Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada.

ABSTRACT

Background: Continuous culture devices can be used for various purposes such as establishing reproducible growth conditions or maintaining cell populations under a constant environment for long periods. However, commercially available instruments are expensive, were not designed to handle small volumes in the milliliter range, and can lack the flexibility required for the diverse experimental needs found in several laboratories.

Methodology/principal findings: We developed a versatile continuous culture system and provide detailed instructions as well as a graphical user interface software for potential users to assemble and operate their own instrument. Three culture chambers can be controlled simultaneously with the proposed configuration, and all components are readily available from various sources. We demonstrate that our continuous culture device can be used under different modes, and can easily be programmed to behave either as a turbidostat or chemostat. Addition of fresh medium to the culture vessel can be controlled by a real-time feedback loop or simply calibrated to deliver a defined volume. Furthermore, the selected light-emitting diode and photodetector enable the use of phenol red as a pH indicator, which can be used to indirectly monitor the bulk metabolic activity of a cell population rather than the turbidity.

Conclusions/significance: This affordable and customizable system will constitute a useful tool in many areas of biology such as microbial ecology as well as systems and synthetic biology.

No MeSH data available.


Related in: MedlinePlus