MINIFOR laboratory fermentor-bioreactor

Based on long personal practical experience with fermentation and cell culture, we have designed an easy to use system with the capacity to measure and control all the important parameters of the biological culture.

The fermentor have to take up minimum space on the bench but with good access to all parts. Several fermentors should, when placed side by side, be suitable for the optimization of the parameters of growth of culture or optimization of bio-transformations etc.

Each fermentor should be able to work independently or be connected to a PC for advanced regulation and extensive data treatment.

To keep the cost of the MINIFOR fermentor-bioreactor low, without compromising quality, several new ideas and innovations have been introduced: 

Instead of a fermentor flask with a stainless steel cover, which is expensive, we use whole glass vessels with threaded fittings. They have been used for many years in cell culture and are proved to maintain perfect sterility. Thanks to this concept, the MINIFOR fermenter-bioreactor is set up in shortest possible time.

The culture is heated by heat radiation produced in a parabolic radiator with a gold reflector placed under the fermentation vessel. The heat is absorbed gently in the culture similarly to the sun heating water. There is no overheating of the culture at any volume and expensive double-wall vessels with thermostatic baths are eliminated. At the same time tubing and cables disappear making the fermentor less complex.

Instead of a traditional propeller agitator, which requires an expensive motor and magnetic coupling, we have introduced a new up-and-down agitation. A motor together with an inexpensive membrane perfectly assure sterility and produce an efficient mixing without formation of a vortex (no baffles needed). At the same time this type of mixing is gentler on cells and produces less foam. Novel bio-mimicking “fish-tail” stirring discs offer maximum mixing efficiency without cutting edges.As far as possible expensive pieces of equipment have been replaced by new high performance plastics. 

Typical fermentation vessels require a rather complex fixing of head plates with many and very closely spaced ports and screws.

Heavy head plates are expensive and the accessibility of all ports on their top is bad, especially in the case of low volume vessels.

A new head plate is necessary for each vessel of different volume which leads to high additional costs.Threads of ports in head plates are shallow. 

This, together with the well-known o-ring flattening after sterilization, leads to contaminations.

MINI-4-GAS is a module for MINIFOR that allows a completely automatic gas-mix.

The MINI-4-GAS consists of MASSFLOWs and PC-Software.

MASSFLOWS will be measuring and regulating the gas-flow of the desired gasses.

It could be controlled remotely using LAMBDA SIAM PC control software extension.

The LAMBDA gas-mixing module allows a flexible mass flow controlled supply of different gases with individual gas flow paths.

LAMBDA REDOX allows the measurement of the Red-Ox potential and the digital transfer of the data to the PC through its RS-485 interface. The measured data can be visualized and recorded for example by the fermentation software SIAM.

The measurement of Red-Ox potential can be made with the laboratory fermenter-bioreactor LAMBDA MINIFOR, using a sterilizable combined pH/temperature probe with an additional Pt electrode fixed on its glass body. This probe is connected to the MINIFOR fermenter-bioreactor in the same way as the standard pH probe.

It does not require any additional connector, cable or side neck. However, the MINIFOR fermenter-bioreactor must have been equipped with the redox option in advance. The output RedOx signal is then provided on the “PUMP” socket at the rear side of the MINIFOR laboratory fermentor-bioreactor base unit.

LAMBDA Peltier electronic cooling loop for MINIFOR fermenter-bioreactor 

Cooling with this device is based on the electronic cooling effect produced by the flow of electric current through a Peltier cell. The Peltier cell allows cooling of the medium without the necessity of other means such as a refrigerating compressor or cooling water baths. LAMBDA has selected a cooling loop working according to the "heat pipe" principle, which has an advantage of having up to 80 times higher heat conduction compared to copper and can be used with various levels of medium. It works even when the loop is not entirely submerged in the medium.

The LAMBDA Peltier cooling system is extremely compact and advantageous when cultures should be run at temperatures close to room temperature or a few degrees below room temperature. Lower temperatures can be achieved by isolation of the vessel with convenient isolating material. The LAMBDA Peltier cooling loop eliminates the need of refrigerated circulating baths, which are expensive and take a lot of valuable bench surface.

Combined with the infrared-heating system of the MINIFOR bioreactor unit it offers very precise temperature control of the cell culture.

A very compact control system, which will allow good measurement and control of all important parameters by the same unit, is preferable for the user. Living organisms are extremely complex and it is desirable to measure and control as many parameters as possible. This will help to identify problems when they possibly arise.

Therefore, we decided to measure and control the five most important parameters: temperature, pH, pO2, air flow rate and stirring. In addition, we wanted to provide the option of controlling one supplementary parameter such as weight, glucose concentration, conductivity, redox potential, optical density (OD) and the like. For this reason, one selectable and controllable parameter "X" has been included. All readings can be seen at a glance without the necessity of scrolling or selecting menus.

The quality of regulation especially in PID controllers depends on the right setting of constants. From experience we know, that only few users know how to set these parameters properly. LAMBDA therefore leaves this task to the microprocessor which monitors what is going on in the current process and sets the right constants continuously. The working volume is recognized from the heating response on medium temperature and the most appropriate parameter setting is made automatically.

To spare the space around bioreactor vessels, LAMBDA has developed the smallest anti-foam control system consisting of a miniature foam detector ANTIFO and a subminiature syringe pump DOZITO.

The LAMBDA INTEGRATOR allows to record how much liquid or gas has been pumped as a function of time. This information was not available until now. Examples are:information for the regulation of reaction conditions such as pH, temperature or other parameters

information about the kinetics of the respective process

Completion or disturbances that have occurred during the process

The LAMBDA INTEGRATOR allows a simple and precise integration of the amount of liquid delivered by the pumps or gas delivered by the MASSFLOW gas flow controller. The electric impulses moving the stepping motor are registered and transformed into a direct current. The resulting voltage can then be measured and recorded. This data yields important information about the culture growth, its kinetics and time of completion.

The INTEGRATOR can also be used for measuring of enzyme activity (e.g. esterases, amidases, lactamases and other enzymes). It can be placed below the peristaltic pump and does not require additional bench space

The high quality LAMBDA peristaltic pumps PRECIFLOW, MULTIFLOW, HIFLOW and MAXIFLOW have been specially developed for long term continuous processes like fermentations and cell cultures:

Feed pump and harvest pump (fed-batch culture, continuous culture, chemostat, turbidostat, perfusion)
Controlled addition of nutrients, minerals
pH control (addition of acid, base, buffers)
Antifoam control (addition of antifoam agent)
Sampling at particular time interval
Feed flow rate profile
Sample addition/injection
Follow growth kinetics
Quantify the metabolic activity of the culture
Media dispenser
Process optimization with C-feed in fed batch
Pump media with foot switch for filling agar plates

LAMBDA's unique tubing compressing mechanics reduces pulsation and is very gentle to the tubing. No clamps, fixings or stoppers are required to hold the tubing in place. This leads to a long tubing life and the long term stability of flow rates even with low cost tubing.

The tubing economy is such that the LAMBDA PRECIFLOW peristaltic pump is paid back after the use of only 80 m of tubing. Thus, this is the only pump on the market, which saves more money than it costs!

Highest pump quality for continuous cultures