J. Chem. Chem. Eng. 5 (2011) 897-902

Remote Control of Fed-Batch Fermentation Systems
Eric Moreau3, Floyd Inman, III1, Sunita Singh2, Heather Walters1 and Leonard Holmes1*
1. Biotechnology Research and Training Center, University of North Carolina at Pembroke, Pembroke, NC, USA 2. Central Institute of Agricultural Engineering, Bhopal, Madhya Pradesh, India 3.Université de Picardie Jules Verne, Amiens, France

Received: June 14, 2011 / Accepted: July 11, 2011 / Published: October 10, 2011. Abstract: Bioreactor operation requires continuous monitoring of fermentation parameters and real-time control over bioreactor devices. Remote monitoring and control of the bioreactor’s computer via the Internet avoids the necessity of personnel being continually onsite during operation. A two liter Sartorius-stedim Biostat® A Plus fermentation system was networked and interfaced with the commercial software from GoToMyPC® to allow remote control of the fermentation system utilizing the internet. The fermentation vessel was equipped with hardware calibrated for monitoring and controlling culture parameters during experimentations. The uniform resource locator controlled night-vision web camera allowed continuous monitoring of the glass fermentation vessel during the day and at night. The main window screen of the laboratory computer can be securely accessed from any portable device (i.e. laptop) capable of establishing an Internet connection and executing the commercial software from GoToMyPC®. The secured internet protocol address, provided by GoToMyPC®, assures that the system can only be controlled by authorized users who have been given access to the account. This interface permits the remote control of the Biostat® A Plus fermentation system and possibly other automated or potentially automated culturing systems at the convenience of the user(s). Key words: Fermentation, Fed-batch, Remote-monitoring, Remote-controlled fermentation systems.

1. Introduction
Fed-batch fermentations can be defined as processes in which a usable substrate is added over particular intervals during the life of the batch to maintain optimal substrate concentrations to promote the maximum production of the desired product. At the conclusion of the batch, the fed-batch culture is further processed to purify the desired product. These fed-batch cultures are maintained and cultured in complex fermentation systems that monitor the fermentation process [1]. Fed-batch fermentation systems are extensively used in the food and pharmaceutical industries where they are mainly utilized because they merge the advantages of both batch and continuous fermentation processes to reduce costs [2]. In industrial fermentation systems, consistent operations are achieved through manual control by
* Corresponding author: Leonard Holmes, Ph.D., research field: fermentation technology. E-mail: len.holmes@uncp.edu.

process operators/technicians. These personnel can detect potential problems and make necessary modifications to the fed-batch process based upon the understanding of the process and the measurements that are provided by the fermentation software [2]. Areas that involve cell or tissue culturing may require constant and real-time control over devices that monitor and/or control different culturing parameters. However, these parameters are mainly controlled through real-time actions that usually require the presence of laboratory personnel to perform. Modern fermentation systems are now controlled through automation based upon software that utilizes a computer interface where the process operator (user) can set online fermentation parameters (pO2, pH, temperature, etc.) to be monitored and controlled by the driver software of the fermentation system requiring little oversight by the user [3]. However, there are many more offline-parameters that cannot be

898

Remote Control of Fed-Batch Fermentation Systems

monitored or controlled through this software that requires the user to manually determine those parameters such as cellular biomass/density, agitation speed or substrate addition [4]. For the fermentation system to be completely automated, a computer network can be established between the fermentation system(s) and a primary laboratory computer where the user can control the culturing system outside of the laboratory [5]. Once all of the equipment, monitors, sensors, and supplies are setup for the fermentation system, the user can then monitor and control, through real-time actions, the fed-batch culture from any location where an internet connection can be obtained. The user can then make adjustments and record data for many culturing parameters that can include pH, pO2, temperature, agitation rate, substrate volume input, cell density/biomass, upscaling and other parameters as determined by the user. Utilization of this technology can lower labor costs by requiring fewer personnel to be present onsite to perform basic procedures such as media preparation and refilling of chemical and/or reagent bottles [6].

two liter glass fermentation vessel, the OxyFerm FDA 225 oxygen sensor probe, the EasyFerm Plus K8-200 pH probe, a PT100 temperature probe and a basic heating blanket along with a basic condenser and cooling finger. The ethernet switch that is used is the Netgear® ProSafe® 5-port ethernet switch that will allow for the connection of up to four fermentation systems and a free port to establish the computer connection. The Foscam FI8908W wireless/wired IP camera is used to visually see the fermentation systems during the day and at night. The Foscam IP camera allows the user to visualize the bioreactor at night utilizing its infrared capabilities. 2.1.2 Software The major software components that are necessary for the network include the PC-Panel µDCU program supplied by the manufacturer of the fermentation systems that requires the laboratory computer to have at least Windows© XP as its operating system, hardware drivers for the digital camera and the ethernet switch, and commercial software from GoToMyPC®. For data recording Microsoft® Excel is needed for data exportation. To access the internet a web browser is needed to logon into the GoToMyPC® account. The web browser that is installed on the laboratory computer is Internet Explorer® version 6.0, but any other web browsers (e.g. Safari or Firefox) and/or later versions may be used that are compatible with the fermentation software and the commercial software from GoToMyPC®. 2.2 Setup of Fermentation Systems The required hardware (e.g. pO2, pH, temperature probes) for the fermentation systems were set up and calibrated according to the manufacturer’s specifications [7]. Sterilized nutrient broth media (500 mL) was added to the sterile 2-liter fermentation vessel along with sterilized reagents, bottles, and tubing. One peristaltic pump was designated and calibrated to a pre-determine flow rate and was used during the remote input of the fresh sterilized substrate (nutrient broth).

2. Establishing the Fermentation Network
2.1 Network Components Components used in the establishment of this fermentation network include various hardware, software and internet based technologies. The use of these technologies to establish a laboratory based fermentation network will allow the user to securely access the primary laboratory computer to monitor, control and record data from any connected fermentation system utilizing the internet as a direct portal. 2.1.1 Hardware The hardware components of the network include the Sartorius-stedim Biostat® A Plus microbial fermentation package; an internet accessible laptop computer, a five port ethernet switch, and a digital web camera. The microbial fermentation package from Sartorius-stedim consists of the system controller, a

Remote Control of Fed-Batch Fermentation Systems

899

The pre-determined flow rate was based upon time, tubing length, and tubing diameter. An overnight culture of the bacterium Photorhabdus luminescens was used as the seed inoculum at a concentration of 1% (v/v). Parameters of the fed-batch were established utilizing the laboratory computer and the process initiated. The value for pH was set to 7.0; temperature was specified at 27 °C; agitation speed was set to 150 rpm; the set point for substrate input was 10 milliliters min-1; and air flow rate was specified to be 0.5 liters min-1. After 2 days of incubation, 100 mL of substrate was added utilizing the established network from an off-site location. Substrate additions and parameter monitoring continued for a period of 2 weeks (Fig. 1). The production of bioluminescence (an off-line variable) was measured at random intervals to monitor the culture health of the phase I variant of P. luminescens. 2.3 Network Connectivity The Sartorius-stedim Biostat® A Plus fermentation system has the ability to be connected directly to a laboratory computer or an ethernet switch through the use of its ethernet port. In the laboratory the fermentation system is connected to the ethernet switch which is also connected to the laboratory computer

Fig. 1 Fed-batch culture of Photorhabdus luminescens after a 2 week period.

through the computer’s single ethernet port. The laboratory computer obtains its internet connection through the laboratory’s wireless network. The fermentation software (PC-Panel µDCU) was installed onto the primary laboratory computer which allows the control and detection of any Sartorius-stedim fermentation system that is connected to the computer via the ethernet switch. The software for the IP camera was also installed to the laboratory computer to where the camera can be accessed through a secured Uniform Resource Locator (URL) to obtain functionality of the camera. An account was created through GoToMyPC®, a company that provides services for remote access to any host computer, allowed the primary laboratory computer to serve as the host computer for obtaining remote access (Scheme 1). Account and login

Scheme 1 Schematic of the fermentation system network.

900

Remote Control of Fed-Batch Fermentation Systems

information was obtained from the service provider and through this account was able to control and monitor the culturing parameters of the Biostat® A Plus fermentation system. The control and monitoring of the culture parameters tested along with calibration and maintenance (Figs. 2-4) can be performed using this service account from any desired location and wireless device.

3. Results and Discussion
The Sartorius-stedim Biotechnology Laboratory was successful in monitoring and controlling the

fermentation process for remote control culturing. We were successfully able to access the fermentation network from any external computer. Not only were we successful in obtaining network access, we could also monitor culturing processes while performing other tasks (Fig. 5). With the use of this newly obtained technology, we can perform calibration procedures outside of the lab. This technology will allow the user to invite guests to view the fermentation process and its parameters to help educate the use of wireless controlled fermentation systems using modern computer technologies.

Fig. 2 Remote monitoring of the fed-batch culture of Photorhabdus luminescens.

Fig. 3 Remote calibration of fermentation hardware (sensors, probes, balances, etc…).

Remote Control of Fed-Batch Fermentation Systems

901

Fig. 4 Remote maintenance of system parameters (ranges, printing, external devices, etc…).

Fig. 5 Monitoring and viewing trends of the fed-batch while performing other tasks.

4. Conclusions
In summary, the remote accessibility of the fermentation system was a very useful tool to monitor and control the bioprocess remotely based upon visual observations and hardware measurements. These measurements include, but are not limited to pH, temperature, agitation and the addition of fresh substrate. This is an added advantage when continuous monitoring of a batch is constantly required during the life of the batch. The creation of a remote-controlled fermentation network allows for cost efficiency by remote monitoring and reducing the need for more personnel.

Acknowledgments
Financial support for this study was provided in part by the National Institute of Child Health and Development (NICHD) grant number 5G11HD052381-04; the National Institute for General Medical Sciences (NIGMS) grant number 3R25GM078657-03S1; the North Carolina Biotechnology Center (NCBC) grant number 2010-IDG-1008; the International Work and Travel USA program funded by the Council on International Educational Exchange; the Indian Council of Agricultural Research; and Farm Bureau of Robeson

902

Remote Control of Fed-Batch Fermentation Systems Fed-Batch Fermentation Process, June 2003, ISBN 951-42-7083-5. Lennox, B.; Montague, G. A.; Hiden, H. G.; Kornfeld, G.; Goulding, P. R. Process Monitoring of an Industrial Fed-Batch Fermentation. Biotechnol. Bioeng. 2001, 74, 125-135. Ahmad, A.; Samad, N. A. F. A.; Hamid, M. K. A. Product Optimization of a Fed-Batch Fermentation Process, Proceedings of the European Congress of Chemical Engineering, Copenhagen, September 2007. Alford, J. S. Bioprocess Control: Advances and Challenges. Comput. Chem. Eng. 2006, 30, 1464-1475. Gregersen, L.; Jørgensen, S. B. Supervision of Fed-Batch Fermentations. Chem. Eng. J. 1999, 75, 69-76. Cornelius, K. BaeUniVessel and Equipment Operating Manual. Goettingen, Germany: Sartorius Stedim Biotech GmbH, 2009.

County. We also thank Mary Barton, Technology Support Analyst, Division of Information Technology (DoIT) at UNC Pembroke for her technical assistance in gaining access to the University’s network. GoToMyPC® is a trademark owned by Citrix Online, LLC. and is used with permission from Citrix Online, LLC. No endorsement, sponsorship or affiliation with Citrix Online is either intended or implied by use of this trademark.

[3]

[4]

[5] [6] [7]

References
[1] [2] Lidén, G. Understanding the Bioreactor. Bioproc. Biosyst. Eng. 2002, 24, 273-279. Saarela, U.; Leiviskä, K.; Juuso. E. Modelling of a