Implications of the Growth of Anaerobic Bacteria in the Papermaking Process, 1997 Biological Sciences Symposium Proceedings

Numerous locations throughout the paper mill are suitable for the growth of anaerobic and facultatively anaerobic bacteria. The growth of facultative anaerobes may be of particular importance in these systems due to alternating aerobic and anaerobic conditions found in many paper systems. Bacterial growth under anaerobic conditions causes specific problems not associated with bacterial growth under aerobic conditions. Anaerobic bacteria produce H,, HZ’S and volatile fatty acids as part of their metabolism. Along with the health and safety issues related to toxic and explosive gas production, the volatile fatty acids generated cause significant odor problems in both the mill and the products being produced. Anaerobic bacterial growth is not new to the paper mill; however, in recent years problems related to growth of anaerobes has become more prevalent. The major contributor to increased anaerobic growth is likely closure of mill water systems. In addition, the methods of culturing anaerobic bacteria have become more sophisticated in recent years, allowing for better growth and recovery of anaerobic organisms from paper systems. Controlling the anaerobic bacterial population in the mill environment can be difficult. Considering that biocides often target certain bacterial enzyme systems involved in cellular metabolism, the response of anaerobic bacteria to biocides may be different from their aerobic counterparts, which are generally the population being monitored. With an increase in the number of problems related to anaerobic bacteria, a better understanding of the role of these organisms is needed, This paper will deal with issues related to growth, monitoring and control of anaerobic bacteria in the papermaking process.