Traditional and bulk methods for biofilms

Traditional microbiological methods are needed for all scientists working with biofilms and microbes, and for those testing antimicrobial biocides. The first part of the chapter focuses on traditional microbiological isolation and enrichment methods that are needed to provide viable cells from in situ for in vivo approaches in genomics, transcriptomics, proteomics, metabolomics and various biodiversity investigations in fundamental and applied research. The second part of the chapter describes methods for the determination of weight, thickness and the activity of biofilms. Traditional microbiological methods: Traditional microbiological methods are needed for all scientists working with biofilms and microbes, and for those testing antimicrobial biocides. This chapter focuses on traditional microbiological isolation and enrichment methods that are needed to provide viable cells from in situ for in vivo approaches in genomics, transcriptomics, proteomics, metabolomics and various biodiversity investigations in fundamental and applied research. It describes method for the determination of weight, thickness and the activity of biofilms. There are several methods that can be used for counting the cells and spores of bacteria and other microbes. These include direct counts, plate counts, and most probable number (MPN) determinations. Bulk methods: Determination of a biofilm weight, thickness, and biomass is important for better engineering and reduction of operational costs. Biofilm thickness is an important parameter and determines the rate at which nutrients and antibiotics or biocides can penetrate biofilms. This chapter describes a nondestructive technique for biofilm thickness measurement using a light microscope, and discusses the determination of biofilm dry weight. Biological activity of a biofilm can be determined by the amount of adenosine-5'- triphosphate (ATP) present. The chapter presents materials, equipment and methods necessary for the measurement of biofilm thickness and biofilm dry weight determination. It also provides toubleshooting hints and tips for biofilm thickness and ATP measurements.