Evaluation of Media and Techniques to Enumerate Heterotrophic Microbes from Karst and Sand Aquifer Springs

• Published in: Microbial ecology Vol. 31; no. 2; pp. 115 - 124
• Main Authors: Mikell, A. T., Smith, C. L., Richardson, J. C.
• Format: Journal Article
• Language: English
• Published: New York, NY Springer-Verlag New York Inc 01-03-1996; Springer
• Subjects: Animal, plant and microbial ecology; Aquifers; Bacteria; Bacteriological methods and techniques used in bacteriology; Bacteriology; Biological and medical sciences; Freshwater; Fundamental and applied biological sciences. Psychology; Groundwater; Karsts; Microbial ecology; Microbiology; Microorganisms; Microscopy; Natural springs; Sediments; Turbidity; Various environments (extraatmospheric space, air, water); Viability; Culture medium; Heterotrophy; Bacteria; Isolation; Method; Comparative study; Enumeration(counting); Ground water; Aquifers
• ISSN: 0095-3628; 1432-184X
• DOI: 10.1007/BF00167858

Several media and techniques were compared for their efficiency to enumerate viable heterotrophs from both a karst and sand aquifer spring. A medium designed to enumerate bacteria from nutrient-poor waters (HCFU) as well as R2A medium proved superior to tryptic soy agar; however, the difference was always less than one order of magnitude. Membrane filtration resulted in lower counts of microbes than the spread plate, multitube turbidity, or drop plate methods from samples of both sand and karst springs. The drop plate technique yielded higher viable counts from the sand spring and basin of the karst spring, with a precision of 21% (coefficient of variation) and a maximum plating efficiency of 3.4% (viable count/direct count × 100). Subsequently, 63% of isolates from drop plates were recovered on HCFU. Microcolonies were visible by epifluorescence microscopy, acridine orange staining, and subsequent examination of excised agar sections containing drops.