Fluorometric estimation of surface associated microbial abundance.
Surface associated microbes have historically been difficult to accurately and effectively enumerate. In the current study, we propose a rapid and simple method for estimating abundance of surface associated microbial cells by fluorescence of SYBRGreen stained bacteria and in vivo chlorophyll a fluorescence of benthic diatoms in 24 and 48-well microtiter plates. The effectiveness of this high-throughput technique is demonstrated by assessing sensitivity of a clinical strain of Vibrio cholerae, a benthic bacterial isolate and the benthic microalgae Cylindrotheca closterium to three antibiotics--tylosin, lincomycin and ciproflaxacin. We report on the significant linear relationships between spectral chl a fluorescence and cell abundance and between microalgal growth rates derived from cell counts and fluorescence. Additionally, we provide a simplified and improved method for preparation of a silica gel matrix (SGM), which is an ideal plating media for fluorescence applications. These findings indicate that spectrofluorometry is an inexpensive tool for rapidly estimating abundance of surface associated microbiota and can be employed for assessing antibiotic sensitivity.
Biological Sciences, University of South Carolina, Columbia, SC 29208, USA. swensong@mailbox.sc.edu
Gabriel J
GJ
Swenson
Isaac M
IM
Hagenbuch
James L
JL
Pinckney
Richard A
RA
Long
D000704:Analysis of Variance; D058491:Bacterial Load / Q000379:methods*; D052160:Benzothiazoles; D002734:Chlorophyll / Q000032:analysis / Q000737:chemistry; D000077194:Chlorophyll A; D003470:Culture Media; D003959:Diamines; D017377:Diatoms / Q000382:microbiology*; D005456:Fluorescent Dyes / Q000737:chemistry; D057166:High-Throughput Screening Assays / Q000379:methods; D058086:Microalgae / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D009930:Organic Chemicals / Q000737:chemistry; D011804:Quinolines; D015203:Reproducibility of Results; D058428:Silica Gel / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014734:Vibrio cholerae / Q000166:cytology
D052160:Benzothiazoles; D003470:Culture Media; D003959:Diamines; D005456:Fluorescent Dyes; D009930:Organic Chemicals; D011804:Quinolines; D002734:Chlorophyll; C098022:SYBR Green I; D058428:Silica Gel; D000077194:Chlorophyll A