TITLE:
Abundance and Diversity of the Phototrophic Microbial Mat Communities of Sulphur Mountain Banff Springs and Their Significance to the Endangered Snail, Physella johnsoni
AUTHORS:
Michael Bilyj, Dwayne Lepitzki, Elizabeth Hughes, Jolantha Swiderski, Erko Stackebrandt, Charlie Pacas, Vladimir V. Yurkov
KEYWORDS:
Physella johnsoni, Cyanobacterial Mats, Thermal Springs Banff, Canada, Phototrophic Bacteria
JOURNAL NAME:
Open Journal of Ecology,
Vol.4 No.8,
May
30,
2014
ABSTRACT: Seasonal population
fluctuations and diversity of anoxygenic phototrophs and cyanobacteria at the
Sulphur Mountain thermal springs, Banff, Canada were investigated and compared
to drastic population changes of the endangered snail Physella johnsoni.
The microbial community revealed new species of anoxygenic phototrophic
bacteria with novel spectral and morphological characteristics. Major
mat-forming organisms included densely growing Thiothrix-like species,
oxygenic phototrophs of the genera Spirulina, Oscillatoria, and Phormidium and purple nonsulfur bacteria Rhodobacter, Rhodopseudomonas and Rhodomicrobium. Aerobic anoxygenic
phototrophs comprised a significant portion, upwards of 9.6 × 104 CFU/cm2 of mat or 18.9% of total aerobic heterotrophic isolates,
while PNSB and purple sulfur bacteria were quantified at maximum abundance of
3.2 × 105 and 2.0 × 106 CFU/cm2 of mat,
respectively. Photosynthetic activity revealed incredibly productive carbon fixation
rates, averaging 40.5 mg C/cm2/day at one studied spring system. A
temporal mismatch was observed for mat area and available organics to the
fluctuation of P. johnsoni population
in a tracking inertia manner. Mat chlorophyll a content appeared directly
proportional to snail numbers making it an appropriate indicator of population.
This survey of the Sulphur springs microbial communities suggests that
phototrophic species are among the main determinants to the proliferation of P. johnsoni.