Aquatic Microbial Ecology 26:115

• Main Authors: Evelyne Buffan-Dubau, Olivier Pringault, Rutger De Wit, Inter - Research
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2001
• Subjects: Antarctic; Fryxell; Lake Fryxell; Taylor Valley; Antarc*; Antarctica
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1040.1783; http://www.ird.nc/CAMELIA/Pringault/Buffan-Dubau_et_al_2001.pdf

ABSTRACT: Artificial microbial mats were cultured at 4 to 7°C in benthic gradient chambers using inocula of Antarctic lake mats (Lake Fryxell, Dry Valleys). Their formation and structure were studied based on both HPLC pigment quantification and microsensor measurements of oxygen profiles. Accretion rates (2 to 5 mm within the year) were consistent with previous estimations for artificial mats cultured at 17 to 25°C, suggesting that the microbial community was cold-adapted. Mats were vertically structured comprising an upper green layer dominated by cyanobacteria and an underlying pink layer including purple non-sulphur phototrophic bacteria. Pigment contents indicated that both groups of cyanobacteria (Oscillatoriacae and possibly Nostoc sp.) adopted different patterns of vertical distributions within the mats. Heterogeneity of oxygen vertical distributions was determined, and net primary productivity rates were in the range of those previously reported for natural Antarctic microbial mats. Collective considerations of pigment contents and primary productivity strongly suggest that artificial mats presented some characteristics of natural polar mats, although some differences were established. KEY WORDS: Antarctica · Artificial mats · Psychroptrophs · Pigments · HPLC · Net productivity Resale or republication not permitted without written consent of the publisher Aquat Microb Ecol 26: 115-125, 2001 from Antarctic meltwater ponds have been characterised; however, little is known about cold-adaptation processes in Antarctic mats MATERIALS AND METHODS Site and sampling. Lake Fryxell (75°36' S, 163°35' E) is located in the Taylor Valley of the Dry Valley region, western Antarctica. The Dry Valleys are surrounded by 2500 to 3000 m high mountains (Transantarctic mountain range) and this results in an annual snowfall of only 2 to 4 cm Mat cultures in BGC. BGC previously allowed culturing of microbial biofilms of phototrophic bacteria under conditions mimicking light, oxygen, sulfide, and pH gradients occurring in ...