Heterotrophic bacterial diversity in aquatic microbial mat communities from Antarctica

Study Extent

Bacterial strain isolated from five aquatic microbial mat samples from different locations in continental Antarctica and the Antarctic Peninsula, sampled between 2003 and 2007.

Sampling

Microbial mat samples were collected aseptically using a sterile spatula, and were kept frozen continuously after collection until processing in the laboratory.

Method steps

1. One gram of sample was aseptically weighed and homogenized in 9 ml sterile cold (4°C) physiological saline (0.86% NaCl) using a vortex. Tenfold dilution series (kept at 4°C) were plated on four different media (Marine agar 2216 (MA) (BD DifcoTM), R2A (BD DifcoTM), ten times diluted R2A (R2A/10), and PYGV (Pepton-Yeast-Glucose-Vitamin) medium (DSMZ medium 621)) and incubated at 20°C, 15°C and 4°C. R2A (Difco) contains pyruvate, starch and dextrose as C sources and yeast extract, peptone and casaminoacids as N and C sources and PYGV (DSMZ medium 621) contains peptone, yeast extract and glucose as C and/or N sources and additional vitamins and minerals. Both are considered oligotrophic media because the amounts of these components are at least two to ten times lower than in more general media such as nutrient broth. In addition to regular physiological saline (PS) dilution series, sea water (SW) dilutions were used for the LA3 and WO10 samples which originated from lakes close to the ocean and had elevated conductivity values.

Heterotrophic Bacteria (504 strains) isolated from frozen microbial mat samples using culturing techniques.

1. Bacteria
   common name: Bacteria rank: kingdom

Different water bodies (lakes) on the Antarctic continent: East Antarctica, the Trans-Antarctic Mountains, and the Antarctic Peninsula