Thursday 11 June 2009

1-2pm, in Fenner School's Forestry Lecture Theatre

Its a party in there - archaea and bacteria biogeochemical interactions in acid sulfate soils

Mira Durr, PhD Scholar, The Fenner School of Environment and Society

Abstract

Coastal acid sulfate soils in Australia underlie large areas in both NSW and QLD. The oxidation of coastal acid sulfate soils is a cause of widespread environmental degradation and economic loss in Australia. Oxidation of these soils results in the release of low pH metal-laden leachate into the aquatic and soil environment and emission of SO₂ and H₂S to the atmosphere. The impact of acid sulfate soil oxidation reduces the productivity of agricultural land and decreases the ecological health of aquatic ecosystems through the release of acidic leachate.

The chemical and physical properties of acid sulfate soil environments have been well characterised. It is proposed that microbial communities play an important role in the oxidation of acid sulfate soils and the subsequent generation of acid similar to acid mine drainage environments. However, few studies have investigated the role of bacteria and archaea in acid sulfate soils Furthermore, the community structure and identification of species present in acid sulfate soils remain unexamined.

Presented here is an analysis of the bacterial and archaeal community structure, function and the identification of species in a coastal acid sulfate soil under sugar cane production. Soil chemical and physical properties were linked to the characteristics of the bacterial and archaeal communities to produce a model of the biogeochemical interactions occurring in an acid sulfate soil under sugar cane agriculture.

Key findings include:

• Complex community structure of archaea.
• Community function for iron oxidation and sulfur oxidation and reduction was linked to substrate availability.
• Identification of novel species belonging to 20 different bacterial phyla.
• Bacteria and archaea identified participated in sulfur, iron, carbon and nitrogen cycling in acid sulfate soils.

The research presented represents the first analysis of the biological community and biogeochemical interactions occurring within an acid sulfate soil system.

Bio

Mira Durr is a PhD Scholar at the Fenner School of Environment and Society, The Australian National University

The Fenner School Seminar Series is held in the Forestry Lecture Theatre, Forestry Building 48, Linnaeus Way (comes off Daley Road), ANU (Acton) campus, ACT

The seminar will start at 13:00 and finish at 14:00