Effect of ‘Peatland-Use’ Type on Culturable Microbial Groups in Irish Peatlands in the Midlands

Abstract

Soil microbial ecology in the Irish wetlands is still poorly understood, although it is crucial in introducing effective rewetting schemes to restore and conserve the Irish peatlands. As an initiative, peatlands with distinct land-use types (cutaway, raised semi-degraded, unimproved grassland and grassland) were collected from farms in the midlands to analyse various microbial populations. Peat was homogenized and serially diluted to culture on a range of specific and non-specific culture media. Culture isolation and microbial enumeration were performed. Gram staining and other microscopic observations of morphologically distinct microorganisms were performed, followed by isolation procedures. The numbers of total viable bacteria of cutaway bog and unimproved grassland were 4.23 × 103 CFU g−1 and 9.81 × 107 CFU g−1, respectively, with a significant statistical difference (p ≤ 0.05). Raised semi-degraded bogs comprised low values of both aerobes and fungal populations. Penicillium spp. and Trichoderma spp. were common in many vegetation types. Phosphate-solubilizing bacteria were present in the majority of the study sites. This indicated that the soluble form of phosphorus was being assimilated by plants. Cutaway peat contained the bacteria with the highest phosphate-solubilizing index (3.167). Overall, the number of culturable microbial groups in cutaway and raised semi-degraded peatlands exhibited significant differences, while the rest did not show drastic changes according to land-use type. This study provides baseline data to continue studies on bog microbiology, which provides a new outlook for restoration. Future work should consider microbial interaction with environmental variables in different land-use types.