Effects of diurnal temperature variation on microbial community and petroleum hydrocarbon biodegradation in contaminated soils from a sub‐Arctic site

• Published in: Environmental microbiology Vol. 17; no. 12; pp. 4916 - 4928
• Main Authors: Akbari, Ali, Ghoshal, Subhasis
• Format: Journal Article
• Language: English
• Published: England Blackwell Science 01.12.2015; Blackwell Publishing Ltd; Wiley Subscription Services, Inc
• Subjects: Actinobacteria; Actinobacteria - genetics; Actinobacteria - isolation & purification; Actinobacteria - metabolism; Antarctic Regions; Arctic Regions; Base Sequence; Biodegradation; Biodegradation, Environmental; Bioremediation; Cold regions; Cold Temperature; cold zones; Community composition; community structure; DNA, Bacterial - genetics; gamma-Proteobacteria; Gammaproteobacteria - genetics; Gammaproteobacteria - isolation & purification; Gammaproteobacteria - metabolism; genes; hydrocarbons; Hydrocarbons - metabolism; microbial communities; Microbial Consortia - physiology; Mixed Function Oxygenases - genetics; petroleum; Petroleum - metabolism; Petroleum hydrocarbons; polluted soils; ribosomal RNA; RNA, Ribosomal, 16S - genetics; Seasons; sequence analysis; Sequence Analysis, DNA; Soil - chemistry; Soil contamination; Soil Microbiology; soil microorganisms; Soil Pollutants - metabolism; summer; temperature
• ISSN: 1462-2912; 1462-2920
• DOI: 10.1111/1462-2920.12846

Contaminated soils are subject to diurnal and seasonal temperature variations during on‐site ex‐situ bioremediation processes. We assessed how diurnal temperature variations similar to that in summer at the site from which petroleum hydrocarbon‐contaminated soil was collected affect the soil microbial community and the extent of biodegradation of petroleum hydrocarbons compared with constant temperature regimes. Microbial community analyses for 16S rRNA and alkB genes by pyrosequencing indicated that the microbial community for soils incubated under diurnal temperature variation from 5°C to 15°C (VART5‐15) evolved similarly to that for soils incubated at constant temperature of 15°C (CST15). In contrast, under a constant temperature of 5°C (CST5), the community evolved significantly different. The extent of biodegradation of C10–C16 hydrocarbons in the VART5‐15 systems was 48%, comparable with the 41% biodegradation in CST15 systems, but significantly higher than CST5 systems at 11%. The enrichment of Gammaproteobacteria was observed in the alkB gene‐harbouring communities in VART5‐15 and CST15 but not in CST5 systems. However, the Actinobacteria was abundant at all temperature regimes. The results suggest that changes in microbial community composition as a result of diurnal temperature variations can significantly influence petroleum hydrocarbon bioremediation performance in cold regions.