Influence of long-term land application of Class B biosolids on soil bacterial diversity

• Published in: Journal of applied microbiology 2010-08, Vol.109 (2), p.698-706
• Main Authors: Zerzghi, H, Brooks, J.P, Gerba, C.P, Pepper, I.L
• Format: Article
• Language: English
• Subjects: 16S rRNA; Acidobacteria; Actinobacteria; Actinobacteria - genetics; Actinobacteria - isolation & purification; Agricultural land; arid soils; Aridity; Arizona; Bacteria; Bacteria - classification; Bacteria - genetics; Bacteria - isolation & purification; bacterial diversity; Bacteroidetes; Biodiversity; Biological and medical sciences; Biosolids; Cotton; Deoxyribonucleic acid; Desert soils; DNA; Firmicutes; Fundamental and applied biological sciences. Psychology; Gossypium; Land application; long‐term effects; Microbiology; Microorganisms; Nucleotide sequence; Phylogeny; Proteobacteria; Proteobacteria - genetics; Proteobacteria - isolation & purification; ribosomal RNA; RNA, Ribosomal, 16S - genetics; rRNA 16S; Sandy soils; Sequence analysis; Sewage - adverse effects; Sludge; Soil amendment; soil amendments; soil bacteria; Soil Microbiology; Soil microorganisms; Soil surfaces; species diversity
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/j.1365-2672.2010.04698.x

To evaluate the effect of long-term annual land applications of Class B biosolids on soil bacterial diversity at University of Arizona Marana Agricultural Field Center, Tucson, Arizona. Following the final of 20 consecutive years of application of Class B biosolids in March 2005, followed by cotton growth from April to November 2005 surface soil samples (0-30 cm) were collected from control (unamended) and biosolid-amended plots. Total bacterial community DNA was extracted, amplified using 16S rRNA primers, cloned, and sequenced. All 16S rRNA sequences were identified by 16S rRNA sequence analysis and comparison to known sequences in GenBank (NCBI B lastN and Ribosomal Database Project II, RDP). Results showed that the number of known genera (identifiable > 96%) increased in the high rate biosolid plots compared to control plots. Biosolids-amended soils had a broad phylogenetic diversity comprising more than four major phyla: Proteobacteria (32%), Acidobacteria (21%), Actinobacteria (16%), Firmicutes (7%), and Bacteroidetes (6%) which were typical to bacterial diversity found in the unamended arid southwestern soils. Bacterial diversity was either enhanced or was not negatively impacted following 20 years of land application of Class B biosolids. This study illustrates that long-term land application of biosolids to arid southwestern desert soils has no deleterious effect on soil microbial diversity.