Genetic diversity of dinitrogen-fixing bacterial communities in soil amended with olive husks

The industrial production of olive oil is accompanied by the accumulation of large quantities of by-products from the olive milling industry that are commonly dispersed as fertilisers, which are nowadays suspected to have potential toxic effects on is omicroflora. The aim of this work has been the investigation of the genetic diversity of bacterial communities present in soil treated with olive husks focusing on the dinitrogen-fixing bacteria.nifH genes were amplified from total soil DNA using universal primers, cloned and typed by restriction analysis and sequencing of representative haplotypes. On the same samples, DGGE analysis on amplified 16S rDNA was performed aiming at monitoring modifications in the total community pattern. Results showed a high genetic diversity ofnifH genes within the community, which was well in agreement with the total community profiles obtained by DGGE on 16SrDNA. Most of thenifH gene fragments (19 out of 32) were found to be similar to sequences related with clostridia.

[1]  M. Nei,et al.  Molecular Evolution and Phylogenetics , 2000 .

[2]  L. Ranjard,et al.  Comparison of nifH Gene Pools in Soils and Soil Microenvironments with Contrasting Properties , 2001, Applied and Environmental Microbiology.

[3]  T Ueda,et al.  Remarkable N2-fixing bacterial diversity detected in rice roots by molecular evolutionary analysis of nifH gene sequences , 1995, Journal of bacteriology.

[4]  C. R. Lovell,et al.  Stability in Natural Bacterial Communities: I. Nutrient Addition Effects on Rhizosphere Diazotroph Assemblage Composition , 2000, Microbial Ecology.

[5]  G. Muyzer.  DGGE/TGGE a method for identifying genes from natural ecosystems. , 1999, Current opinion in microbiology.

[6]  R. Fani,et al.  Fluctuation of bacteria isolated from elm tissues during different seasons and from different plant organs. , 2003, Research in microbiology.

[7]  F. Corpet.  Multiple sequence alignment with hierarchical clustering. , 1988, Nucleic acids research.

[8]  R. Seidler,et al.  Temporal and Spatial Distribution of the nifH Gene of N2 Fixing Bacteria in Forests and Clearcuts in Western Oregon , 2000, Microbial Ecology.

[9]  N. Saitou,et al.  The neighbor-joining method: a new method for reconstructing phylogenetic trees. , 1987, Molecular biology and evolution.

[10]  Jonathan P Zehr,et al.  Nitrogenase gene diversity and microbial community structure: a cross-system comparison. , 2003, Environmental microbiology.

[11]  C. R. Lovell,et al.  Molecular Analysis of Diazotroph Diversity in the Rhizosphere of the Smooth Cordgrass, Spartina alterniflora , 2000, Applied and Environmental Microbiology.

[12]  A. Uitterlinden,et al.  Profiling of complex microbial populations by denaturing gradient gel electrophoresis analysis of polymerase chain reaction-amplified genes coding for 16S rRNA , 1993, Applied and environmental microbiology.

[13]  Francisco Cabrera,et al.  Land treatment of olive oil mill wastewater , 1996 .

[14]  B. Ward,et al.  Oligonucleotide Microarray for the Study of Functional Gene Diversity in the Nitrogen Cycle in the Environment , 2003, Applied and Environmental Microbiology.

[15]  A. Mergel,et al.  Biodiversity of Denitrifying and Dinitrogen-Fixing Bacteria in an Acid Forest Soil , 2002, Applied and Environmental Microbiology.

[16]  M. Nei,et al.  MEGA: Molecular Evolutionary Genetics Analysis, Version 1.02. , 1995 .

[17]  M. Aragno,et al.  nifH gene diversity in the bacterial community associated with the rhizosphere of Molinia coerulea, an oligonitrophilic perennial grass. , 2002, Environmental microbiology.

[18]  Zhiyuan Tan,et al.  Effect of N-fertilization, plant genotype and environmental conditions on nifH gene pools in roots of rice. , 2003, Environmental microbiology.

[19]  R Usami,et al.  Diversity of Nitrogen Fixation Genes in the Symbiotic Intestinal Microflora of the Termite Reticulitermes speratus , 1996, Applied and environmental microbiology.

[20]  W. D. de Vos,et al.  Response of a Soil Bacterial Community to Grassland Succession as Monitored by 16S rRNA Levels of the Predominant Ribotypes , 2000, Applied and Environmental Microbiology.

[21]  Jonathan P. Zehr,et al.  New Nitrogen-Fixing Microorganisms Detected in Oligotrophic Oceans by Amplification of Nitrogenase (nifH) Genes , 1998, Applied and Environmental Microbiology.

[22]  Hans W. Paerl,et al.  Consortial N2 fixation: a strategy for meeting nitrogen requirements of marine and terrestrial cyanobacterial mats , 1996 .

[23]  C. Sorlini,et al.  Microbiological Aspects of Humid Husk Composting , 2003, Journal of environmental science and health. Part. B, Pesticides, food contaminants, and agricultural wastes.

[24]  Jizhong Zhou,et al.  Evaluation of 50-mer oligonucleotide arrays for detecting microbial populations in environmental samples. , 2004, BioTechniques.

[25]  Maria Loizidou,et al.  Study of a demonstration plant for the co-composting of olive-oil-processing wastewater and solid residue , 1996 .

[26]  R. Seidler,et al.  Analysis of nifH Gene Pool Complexity in Soil and Litter at a Douglas Fir Forest Site in the Oregon Cascade Mountain Range , 1999, Applied and Environmental Microbiology.