Abstract:
The distribution of the common soil bacteria, Streptomyces, is believed to be influenced by soil characteristics. Studies have indicated that soil properties can be influenced by land use, suggesting different communities of Streptomyces may be found in soils from varying land use patterns. Additionally, previous research has demonstrated the potential of some species of Streptomyces to produce a neurodegenerative compound. With higher incidence of Parkinson's disease, a neurodegenerative disorder, being reported from rural areas, identifying the diversity and prevalence of compound-producing Streptomyces spp. could lead to a greater understanding of the etiology of Parkinson's. This study characterized the cultivable Streptomyces communities within soil from different land uses and examined the distribution and prevalence of neurodegenerative compound-producing species. Various Streptomyces-specific and soil-specific media were used for cultivation and isolates were confirmed as Streptomyces by the generation of appropriately sized amplification products using Streptomyces-specific PCR primers. Box PCR was employed to differentiate strains, allowing evaluation of the diversity of Streptomyces spp. present within a sample. The results indicated that distribution of Streptomyces was affected by differing land uses and edaphic properties. Greater recovery of Streptomyces was found for soils used for cultivation, with less recovery from urban and undeveloped soils. The only significant difference in recovery existed between agricultural and undeveloped soils. Production of the neurodegenerative compound did not follow the observed distribution of Streptomyces spp. and was instead broadly distributed across physiography and land use patterns. While soil pH correlated with streptomycete recovery, the amount of soil organic matter and soil texture did not exhibit a strong influence on the distribution of Streptomyces spp. or compound production. Approximately 32% of isolates were capable of producing the neurodegenerative compound and, based on the genomic fingerprints, this capability is widespread throughout the genus. This study provides needed information on the diversity of Streptomyces communities and yield insights into potential environmental links to human neurodegenerative diseases.
