Taxonomic Diversity of Rhizosphere Bacteria in Golf Course Putting Greens at Representative Sites in the Southeastern United States

Abstract

Taxonomic diversity of bacteria associated with golf course putting greens is a topic that has not been widely explored. The purpose of this project was to isolate and identify culturable bacteria from the rhizosphere of creeping bentgrass (Agrostris palustris Huds.) at two sites (Alabama and North Carolina) and hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy] at two sites (Florida and South Carolina) for a minimum of 3 years with sampling initiated after the construction process. Randomly selected colonies were identified using gas chromatography for analysis of fatty acid methyl ester profiles. Over 9000 isolates were successfully analyzed. When a similarity index of 0.300 or higher was used, the average number of unidentifiable isolates was 38.6%. The two dominant genera in both bentgrass and bermudagrass rhizospheres were Bacillus and Pseudomonas with Bacillus dominant in bermudagrass and Pseudomonas dominant or equal to Bacillus in bentgrass. Other genera that comprised at least 1% of the isolates at all four sites were Clavibacter, Flavobacterium, and Microbacterium. Arthrobacter also comprised a significant portion of the bacterial isolates in the bentgrass rhizosphere, but not the bermudagrass rhizosphere. Overall, there were 40 genera common to all four sites. At the species level, there were five that comprised at least 1% of the isolates at each location: B. cereus, B. megaterium, C. michiganensis, F. johnsoniae, and P. putida. As has been reported for many grasses, we found considerable taxonomic diversity among the culturable bacterial populations from the rhizospheres of bentgrass and bermudagrass grown in sand-based putting greens.