The discovery of a novel bacterial species in the genus Paenibacillus found in Great Smoky Mountains National Park

WCU Author/Contributor (non-WCU co-authors, if there are any, appear on document)
Tori Kaytlyn Carlson (Creator)
Institution
Western Carolina University (WCU )
Web Site: http://library.wcu.edu/
Advisor
Sean O'Connell

Abstract: The All Taxa Biodiversity Inventory (ATBI) is an effort to record all species within Great Smoky Mountains National Park (GSMNP). When it was first begun nearly 20 years ago, prokaryotic organisms were not included as targets of the ATBI, but the project has been expanded to include prokaryotic organism and even viruses. The purpose of this study was to fully characterize and identify a unique bacterium cultured from soil from the Kephart Prong area of GSMNP as a novel species to science and for inclusion in the ATBI. Previous work showed that the isolate being studied aligned to the genus Paenibacillus based on 16S rDNA analyses but it was not closely related to any known species. The isolate was tested using various phenotypic measurements including colony characteristics, growth assessment under numerous conditions and many media formulations, in addition to cellular features observed using microscopy (e.g., Gram staining, flagella staining, endospore staining). Phylogenetic analysis of the entire 16S rDNA was undertaken and whole genome sequencing was performed to better differentiate the isolate from its closest relatives. The isolate is a Gram-positive, spore-forming rod that grows best at a pH from 7-9, NaCl concentration of 0-1%, and temperatures from 25-30C. Transmission electron microscopy revealed cells that were rod shaped and 0.8m in diameter x 2.8-3.2 m in length, with flagella associated with the cells. The isolate was able to hydrolyze lipids, gelatin, casein, and starch in addition to having the ability to reduce nitrate to nitrite, and could utilize glucose via the butanediol fermentation pathway under anaerobic conditions. The isolate was resistant to the antibiotic colistin, but susceptible to tetracycline, chloramphenicol, nitrofurantoin, nalidixic acid, penicillin, and clindamycin. The 16S rDNA sequence of the isolate most closely matched Paenibacillus castaneae with an 84.6% similarity. Analysis of the whole genome showed the closest match to Paenibacillus harenae, but major DNA sequence differences exist between the two species. With the information obtained from the 16S rDNA analyses, whole genome sequencing, and the growth-based tests, it appears that this isolate is likely a novel species within the genus Paenibacillus. This work represents the most complete account of a species of Paenibacillus to date in GSMNP. Phenotypic testing and whole genome sequencing results suggest that this organism can break down insect and fungi material via the use of chitinase genes, it can break down blood cells and utilize heme, and that it is resistant to colistin and, potentially tetracycline based on putative genes. Some genes found within the genome suggest that this species could have pathogenic capabilities. Outside of GSMNP, this research can aid in the understanding of other Paenibacillus species throughout the world that may not have been discovered yet by providing a template genomic sequence from a closely related species. Understanding of this novel species could also provide information on new ecological capabilities that may have not been established in previously discovered Paenibacillus species.

Additional Information

Publication
Thesis
Language: English
Date: 2017

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