Biology (BIO O17-O19)

 
 
Cochliopodium species are difficult to identify based on morphological characters due to cryptic diversity. Recent molecular analyses (DNA sequence data) of barcoding markers such as Cytochrome c oxidase subunit I (COI) have begun to reveal the true diversity of this genus. Here, we present morphological (light microscope), immunocytochemistry (ICC), and molecular data (COI) for three new Cochliopodium species, named ‘crystal UK-YT2’, ‘crystal-like UK-YT3’, and ‘Marrs Spring UK-YT4’’. They were sampled from Arabia Lake, Lithonia, GA, and on campus at The University of Alabama, Tuscaloosa, AL, respectively. A maximum likelihood phylogenetic analysis and pairwise comparison of COI sequences showed these three species were distinct from any other known Cochliopodium species. Two of the new isolates, ‘crystal UK-YT2’ ( C. crystalli n. sp.) and ‘crystal-like UK-YT3’ (C. jaguari n. sp.), formed a clade with C. larifeili. The ‘Marrs Spring UK-YT4’ isolate, C. marrii n. sp., formed a clade with C. actinophorum and C. arabianum. The pairwise distances of the COI sequence data for each species fell outside the known barcode gap of approximately 2% thus, represents a distinct, new species. Our morphological and molecular data of Cochliopodium species will result in the description of three species that are new to science.
 

Microbes live in diverse natural habitats, ranging from hot hydrothermal vents deep into the ocean, to the insides of our guts. Microbes have not been passive passengers, but active contributors to the transformation of our planet and evolution of its inhabitants. Soil harbors an abundance of microbes in terms of biodiversity and biomass. Microbes that live in soil, have adapted to their environment, such as producing antibiotics or interacting with plants. Here, we tested whether the antibiotic-producing bacterium in the soil sample impacted the growth of plants, using flax seeds as a model organism. We predict that the antibiotic-producing bacteria will positively impact the development of flax seeds given that plants thrive where the soil sample was collected from. We isolated an antibiotic-producing bacterium, plated it in the presence of flax seeds, and measured the development of flax seeds. We performed Gram staining, 16S rDNA sequencing and biochemical assays and identified the bacterium as Chromobacterium violaceum. Our results show that C. violaceum promotes the development of flax seeds. This research supports the benefits bacteria can provide for the development of seeds.

Biofilms are aggregates of bacteria that adhere to surfaces and display increased resistance to antibiotics. Two main healthcare concerns are the disinfection of surgical surfaces and equipment and the treatment of infections in humans. Individuals infected with biofilm-forming bacteria present recurring infections and require severe drug treatment. Commensal Neisseria species are found in human oral and nasopharynx. These commensal species are closely related to the pathogenic N. gonorrhoeae which is known to form biofilms. Here, we characterize biofilm formation by commensal Neisseria species, N. cinerea, N. mucosa, and N. elongata. I predict that N. cinerea will have the highest level of biofilm formation. We performed a standard multiwell static model biofilm assay and measured the accumulation of crystal violet by the biofilm. Overall, all commensals studied formed less biofilm than N. gonorrhoeae, and in particular, N. cinerea formed 3.2 times less biofilm than N. mucosa and 2.7 times less than N. elongata. These results were unexpected given the great genomic similarity between all Neisseria genus species. Hence, while Neisseria seem able to form biofilms, there is a wide range of their ability to form these structures. We will analyze the potential genetic differences that explain this variation.