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Diversity of Lichens in New Haven County and Their Antibacterial Properties Evan Luca*, Elizabeth Lewis Roberts Ph.D Department of Biology, Southern Connecticut State University, New Haven, CT Abstract The lichen populations in New Haven have been deteriorating from what is believed to be exposure to air pollutants. Using a combination of DNA sequencing and morphological observations, the diversity of lichens found in New Haven County Connecticut has been monitored. Preliminary data indicates that certain lichen species are only found in more rural areas and are absent in an urban downtown setting. As more traffic and industries are located downtown, it is thought that the presence of certain pollutants limits the growth of those particular lichen types. Lichens were further examined for their antibacterial properties. The existence of antibiotics in lichens indicates that Connecticut lichens might be a rich source of effective antibacterial agents. Antibiotics produced by the lichen are not only beneficial to the lichen, but could pave the way antibiotics are used by humans in the future. Methods Samples were collected from the trunks of 30 Acer rubrum and Acer saccharum trees from 5 urban and suburban areas in New Haven County, Connecticut. DNA was extracted from a fungal partner and analyzed via genetic sequencing to determine lichen identity. By using acetone as a solvent, lichen antibiotic chemicals were extracted from the thallus and tested against pathogenic bacteria. They were then compared to a standard antibiotic. Figure 3. Molecular Phylogenetic Analysis by Maximum Likelihood Method to Study the Evolutionary History of Samples: Strains found in our study are labeled with a . Other taxa represent strains typically found in Connecticut. Summary While this study is still in it’s preliminary state, it should be noted that: Trees from an urban environment showed less diversity than trees from a suburban environment. (See Fig. 5.) Some lichens do exhibit antibacterial properties, such as Flavoparmelia sp., Physcia stellaris, and Phaeophyscia sp. against certain bacteria (see Fig 2.) Results 1 2 Figure 1. Map of Connecticut with New Haven County Shaded: Sample collection sites (1) urban area (2) ex-urban and suburban area Control Flavoparmelia sp. Physcia stellaris Phaeophyscia sp. 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 Antibacterial Presence in Lichens Extracts S. epidermidis B. subtilis E. carotovora E. raffinosus Lichen Species Inhibition of Growth in Centimeters Figure 2. Representation of Different Lichen Extracts Compared to Other Lichen Extracts with Respect to Their Zone of Inhibition Against Different Bacteria: Zone of inhibition distance was determined by measuring from the edge of the disk to the end of the zone of inhibition. A . C . B . Figure 5. Comparison of Suburban (5.1) vs. Urban (5.2) Environments: The suburban environment had four different types of lichens growing on one tree: Flavoparmelia sp. (A.), Physcia stellaris (B.), Phaeophyscia sp. (C.) and Candelaria sp. (D.) (not included in the antibacterial study), whereas the urban environment only had only a single lichen growing on one tree: Candelaria sp. (D.) 5. 1 5. 2 D . D . Figure 4. Antibacterial Susceptibility Test Against E. carotovora, with Zone of Inhibition shown: Controlled (A.), Physcia stellaris (B.), Phaeophyscia sp. (C.), and Flavoparmelia sp. (D.) A. B. C. D.

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Diversity of Lichens in New Haven County andTheir Antibacterial Properties

Evan Luca*, Elizabeth Lewis Roberts Ph.DDepartment of Biology, Southern Connecticut State University, New Haven, CT

AbstractThe lichen populations in New Haven have been deteriorating from what is believed to be exposure to air pollutants. Using a combination of DNA

sequencing and morphological observations, the diversity of lichens found in New Haven County Connecticut has been monitored. Preliminary data indicates that certain lichen species are only found in more rural areas and are absent in an urban downtown setting. As more traffic and industries are located downtown, it is thought that the presence of certain pollutants limits the growth of those particular lichen types. Lichens were further examined for their antibacterial properties. The existence of antibiotics in lichens indicates that Connecticut lichens might be a rich source of effective antibacterial agents. Antibiotics produced by the lichen are not only beneficial to the lichen, but could pave the way antibiotics are used by humans in the future.

Methods• Samples were collected from the trunks of 30 Acer rubrum

and Acer saccharum trees from 5 urban and suburban areas in New Haven County, Connecticut.

• DNA was extracted from a fungal partner and analyzed via genetic sequencing todetermine lichen identity.

• By using acetone as a solvent, lichen antibiotic chemicals were extracted from thethallus and tested against pathogenic bacteria. They were then compared toa standard antibiotic.

Figure 3. Molecular Phylogenetic Analysis by Maximum Likelihood Method to Study the Evolutionary History of Samples: Strains found in our study are labeled with a . Other taxa represent ★strains typically found in Connecticut.

SummaryWhile this study is still in it’s preliminary state, it should be noted that:

• Trees from an urban environment showed less diversity than trees froma suburban environment. (See Fig. 5.)

• Some lichens do exhibit antibacterial properties, such as Flavoparmelia sp.,Physcia stellaris, and Phaeophyscia sp. against certain bacteria (see Fig 2.)

Results

1

2

Figure 1. Map of Connecticut with New Haven County Shaded: Sample collection sites (1) urban area (2) ex-urban and suburban area

Control Flavoparmelia sp. Physcia stellaris Phaeophyscia sp.0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

Antibacterial Presence in Lichens Extracts

S. epidermidisB. subtilisE. carotovoraE. raffinosus

Lichen Species

Inhi

bitio

n of

Gro

wth

in C

entim

eter

s

Figure 2. Representation of Different Lichen Extracts Compared to Other Lichen Extracts with Respect to Their Zone of Inhibition Against Different Bacteria: Zone of inhibition distance was determined by measuring from the edge of the disk to the end of the zone of inhibition.

A.

C.

B.

Figure 5. Comparison of Suburban (5.1) vs. Urban (5.2) Environments: The suburban environment had four different types of lichens growing on one tree: Flavoparmelia sp. (A.), Physcia stellaris (B.), Phaeophyscia sp. (C.) and Candelaria sp. (D.) (not included in the antibacterial study), whereas the urban environment only had only a single lichen growing on one tree: Candelaria sp. (D.)

5.1 5.2

D.

D.

Figure 4. Antibacterial Susceptibility Test Against E. carotovora, with Zone of Inhibition shown: Controlled (A.), Physcia stellaris (B.), Phaeophyscia sp. (C.), and Flavoparmelia sp. (D.)

A.

B.C.

D.