Chasing antibiotic activity from Florida algae chloroform partitions
Poster Number
28
Research or Creativity Area
Natural Sciences
Abstract
Climate change is leading to increasing ocean acidity and rising temperatures which effects the surface microbiome of macroalgae. These environmental changes could lead to an increase in pathogenic bacteria. In a previous study of the invasive green algae Caulerpa spp. from Florida, it was found that algal extracts chemically mediate the culturable microbiome. This led to a survey of a red and brown, and a non-Caulerpa sp. green algae from Florida to see if there was a similar relationship between different types of algae and their surface associated bacteria (SAB). Algae were collected from the Florida Keys in 2022, the surface of the algae was swabbed in the field and plated onto a variety of agar. Bacteria were isolated on A1 (10 g/L starch, 4 g/L yeast, 2 g/L peptone, 30 g/L Instant Ocean) and cryopreserved for later use. The algae samples were frozen, lyophilized, and extracted using 50:50 EtOAc:MeOH. These extracts partitioned between hexane and water; the hexane partition was further partitioned between CHCl3 and 70:30 MeOH:H2O. Each SAB from each alga was incubated in 200 μL of A1 in a 96-well plate with 100 μg/mL of each algal extract and incubated at room temperature overnight. We observed that the chloroform partitions were 79% of all the notable growth inhibition in the panel. This inhibitory activity indicated that the algae were likely producing antimicrobial compounds. The chloroform partitions were fractionated and screened against against 4 human pathogens: Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Salmonella sp.. We are pursuing this activity using high-performance liquid chromatography and liquid chromatography-mass spectrometry to dereplicate, isolate, and identify the active metabolite. Identifying these compounds will not only help elucidate the role of specific metabolites on the surface microbiome of Florida algae, but also potentially identify novel antimicrobial compounds.
Location
Don and Karen DeRosa University Center (DUC) Poster Hall
Start Date
27-4-2024 10:30 AM
End Date
27-4-2024 12:30 PM
Chasing antibiotic activity from Florida algae chloroform partitions
Don and Karen DeRosa University Center (DUC) Poster Hall
Climate change is leading to increasing ocean acidity and rising temperatures which effects the surface microbiome of macroalgae. These environmental changes could lead to an increase in pathogenic bacteria. In a previous study of the invasive green algae Caulerpa spp. from Florida, it was found that algal extracts chemically mediate the culturable microbiome. This led to a survey of a red and brown, and a non-Caulerpa sp. green algae from Florida to see if there was a similar relationship between different types of algae and their surface associated bacteria (SAB). Algae were collected from the Florida Keys in 2022, the surface of the algae was swabbed in the field and plated onto a variety of agar. Bacteria were isolated on A1 (10 g/L starch, 4 g/L yeast, 2 g/L peptone, 30 g/L Instant Ocean) and cryopreserved for later use. The algae samples were frozen, lyophilized, and extracted using 50:50 EtOAc:MeOH. These extracts partitioned between hexane and water; the hexane partition was further partitioned between CHCl3 and 70:30 MeOH:H2O. Each SAB from each alga was incubated in 200 μL of A1 in a 96-well plate with 100 μg/mL of each algal extract and incubated at room temperature overnight. We observed that the chloroform partitions were 79% of all the notable growth inhibition in the panel. This inhibitory activity indicated that the algae were likely producing antimicrobial compounds. The chloroform partitions were fractionated and screened against against 4 human pathogens: Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Salmonella sp.. We are pursuing this activity using high-performance liquid chromatography and liquid chromatography-mass spectrometry to dereplicate, isolate, and identify the active metabolite. Identifying these compounds will not only help elucidate the role of specific metabolites on the surface microbiome of Florida algae, but also potentially identify novel antimicrobial compounds.
