Additional Funding Sources
This research project is supported by the National Science Foundation S-STEM Gateway Scholarships in Biological Sciences under Grant Award No. DUE-1644233 to Boise State University and the College of Arts and Sciences. Support was provided by the Institutional Development Awards (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under Grant Nos. P20GM103408 and P20GM109095. We also acknowledge support from the Biomolecular Research Center at Boise State with funding from the National Science Foundation, Grant Nos. 0619793 and 0923535, the NSF Idaho EPSCoR Program, the National Science Foundation under Award No. OIA-1757324, the M.J. Murdock Charitable Trust, and the Idaho State Board of Education.
Abstract
The carnivorous pitcher plant Sarracenia purpurea is habitat to a diverse aquatic community of insects, mites, rotifers, fungi and bacteria, and captures different insects in order to gain nutrients, like nitrogen. In order for the nutrients to be absorbed by the plant, the associated bacterial communities help break down the prey, and thus they are closely tied to the plant’s growth. Many bacteria in this inquiline community produce enzymes such as chitinases, lipases, and phosphatases that help to deteriorate insects and their exoskeletons, so that the pitcher plants can fully access all the nutritional components of the prey. We hypothesized that the bacterial communities grown in fly medium would have less chitinase activity, have a higher growth rate and carrying capacity, and use different substrates than those grown in cricket medium, due to chemical and textural differences between the cricket and fly prey. Insect media was made by adding dried and ground insect prey (Acheta domesticus or Drosophila melanogaster) to distilled water, which was acidified to a pH level of approximately 5.6. Sterile media was used to transfer bacterial cultures at a 1:1 ratio every 72 hours, and mature cultures were sampled to test the activity of two different chitinases using fluorescence measurements. The growth rate was measured using optical density measurements taken over time, and community-level physiological profiling was carried out, as determined by substrate-use measurements based on the metabolism of 31 carbon sources using Biolog EcoPlates. In these S. purpurea microbial communities, one chitinase had significantly more activity in cricket medium than fly medium; however, there was no significant difference in the activity of the second chitinase. The bacterial community cultures had similar physiological profiles in the two media types, with exceptions of three out of the communities (2, 4, and 5). Lastly, microbial communities grew logistically on both media types, but cricket medium had a higher growth rate and carrying capacity as compared to fly medium. These community cultures have been adapted to grow on cricket medium which might explain many of the differences in metabolic activity.
Different Prey Impact Metabolic Activity in Pitcher Plant Microbial Communities
The carnivorous pitcher plant Sarracenia purpurea is habitat to a diverse aquatic community of insects, mites, rotifers, fungi and bacteria, and captures different insects in order to gain nutrients, like nitrogen. In order for the nutrients to be absorbed by the plant, the associated bacterial communities help break down the prey, and thus they are closely tied to the plant’s growth. Many bacteria in this inquiline community produce enzymes such as chitinases, lipases, and phosphatases that help to deteriorate insects and their exoskeletons, so that the pitcher plants can fully access all the nutritional components of the prey. We hypothesized that the bacterial communities grown in fly medium would have less chitinase activity, have a higher growth rate and carrying capacity, and use different substrates than those grown in cricket medium, due to chemical and textural differences between the cricket and fly prey. Insect media was made by adding dried and ground insect prey (Acheta domesticus or Drosophila melanogaster) to distilled water, which was acidified to a pH level of approximately 5.6. Sterile media was used to transfer bacterial cultures at a 1:1 ratio every 72 hours, and mature cultures were sampled to test the activity of two different chitinases using fluorescence measurements. The growth rate was measured using optical density measurements taken over time, and community-level physiological profiling was carried out, as determined by substrate-use measurements based on the metabolism of 31 carbon sources using Biolog EcoPlates. In these S. purpurea microbial communities, one chitinase had significantly more activity in cricket medium than fly medium; however, there was no significant difference in the activity of the second chitinase. The bacterial community cultures had similar physiological profiles in the two media types, with exceptions of three out of the communities (2, 4, and 5). Lastly, microbial communities grew logistically on both media types, but cricket medium had a higher growth rate and carrying capacity as compared to fly medium. These community cultures have been adapted to grow on cricket medium which might explain many of the differences in metabolic activity.