My Summer Education: The Microscopic World

This post was written by Vanessa Marshall, 2017 summer intern and student at The University of Alabama.

BRIT has been amazing – a catalyst that has unlocked the doors to the natural world and shown me wonders that I had never fully appreciated. I have always loved hiking, climbing trees, being outside in general, but my connection to the surrounding plant-life was distant, similar to the relationship between a homeowner and the trees that form the hardwood floors. I appreciated plants’ beauty and enjoyed the shade, but now there is a definite connection between my (limited) scientific knowledge and the physical plants. It means so much more to know the scientific name of a tree you just ran past, or to recognize Vitis mustangensis and know that you can eat the wild grapes growing on the vines.

Perhaps most exciting thing to me is this: the further realization that the microscopic world is bursting with life.

Let me explain. I began my 2017 summer internship at BRIT in the herbarium working with Collections Manager Tiana Rehman, learning to mount, geo-reference, digitize, and file specimens. My main project was sorting and filing the Myxomycete Collection of Dr. Harold W. Keller. (Myxomycetes are more commonly known as slime molds, but they aren’t fungi; they belong in the Protista Kingdom.) As I went through the slime mold collection, I learned to recognize and identify many specimens to the genus and species levels. Stemonitis looks like hair growing on wood, some Diachea species are beautifully iridescent, Lycogala immature fruiting bodies are Pepto-Bismol pink, Tubifera looks like a brown sponge when its peridium comes off, and while the genus Physarum is incredibly common, only the rarer Physarum roseum has striking red fruiting bodies.

Collecting bark from trees. Once back at BRIT, we examined the samples under a microscope to observe lichens, mosses, and myxomycetes.

Left: Me with Bob O’Kennon and Dr. Harold Keller. Right: Me with Tiana Rehman and Dr. Keller.

Most slime mold species are naturally small, and many require a hand-lens or a microscope to be seen. This is where moist chamber cultures come into play. Part of my internship included working directly with Dr. Keller, and my education involved collecting bark from large, old, live trees, placing them in large Petri dishes, and then wetting the bark. After the excess water is removed, this tiny world explodes with life. Under the microscope, lichens and mosses swell up from the bark, becoming bright green, dark green, even red; translucent nematodes can be seen wriggling around; pale yellow nymphs and adult brown mites are relatively easy to spot; little crevices in the bark remain full of water, while dryer spots become perfect places for white, turquoise, bright orange, translucent, and amber colored molds, fungi, and myxobacteria to grow.

And, of course, there are slime molds. Myxomycetes are tricky, popping up in unexpected places and assuming a multitude of shapes and colors. Ulmus americana (American Elm) bark proved best for the moist bark cultures, having the highest myxomycete species diversity, and yielding slime molds from the ComatrichiaCribrariaEchinosteliumLicea, and Macbrideola genera. With such productive bark, the possibility of unusual, rare, or new species of myxomycetes was quite high. In fact, an Echinostelium species, smaller than the naked eye can see, had to be painstakingly removed from the bark cultures and placed on microscope slides to be accurately identified; the agony of defeat and the joy of victory certainly applied.

Collecting fungi with Dr. Denis Benjamin.

Overall, the time I spent studying and looking at Myxomycetes in bark cultures and in the herbarium exponentially increased my knowledge of what I once thought were microscopic fungi. More importantly, the time I spent with other researchers at BRIT has provided me with a wealth of hands-on knowledge about research in general, research as a career, how to obtain funding for research projects, and of course, how best to enjoy the wonders the natural world has to offer.

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