Tuesday, February 3, 2009

Actinomycetes


Good smells exude from crumpled earth.
The rough bark of humus erupts
knots of potatoes (a clean birth)
whose solid feel, whose wet inside
promises taste of ground and root.


Seamus Heaney, from "At a Potato Digging", Death of a Naturalist


Mid-winter thaw. The earth softens a bit under a soft rain. You wander outside, trying to shake off the heaviness of winter, to smell the awakening earth.

The mud disappoints your nose. Inert. Lifeless.

You wander back inside, dreaming of May.



Actinomycetes is a class of bacteria essential to making good dirt. They are what give compost the sweet, earthy smell that makes gardeners wild with desire.

Actinomycetes give us the smell of rain in the summer. Storms draw life from the mud. Poets and lovers already know this. Microbiologists now know why.

Actinomycetes, which look like strands of fungus, break down rotting piles of vegetation, producing geosmin, the source of the aroma of healthy soil.

The smell, considered pleasant by (most) humans, has been added to some perfumes to give them an earthiness.

So why does mud smell lifeless in February? Actinomycetes go dormant in colder climes. While it is possible to grow actinomycetes in a petri dish (and yes, it will smell like the rich, sweet soil that makes gardeners swoon), waiting for the Earth to awaken reminds me of the cycle of life.

I think I can wait.




Besides adding romance to summer showers, actinomycetes has antibacterial properties. Streptomycin and related antibiotics come directly from actinomycetes; Biaxin and Zithromax are semi-synthetic antibiotics made from this same class of bacteria.


Image from UK-JAPAN 2008 website,

3 comments:

Ms. Vayda said...

How can something so thrilling and invigorating have such a difficult and uninspiring name? I spent most of my childhood summers in a rural Russian village where among many fruits and vagetables, my grandmother had a potato field. No Whole Foods can ever match a truly fresh potato batch pulled from the moist dark soil.

Anonymous said...

I too can not wait for spring! My 18 month old son and I have been scouting out guerilla gardening spots in our neighborhood all week and planning our community garden plot. Actually I do most of the planning and he just picks up sticks and finds mud to walk in. However, as I sit here typing this Gloucester City is getting about four inches of new snow.

doyle said...

Dear Alla,

I love the feeling of pulling a potato out of the ground--I threw a potato sprout that sat in the high school for a whole year, then was surprised in the fall when the spud grew several more!

(Now you got me thinking about growing potatoes this summer--potatoes are underrated).

Dear captainawsome,

Guerrilla gardening is a wonderful lesson to teach your child! Land is a gift of Creation--and guerrilla gardens respect this. (Lawns, on the other hand....)