In this series I will follow the making of a specially-designed box for petri dishes into which I’ll grow Chlorociboria species fungi.
I of course could have come with your average box, but as cultivating fungi on agar is quite delicate matter, because of the risk of contamination by airborne molds, I ended up with a forced-air, filtered design for the box, with pressured air provided by a fish tank air compressor, which is quite overkill for the oxygen needs of fungi.
After some serious thinking for a few weeks, I ended up with a design incorporating two compartments side by side: a filtration stage on one side, and the main culture chamber for six petri dishes on the other side, a major condition being that the whole system must fit into the Muji drawers I have in my dresser, away from light.
The culture chamber is covered with a lid with an inset glass, to allow for periodical checking of the growth status of the tiny beasts (which only grow under no light conditions!). Rubber foam on the underside of the lid helps keep everything free of any entrance paths for airborne molds, and in any case of a tiny air gap in the lid, the pressurized culture chamber remains isolated from molds anyway.
The petri dishes receive pressurized, filtered air from under the base plate. The base itself is made up of three 3mm MDF layers: a base plane, an isobare (constant pressure) air distributing plane, and an air delivery and dishes holding plane. Individual air outlets ensure that each petri dish receives an equal amount of air, and three auxiliary smaller air outlets direct the airflow towards the air exhaust layers of the filtration stage. This is blatant overkill, but I like overkill, and Chlorociboriae have revealed to seasoned pro biologists to be a bear to grow anyway. So whatever helps harness these suckers is good for me: when the time comes to grow them, I want them healthy and well fed.
In part two we will review the making of the air-ducted base of the box.
-- Thomas - Pondering the inclusion of woodworking into physics and chemistry classes...