Bacteria of the geochemical Iron Cycle

Field trip for Participants of Pieter Visscher’s Geomicrobiology Course,
students of Kurt Hanselmann’s Course on the "Biochemistry and Physiology of Prokaryotes"
and guests

Form for Internet Application

Former Iron Mine Gonzen near Sargans/SG

Wednesday morning, May 1, 2002.

A number of bacteria are able to make use of the energy which is released during the oxidation of ferrous iron to ferric iron. Since only one electron gets transfered during Fe(II) oxidation to Fe(III) and since only small amounts of energy get released, a lot of Fe(II) needs to be oxidized to support growth.
Large volumes of biological ”rust” can be seen everywhere, in iron domiated ecosystems, particularly in redox transition zones at the surface of ponds and in biofilms on rock walls. The “rust” consists of badly soluble iron(III)-oxides and iron(III)-hydroxides which dominate the habitats of the ferrous iron oxidizing bacteria. Bacteria which catalyze the ferrous iron oxidation (e.g. Gallionella ferruginea) protect themselves from being completely encapsulated with “rust” by forming an extracellular sheath from which the cells can “escape” as soon as exchanges of metabolites by diffusion becomes limiting.
During the excursion we will see mass developments of sheath-forming ferrous iron oxidizing bacteria and many empty sheaths. And we will try to understand the habitat conditions which must prevail to select specifically for the kind of bacteria found here in large numbers and how they might be maintained.

Zürich HB dep. 08:10 (train to Sargans, Landquart, Chur)
Sargans SBB arr. 09:19
10-minute walk to the Visitors’ Center and the Mine Train Station
If you travel by car, you may park on the parking place of the Visitors’ Center.

09:40 Train ride from the Visitors’ Center to the central hall of the mine.
10.00 - 11.15 Information about iron mining in Gonzen and walk through some of the
former mine tunnels.
Collecting ferrous iron oxidizing bacteria from iron mats and microscopy at the site.

12.30 Return to the Visitor’s Center
Short break and time to warm up in the Visitors’ Restaurant

Walk to SBB train station Sargans
Sargans SBB dep. 13:40
Zürich HB arr. 14:50

You will be equipped at the Visitor's Center with a hard hat and a lamp. Please wear sturty boots, a water protective jacket and wear warm clothes, since it is still rather cool inside the mountain.

Take collecting vials for bacteria with you and a camera with a flash light if you intend to make pictures of iron mats.

Since we will be inside the mountain the excursion can take place regardless of the weather forecast.

For University Course students who signed up in class, a group ticket will be purchased. Please take you half-tax card or your general abonnement if you have one.
We are able offer a few travel stipends and will cover part of the ticket costs and of the entrance fee for immatriculated students of the University. Guests are asked to buy their own tickets from Zürich to Sargans round trip.

Entrance fee to the mine and transportation with the mine train is Fr. 19.- per person. The fee will be collected during the trip.

is the responsibility of the participant. The tour guides cannot be held liable for damages or lost items.
Please do not leave the group in the mine since you might get lost or get yourself into danger in the extensive tunnel system of the mine.

Signing up
There are 35 places available. Please sign up as soon as possible during class, via the internet using the application form below or via e-mail to If you are a student who would like to profit from the travel subsidy, please mention any travel benefits (GA, 1/2-Tax, etc.) in your application and mention your immatriculation number.
Should you be prevented from attending, please let us know before Tuesday noon (April 30). Fees already paid minus an administrative fee of Fr. 5.- will be reimbursed if your reserved place can be passed on to person on the waiting list.

Kurt Hanselmann, Institute for Plant Biology / Microbial Ecology Group, University of Zürich Zollikerstrasse 107, 8008 Zürich. Tel. 01/ 6348284 or 01/6348211.
Please also consult the Group News under
for last minute changes.