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
Location
Former
Iron Mine Gonzen near Sargans/SG
Date
Wednesday
morning, May 1, 2002.
Contents
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.
Program
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
Clothing
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.
Tickets
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.
Costs
Entrance
fee to the mine and transportation with the mine train is Fr. 19.- per person.
The fee will be collected during the trip.
Insurance
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
microeco@botinst.unizh.ch
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.
Information
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.