Medium data

Search for medium no. = [1148].
Unless otherwise stated, sterilize media by autoclaving at 121°C for 15 min.

1148   NITROSOSPHAERA GARGENSIS MEDIUM

KH2PO4  0.05    g
KCl  0.075   g
MgSO4·7H2O  0.05    g
NaCl  0.584   g
CaCO3  4.0     g
Distilled water  1.0     L
Mix components and autoclave (CaCO3 will not fully dissolve). After cooling, add the following solutions to the medium (autoclaved or *filter-sterilized):
50 mM NH4Cl solution  20.0     ml
Trace element solution* (see below)  1.0     ml
Selenite-tungstate solution (see Medium No. 431)  0.5     ml
Comments: Typically, prepare the medium in glass bottles with plastic caps leaving an ample head space (e.g., 50 ml medium in 250 ml-Duran® glass bottles). Cultivate in the dark without agitation. Check growth by phase-contrast microscopy. Also, it can be checked by measuring ammonium concentration. Once ammonium in the medium is depleted, it can be fed by the addition of another 50 mM NH4Cl solution (final 1.0 mM). The ammonium-feeding can be repeated several times. If the culture stops the ammonium oxidation or begins to grow even slower, nitrite may be accumulated up to a level causing growth inhibition in the culture (ca. 15 mM). If so, replace the medium as follows: spin down the culture (< 65,000 g for 15 min), remove the supernatant, and add fresh culture medium to the white pellet. Then, suspend the pellet and remove the suspension to a new glass bottle.
Trace element solution:
HCl (conc.)  2.5     ml
MnSO4·5H2O  0.048   g
H3BO3  0.05    g
ZnCl2  0.07    g
Na2MoO4·2H2O  0.073   g
CuCl2·2H2O  0.02    g
NiCl2·6H2O  0.024   g
CoCl2·6H2O  0.08    g
FeSO4·7H2O  1.0     g
Distilled water  1.0     L