Hi there,

I don't think there is any substitute to YNB... What you can do is to reconstitute YNB according to its content but it's a bit complex:

http://openwetware.org/wiki/Composition_of_Yeast_Nitrogen_Base_%28YNB%29

If you just want to check that your clone(s) express the target protein, you can try plain YPD medium instead, centrifuging the cells and resuspending in YP (without glucose) +methanol for induction. Not as efficient, but it does work.

Dear Shanice

There are described several mineral media to cultivate Pichia pastoris, in the attached reference you can see one minimal medium.

Defined medium composition for P. pastoris fermentations

Constituent Quantity (g/L)

Glycerol 40.0

CaSO4 0.93

K2SO4 18.2

MgSO4.

7H2O 14.9

KOH 4.13

K2HPO4 7.0

+22.7 ml 85% H3PO4 +12 ml trace solution

Trace salts solution

Constituent Quantity (g/L)

CuSO4.5H2O 6.0

NaI 0.08

MnSO4.H2O 3.0

Na2MoO4.2H2O 0.2

H3BO3 0.02

CoCl2 0.5

ZnCl2 20.0

FeSO4.7H2O 65.0

Biotin 0.2

 +5 ml conc. H2SO4

Based on: Bushell ME, Rowe M, Avignone-Rossa CA, Wardell JN. 2003. Cyclic fed-batch culture for production of human serum albumin in Pichia pastoris. Biotech Bioeng 82(6): 678–68

Best regards

http://www.ifsc.usp.br/~ilanacamargo/FFI0740/pichia.pdf

Definitely it is possible to replace the Nitrogen source fro two important reason (i) to reduce the const with economically affordable nitrogen source (ii) the most important is by changing nitrogen source the end product of your interest will also altered. The last one have large scope to improve and get your end product of your interest with desired properties.

I hope it will be useful, please refer one of my article with the same interest.

Best wishes,

Aru