1. Castellar M.R., Aires-Barros M.R., Cabral J.M.S.: Effect of zeolite on ethanol fermentation, inProc. FEBS Internat. Symp. Immobilized Cells: Basic and Applications (R.H. Wijffels, R.M. Buitelaar, H.G. Westels, C. Buckl, J. Tramper, Eds). Noordwijkerhont, The Netherlands 1995.
2. Chaloupka J., Obdržálek V., Křečková P. Nesmeyanova M.A., Zalabák V.: Protease activity in cellsBacillus megaterium during depression.Folia Microbiol. 20, 277–288 (1975).
3. Luebbe C., Demain A.L., Bergman K.: Use of controlled-release polymer to feed ammonium toStreptomyces clavuligerus cephalosporin fermentations in shake flask.Appl. Microbiol. Biotechnol. 22, 424–427 (1985).
4. Ma T.S., Zuazaga G.: Micro-Kjeldahl determination of nitrogen. A new indicator and improvement of method.Ind. Eng. Chem. Anal. 14, 280–286 (1942).
5. Markham R.: A steam distillation apparatus suitable for micro-Kjeldahl analysis.Biochem. J. 36, 790–791 (1942).