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A method for obtaining protein concentrates from microorganisms
Author(s) -
Hedenskog Gudmund,
Mogren HÅRkan,
Enebo Lennart
Publication year - 1970
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260120607
Subject(s) - sodium hydroxide , nitrogen , chemistry , microorganism , extraction (chemistry) , chromatography , sodium , volume (thermodynamics) , bacteria , organic chemistry , biology , genetics , physics , quantum mechanics
In order to isolate proteins from microalgae, yeasts and bacteria, cell disintegration in a special ball‐mill was performed. The degree of disintegration of the different microorganisms was compared. The dependence of disintegration on bead size and on the ratio between the volume of suspension and the volume of glass beads was also investigated. Nondisintegrated and disintegrated cells were extracted with sodium hydroxide and the amount of extractable nitrogen and the amount of nitrogen precipitable at pH 4.0 were determined. The dependence of yield on the sodium hydroxide concentration, extraction time, and temperature was studied. When extracting undisintegrated cells, very low yields were obtained and the nitrogen extracted was mostly nonproteinous. For disintegrated cells high yields were obtained. An optimum was found after extraction with 0.3–0.5% sodium hydroxide; at pH 11.0–11.5. The precipitate obtained represented 60–70% of the cell nitrogen. The nitrogen content of the precipitate was 12–14% of the dry weight.