4 Characteristics of Microbial Transglutaminase

“Microbiological transglutaminase is a single polypeptide with a molecular weight of approx. 38 kDa.  It is composed of 331 amino acids, with an isoelectric point at pH 8.9. It is a simple monomeric protein (not a glycoprotein or lipoprotein).  (Kieliszek, M and Misiewicz, A.;  2013

“A temperature of 40 °C at pH 5.5 is the most favourable for the catalytic activity of transglutaminase, with the exception of transglutaminase isolated from Streptomyces sp., which acts most effectively at a higher temperature of 45 °C. This enzyme is not stable at 50 °C (since it loses 50 % of its activity when heated for 30 min) and is very susceptible to heat in the presence of ethanol.  (Kieliszek, M and Misiewicz, A.;  2013)

Smoking – keep core temperature > 40 deg C and < 45 deg C.

This temperature range is very fortunate for bacon producers since adverse visual changes start happening at around 51 deg C in meat.   The subject of the denaturing of proteins is a bit more complex than one may think.  Generally “thermal denaturation of muscle proteins such as myosin, sarcoplasmic proteins and collagen, and actin, occurs at different temperatures. ”  (KAJITANI, S., et al; 2011)   Due to the importance of this topic, it will be considered in a separate article, attached to this discussion article.

The addition of carbohydrates, such as maltodextrin, saccharose, mannose, trehalose and reduced glutathione (GSH), significantly increases the thermal stability of the enzyme. Casein may protect transglutaminase against degradation by extracellular proteolytic enzymes. At temperatures close to 0 °C, transglutaminase maintains its total enzymatic activity.”  (Kieliszek, M and Misiewicz, A.;  2013)

Micro is key in factory temp.  We can keep it cool!  No problem for TG!

“Enzymes biosynthesised by bacteria are stable at a wide range of pH values, i.e. from 4.5 to 8.0. In addition, they do not require calcium ions to be activated, which is in contrast to transglutaminases of animal origin. This is a highly desirable property, from a practical point of view, for use in enzymatic preparation. The activity of transglutaminase increases in the presence of Co2+, Ba2+ and K+.” (Kieliszek, M and Misiewicz, A.;  2013)  We will exploit this feature by designing a complimentary injection brine.

Microbial transglutaminase is inhibited by Zn2+, Cu2+, Hg2+ and Pb2+ ions which bind to the thiol group of cysteine in the active centre.  (Kieliszek, M and Misiewicz, A.;  2013)  We will evaluate the implications by analysing our water and salt.

Determine through experiment the impact of dissolved potassium chloride on the functionality of TG.

Due to the importance of this topic will be considered in a separate article, “Curing Brine and Microbial Transglutaminase (MTG) – designing the optimal blend

 

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