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Encapsulation of immobilised in situ intracellurar lipases of Mucor

100%

Antczak T. , Bugla J. , Szeja W. , Galas E.

Biotechnologia

1999

nr 1

172-179

Endolipases associated with the cell structures of microorganisms are more active in comparison with purified enzymes. Due to the weak mechanical resistance lipases immobilised in situ cannot be used many times. The method of lipases encapsulation in polysacharides hydrophilic gels was elaborated. The lipases Mucor immobilised in situ were treated with oleic acid in hexane and then dispersed in an aqueous solution of sodium alginate or karagenate. Immobilisation of enzymes was achieved by intermolecular cross-linking of the polysacharide chains using the solution of calcium or potassium salts. The biocatalysts prepared under proposed conditions were active in hydrolysis of esters, as well as in esterification reaction. It was found that immobilised enzymes were active for a long time, were mechanically resistant and could be used many times in periodic and continuous processes.

Microorganisms in stereoselective organic synthesis

100%

Niemiec A. , Szeja S. W. , Szeja W.

Biotechnologia

2001

nr 3

104-123

This paper deals with the use of microorganisms for the synthesis of homochiral compounds. The influence of various factors on the efficiency of biotransformation employing whole cells is discussed. The author?s attention was focused on stereochemistry of reaction since the knowledge of its rules allows to control the stereoselectivity and productivity of biotransformation. Some interesting examples of best documented bioreduction and biooxidation reactions were selected and are reported in this article.

Entrapment of immobilised in situ intracellular lipase of Mucor in microporous capsules

75%

Antczak T. , Bugla J. , Mastalerz M. , Niemiec A. , Szeja W. , Slek M. , Galas E.

Biotechnologia

2000

nr 4

142-151

Lipases Mucor circinelloides and Mucor racemosus immobilised in situ were closed in microporous polysacharides hydrophilic gel cross-linked using a solution of calcium salts. In order to increase the porosity of polysacharides matrix during its cross-linking oligomer molecules of ethylene oxide (optimal Polikol 1000) were incorporated in the structure of the matrix. Then the oligomer was removed by acetone extraction. The obtained biocatalyst preparations were tested in hydrolysis of esters and esterification of oleic acid with butanol. The hydrolysis was carried out in water saturated organic solvents medium (n-hexane and diisopropylether). It was found that the efficiency of M. racemosus lipase immobilisation in hydrolysis of n-butyl oleate, n-butyl palmitate, n-butyl stearate, n-butyl laurate amounted to 60%. The efficiency of M. circinelloides lipase immobilisation in esterification of oleic acid with 1-butanol in hexane achieved 45%.