Production of L-leucine aminopeptidase by selected Streptomyces isolates.
OBJECTIVE
To screen various Streptomyces cultures producing L-leucine aminopeptidase (LAP).


RESULTS
Twenty-one Streptomyces strains were screened for LAP production. The best three producers were found to be Streptomyces mobaraensis NRRL B-3729, Streptomyces gedanensis IFO 13427, and Streptomyces platensis NRRL 2364. pH optima of the three enzymes were in the range of 8.0-8.5 and the temperature optima varied between 50 and 65 degrees C. LAP of S. mobaraensis was stable at 60 degrees C and pH 8.5 for 60 min. Metal ion salts, CoCl(2).6H(2)O and ZnSO(4).7H(2)O in 0.7 mmol l(-1) concentration enhanced the relative enzyme activity in all three enzymes. Molecular mass of LAP of S. mobaraensis was found to be approx. 37 kDa.


CONCLUSIONS
Streptomyces mobaraensis NRRL B-3729, S. gedanensis IFO 13427, and S. platensis NRRL 2364 were found to be good producers of extracellular LAP. The approx. 37 kDa enzyme of S. mobaraensis is considerably thermostable.


CONCLUSIONS
A good number of Streptomyces were screened and the ability of the aminopeptidases to release a particular N-terminal amino acid along with its good thermal stability makes them interesting for controlling the degree of hydrolysis and flavour development for a wide range of substrate.
Nagy
V
V
Department of Applied Biotechnology and Food Sciences, Budapest University of Technology and Economics, Budapest, Hungary.
Nampoothiri
K M
KM
Pandey
A
A
Rahulan
R
R
Szakacs
G
G
D000626:Aminopeptidases / Q000032:analysis / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D001431:Bacteriological Techniques; D003300:Copper / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D006877:Hydroxamic Acids / Q000494:pharmacology; D007218:Industrial Microbiology; D007931:Leucyl Aminopeptidase / Q000032:analysis / Q000096:biosynthesis*; D045726:Metalloproteases / Q000037:antagonists & inhibitors; D063208:Methionyl Aminopeptidases; D013302:Streptomyces / Q000302:isolation & purification / Q000378:metabolism*; D013379:Substrate Specificity; D013696:Temperature; D015032:Zinc / Q000494:pharmacology
D006877:Hydroxamic Acids; D003300:Copper; D004492:Edetic Acid; D045726:Metalloproteases; D000626:Aminopeptidases; D007931:Leucyl Aminopeptidase; D063208:Methionyl Aminopeptidases; D015032:Zinc; C010531:actinonin