Thermostable invertases from Paecylomyces variotii produced under submerged and solid-state fermentation using agroindustrial residues.
The filamentous fungus Paecylomices variotii was able to produce high levels of cell extract and extracellular invertases when grown under submerged fermentation (SbmF) and solid-state fermentation, using agroindustrial products or residues as substrates, mainly soy bran and wheat bran, at 40°C for 72 h and 96 h, respectively. Addition of glucose or fructose (≥1%; w/v) in SbmF inhibited enzyme production, while the addition of 1% (w/v) peptone as organic nitrogen source enhanced the production by 3.7-fold. However, 1% (w/v) (NH(4))(2)HPO(4) inhibited enzyme production around 80%. The extracellular form was purified until electrophoretic homogeneity (10.5-fold with 33% recovery) by DEAE-Fractogel and Sephacryl S-200 chromatography. The enzyme is a monomer with molecular mass of 102 kDa estimated by SDS-PAGE with carbohydrate content of 53.6%. Optima of temperature and pH for both, extracellular and cell extract invertases, were 60°C and 4.0-4.5, respectively. Both invertases were stable for 1 h at 60°C with half-lives of 10 min at 70°C. Mg(2+), Ba(2+) and Mn(2+) activated both extracellular and cell extract invertases from P. variotii. The kinetic parameters K(m) and V(max) for the purified extracellular enzyme corresponded to 2.5 mM and 481 U/mg prot(-1), respectively.
Instituto de Química de Araraquara, UNESP, Rua Francisco Degni s/n, 14800-900, Araraquara, São Paulo, Brazil.
Marielle Aleixo
MA
Giraldo
Tony Márcio
TM
da Silva
Fernanda
F
Salvato
Héctor Francisco
HF
Terenzi
João Atílio
JA
Jorge
Luis Henrique Souza
LH
Guimarães
D004795:Enzyme Stability; D005285:Fermentation / Q000502:physiology*; D005656:Fungal Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D013395:Sucrose / Q000378:metabolism; D013696:Temperature; D043324:beta-Fructofuranosidase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*
D005656:Fungal Proteins; D013395:Sucrose; D043324:beta-Fructofuranosidase