Evaluation of carbon sources for the production of inulinase by Aspergillus niger A42 and its characterization

Germec M., TURHAN İ.

BIOPROCESS AND BIOSYSTEMS ENGINEERING, cilt.42, sa.12, ss.1993-2005, 2019 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 42 Sayı: 12
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1007/s00449-019-02192-9
  • Dergi Adı: BIOPROCESS AND BIOSYSTEMS ENGINEERING
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1993-2005
  • Anahtar Kelimeler: Inulinase, Sucrose, Aspergillus niger, Activation energy, Thermal inactivation, Thermodynamics, YEAST PICHIA-GUILLIERMONDII, KLUYVEROMYCES-MARXIANUS, MICROBIAL INULINASES, EXTRACELLULAR INULINASE, BIOETHANOL PRODUCTION, EXO-INULINASE, PURIFICATION, OPTIMIZATION, HYDROLYSIS, STRAINS
  • Akdeniz Üniversitesi Adresli: Evet

Özet

Inulinases are used for the production of high-fructose syrup and fructooligosaccharides, and are widely utilized in food and pharmaceutical industries. In this study, different carbon sources were screened for inulinase production by Aspergillus niger in shake flask fermentation. Optimum working conditions of the enzyme were determined. Additionally, some properties of produced enzyme were determined [activation (E-a)/inactivation (E-ia) energies, Q(10) value, inactivation rate constant (k(d)), half-life (t(1/2)), D value, Z value, enthalpy (Delta H), free energy (Delta G), and entropy (Delta S)]. Results showed that sugar beet molasses (SBM) was the best in the production of inulinase, which gave 383.73 U/mL activity at 30 degrees C, 200 rpm and initial pH 5.0 for 10 days with 2% (v/v) of the prepared spore solution. Optimum working conditions were 4.8 pH, 60 degrees C, and 10 min, which yielded 604.23 U/mL, 1.09 inulinase/sucrase ratio, and 2924.39 U/mg. Additionally, E-a and E-ia of inulinase reaction were 37.30 and 112.86 kJ/mol, respectively. Beyond 60 degrees C, Q(10) values of inulinase dropped below one. At 70 and 80 degrees C, t(1/2) of inulinase was 33.6 and 7.2 min; therefore, inulinase is unstable at high temperatures, respectively. Additionally, t(1/2), D, Delta H, Delta G values of inulinase decreased with the increase in temperature. Z values of inulinase were 7.21 degrees C. Negative values of Delta S showed that enzymes underwent a significant process of aggregation during denaturation. Consequently, SBM is a promising carbon source for inulinase production by A. niger. Also, this is the first report on the determination of some properties of A. niger A42 (ATCC 204,447) inulinase.