Enhanced production of thermostable laccases from a native strain of Pycnoporus sanguineus using central composite design.
The production of thermostable laccases from a native strain of the white-rot fungus Pycnoporus sanguineus isolated in Mexico was enhanced by testing different media and a combination of inducers including copper sulfate (CuSO4). The best conditions obtained from screening experiments in shaken flasks using tomato juice, CuSO4, and soybean oil were integrated in an experimental design. Enhanced levels of tomato juice as the medium, CuSO4 and soybean oil as inducers (36.8% (v/v), 3 mmol/L, and 1% (v/v), respectively) were determined for 10 L stirred tank bioreactor runs. This combination resulted in laccase titer of 143,000 IU/L (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), pH 3.0), which represents the highest activity so far reported for P. sanguineus in a 10-L fermentor. Other interesting media resulting from the screening included glucose-bactopeptone which increased laccase activity up to 20,000 IU/L, whereas the inducers Acid Blue 62 and Reactive Blue 19 enhanced enzyme production in this medium 10 times. Based on a partial characterization, the laccases of this strain are especially promising in terms of thermostability (half-life of 6.1 h at 60 °C) and activity titers.
Centro del Agua para América Latina y el Caribe, Tecnológico de Monterrey, Campus Monterrey, NL 64849, Mexico; Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany; Bioengineering Group, Earth and Life Institute, Université Catholique de Louvain, Place Croix du Sud, 2, Box L7.05.19, 1348 Louvain-la-Neuve, Belgium; Laboratorio de Enzimología, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, Av. Universidad s/n, Ciudad Universitaria, San Nicolás de los Garza, NL 64450, Mexico.
Leticia I
LI
Ramírez-Cavazos
Charles
C
Junghanns
Rakesh
R
Nair
Diana L
DL
Cárdenas-Chávez
Carlos
C
Hernández-Luna
Spiros N
SN
Agathos
Roberto
R
Parra
D019149:Bioreactors; D001709:Biotechnology; D003470:Culture Media; D004790:Enzyme Induction; D004795:Enzyme Stability; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology; D042845:Laccase / Q000096:biosynthesis*; D008800:Mexico; D055494:Pycnoporus / Q000201:enzymology* / Q000302:isolation & purification
D003470:Culture Media; D042845:Laccase