Fungal co-culture increases ligninolytic enzyme activities: statistical optimization using response surface...

Area of Science:

• Biotechnology and Bioengineering
• Enzyme Engineering
• Mycology

Background:

• Ligninolytic enzymes (LEs) are crucial for degrading lignin, a complex biopolymer.
• Fungal co-cultures offer potential for enhanced enzyme production compared to monocultures.
• Understanding the role of hydrogen peroxide (H₂O₂) in LE activity is vital for optimization.

Purpose of the Study:

• To optimize ligninolytic enzyme activities in a novel co-culture of Pycnoporus sanguineus and Beauveria brongniartii.
• To investigate the influence of key medium components and hydrogen peroxide on enzyme production.
• To enhance laccase (EC 1.10.3.2) and manganese peroxidase (MnP, EC 1.11.1.14) activities.

Main Methods:

• Utilized Plackett-Burman experimental design (PBED) to identify significant factors.
• Employed central composite design (CCD) for optimizing yeast extract (YE) and ferrous sulfate (FeSO₄).
• Analyzed hydrogen peroxide (H₂O₂) production and its correlation with enzyme activities.

Main Results:

• Co-culturing P. sanguineus with B. brongniartii increased laccase and MnP activities by 6.0- and 2.3-fold, respectively.
• PBED identified YE, FeSO₄, and inoculum amount as significant factors, increasing activities by 8.2-, 5.2-, and 1.03-fold.
• CCD optimization further enhanced laccase by 1.5-fold and MnP by 4.28-fold; increased H₂O₂ correlated with higher enzyme activities.

Conclusions:

• The fungal co-culture system significantly enhances ligninolytic enzyme production.
• Yeast extract and ferrous sulfate are critical for optimizing laccase and MnP activities.
• Increased hydrogen peroxide levels are positively correlated with enhanced laccase and MnP activities in the co-culture.