Optimization of Cellulase Production by a Novel Endophytic Fungus Penicillium oxalicum R4 Isolated from Taxus cuspidata

Hongkun Li,Jiao Jiao,Meijia Dou,Xinyu Wang,Na Guo,Ping Kou,Yujie Fu

doi:10.3390/su13116006

Hongkun Li, Jiao Jiao + Show 5 more

Open Access

https://doi.org/10.3390/su13116006

Copy DOI

Abstract

Endophytic fungi inside a plant can degrade a portion of plant lignin and cellulose. Endophytic Penicillium is one of the industrial microorganisms with the advantage of producing enzymes with a complete enzyme system that can be secreted into the extracellular space. The natural evolution of ancient tree species from special natural geographic environments to screen out cellulase-producing strains with excellent characteristics provides a promising direction for future industrial enzymes. The present study successfully isolated and screened a novel fungal endophyte, Penicillium oxalicum R4, with higher cellulase activity from Taxus cuspidata. Under the optimized culture conditions obtained by a Box–Behnken design (BBD) and an artificial neural network–genetic algorithm (ANN–GA), yields of Filter Paperase (FPase), Carboxymethyl Cellulase (CMCase) and β-glucosidase (βGLase) produced by P. oxalicum R4 were 1.45, 5.27 and 6.35 U/mL, which were approximately 1.60-fold, 1.59-fold and 2.16-fold higher than those of the non-optimized culture, respectively. The discovery of cellulase-producing strains of endophytic fungi located in special natural geographic environments, such as Taxus cuspidata, which is known as a living plant fossil, provides new research directions for future industrial enzymes.

Highlights

IntroductionWith the rapid economic development and the rapid increase in population, the human demand for energy is increasing [1,2]
Among 58 endophytic fungi isolated from 20-year-old Taxus cuspidata, congo red and cellulase, activity assays were used to screen the cellulose decomposition activity of the isolated fungi
When the macromolecular polysaccharide like cellulose degraded by cellulase, the small molecular sugars could not interact with the congo red

Summary

Introduction

With the rapid economic development and the rapid increase in population, the human demand for energy is increasing [1,2]. As one of the main sources of energy consumed by human beings, is irreducible and finite, and the pollutants released during the combustion process can cause serious pollution to the environment [3,4,5]. For the sake of sustainable economic progress and human survival, people have to gradually focus on the use of renewable energy [6,7]. The most abundant and cheapest renewable resource on Earth, is usually disposed of in a simple and crude way, such as burning or burying straw on site, causing serious air pollution and even haze. Cellulose is a promising renewable fuel and chemical raw material. It has important applications in textile, food, pharmaceutical, biofuel and other fields [8,9]

Methods

Results

Discussion

Conclusion