Towards a Miniaturized Culture Screening for Cellulolytic Fungi and Their Agricultural Lignocellulosic Degradation

Abstract

The substantial use of fungal enzymes to degrade lignocellulosic plant biomass has widely been attributed to the extensive requirement of powerful enzyme-producing fungal strains. In this study, a two-step screening procedure for finding cellulolytic fungi, involving a miniaturized culture method with shake-flask fermentation, was proposed and demonstrated. We isolated 297 fungal strains from several cellulose-containing samples found in two different locations in Thailand. By using this screening strategy, we then selected 9 fungal strains based on their potential for cellulase production. Through sequence-based identification of these fungal isolates, 4 species in 4 genera were identified: Aspergillus terreus (3 strains: AG466, AG438 and AG499), Penicillium oxalicum (4 strains: AG452, AG496, AG498 and AG559), Talaromyces siamensis (1 strain: AG548) and Trichoderma afroharzianum (1 strain: AG500). After examining their lignocellulose degradation capacity, our data showed that P. oxalicum AG452 exhibited the highest glucose yield after saccharification of pretreated sugarcane trash, cassava pulp and coffee silverskin. In addition, Ta. siamensis AG548 produced the highest glucose yield after hydrolysis of pretreated sugarcane bagasse. Our study demonstrated that the proposed two-step screening strategy can be further applied for discovering potential cellulolytic fungi isolated from various environmental samples. Meanwhile, the fungal strains isolated in this study will prove useful in the bioconversion of agricultural lignocellulosic residues into valuable biotechnological products.

Isolasi dan Karakterisasi Jamur Selulolitik pada Fermetodege: Pakan Fermentasi Berbahan Campuran Eceng Gondok, Bekatul Padi, dan Tongkol Jagung

“…Bahan pakan yang bersifat padat dengan kadar air sedikit mendukung terbentuknya kondisi mirkroaerofilik selama fermentasi sehingga terbentuk kondisi fermentasi dengan ketersediaan oksigen dalam jumlah terbatas yang diperlukan oleh jamur selulolitik untuk mendegradasi bahan yang tinggi selulosa selama proses fermentasi. Jamur selulolitik berpotensi dalam degradasi lignoselulosa pada bahan ditunjukkan dengan adanya biokonversi lignoselulosa menjadi glukosa (Arnthong et al, 2020). Jamur selulolitik mendegradasi selulosa untuk digunakan sebagai sumber karbon untuk pertumbuhan, metabolisme, dan pengaturan ekspresi gen (Hu et al, 2020).…”

A high throughput screening process and quick isolation of novel lignin-degrading microbes from large number of natural biomasses

“…Additionally, through the use of specific assay conditions or detection methods, the target enzymes can be identified with better specificity and sensitivity compared to agar plate screening methods. Moreover, screening in liquid media also mimics industrial submerged culture conditions, thus allowing the identification of potential microbes and enzymes for industrial applications [ 17 ].…”

Efficient Constitutive Expression of Cellulolytic Enzymes in Penicillium oxalicum for Improved Efficiency of Lignocellulose Degradation

“…Therefore, they are considered as potential alternatives to the industrial cellulase-producer Trichoderma reesei [ 18 , 19 ]. Penicillium oxalicum strains are commonly isolated from the natural environment for their high cellulase-producing capacities [ 20 , 21 ]. Genomic and proteomic analyses of a P. oxalicum wild-type strain 114-2 have revealed that it produces a lignocellulolytic enzyme system rich in hemicellulases [ 22 ].…”