Strains of cellulose-degrading Trichoderma spp. were isolated and identified from acid sulfate soil for pineapple cultivation in Vi Thanh, Hau Giang Province

Pineapple cultivation in Vietnam results in many byproducts that are costly to be chemically decompose, while acid sulfate soil for pineapple is deficient in nutrients. Trichoderma spp. fungi are more significant means of bio-decomposers in agriculture and can degrade agricultural byproducts to produce organic fertilizers for crops, which is one of the trends of sustainable agriculture. Therefore, the current study aimed to isolate Trichoderma spp. strains that could degrade cellulose in byproducts after pineapple harvest in Vi Thanh City, Hau Giang Province. Forty-eight soil samples for Trichoderma spp. isolation was collected at 5–20 cm depth in the rhizosphere of pineapple farms in Vi Thanh City, Hau Giang province, Vietnam. The isolation was based on the Trichoderma Specific Medium. The isolated strains were investigated for growth rate and production of cellulose-degrading enzymes under acidic conditions (pH 4.0) and finally identified based on their Internal Transcribed Spacer regions. The results revealed that 90 Trichoderma spp. strains were morphologically described and found to degrade cellulose under pH 4.0. Their growth was roughly 1.50–2.90 cm in 24 h. The key mechanism for cellulose degradation was enzymes produced by the selected fungi, in which TCD-VT-02, TCD-VT-85, and TCD-VT-88 strains had significant endo-?-1,3-glucanase, endo-?-1,4-glucanase, and exo-?-1,3-glucanase productions, with 853.4, 438.7 and 320.8 UI/h, respectively. These fungal strains were identified as Trichoderma hamatum TCD-VT-02, T. asperellum TCD-VT-85, and T. asperellum TCD-VT-88 with 99 % similarity. These strains should be further investigated for making bio-compost from the local pineapple waste