Production of cellulases by Xylaria sp. and Nemania sp. using lignocellulose substrates for bioethanol production from maize cobs.

Autor:	Kamande SM; Technical University of Kenya, Department of Biochemistry and Biotechnology, P.O. Box 52428-00200, Nairobi, Kenya.; Kenyatta University, Department of Biochemistry, Biotechnology and Microbiology, P.O. Box 43844-00100, Nairobi, Kenya., Omwenga GI; Kenyatta University, Department of Biochemistry, Biotechnology and Microbiology, P.O. Box 43844-00100, Nairobi, Kenya., Ngugi MP; Kenyatta University, Department of Biochemistry, Biotechnology and Microbiology, P.O. Box 43844-00100, Nairobi, Kenya.
Jazyk:	angličtina
Zdroj:	Heliyon [Heliyon] 2024 Aug 30; Vol. 10 (17), pp. e36802. Date of Electronic Publication: 2024 Aug 30 (Print Publication: 2024).
DOI:	10.1016/j.heliyon.2024.e36802
Abstrakt:	Two species of Xylaria (KM01, KM03) and Nemania sp.KM02 isolated from decaying plant biomass were evaluated for their ability to produce cellulases on maize cob, eucalyptus, and cypress substrates under solid-state fermentation. A total of 10 fungal samples from decaying plant biomass were collected from Karura forest based on morphological variations. The fungi isolated were screened for cellulase activity and positive isolates were selected for the study. ITS4 R and ITS86 F primers were used to identify the fungal isolates with accuracy ranging from 98 % to 100 %. The crude cellulases produced was assayed for FPase, exoglucanase, endoglucanase and β-glucosidase. Cellulases of Xylaria sp. KM01 produced higher FPase and exoglucanase (2.01 ± 0.13 IU/ml and 0.94 ± 0.08 IU/ml) on pretreated maize cobs with 0.1M HCl at 121 o C, while that of Xylaria sp.KM03 produced higher β-glucosidase and endoglucanase (588.6 ± 64.2 IU/ml and 3.59 ± 0.02 IU/ml) on maize cobs pretreated with 0.1M NaOH at 121 o C. However, cellulases of Xylaria sp. KM01 produced higher β-glucosidase and FPase (629.7 ± 20.2 IU/ml and 1.67 ± 0.03 IU/ml) on untreated maize cobs after the 9th day of incubation, whereas cellulases of Xylaria sp.KM03 and Nemania sp.KM02 produced higher endoglucanase and exoglucanase (2.80 ± 0.21 IU/ml and 0.83 ± 0.02 IU/ml) on untreated maize cobs after the 3rd and 6th day of incubation. Saccharification of maize cobs by cellulase of Xylaria sp.KM03 produced the highest reducing sugars at 8 % substrate loading (10.17 ± 0.37 mg/ml) after 72 h of incubation. Simultaneous hydrolysis and fermentation of maize cobs by cellulase of Nemania sp.KM02 and Saccharomyces cerevisiae yielded higher bioethanol (28.72 ± 3.82 mg/ml) after 96 h of fermentation. Maize cob is established as a suitable feedstock for cellulases and bioethanol production. Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. (© 2024 The Authors.)
Databáze:	MEDLINE
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