Optimizing fungal treatment of lignocellulosic agro-industrial by-products to enhance their nutritional value.

This study delves into the dynamic interaction between various fungal strains, substrates, and treatment durations to optimize the nutritional value of these by-products. Six fungi, including Penicillium chrysogenum, Fusarium sp., Fusarium oxysporum, Fusarium solani, Penicillium crustosum, and Cosmospora viridescens, were evaluated across three substrates: wheat straw (WS), cedar sawdust (CW), and olive pomace (OP) over treatment periods of 4, 8, and 12 weeks. The study discerned profound impacts of these fungi across multiple parameters, including cellulose variation (C.var), lignin variation (L.var), and in vitro true digestibility variation (IVTD.var). Our results demonstrated that the various fungi had a significant effect on all parameters (p < .001). Noteworthy, F. oxysporum and F. solani emerged as exemplars, displaying notable lignin degradation, cellulose liberation, and IVTD enhancement. Importantly, P. crustosum demonstrated substantial cellulose degradation, exhibiting optimal efficacy in just 4 weeks for all substrates. Notably, F. sp. excelled, yielding favorable results when treating WS. P. chrysogenum achieved optimal outcomes with 8-week treatment for WS. Both Fusarium sp. and P. chrysogenum exhibited slight cellulose release, with remarkable reduction of WS lignin compared to other substrates. Especially, WS and OP displayed superior digestibility enhancements relative to CW. It should be noted that the treatment duration further shaped these outcomes, as prolonged treatment (12 weeks) fostered greater benefits in lignin degradation and digestibility, albeit with concomitant cellulose degradation. These findings underscore the intricate balance between fungal strains, substrates, and treatment durations in optimizing the nutritional value of lignocellulosic agro-industrial by-products. The outcomes of this study lead to the enhancement in the overall value of by-products, promoting sustainable livestock feed and advancing agricultural sustainability.

Lignocellulose-degrading fungi newly isolated from central Morocco are potent biocatalysts for olive pomace valorization.

The investigation of lignocellulolytic catalysts is an important feature to face the challenges of lignocellulosic biomass valorization. In central Morocco, fungi were isolated from decaying wood, soil, olive crushing by-products and their compost. One hundred fifty-five isolates were submitted to a selective screening, which served to distinguish 83% of lignocellulolytic isolates. Then, a collection of 56 fungi was subjected to morphological and molecular identification with the ITS5 and ITS4 primers. This approach showed that 45% of the fungal population belonged to the genus Penicillium, followed by Aspergillus 14%, and Fusarium 11%. Alternaria, Trichoderma, Paecilomyces, Cladosporium, Trichocladium, Circinella, and Doratomyces genera are founded with a minority occurrence. Finally, validation of the enzymatic profile was done for 20 isolates, by testing their enzymatic performance on a liquid medium in the presence of cellulose, lignin, and olive pomace. The maximum protein production of 788 µg ml-1 was reached by an Alternaria strain, which produced also 10.6 IU ml-1 of endoglucanase. Thus, a ß-glucosidase activity of 5.1 IU ml-1 was obtained by a Penicillium strain isolated from decaying wood. Regarding ligninolytic activities, olive pomace was the most suitable substrate to detect these activities. Decaying wood strains presented the most remarkable results with 1.1 IU ml-1, 0.7 IU ml-1 et 0.3 IU ml-1 for laccase, LiP and MnP, respectively. The use of the selected fungi and olive pomace as local biomass are important factors for the development of green processes targeting the valorization of this by-product into high-value molecules.

Consolidated bioethanol production from olive mill waste: Wood-decay fungi from central Morocco as promising decomposition and fermentation biocatalysts.

Meknes region is a Moroccan olive-processing area generating high amounts of non-valorized Olive Mill Waste (OMW). Fungi are natural decomposers producing varied enzyme classes and effectively contributing to the carbon cycle. However, structural complexity of biomass and modest performances of wild fungi are major limits for local biorefineries. The objective of current research is to assess the ability of local fungi for bioethanol production from OMW using Consolidated Bioprocessing (CBP). This is done by characterizing lignocellulolytic potential of six wood-decay and compost-inhabiting ascomycetes and selecting potent fermentation biocatalysts. High and diversified activities were expressed by Fusarium solani and Fusarium oxysporum: 9.36 IU. mL-1 and 2.88 IU. mL-1 total cellulase activity, 0.54 IU. mL-1 and 0.57 IU. mL-1 laccase activity, respectively, and 8.43 IU. mL-1 lignin peroxidase activity for the latter. F. oxysporum had maximum bioethanol production and yield of 2.47 g.L-1 and 0.84 g.g-1, respectively, qualifying it as an important bio-agent for single-pot local biorefinery.