Solid-State Fermentation of Sago Pith Waste with Aspergillus niger and Trichoderma harzianum for Nutritional Enhancement in Animal Feed Benecar B. Olaybar, Rosary Anne M. Serrano, Rhenzlyn Joy M. Agtong, and John Mark S. Ramada
Department of Animal Science, College of Agriculture and Agri-Industries, Caraga State University, Ampayon, Butuan City, 8600, Philippines
Department of Biology, College of Mathematics and Natural Sciences, Caraga State University, Ampayon, Butuan City 8600, Philippines
Department of Animal Science, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand
Abstract
Agro-industrial residues like sago pith waste (SPW), a starch-rich by-product of sago palm (Metroxylon sagu) processing, are abundant in the Caraga Region, Philippines, but their direct use in animal feeding is constrained by low crude protein and high crude fiber contents. This study explored solid-state fermentation (SSF) with Aspergillus niger and Trichoderma harzianum, applied individually and in co-culture, to enhance SPW^s nutritive value and ensure safety. The fungi were selected for their ability to produce cellulolytic and amylolytic enzymes capable of breaking down lignocellulosic structures. Pre-dried, ground SPW was inoculated with a 2% spore suspension and fermented for 48, 72, 96, 120, or 144 hours, followed by proximate and aflatoxin analyses. Data were analyzed using two-way ANOVA with Tukey^s HSD post-hoc test, while crude fiber was assessed via Kruskal-Wallis test at p < 0.05. A. niger achieved the highest fiber reduction at 144 h, lowering crude fiber by 26.3% from baseline, while T. harzianum yielded the highest protein content at 144 h (2.89% vs. 2.56% in control). Co-cultures produced inconsistent improvements, likely due to early antagonistic interactions. Ash content increased in monocultures, while aflatoxin levels remained well below the 20 ppb limit, with A. niger reaching as low as 0.70 ppb at 144 h. These findings demonstrate that fungal SSF offers a low-cost, safe, and and eco-friendly strategy to bio-convert SPW into a value-added feed resource while mitigating environmental waste.
