Potential of Red, Green and Brown Seaweeds as Substrates for Solid State Fermentation to Increase Their Nutritional Value and to Produce Enzymes

Abstract

Seaweeds are valuable feedstocks with the potential to be used as ingredients in aquafeeds. However, their use are still limited, given their recalcitrant polysaccharide structure. To break this structure, a biotechnological approach such as solid-state fermentation (SSF) by filamentous fungi can be used, which simultaneously increases the nutritional value of the biomass. However, SSF has hardly been studied in seaweeds; thus, in this study, five different seaweeds (Gracilaria sp., Porphyra dioica, Codium tomentosum, Ulva rigida, and Alaria esculenta) were used as substrates in SSF with Aspergillus ibericus MUM 03.49 and A. niger CECT 2915. Firstly, the seaweeds were fully characterized, and, then, changes in the crude protein and carbohydrate contents were assessed in the fermented biomass, as well as any carbohydrases production. The SSF of U. rigida with both fungi resulted in the maximum xylanase and β-glucosidase activities. The maximum cellulase activity was achieved using Gracilaria sp. and U. rigida in the SSF with A. niger. The protein content increased in C. tomentosum after SSF with A. ibericus and in U. rigida after SSF with both fungi. Moreover, U. rigida’s carbohydrate content decreased by 54% and 62% after SSF with A. ibericus and A. niger, respectively. Seaweed bioprocessing using SSF is a sustainable and cost-effective strategy that simultaneously produces high-value enzymes and nutritionally enhanced seaweeds to be included in aquafeeds.

Codium fragile (Suringar) Hariot as Biostimulant Agent to Alleviate Salt Stress in Durum Wheat: Preliminary Results from Germination Trials

“…This effect is likely due to the presence of phytohormones, as well as the content of macro- and micronutrients. In particular, in Codium species, the effect can be due to the presence of elements such as calcium and zinc [ 86 , 98 ]. The exogenous application of these two elements resulted in a general enhancement of the germination percentage and seedling vigour [ 99 , 100 , 101 ].…”

Effects of dietary supplementation with mannan-rich oligosaccharides and solid-state fermented Aspergillus niger on the growth performance of juvenile Asian seabass, Lates calcarifer

“…The SSF fermentation process facilitates the microbe-assisted transformation of raw materials, including those with anti-nutritional properties, into a more digestible, bioavailable form. This process results in the enhanced nutritional value and overall quality of the feed (Chilakamarry et al 2022, Ferreira et al 2022, Ibarruri et al 2021, Wang et al 2023. SSF could generate a variety of hydrolytic enzymes capable of degrading fibers and antinutrient components, notably from plant-based sources, into higher quality essential amino acids such as methionine and lysine in aquafeed (Jannathulla and Dayal 2022).…”

Identifying the Environmental Factors that Determine the Agar Content of Seaweed <i>Gracilaria verrucosa</i> in Acid Sulfate Soil-Affected Brackishwater Ponds

“…It has also been reported by Stedt et al [55] which states that there is a strong relationship between the NH 4 + content and the growth of seaweed Gracilaria sp. Seaweed Gracilaria sp absorbs NH [58].…”