Enhanced reutilization value of shrimp-shell waste via fed-batch biodegradation with higher production of reducing sugar, antioxidant, and DNA protective compounds

Abstract

As a process for commercial application, production of reducing sugar, antioxidant, and DNA protective compounds from shrimp-shell powder was investigated in a fed-batch biodegradation using Bacillus cereus EW5. The fed-batch biodegradation was operated in a 5-L bioreactor for 96 h according to three times pulse-feeding strategy. On the basis of the equal working volume (3 L), the fed-batch biodegradation showed a better production of the target compounds than the batch biodegradation, with higher cell density and shortened biodegradation period. The maximum values of the target compounds were 0.297 mg/mL of reducing sugar, 92.35% DPPH radical scavenging activity, 98.16% ABTS radical scavenging activity, and 1.55 reducing power at A 700 , which were approximately 12.1, 3.4, 5.2, and 8.4% enhanced, respectively, compared with those obtained from the batch biodegradation. The fed-batch culture supernatant also showed the enhanced DNA damage inhibition activity than the batch culture supernatant. As a result, the fed-batch biodegradation accompanied by high cell density could produce more useful compounds, enabling an increase in the reutilization value of shrimp-shell waste.

Antioxidant and Tyrosinase Inhibitory Properties of an Aqueous Extract of Garcinia atroviridis Griff. ex. T. Anderson Fruit Pericarps

“…Free radical scavenging activity of extract was estimated by ABTS decolorization assay. 22 ABTS .+ was produced by mixing 7 mM ABTS . and 2.45 mM potassium sulfate at a ratio of 2:3 v/v, and storage in the dark at room temperature for 12-16 h until analysis.…”

Valorization of Seafood Processing Discards: Bioconversion and Bio-Refinery Approaches

“…Fermentation is a viable alternative to chemical treatment for the extraction of collagen (Song et al, 2021). Rashid et al (2018) fermented shrimp-shell powder with B. cereus to produce sugar, antioxidant, and DNA protective compounds. The fed-batch biodegradation was operated in a 5-L bioreactor for 96 h according to three time pulse-feeding strategy.…”

Hybrid Amyloid–Chitin Nanofibrils for Magnetic and Catalytic Aerogels

“…On the other hand, chitin, a polymer composed of N -acetylglucosamine (β-1,4-linked 2-acetamido- d -glucose), is the most abundant aminopolysaccharide found in nature, primarily in crustaceans, mollusks, insects, and fungi. , There are three chitin allomorphs (α-chitin, β-chitin, γ-chitin) with different structural and mechanical properties. , While α-chitin is primarily found in shells and stiff materials, β-chitin and γ-chitin are mostly found in soft and flexible structures . These structural and mechanical variations are attributed to the different arrangements of polysaccharide chains; α-chitin chains align antiparallel to the reducing end, β-chitin chains are parallel, and γ-chitin chains feature a combination of parallel and antiparallel arrangements. , Chitin accounts for approximately 15–40% of the 6–8 million tons of annually produced waste shells from crustaceans such as lobsters, shrimp, and crabs. , Most of this waste is disposed of into the sea, leading to marine environmental pollution and consequent deterioration in affected ecosystems . However, this seafood waste can be valorized to recover chitin via various mechanical and chemical methods .…”

“…19,23 Most of this waste is disposed of into the sea, leading to marine environmental pollution and consequent deterioration in affected ecosystems. 24 However, this seafood waste can be valorized to recover chitin via various mechanical and chemical methods. 19 Exfoliating nanochitin building blocks and reassembling them via bottom-up approaches are viable methods for developing functional materials.…”