This study used pineapple waste crude extract (PWCE) to increase the potential of Pacific white shrimp (Litopenaeus vannamei) production for food sustainability and stability. The objective was to investigate the appropriate technique to increase the yield production and quality of shrimp and decrease waste from shrimp culture. Pacific white shrimp (average body size: 0.51 g) were fed with commercial feed supplemented with PWCE at various concentrations of 0 (control), 90, 170, and 250 ppt. Shrimp were fed five times per day for 80 days. At the end of the trial, the results showed that shrimp fed with the PWCE 250 ppt supplementation provided the highest growth rate and the best feed utilisation and yield ( ). The protein content of whole shrimp in all shrimp fed with the PWCE supplementation diet was higher than that in the control group ( ). On the contrary, the variation of endogenous digestive enzymes, including protease, trypsin, and the T/C ratio, was significantly lower in shrimp fed a diet supplemented with PWCE 250 ppt ( ). While in this group, the number of microorganisms on thiosulfate-citrate-bile salt-sucrose (TCBS), blood agar, and trypticase soy agar (TSA) was lowest ( ). Furthermore, the dietary PWCE at 250 ppt increased the volume of microvilli in the hindgut of shrimp, but the supplementation at 170 ppt improved the number of F-cells in the epithelial cells of the hepatopancreas. Nevertheless, the supplementation of PWCE in the diet did not affect the water quality ( ). Therefore, pineapple waste crude extract supplementation improves both quantitative and qualitative yields and tends to reduce waste.

The present study aimed to isolate and characterize proteolytic Bacillus spp. from termite guts to test the possibility of application for improving the nutritional value and bioactivity of fermented soybean meal (FSBM). Aerobic endospore-forming bacteria were isolated from the gut of the termite Termes propinquus. Ten isolates with high levels of soy milk degradation were selected and tested for extracellular enzyme production. Among them, two isolates, Tp-5 and Tp-7, exhibited all tested hydrolytic enzyme activities (cellulase, xylanase, pectinase, amylase, protease, lipase and phytase), weak alpha hemolytic and also antagonistic activities against fish pathogenic species of Aeromonas and Streptococcus. Both phylogenetic and biochemical analyses indicated that they were closely related to Bacillus amyloliquefaciens. During solid-state fermentation of SBM, Tp-5 and Tp-7 exhibited the highest protease activity (1127.2 and 1552.4 U g^–1, respectively) at 36 h, and the resulting FSBMs showed a significant increase in crude protein content and free radical-scavenging ability (P < 0.05), as well as an improvement in the composition of amino acids, metabolites and other nutrients, while indigestible materials such as fiber, lignin and hemicellulose were decreased. The potential strains, especially Tp-7, improved the nutritional value of FSBM by their strong hydrolytic and antioxidant activities, together with reducing antinutritional components.

Chitinolytic bacteria were isolated from guts and shells of the termite Microcerotermes sp. Among the nineteen morphologically different chitinolytic isolates, three isolates with highest extracellular chitinase production ratio (≥ 2.26) were selected. Based on molecular identification of 16S rRNA gene sequences and biochemical characterizations using API test kits and MALDI-TOF MS, these isolates were closely related to Bacillus thuringiensis (Mc_E02) and Paenibacillus species (Mc_E07 and Mc_G06). Isolate Mc_E02 exhibited the highest chitinase specific activity (2.45 U/mg protein) at 96 h of cultivation and the enzyme activity was optimized at pH 7.0 and 45°C. The isolate showed highest and broad-spectrum inhibitory effect against three phytopathogenic fungi (Curvularia lunata, Colletotrichum capsici, and Fusarium oxysporum). Its 36-kDa chitinase exhibited the biomass reduction and mycelium inhibition against all fungi, with highest effects to Curvularia lunata. This research provides novel information about termite chitinolytic bacteria and their effective chitinase, with potential use as biocontrol tool.

The use of agro-industrial by-products as functional feed additives represents a promising strategy to enhance sustainability and digestive efficiency in aquaculture. This study investigated the dose-dependent effects of bromelain derived from pineapple processing waste on digestive physiology, nutrient utilization, and economic performance in snakeskin gourami, Trichopodus pectoralis Regan, 1910. Fish (95-98 g) were fed diets supplemented with 0, 4, 8, or 12% bromelain for 90 days in a completely randomized design. Growth performance, survival, and feed utilization were not significantly affected by dietary treatments (p > 0.05), suggesting that exogenous protease supplementation did not enhance growth under nutritionally adequate conditions. However, bromelain inclusion elicited a pronounced, dose-dependent modulation of digestive enzyme activity. The 8% supplementation significantly enhanced pancreatic protease and amylase activities. This indicates improved digestive capacity and better nutrient assimilation. In contrast, the 12% inclusion level was associated with reduced activity of specific enzymes, suggesting feedback inhibition or enzymatic imbalance at excessive doses. Despite the absence of significant growth responses, a progressive increase in benefit-cost ratio was observed with increasing bromelain inclusion, reflecting improved production efficiency. Variations in muscle composition were primarily attributed to moisture-associated dilution effects rather than reduced protein deposition. Collectively, these findings demonstrate that bromelain derived from pineapple waste functions as a physiologically active feed additive that modulates digestive processes in a dose-dependent manner, with 8% identified as the optimal inclusion level. This study provides mechanistic evidence supporting the valorization of agro-industrial waste as a functional input in sustainable aquaculture systems.