Pinsurang Deevong

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.

The fungus Aspergillus flavus is one of the most important mycotoxigenic species that produces potent carcinogenic secondary metabolites called aflatoxins, and its harmful ability has a considerable negative impact on human and livestock health. This study assessed an antifungal activity against A. flavus and evaluated in vitro probiotic properties of lactic acid bacteria newly isolated from the digestive tract of two popular edible crickets, Gryllus bimaculatus (GL) and Acheta domesticus (AL). Moreover, metabolic profiles including anti-A. flavus compounds produced by promising lactic acid bacteria were investigated. In total of 22 isolates, four lactic acid bacterial candidates comprising AL01, GL01, GL05, and GL11 exhibited inhibitory effect on mycelial growth and anti-fungal spore germination of Aspergillus flavus TISTR 3366. Based on molecular analysis of 16S rRNA gene sequences and biochemical tests using API 50 CHL, these isolates were identified as Lacticaseibacillus paracasei (AL01), Lacticaseibacillus rhamnosus (GL01, and GL11), and Pediococcus pentosaceus (GL05). Among them, two potential strains comprising Lb. paracasei AL01 and P. pentosaceus GL05 showed the potent probiotic characteristics based on bacterial viability in gastrointestinal tract conditions, good cell surface properties, and bacterial safety. Metabolic profiles of the cell-free supernatant (CFS) obtained from AL01- and GL05-cultures were investigated using gas chromatography mass spectrometry (GC-MS), and revealed a complex mixture of bioactive compounds, including short-chain hydrocarbons, organic acids, and other antifungal metabolites. Overall results suggested that the lactic acid bacteria obtained from edible crickets can be a promising probiotic and biocontrol agent against A. flavus. The finding in this study benefits for biologically reducing mycotoxicity of harmful fungi in food and agriculture. Graphical abstract

Termite guts represent a unique microbial habitat harboring bacteria with potential probiotic properties, owing to their ability to inhibit pathogenic microorganisms. This study investigated the probiotic characteristics of lactic acid bacteria newly isolated from the guts of the termite Termes propinquus, aiming to enhance growth performance and reduce the incidence of foodborne pathogen contamination in the commonly consumed edible two-spotted crickets (Gryllus bimaculatus). In this study, five morphologically different bacteria (TPL-1 to TPL-5) were isolated and respectively identified as Levilactobacillus brevis, Lactiplantibacillus plantarum, Streptococcus anginosus, Companilactobacillus alimentarius, and Aerococcus viridans based on 16S rRNA gene sequences and MALDI-TOF MS. All isolates were evaluated for tolerance to stressful conditions (pH 2.5 and 0.3% bile salts), cell surface properties, antioxidant activity, antimicrobial activity against foodborne pathogens, safety profiles, and adhesion to human colon adenocarcinoma cells (Caco-2 and HT-29). Among them, Lactiplantibacillus plantarum TPL-2 demonstrated the strongest probiotic attributes and was further assessed for anti-adhesion activity against foodborne pathogens and in vivo effects on the crickets. Dietary supplementation with Lb. plantarum TPL-2 significantly improved cricket growth, survival, and gut microbiota homeostasis. These findings point to the prospect of termite-derived lactic acid bacteria as beneficial probiotics for use in biotechnological applications and edible insect farming.

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.

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.