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Abstract This study investigates the impact of environmental factors on the quality changes of mackerel (Scomber japonicus), a globally significant fish species valued for its high nutritional content, especially its unsaturated fatty acids and proteins. In South Korea, marine products like mackerel undergo auction, sorting, packaging, and transportation. Assessing the fish freshness and quality during these processes, before it reaches consumers, is crucial. This research aimed to track the changes in mackerel quality indicators after the auction and correlate them with the environmental factors affecting transportation. Using a transportation model established for both summer and winter, mackerel samples were categorized by their weight (200 and 300 g). Results show poorer quality indicators in summer compared to winter, particularly in the 200 g group. Microbiological indicators such as the total viable count (0.923) and total coliforms (0.958) were most strongly correlated with the season, whereas the lipid oxidation indicators acid value (0.627) and peroxide value (0.536) were moderately correlated with the season. Interestingly, the wider standard deviation distribution observed in summer suggests that individual mackerel characteristics may influence the degree of quality changes. These findings offer insights into mackerel quality fluctuations during auction and transportation, aiding in future efforts to maintain seafood quality amidst climate change.

The supply of macroalgal feed materials for abalone aquaculture is threatened by increasing costs, limited availability. and the allocation of seaweed resources for other purposes. The use of biofouling Sargassum horneri (SH) as additional macroalgal biomass for abalone has been studied, albeit full inclusion is discouraged due to low utilization. This study applied heat treatment and fermentation to increase the nutritive value of SH meals for the aquaculture feed industry. Untreated (UN) as control, heat treated (HT, 121[degrees]C for 20 min), and fermented (FE, 10' CFU/mL each of Bacillus sp. SJ-10 and Bacillus sp. KRF-7) SH meal was fed to the abalone (11.60 [+ or -] 0.02 g body weight and 42.98 [+ or -] 0.53 mm shell length) for 8-wk growth trial. The results showed that there is no apparent difference in the growth performance (body weight and shell length morphometries) and survival of abalone given experimental diets (P > 0.05). The crude protein, lipid, and ash composition of edible abalone flesh were similarly unaffected (P > 0.05). The gut microbiota profile of abalone was analyzed through next-generation sequencing. The [alpha]-diversity indicators (microbial richness and abundance) were statistically similar (P > 0.05). and the [beta]-diversity of operational laxonomic units revealed short distances within samples and clustering among diet groups. The core phyla (Fusobacteria, Proteobaeteria. Tenericutes) and genera (Psychrilyohacter, Vibrio, Mycoplasma) known to inhabit the gut of abalone predominantly were likewise identilied irrespective of diets; however, there is a difference in their relative abundance. Genus Psychrilyohacter was relatively abundant in UN and FE compared with HT, whereas Vibrio and Mycoplasma had higher abundance in FE and HT-fed abalone, respectively. Taste sensory attributes were discriminated in the abalone meat using an electronic tongue. Principal component analysis of sensor scores revealed several overlapping points, resulting in a negative discrimination index (-184). which means no apparent difference in the general taste profile was detected. Furthermore, the taste screening matrix through radar mapping revealed slight intensity differences in the umami. saltiness, and sourness flavor. Overall, the methods used for heat treatment and fermentation procedures herein were ineffective in improving the nutritive value of seaweed meal for abalone. KEY WORDS: abalone, gulfweed. heat treatment, fermentation. Haliotis discus harmed, Sargassum horneri, INTRODUCTION The abalone (Haliotis spp.) is an ecologically and economically important marine gastropod mollusc worldwide. They are found in tropical and temperate regions, particularly in the low intertidaj zone of [...]

The strategy of cultivating healthy fish by manipulating their gut microbiota composition using probiotics is crucial for establishing sustainable fish farms. Information on the gut microbiota composition of healthy fish is important for the efficient development of probiotics and the aquaculture strategies that would apply them. This study assessed the gut microbiota composition of farmed olive flounder according to the growth stage to provide useful information for the development of probiotics. The fish were classified according to their weight, and the intestines of five juveniles weighing less than 100 g and five subadults weighing between 400 and 800 g were used for analysis. The results of alpha diversity analysis confirmed higher richness and diversity in the subadult group than in the juvenile group. Beta diversity analysis revealed clear boundaries and distances between the groups; however, individuals within each group were similar. The two groups showed marked differences in their gut microbiota composition. Phylum-level analysis revealed that the most abundant phylum was Proteobacteria in the juvenile group and Firmicutes in the subadult group. Notably, genus-level analysis revealed that Vibrio accounted for more than 50% of the total composition in the juvenile group. Linear discriminant analysis effect size revealed that the genera Vibrio, Photobacterium, and Leuconostoc were representative of the juvenile group, whereas 19 genera, including Lactococcus and Vagococcus, were representative of the subadult group. Thus, information on the representative microorganisms abundantly present in the intestines of healthy olive flounder can be considered for the selection and development of a probiotic genus for olive flounder farming.

Beta-glucan (β-glucan), a naturally occurring complex polysaccharide, has drawn attention for its diverse health benefits, including immune system modulation. β-glucan was extracted from two fungi, Monascus purpureus (Mp) and Monascus kaoliang (Mk), cultured in Saccharina japonica via submerged fermentation. The yield, solubility, total sugar, reducing sugar, protein content, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Thermogravimetric analysis (TGA), Scanning Electron Microscopy (SEM), in vitro free radical scavenging activity, and cytotoxicity were analyzed. A significant yield of β-glucans, with the contents of 51.30 ± 1.54% in Mp and 44.24 ± 1.18% in Mk was observed on a dry weight basis. Water solubility slightly varied, measuring 36.25 ± 1.14% in Mp and 31.25 ± 0.94% in Mk. Total sugar and reducing sugar content in Mp and Mk derived β-glucans were 114.75 ± 2.54 mg/g and 100.25 ± 1.86 mg/g, 7.38 ± 0.78 mg/g, and 8.39 ± 0.46 mg/g, respectively. FTIR spectra resembled the standard, and TGA confirmed heat stability. XRD patterns indicated that the extracted β-glucans, including the standard one, showed the most prominent diffraction peaks in the lower 2θ range, suggesting similar crystalline phases; however, they differed in crystallinity and degree of amorphous content. SEM images displayed characteristic rough and fibrous shapes and surfaces for extracted β-glucans but it was uniform and of a regular shape in the standard sample. The isolated β-glucans exhibited in vitro free radical scavenging and no cytotoxicity was observed in the MTS assay. Therefore, utilizing S. japonica as a substrate in the fermentation process by Monascus spp. presents a unique opportunity in the production and utilization of β-glucans.

The present study constitutes the first attempt to identify low-temperature intestinal probiotics for olive flounder (Paralichthys olivaceus) and analyze their effects on this species at 20 °C, which is its optimum culture temperature. Initially, 291 intestinal bacteria were isolated, and Rummeliibacillus stabekisii PM227 (PM227), Microbacterium oxydans NB29 (NB29), and Microbacterium foliorum BZ24 (BZ24), which successfully passed the characterization tests, were considered for dietary supplementation. The formulated diets, denoted as Pro1, Pro2, and Pro3, contained 1 × 108 CFU/g of PM227, NB29, and BZ24, respectively, whereas the control diet contained no probiotics. Triplicates of 20 fish (10.34 ± 0.26 g) were randomly allocated to the four diet groups and fed one of the diets for 8 weeks. At the end of the trial, Pro2 and Pro3 significantly increased growth and feed utilization parameters compared to the control and Pro1 groups. Only Pro2 and Pro1 improved (p < 0.05) myeloperoxidase activity and the transcription of interleukin (IL)-10 in the fish liver, respectively. Amylase, lipase, and protease activities were increased in the flounder intestine in all three potential probiotics groups, except for amylase in Pro2. Intestinal microbial richness (Chao1 index) and diversity (Shannon index) were higher in Pro2 than in the other diet groups, with some similarities observed between Pro1 and Pro3. A significantly lower relative abundance of Firmicutes and Staphylococcales was found in the intestine of all probiotics-supplemented flounder. Moreover, the relative abundance of Lactobacillus and Staphylococcus exhibited the following order among the examined groups: Pro1 > Pro3 > Pro2 > control and control > Pro2 > Pro1 > Pro3, respectively. Therefore, the identified low-temperature potential probiotics increased growth, immunity, digestive enzyme activities, and intestinal microbial populations in olive flounder, demonstrating their value as feed supplements in the flounder industry.

As the older population increases worldwide, frailty is the area of research that deserve further investigation and is considered a major social and public health concern. Frailty appears physically and mentally, and recently, the term cognitive frailty has been used to combine physical frailty and mild cognitive impairment syndrome. Frailty in older adults is characterized by low physical activity levels and a sedentary lifestyle. Physical activity is essential in managing mental health issues such as depression and can improve the executive function and memory of older adults with mild cognitive impairment. Therefore, this study aimed to examine the prevalence of cardiometabolic diseases, self-reported memory loss, and depression among older adults in Korea according to frailty and physical activity status. Using data from the 2019 Korea National Health and Nutrition Survey, this study analyzed 613 community-dwelling older males aged ≥65 years. Physical activity was measured using a Global Physical Activity Questionnaire. A health-related quality of life instrument with eight items (HINT-8) was used to assess self-reported memory loss and depressed mood. Relationships between physical activity levels, self-reported memory loss and depressed mood were analyzed using logistic regression. The incidence of HINT-8 memory (0.52 (95% confidence interval (CI): 0.32–0.85)) was significantly lower in the Physical Activity Level (PAL)-high/pre-frail; the incidence of HINT-8 depression (0.35 (95% CI: 0.21–0.59); 0.29 (95% CI: 0.17–0.52)) was significantly lower in the and PAL-high/pre-frail. We verified that the group with PAL-low/frail had the highest self-reported memory loss and depressed mood, suggesting that more physical activity may reduce self-reported memory loss and depressed mood among frail older males in Korea. However further research is needed to analyze the level of physical activity separately between work and leisure.

Host-associated probiotics (HAPs) are bacteria originally isolated from rearing water or the host's gastrointestinal tract in order to enhance the host's growth and health. This study investigated the HAP potential of Bacillus sp. PM8313, isolated from wild red sea bream (Pagrus major), through characterization and feeding trials. Results based on in vitro tests showed that PM8313 is safe, confirming its hemolytic, cytotoxic, and antibiotic resistance. In addition, PM8313 showed advantages as a probiotic with high viability in the gastrointestinal model and a high cell adhesion rate. Whole-genome sequencing demonstrated that PM8313 has a 4,615,871 bp single circular chromosome and a guanine–cytosine content of 45.25%. It also showed the absence of genes encoding virulence factors, such as cytotoxin, enterotoxin, hemolysin, sphingomyelinase, and phospholipase. In the feeding trial, a supplemental diet of 1 × 108 CFU/g PM8313 positively altered the weight gain, digestive enzyme activity, and intestinal microbiota composition of red sea bream. Analysis of nonspecific immune parameters and immune-related gene expression, and a challenge test showed that PM8313 supplementation increases immunity and pathogenic bacteria resistance. Our findings suggest that PM8313 should be considered for application as a novel HAP to red sea bream aquaculture.

PURPOSE This study aimed to explore the functional movement in rope climbing. METHODS The rope climbing experiment included 16 healthy young male participants, and the methods of hand, cross-leg, and foot-hooking climbing were employed. The muscle activity and joint range of motion were measured and analyzed using EMG (Electromyography) and IMU (Inertial Measurement Unit) sensors. One-way analysis of variance was conducted (α

The necessity for additional macroalgal biomass is warranted amid the ongoing expansion of abalone aquaculture. In the current study, an in-depth investigation of the food value of Sargassum horneri as a replacement for Undaria pinnatifida on growth, body composition, body histology, gut microbiota, and the taste sensory profile of abalone Haliotis discus hannai was carried out. After a 12-week feeding trial, the results indicated that 25% replacement (SH25) induced the highest shell-growth performance and best feed utilization values, although there was no significant difference in weight-related growth parameters with the basal (no inclusion of S. horneri) and 50% replacement (SH50) diets. Interestingly, the highest protein content was detected in abalone fed the basal diet followed by SH25 and SH50. The high replacement of S. horneri in the diet showed signs of structural integrity loss in the digestive gland. The results from the pyrosequencing of the genomic DNA from the gut of the abalone indicated an insignificant difference in α-diversity parameters and only a clear boundary was observed between SH0 and SH100 diets based on principal coordinate analysis. The bacterial genera Psychrilobacter, Vibrio, and Mycoplasma predominantly occupied the gut of the abalone, although there is a difference in their relative abundance. The taste screening experiment through the use of an electronic tongue showed a comparable taste profile of the abalone and is independent of the diets given. The findings of the present study showed that S. horneri, up to 50% replacement of macroalgal ingredients, can be utilized in feed formulation for H. discus hannai. These, in turn, contribute to the expanding knowledge on the utilization of biofouling and non-traditional macroalgae for sustainable abalone aquaculture practices.

Two novel strains of Rummeliibacillus sp. and Microbacterium sp. were identified from the intestine of olive flounder (Paralichthys olivaceus) and characterized in vitro as potential probiotics. Feeds without probiotic and with a 50:50 mixture of these two strains (1 × 108 CFU/g feed) were denoted as the control and Pro diets, respectively. Three randomly selected tanks (20 flounders/tank, ~11.4 g each) were used for each diet replication. After 8 weeks of feeding, the growth and feed utilization of the flounder in the Pro group improved (p < 0.05) compared to the control. Among four immune parameters, only myeloperoxidase activity was elevated in the Pro group. Serum biochemistry, intestinal microbial richness (Chao1), and diversity (Shannon index) remained unchanged (p ≥ 0.05), but phylogenetic diversity was enriched in the Pro fish intestine. Significantly lower Firmicutes and higher Proteobacteria were found in the Pro diet; the genus abundance in the control and Pro was as follows: Staphylococcus > Lactobacillus > Corynebacterium and Lactobacillus > Staphylococcus > Corynebacterium, respectively. Microbial linear discriminant scores and a cladogram analysis showed significant modulation. Therefore, the combination of two host-associated probiotics improved the growth and intestinal microbial population of flounder and could be supplemented in the Korean flounder industry.

Abstract We investigate the magnetic properties in carbonyl iron (CI) particles before and after Ni $$^{+}$$ + and H $$^{+}$$ + ion beam irradiation. Upon increasing temperatures, the saturation magnetization ( $$M_{\text {s}}$$ M s ) in hysteresis loops exhibits an anomalous increase at a high temperature for the unirradiated and the Ni $$^{+}$$ + -beam-irradiated samples, unlike in H $$^{+}$$ + -beam-irradiated sample. Moreover, the magnetization values at low and high temperatures are more intense after Ni $$^{+}$$ + beam irradiation, whereas after H $$^{+}$$ + beam irradiation those are remarkably suppressed. Hematite ( $$\alpha $$ α -Fe $$_{2}$$ 2 O $$_{3}$$ 3 ) phase introduced on the surface of our CI particles undergoes the Morin transition that was observed in our magnetization-temperature curves. The Morin transition causing canted antiferromagnetism above the Morin temperature was found in the unirradiated and Ni $$^{+}$$ + -beam-irradiated samples, but not in H $$^{+}$$ + -beam-irradiated sample. It is thus revealed that the CI particles undergoing the Morin transition cause the anomalous increase in $$M_{\text {s}}$$ M s . We may suggest that Ni $$^{+}$$ + ion beam increases uncompensated surface spins on the CI particles resulting in a more steep Morin transition and the intensified $$M_{\text {s}}$$ M s . Ion-beam irradiation may thus be a good tool for controlling the magnetic properties of CI particles, tailoring our work for future applications.

A 6-month feeding trial was conducted to compare the effects of extruded pellet (EP) and moist pellet (MP) feed on the growth performance, non-specific immunity, and intestinal microbiota of olive flounder. A total of 60,000 fish with an average weight of 70.8 ± 6.4 g were divided into two groups and fed with one of two experimental diets. At the end of a 6-month feeding trial, the weight gain and specific growth rate of the fish fed with the MP diets were significantly higher than those of fish fed with EP (P < 0.05). However, the EP group exhibited a lower feed conversion rate than the MP group, meaning that the EP diet was more cost-effective. Whole-body proximate compositions and non-specific immune responses (superoxide dismutase, myeloperoxidase, and lysozyme activity) were not significantly different between the two groups. There were no significant differences in the α-diversity of the intestinal bacterial community of the two groups. However, the composition of microorganisms at the phylum to genus level was different between the groups. The EP group was rich in Actinobacteria, Corynebacterium, Bacillus, and Lactobacillus, whereas the MP group was dominated by Proteobacteria, Vibrio, and Edwardsiella. Collectively, the MP diet increased growth performance and pathogen concentration in the gut; whereas EP improved feed conversion and beneficial Bacillus and Lactobacillus proportion in the intestinal microbial community.

The fish gut microbiota plays an important role in overall health. However, few reports have described the changes in the composition of gut microbiota following infection with pathogenic bacteria in olive flounder (Paralichthys olivaceus). Here, we reported the changes in the gut microbiota composition of flounder after treatment with each of the three pathogenic bacteria (Edwardsiella tarda, Streptococcus iniae, and Vibrio harveyi). Edwardsiella tarda infection decreased the relative abundance of Verrucomicrobia and increased Proteobacteria abundance at the phylum level of the gut microbiota over time. Similarly, Streptococcus iniae infection reduced the relative abundance of Verrucomicrobia. Vibrio harveyi infection caused a decrease in the relative abundance of Firmicutes and Verrucomicrobia and increased Proteobacteria. At the genus level, infection with all three pathogens increased the relative abundance of Ralstonia and Sphingomonas species. Conversely, this infection decreased the relative abundances of Rubritalea, Saccharimonas, and Bacillus species. Therefore, reducing the abundance of Ralstonia and Sphingomonas and increasing the abundance of Rubritalea, Saccharimonas, and Bacillus in the gut microbiota composition of flounder might help maintain a healthy gut microbiota balance. This research might be useful for future studies on improving the health of flounder through gut microbiota regulation.

Beta-glucan (β-glucan), a naturally occurring complex polysaccharide, has drawn attention for its diverse health benefits, including immune system modulation. β-glucan was extracted from two fungi, Monascus purpureus (Mp) and Monascus kaoliang (Mk), cultured in Saccharina japonica via submerged fermentation. The yield, solubility, total sugar, reducing sugar, protein content, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Thermogravimetric analysis (TGA), Scanning Electron Microscopy (SEM), in vitro free radical scavenging activity, and cytotoxicity were analyzed. A significant yield of β-glucans, with the contents of 51.30 ± 1.54% in Mp and 44.24 ± 1.18% in Mk was observed on a dry weight basis. Water solubility slightly varied, measuring 36.25 ± 1.14% in Mp and 31.25 ± 0.94% in Mk. Total sugar and reducing sugar content in Mp and Mk derived β-glucans were 114.75 ± 2.54 mg/g and 100.25 ± 1.86 mg/g, 7.38 ± 0.78 mg/g, and 8.39 ± 0.46 mg/g, respectively. FTIR spectra resembled the standard, and TGA confirmed heat stability. XRD patterns indicated that the extracted β-glucans, including the standard one, showed the most prominent diffraction peaks in the lower 2θ range, suggesting similar crystalline phases; however, they differed in crystallinity and degree of amorphous content. SEM images displayed characteristic rough and fibrous shapes and surfaces for extracted β-glucans but it was uniform and of a regular shape in the standard sample. The isolated β-glucans exhibited in vitro free radical scavenging and no cytotoxicity was observed in the MTS assay. Therefore, utilizing S. japonica as a substrate in the fermentation process by Monascus spp. presents a unique opportunity in the production and utilization of β-glucans. [ABSTRACT FROM AUTHOR]

A 56-day feeding trial was conducted to determine the effect of dietary supplementation with Bacillus sp. isolated from the intestines of red sea bream on the growth performance, immunity, and gut microbiome composition of red sea bream. Three diets (a control diet and two treatments) were formulated without Bacillus sp. PM8313 or β-glucan (control, CD), 1 × 108 CFU g−1 PM8313 (BSD), and 1 × 108 CFU g−1 PM8313 + 0.1% β-glucan (BGSD). At the end of the experiment, the weight, specific growth rate, feed conversion ratio, and protein efficiency ratio of the fish in the BSD and BGSD diet groups were significantly improved than those of the control group (P < 0.05). Additionally, amylase and trypsin activities were significantly higher (P < 0.05) in both groups compared to the control. Superoxide dismutase and lysozyme activity, which are serum non-specific immune responses, only increased in the BGSD group. The two treatment groups exhibited a marked difference in the intestinal microbiota composition compared to the control group. Furthermore, the treatment groups exhibited an upregulation of IL-6 and NF-κb, coupled with high survival rates when challenged with Edwardsiella tarda. Therefore, dietary supplementation with PM8313 improved the growth performance, digestive enzyme activity, non-specific immunity, and pathogen resistance of red sea bream, in addition to affecting the composition of its intestinal microflora.

This study was performed to investigate the effect of microbial supplementation diet on the survival rate and microbiota composition of artificially produced eel larvae. Microorganisms supplemented in the diet were isolated from wild glass eel intestines and identified as Bacillus sp. through 16S rRNA sequencing analysis. In vitro tests confirmed that the strain had no hemolytic activity and virulence genes. Microbial supplemental feeding significantly increased the survival rate of artificially produced eel larvae for 30 days post-hatchling compared with that of the control group. It also caused changes in the α-diversity, β-diversity, and relative abundance of the bacterial communities. Analysis via phylogenetic investigation of communities by reconstruction of unobserved states predicted that these microbial community changes would significantly increase the carbohydrate metabolism, membrane transport, and cellular community pathway of the microbial supplementation group. Therefore, microbial supplementation feeding for eel aquaculture could increase the viability of artificially produced eel larvae and alter the microbial composition to induce metabolic changes.