Immune Enzyme Activities Research Articles

Influence of Oral Administration of Bacillus subtilis on Growth Performance and Physiological Responses in Litopenaeus vannamei Cultured in Low Saline Waters.

The present study examined the effect of Bacillus subtilis on growth performance, digestive enzyme activity, and immune response of juvenile white-leg shrimp (Litopenaeus vannamei) in 100 m2 lined ponds. Control (without B. subtilis) and experimental (with B. subtilis) diets were fed at 10% of animal body weight, four times daily for 6weeks in duplicate ponds. Significantly increased final weight, weight gain, specific growth rate, average daily growth, and survival rate were observed in the B. subtilis treated group (P < 0.05). Significantly higher (P < 0.05) digestive enzyme activities of protease, lipase, amylase, and cellulase were found in the B. subtilis supplemented diet fed group. At the end of trial, a challenge study, using Vibrio alginolyticus, found lower (15.00 ± 2.88%) cumulative mortality in the B. subtilis treated group compared to control (73.33 ± 3.33%). Activities of immune and antioxidant enzymes (phenoloxidase, SOD, and catalase) were significantly higher (P < 0.05) in the B. subtilis-incorporated diet fed group. Interestingly, histopathology of the hepatopancreas and intestine revealed that the B. subtilis-supplemented group showed no deformity. Overall, the study found inclusion of B. subtilis in P. vannamei diet improves growth, physiometabolic activities, and immunity, indicating B. subtilis as a potential probiotic for shrimp feed.

Effects of varying dietary black garlic supplementation on the growth, immune response, digestive and antioxidant activities, intestinal microbiota of Litopenaeus vannamei and its resistance to Vibrio parahaemolyticus infection

A 56-day feeding try was conducted to evaluate the effects of processed garlic known as black garlic (BG) fed at different inclusion levels (0 (BG0, control), 5 (BG0.5), 10 (BG1), 20 (BG2), 40 (BG4), and 80 (BG8) g/kg feed) on the growth, whole body composition, immune and antioxidant enzyme activities, gut microbiota and resistance to Vibrio parahaemolyticus infections in Litopenaeus vannamei (initial weight = 0.60 ± 0.001 g). The results revealed a significant improvement (p < .05) in the final weight, weight gain rate, specific growth weight, condition factor, protein efficiency ratio, survival rate, hepatosomatic index, and feed conversion ratio in the BG-treated-groups compared to the untreated. Correspondingly, the whole body proximate composition, immune, and antioxidant enzyme activities significantly improved in the treated groups than the untreated. Dietary BG had shaped the gut microbiota by significantly increasing (p < .05) the abundance of Phylobacterium, Ruegeria, and Pseudoalteromonas genera and decreasing (p < .05) the abundance of Vibrio genus than the control. Disease test with V. parahaemolyticus revealed significantly high (p < .05) resistance in the BG-teated-groups than the untreated. The BG8, BG4, BG2, BG1, and BG0.5-treated groups respectively showed 72.1%, 62.8%, 55.8%, 41.9%, and 25.6% relative percentage survival. Dietary BG inclusion at 8% or at 80 g/kg feed could help improve shrimp growth and health.

Therapeutic effect and immune mechanism of chitosan-gentamicin conjugate on Pacific white shrimp (Litopenaeus vannamei) infected with Vibrio parahaemolyticus

To explore the disease resistance mechanism of chitosan conjugates, chitosan-gentamicin conjugate (CS-GT) was synthesized and systematically characterized, the immune mechanism of CS-GT on Litopenaeus vannamei infected with Vibrio parahaemolyticus was further explored. The results showed that imine groups in CS-GT were effectively reduced. Dietary supplementation of CS-GT can significantly increase the survival rate, total hemocyte counts, the antioxidant and immune related enzyme activity levels of shrimps (P < 0.05), which are all dose-dependent under the experimental conditions. In addition, CS-GT can protect the hepatopancreas from invading bacteria and alleviate inflammation. Particularly, CS-GT promotes the expressions of legumain (LGMN), lysosomal acid lipase (LIPA) and Niemann-Pick type C2 (NPC2) up-regulated. It is speculated that CS-GT may stimulate the lysosome to phagocytose pathogens more effectively. In conclusions, shrimps fed with CS-GT can produce immune response via lysosome and greatly improve the disease resistance to Vibrio parahaemolyticus.

Enhanced immunity and hemocytes proliferation by three immunostimulants in tri-spine horseshoe crab Tachypleus tridentatus

Tachypleus amebocyte lysate (TAL) is crucial in medical testing, but its industry in China has been restricted due to the decline of horseshoe crab population in recent years. Exploring methods of enhancing immunity and rapid hemocytes proliferation is urgent for the industrial horseshoe crab culture. In this study, β-glucan (G), peptidoglycan (P), and squalene (S) were injected to horseshoe crabs at two concentrations (5 and 10 mg/kg), in order to compare their effects on total hemocyte count (THC), reactive oxygen species (ROS), and non-specific immune enzyme activities. Results showed that the THC, superoxide dismutase (SOD), catalase (CAT), and total antioxidant capacity (T-AOC) were significantly increased by three immunostimulants at different points of time; ROS was significantly increased except at two squalene groups; lysozyme (LZM) and alkaline phosphatase (AKP) activity were increased except at low dose (5 mg/kg) squalene group; malondialdehyde (MDA) activity was decreased in all treatments; and hemocyanin concentration (HC) changed little during the experiment. At the 48th hour, THC, ROS, SOD, CAT, T-AOC, LZM, and AKP activities were significantly higher in the two peptidoglycan groups than those in the control group; the low dose β-glucan and squalene groups showed significantly higher SOD and CAT, but their THC and AKP were not significantly different from those of the control group. In general, all three immunostimulants stimulated the hemolymph parameters of horseshoe crabs, notably, peptidoglycan could significantly increase the THC and enzyme activities, suggesting that peptidoglycan can be developed as an efficient immunostimulant for horseshoe crabs.

Bioflocs attenuates lipopolysaccharide-induced inflammation, immunosuppression and oxidative stress in Channa argus

The regulation of C/N in aquaculture water is an important means of environmental regulation, of which the most common is bioflocs technology (BFT). Here, an eight-week feeding experiment and a lipopolysaccharide (LPS) challenge test were proceed to investigate the growth, oxidative stress, immunosuppression and GR–NF–κB related genes expression of Channa argus rearing in the BFT. Four groups were set, the control group was a basic diet (C/N = 7.6:1), and the other three groups were adjusted by glucose, which was C/N 10: 1, C/N 15: 1 and C/N 20:1, respectively. And we detected the two-stage test indexes of C. argus before and after the LPS challenge. The results showed that the bioflocs of C/N 15:1 group significantly (P < 0.05) promoted the growth performance. Similarly, the trend of immune enzyme activity was the same before and after LPS challenge, but decreased after challenge (except AKP and IgM). The best group is still treatment C/N 15:1. Liver and intestine SOD, CAT, GPX, ASA and T-AOC levels of juveniles in treatment C/N 15:1 were markedly increased (P < 0.05) compared to control before and after the LPS challenge. Simultaneously, the content of MDA in control group was considerably higher than that in treatment C/N 15:1 (P < 0.05). Furthermore, C/N 15:1 group significantly down-regulated the expression level of pro-inflammatory factors (NF-κB, TNF-α, IL-1β and IL-8), and up-regulated IκBα, GR, HSP70 and HSP90 expression levels considerably (P < 0.05). Also, intestinal morphology appeared injury in control group, while intestinal integrity was better in treatment C/N 10:1 and C/N 15:1 after challenge. Taken together, these upshot indicated that bioflocs could enhance growth and alleviate C. argus from LPS-induced oxidative stress, immunosuppression and inflammation through restraining GR–NF–κB signaling pathway. The best C/N ratio for alleviating LPS is 15:1.

Effects of Lactobacillus acidophilus and tussah immunoreactive substances on disease resistance of sea cucumber ( Apostichopus japonicus ) against Vibrio splendidus

Effects of dietary Lactobacillus acidophilus and tussah immunoreactive substances (TIS) on disease resistance of sea cucumber (Apostichopus japonicus) against Vibrio splendidus were investigated. Sea cucumbers were fed with a basal diet in the control group (CK group) or were supplemented with L. acidophilus (L group), TIS (T group) or both (LT group). The challenge test with V. splendidus was conducted after the feeding trial. The cumulative mortality rate in the LT group was significantly lower, while the highest mortality occurred in the control group. The LT group showed better digestive and immune parameters compared with the other treatments. Dietary L. acidophilus and TIS in combination could effectively enhance digestive function and food uptake, depress oxidative damage and improve the organismal defence capability. Regarding gut microbiota profiles, the LT group was more capable of inhibiting potentially opportunistic pathogens and regulating intestinal flora balance compared with the other groups. The administration of L. acidophilus and TIS in the diet could effectively improve disease resistance against V. splendidus of sea cucumbers by improving the immune and digestive enzyme activities and modulating intestinal microflora, signalling a potential role in the development and production of aquatic feed.

Effects of photoperiod on growth, digestive, metabolic and non-special immunity enzymes of Takifugu rubripes larvae

Photoperiod is one of the important environmental factors, which have important effects on the early growth and development, survival, metabolism and immune system of larvae. In the present study, Takifugu rubripes larvae were exposed to four different LED photoperiods: 8 L:16 D, 16 L:8 D, 20 L:4 D and 24 L:0 D from −1 to 30 days post hatching (DPH). We measured growth, activity of pepsin (PPS), lipase (LPS), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and non-specific immune enzyme activity of alkaline phosphatase (AKP), and acid phosphate (ACP), superoxide dismutase (SOD), Catalase (CAT), glutathione peroxide (GSH-PX), total antioxidant capacity (T-AOC) at 1, 5, 10, 15, 20, and 30 DPH. The results showed that there was no difference in the effects of photoperiod on the growth within 18 DHP, while 20 L:4 D had a positive effect on the growth of the larvae after 19 DPH. The effect of photoperiod on digestive enzymes did not show obvious regularity. Compared with photoperiod, the changes of some digestive and metabolic enzymes were mainly affected by exogenous food (LPS, ALT, AST changed obviously after feeding Artemia). On the 30 DPH, the AKP of 8 L: 16 D and 24 L: 0 D groups was significantly higher than that of the other two groups, which indicated that 8 L: 16 D and 24 L: 0 D lighting might cause stress to fish body and lead to the increase of AKP. GSH-PX in newly hatched fish at 24 L:0 D was significantly higher than that in other groups. Photoperiod had no significant effect on the enzyme activity of PPS, LDH, ACP, CAT and no obvious pattern was found. Overall, our results suggested that 20 L:4 D promoted larval growth after 19 DPH and shorter photoperiods can be used to save electricity before 18 DPH of Takifugu rubripes larva.

Hepatopancreatic transcriptome analysis and humoral immune factor assays in red claw crayfish (Cherax quadricarinatus) provide insight into innate immunomodulation under Vibrio parahaemolyticus infection

Red claw crayfish (Cherax quadricarinatus) is an economically and nutritionally important specie. We aimed to assess the immunostimulatory response to C. quadricarinatus infection with Vibrio parahaemolyticus. After determining the LD50, we infected C. quadricarinatus and examined the differential expression profiles of hepatopancreas transcriptional genes, and observed the temporal changes of hepatopancreas pathological sections and serum immunoenzymatic activities at different time points to reveal the infection mechanism of V. parahaemolyticus and the immune detoxification mechanism of the organism. The results showed that V. parahaemolyticus infection with C. quadricarinatus caused hepatopancreas injury and the immune enzyme activity of the organism changed with time delay. Transcriptome analysis of 47,338 single genes obtained by RNA sequencing and de nove transcriptome assembly identified a total of 3678 differentially expressed genes (P < 0.05) in the expression profiles of susceptible and normal animals for comparative analysis, and 2516 differentially expressed genes (P < 0.05) in the expression profiles of asymptomatic (infection-resistant) and normal animals. GO and KEGG and analyses revealed immune-related pathways under V. parahaemolyticus infection, including Vibrio cholerae infection, phagosome, lysozyme, oxidative phosphorylation, antigen processing and presentation, apoptosis, and Toll-like receptor signaling, as well as significant differences in the expression patterns of related immune genes at different times (P < 0.05). These new experimental results reveal the molecular response of the hepatopancreas to V. parahaemolyticus infection and the corresponding adaptive mechanisms, thus further revealing the pathogenesis due to bacterial infection in the aquatic environment, and providing a reference for further understanding of microbial-host interactions in aquatic systems.

Screening of intestinal probiotics and the effects of feeding probiotics on the digestive enzyme activity, immune, intestinal flora and WSSV resistance of Procambarus clarkii

In this experiment, a potential probiotic strain A23 with high antimicrobial activity against common aquatic pathogens and extracellular enzyme production was isolated from the intestine of healthy Procambarus clarkii. Biochemical and 16S rDNA sequencing analysis identified A23 as Bacillus amyloliquefaciens, and a haemolytic test and antibiotic susceptibility test were carried out on strain A23 to determine its safety. First, the whole genome of B. amyloliquefaciens A23 was determined to explore its mechanism of action. The results showed that the total length of the genome was 3,974,398 bp, the GC content was 46.56%, and 3843 genes were encoded, including 27 rRNA operons and 86 transfer RNA genes. Three bacilysin-related genes and 10 antimicrobial peptide (AMP)-related genes were found through manual inspection. Second, we evaluated the beneficial effects of strain A23 in P. clarkii by performing in vivo feeding experiments. The results showed that probiotic supplementation could effectively enhance the intestinal digestive enzyme activities, innate immune enzyme activities and white spot syndrome virus (WSSV) resistance of P. clarkii. Finally, the intestinal microbial community and diversity of crayfish were compared and analyzed by high-throughput sequencing. At the phylum level, the abundance of Proteobacteria decreased with 108 CFU/g probiotics supplement, while the abundance of Firmicutes and Bacteroides increased. The Shannon index of the intestinal microorganism community of the 108 CFU/g probiotic supplementation group was significantly higher than that of the control group, indicateding that 108 CFU/g probiotic supplementation enhanced intestinal microbial diversity. The results from this study demonstrated that B. amyloliquefaciens A23 is a promising probiotic candidate that provides multiple benefits for crayfish cultivation.

EFFICACY OF PENTAVALENT ANTIMONIAL INJECTION IN IMPROVING THE OXIDATIVE, NITROSATIVE STATUS AND IMMUNE CELLULAR ENZYME ACTIVITY IN TREATING SAUDI PATIENTS WITH CUTANEOUS LEISHMANIASIS

Macrophages, within which Leishmania sp. replicate, generate large amounts of reactiveoxygen species and reactive nitrogen species to kill these parasites. The present study aimed toassess the oxidative and nitrosative stresses and activities of key immune response enzymes inthe serum of patients with cutaneous leishmaniasis (CL) before and after treatment withsodium stibogluconate as well as in the control individuals. Serum activities of superoxidedismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and levels of reducedglutathione, malondialdehyde (MDA), and nitric oxide (NO) as well as those of L-arginase,myeloperoxidase (MPO), and adenosine deaminase (ADA) were studied. The activities of Larginase,MPO, ADA, and MDA and levels of NO were significantly elevated (P < 0.001),whereas those of SOD, CAT, and GSH-Px and levels of GSH were significantly reduced (P <0.001) before treatment compared with those after treatment and in control individuals.Treatment ameliorated these agents in comparison with the untreated group, but there werestill variations between the values of the treated and control groups. Thus, oxidative andnitrosative stresses may play an essential role in the pathogenesis of untreated CL.

Early Life Intervention Using Probiotic Clostridium butyricum Improves Intestinal Development, Immune Response, and Gut Microbiota in Large Yellow Croaker (Larimichthys crocea) Larvae.

Marine fish larvae are vulnerable during the early life period. The early intervention using probiotics may be a promising method to improve growth of fish larvae. In this study, a 30-day feeding trial was conducted to evaluate the effects of early life intervention using probiotic Clostridium butyricum (CB) on growth performance, intestinal development, immune response and gut microbiota of large yellow croaker (Larimichthys crocea) larvae. Four isonitrogenous and isolipidic diets were formulated with the supplementation of four different levels of CB (5 × 109 CFU g−1), 0.00% (Control), 0.10% (CB1), 0.20% (CB2), and 0.40% (CB3). Results showed that larvae fed diets with CB had significant higher final length than the control group. Meanwhile, larvae fed the diet with 0.10% CB had significant higher final weight and specific growth rate (SGR) than the control group. However, no significant difference in survival rate was observed among dietary treatments. CB supplementation significantly increased the height of intestinal villus and the length of intestinal enterocyte. Similarly, CB supplementation significantly increased the expression of tight zonula occludens-2 (zo-2) and ornithine decarboxylase (odc) than the control group. Larvae fed the diet with 0.20% CB had significant higher lipase and leucine-aminopeptidase (LAP) activity than the control group. Moreover, CB supplementation significantly improved immune enzyme activities than the control group. Sequencing of bacterial 16S rRNA V4-5 region indicated that dietary CB altered intestinal microbiota profile and decreased intestinal microbial diversities of larvae. CB supplementation could effectively increase the abundance of CB, and decrease the abundance of some potential pathogenic bacteria in larval gut. These results revealed that early life intervention using 0.10–0.20% CB could promote growth of large yellow croaker larvae probably through promoting intestinal development, improving immune enzyme activities and modulating gut microbiota.

Multi-Modal Multi-Spectral Intravital Macroscopic Imaging of Signaling Dynamics in Real Time during Tumor-Immune Interactions.

A major obstacle in studying the interplay between cancer cells and the immune system has been the examination of proposed biological pathways and cell interactions in a dynamic, physiologically relevant system in vivo. Intravital imaging strategies are one of the few molecular imaging techniques that can follow biological processes at cellular resolution over long periods of time in the same individual. Bioluminescence imaging has become a standard preclinical in vivo optical imaging technique with ever-expanding versatility as a result of the development of new emission bioluminescent reporters, advances in genomic techniques, and technical improvements in bioluminescence imaging and processing methods. Herein, we describe an advance of technology with a molecular imaging window chamber platform that combines bioluminescent and fluorescent reporters with intravital macro-imaging techniques and bioluminescence spectral unmixing in real time applied to heterogeneous living systems in vivo for evaluating tumor signaling dynamics and immune cell enzyme activities concurrently.

Evaluation of defatted Hermetia illucens larvae meal for Litopenaeus vannamei : effects on growth performance, nutrition retention, antioxidant and immune response, digestive enzyme activity and hepatic morphology

Defatted black soldier fly (Hermetia illucens) larvae meal (DBSFLM) has been shown an important alternative protein ingredient for fish, but little information is available about the effect of DBSFLM on growth and health of Litopenaeus vannamei. A 56-day feeding trial was conducted to assess the effects of partial replacement of fish meal with DBSFLM on growth performance, body composition, nutrition retention, blood metabolites, antioxidant and immune response, digestive enzyme activities and hepatic morphology of L. vannamei. Six isonitrogenous and isoenergy diets were formulated by replacing 0% (G0), 15% (G15), 30% (G30), 45% (G45), 60% (G60) and 80% (G80) of fish meal with DBSFLM. Each diet was randomly assigned to quadruplicate groups of 40 shrimp per tank. Shrimp were fed three times daily to apparent satiation. Blood samples were collected at the terminal trial to analyse antioxidant and non-specific immune enzyme activities. Hepatopancreas and intestine samples were collected to determine digestive enzyme activities and hepatic morphology. Shrimp fed G80 had lower (p < .05) final body weight, weight gain and specific growth rate, and higher (p < .05) feed conversion ratio than other groups. Crude protein (CP) in the whole body and muscle, coupled with CP and lipid retention of shrimp were decreased (p < .05) as dietary DBSFLM increasing. Shrimp fed G80 had lower (p < .05) serum total cholesterol but higher (p < .05) total antioxidant capacity than other diets, and serum malondialdehyde was lower (p < .05) in shrimp fed G45-G80 than those fed G0-G30. Hepatic and intestinal digestive enzyme activities were not altered by treatments (p > .05). Hepatocytes were shown to have different degrees of vacuolar degeneration, hepatic corpuscle atrophy and starlike lumen lose as observed in G60 and G80. The results demonstrated that up to 60% of fish meal could be replaced by DBSFLM without any adverse effects on growth performance, antioxidant and immune enzyme activities, and digestive enzyme activities of L. vannamei. However, hepatocyte damage was observed when the replacement levels exceeded 60%.

Dietary supplementation with Sporosarcina aquimarina MS4 enhances juvenile sea cucumber ( Apostichopus japonicus ) growth, immunity and disease resistance against Vibrio splendidus infection at low temperature

Probiotics are important biological control products in the aquaculture of sea cucumber, but probiotics used specifically in low-temperature environments are rare. The present study used treatment with low-temperature-resistant Sporosarcina aquimarina MS4 and investigated changes in growth, immunity, intestinal flora and immune-related gene expression in sea cucumber at low water temperature (8°C). After 60 days of feeding, S. aquimarina MS4 significantly improved growth performance and immune enzyme activity and reduced mortality in sea cucumbers infected with Vibrio splendidus compared with the commercial diet. The intestinal flora structure of the sea cucumbers fed S. aquimarina MS4 differed from that of the control group. Compared with that of the control group, the intestinal flora of sea cucumbers fed S. aquimarina MS4 was always dominated by Proteobacteria and had a higher abundance of Verrucobacteria, and the flora structure was more stable. The expression of the TLR, MyD88, IRAK4, p38 and NFκB genes was upregulated significantly after the addition of S. aquimarina MS4 to the diet. In summary, low-temperature-resistant S. aquimarina MS4 could regulate the intestinal flora and immune-related gene expression of sea cucumber, thereby improving its immunity and resistance to pathogenic bacteria such as V. splendidus.

Changes in metabolism and immunity in response to acute salinity stress in Chinese razor clams from different regions

Salinity change is a vital abiotic stress that dramatically affects the growth and survival of marine bivalves. Three groups of Chinese razor clams (Sinonovacula constricta) were collected from high (Lianyungang City, China, LYGSC) and low (Ninghai County, China, NHSC, and Shenzhe No. 1, SZSC) salinity regions. The survival rate (SR), metabolism (oxygen consumption rate, OCR; ammonia excretion rate, AER), Na+/K+-ATPase (NKA), and immune-related enzymes (superoxide dismutase, catalase, and alkaline phosphatase) were measured at different times under acute salinity stress. The results showed that death occurred only in NHSC and SZSC in salinities of 30 and 35 ppt at 72 h. All above mentioned parameters increased at first and then decreased over time. The maximum value appeared at 12 or 24 h and increased with a rise in salinity. The OCR and AER of LYGSC were the highest and SZSC was higher than NHSC after stress. The NKA activity of LYGSC was higher than that of SZSC and NHSC in general. The activities of immune enzymes of LYGSC were significantly low in salinities of 30 and 35 ppt (P < 0.05). These results indicated that the SR and metabolic capacity of LYGSC were higher than those of SZSC and NHSC. Short-term salinity stress may not lead to significant differences between SZSC and NHSC. Our results demonstrated that Chinese razor clams living in a high-salt environment have stronger salt tolerance than those of living in a low-salt environment. The study provides a reference for exploring the physiological mechanism of salt tolerance in bivalves and the selective breeding of new stress-resistant varieties.

Modulatory effect of fructooligosaccharide against triphenyltin-induced oxidative stress and immune suppression in goldfish (Carassius auratus)

Triphenyltin (TPT) is a widely used pesticide that is highly toxic to a variety of organisms, including humans, and is a potential contributor to environmental pollution. The present study was conducted to evaluate the oxidative stress and immunotoxicity induced by TPT in goldfish (Carassius auratus) and the protective effects of fructooligosaccharide (FOS). Goldfish (mean weight of 13.3 ± 0.2 g) were randomly divided into six groups with three replicates: (G1) the control group, (G2) the 10 ng/L TPT group, (G3) the 0.4% FOS group, (G4) the 10 ng/L TPT + 0.4% FOS group, (G5) the 0.8% FOS group, and (G6) the 10 ng/L TPT + 0.8% FOS group. The results showed that 10 ng/L TPT induced oxidative stress and significantly decreased the activities of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), in the liver and the gene expression of SOD, GPx, metallothionein (MT), and peroxiredoxin-4 (Prdx-4). The concentration of malondialdehyde (MDA) and the gene expression of cytochrome P450 (CYP) and glutathione S-transferase (GST) in the liver were significantly increased in the TPT-treated group. Exposure to 10 ng/L TPT in water induced immune suppression and significantly decreased the activities of immune enzymes, such as lysozyme, myeloperoxidase (MPO), alternative complement (ACH50), acid phosphatase (ACP) and alkaline phosphatase (AKP), in the serum. TPT could stimulate the fish to generate large amounts of proinflammatory cytokines, including increased tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), and nitric oxide (NO) levels and TNF-α, IL-6, IL-1β, and NF-κB mRNA expression. However, TPT-induced toxicity was significantly ameliorated in the groups treated with FOS, and FOS partly prevented alterations in the activities of antioxidant enzymes and the expression of antioxidant- and ROS scavenger-related genes. In addition, TPT-induced immune toxicity was significantly ameliorated in the groups treated with FOS. FOS markedly suppressed TNF-α, IL-6, IL-1β, and NO production and TNF-α, IL-6, and IL-1β mRNA expression in the TPT-treated groups. The study indicated that TPT-induced oxidative stress may play a critical role in inhibiting immunity. However, FOS administration attenuates TPT-induced oxidative stress and immune suppression in goldfish.

Differences in the Activities of Serum Antioxidant and Immune Factors between Wild and Captive Spotted Seal (Phoca largha) Pups from the Liaodong Bay Colony

The innate immune system plays a vital role to resist the environmental stresses and infectious pathogens in marine mammal pups. To get a baseline level of innate immune capacity in spotted seals, the concentrations of several antioxidant and immune-related factors in the serum of wild and captive spotted seal (Phoca largha) pups from the Liaodong Bay colony were measured and compared. Cu/Zn superoxide dismutase and peroxidase were mainly responsible for the antioxidant system of spotted seal pups, and wild pups possessed stronger antioxidant capacity than captive ones. Against infectious pathogens, wild spotted seal pups also had an advantage over the captive counterparts. Specifically, the activities of acid phosphatase, phenoloxidase, and lysozyme in the serum of wild spotted seal pups were significantly higher than those in captive animals. The present study provides the normal activities of several serum immune enzymes for wild and captive spotted seal pups from the Liaodong Bay colony, which is benefit to the conservation of this species.

Assessing hexavalent chromium tissue-specific accumulation patterns and induced physiological responses to probe chromium toxicity in Coturnix japonica quail

Hexavalent chromium (Cr(VI)) is an environmental pollutant with vast mutagenic and carcinogenic potential. Various past and recent studies confirm the deleterious effects of Cr(VI) in different models, from invertebrates to mammalians. However, there is a lack of studies that comprehensively assess and correlate Cr(VI) accumulation patterns and the resulting physiological responses. Here we used an attractive toxicological model, male Japanese quail (Coturnix japonica), as an alternative probing system to evaluate Cr(VI) accumulation in the vital organs, including the brain, heart, kidneys, liver, and testes after 20 days of exposure to 1.2 μg/mL and 2.4 μg/mL potassium dichromate-K2Cr2O7 ingested in the form of drinking water. The observed effects were correlated with the shift in immune system readiness, hematological indices, serum biochemistry and enzyme activity. Regardless of the exposure dose, the Cr(VI) distribution and accumulation pattern in terms of relative Cr(VI) concentration in tissues was: testes > kidneys > liver > heart > brain. Moreover, Cr(VI) triggered the development of microcytic and hypochromic anemia and reduced the immune system’s readiness to cope with challenges. Besides, serum biochemistry presented significant shifts, including reduction of serum electrolytes and proteins and an increase in creatine kinase (CK) and lactate dehydrogenase (LDH) activity. Our study provides novel toxicological data that can be translated to higher animal models to help in the extrapolation of Cr(VI) toxicity in humans.

Culture of benthic diatom Nitzschia sp. with macroalgae carriers and its application as feed of juveniles Stichopus japonicus

Carrier culture is the combination of suspension culture and adherent culture. Carriers could be used to improve the culture efficiency of large-scale culture of adherent benthic diatom. In order to identify a suitable carrier for mass suspension culture of the benthic diatoms Nitzschia sp. powders of seven macroalgae were used as carriers for diatom attachment including Ulva pertusa, degummed Laminaria japonica, Sargassum muticum, Chaetomorpha valida, Zostera marina, Sargassum fusiforme and Sargassum thunbergii. Diatoms could grow on the surface of the suspended carriers and could effectively utilize the nutrients released by the decomposition of these carriers. Among the seven carriers, Ulva pertusa powder was the most effective for Nitzschia culture when comprehensively considering the nutrition of the harvested diatoms and nutrient utilization of the algae carrier by diatoms. The seaweed powder was dried at 80 °C before used as carrier, this process should meet the sterilization requirements for microalgal culture and is easy to implement in the large-scale cultivation of diatoms. Diatoms cultured with carriers were used to feed juveniles Stichopus japonicus with a wet weight of 5.0 ± 2.0 g, as well as diatoms cultured using conventional methods without carriers, and no significant differences were observed between the two kinds of feed. Compared to sea cucumbers fed with commercial feed, the growth rate of S. japonicus fed with carrier-cultured diatoms was approximately 1.5 times greater, and the activities of non-specific immune enzymes were improved in the coelomic fluid including acidic phosphatase, alkaline phosphatase and superoxide dismutase. Feeding sea cucumber with fresh diatoms could effectively reduce the total nitrogen and total phosphorus in the culture water, improve the water quality, and promote the breeding of sea cucumbers, regardless of whether the carrier culture was adopted.

Rice-shrimp culture: a better intestinal microbiota, immune enzymatic activities, and muscle relish of crayfish (Procambarus clarkii) in Sichuan Province.

Intestinal microbiota play an important role in the intestinal immunity and nutrient absorption, even muscle nutritional components, and the composition and function were affected by environment. In this study, the intestinal microbiota and immune enzyme, nutritional flavor of muscle of crayfish in rice field, and pond cultivation model were compared in summer and autumn. The results of Shannon diversity and Chao 1 index of intestinal microbiota based on 16S sequencing analysis showed that the diversity and abundance in autumn were higher than in summer. And the diversity and abundance of intestinal microbiota of different model in the same season were different. Four dominant phyla (relative abundance > 5% at least in one sample) of the intestinal microbiota were Bacteroidetes, Firmicutes, Proteobacteria, and Tenericutes. From summer to autumn, the intestinal immune enzyme activity of crayfish in both models showed a decreasing trend. In summer, the activity of catalase and alkaline phosphatase of crayfish cultured in the pond was significantly higher than that in rice field (P < 0.05). In autumn, the activity of catalase and lysozyme of crayfish cultured in rice field was significantly higher than that in pond (P < 0.05). The contents of umami and sweetish amino acids of muscle were higher in rice field than in pond, and the percentage of glutamic acid and alanine was significantly higher in rice field than in pond (P < 0.05). Thus, rice field model can make crayfish a more stable intestinal environment and a better intestinal immune enzyme activity and muscular flavor. Key points • The intestinal microbiota of crayfish in rice field had tended to stabilize from summer to autumn. • The crayfish had better nutrient absorption and stronger immune abilities in the rice field. • The crayfish cultured in rice field had higher overall umami concentration than in pond.