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This study was conducted to evaluate the effects of Bacillus licheniformis and combined herbs extracts on the physiological and immune characteristics, intestinal microbiota, and vibriosis resistance of sea cucumber Apostichopus japonicus. The sea cucumbers were fed with basal diets supplemented with B. licheniformis (B group), combined herbs extracts (C group), or both (BC group). The BC group exhibited the better growth performance and higher digestive and immune enzyme activities, whereas the lowest parameters appeared in the control group. This revealed that dietary B. licheniformis and combined herbs extracts in combination could improve digestion, food intake, phosphatase-responsiveness, and oxidation resistance more efficiently compared with the other groups. The BC group was also more capable of regulating intestinal flora balance of sea cucumbers by increasing the beneficial bacteria related to energy synthesis and metabolic conversion, and inhibiting the potential pathogens associated with organic damage and metabolic disorders. Furthermore, the BC group showed greater ability of improving disease resistance by reducing the cumulative mortality rates and the counts of Vibrio splendidus. These results collectively demonstrated that dietary B. licheniformis and combined herbs extracts could improve the physiological and immune parameters, optimize the microbial community, and enhance the resistance to vibriosis of sea cucumbers, and the health-promoting effects were more obvious by supplying them in combination. [ABSTRACT FROM AUTHOR]

Aquaculture pond sediments have a notable influence on the ecosystem balance and farmed animal health. In this study, microalgal-bacterial immobilization (MBI) was designed to improve aquaculture pond sediments via synergistic interactions. The physicochemical characteristics, bacterial communities, and the removal efficiencies of emerging pollutants were systematically investigated. The consortium containing diatom Navicula seminulum and Alcaligenes faecalis was cultivated and established in the free and immobilized forms for evaluating the treatment performance. The results indicated that the immobilized group exhibited superior performance in controlling nutrient pollutants, shaping and optimizing the bacterial community compositions with the enrichment of functional bacteria. Additionally, it showed a stronger positive correlation between the bacterial community shifts and nutrient pollutants removal compared to free cells. Furthermore, the immobilized system maintained the higher removal performance of emerging pollutants (heavy metals, antibiotics, and pathogenic Vibrios) than free group. These findings confirmed that the employment of immobilized N. seminulum and A. faecalis produced more synergistic benefits and exerted more improvements than free cells in ameliorating aquaculture pond sediments, suggesting the potential for engineering application of functional microalgal-bacterial consortium in aquaculture. [Display omitted] • The cooperative interactions of MBI for reducing nutrient pollutants were explored. • MBI performed better in improving physicochemical properties than free system. • The bacterial communities were shaped and optimized by MBI more significantly. • MBI exhibited a higher emerging pollutants removal performance than free system. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

To investigate the effects of Lactobacillus acidophilus and tussah immunoreactive substances (TIS) supplementation alone or together on the growth performance, digestive and immune-related enzyme activities, and intestinal microbiota of the sea cucumber Apostichopus japonicus , a feeding experiment was conducted. The supplementation of L. acidophilus and TIS together produced the maximum digestive and immune activities, while the minimum values occurred in the control group. No remarkable differences in enzyme activities were observed when supplemented individually. Dietary L. acidophilus and TIS in combination might be more capable of improving digestive capacity, food utilization rate, phosphatase-responsiveness and antioxidants. Furthermore, the supplementation of L. acidophilus and TIS in combination demonstrated a greater ability to optimize the intestinal microbiota of A. japonicus by increasing the potentially beneficial bacteria involved in energy production and biosynthesis, and suppressing the opportunistic pathogens. These results collectively indicated that the combined supplementation of L. acidophilus and TIS has a synergistic effect on enhancing immunity and digestibility, and could improve the intestinal microbiota structure of A. japonicus , suggesting potential for industrial feeding applications. [Display omitted] • L. acidophilus and TIS improved the digestibility and immunity of sea cucumbers. • L. acidophilus and TIS optimized the community composition of sea cucumbers. • The positive effects were more obvious by applying L. acidophilus and TIS together. [ABSTRACT FROM AUTHOR]

A new double asymmetric μ1,1-azido bridged binuclear copper(II) complex, [Cu2(μ1,1-N3)2(Him2-py)2(N3)2] (Him2-py = 2-(2'-pyridyl)-4,4,5,5-tetramethylimidazoline-1-hydroxy), has been synthesized and characterized structurally and magnetically. The crystal structure shows this complex is binuclear with copper(II) in a distorted square-pyramidal geometry, bridged by double asymmetric end-on azide ligands. The variable temperature magnetic susceptibility analyses reveal weak antiferromagnetic interaction mediated by the bridge. [ABSTRACT FROM AUTHOR]

Salinity is an important environmental factor in microbial ecology for affecting the microbial communities in diverse environments. Understanding the salinity adaptation mechanisms of a microbial community is a significant issue, while most previous studies only covered a narrow salinity range. Here, variations in seawater prokaryotic communities during the whole salt drying progression (salinity from 3% to 25%) were investigated. According to high‐throughput sequencing results, the diversity, composition, and function of seawater prokaryotic communities varied significantly along the salinity gradient, expressing as decreased diversity, enrichment of some halophilic archaea, and powerful nitrate reduction in samples with high salt concentrations. More importantly, a sudden and dramatic alteration of prokaryotic communities was observed when salinity reached 16%, which was recognized as the change point. Combined with the results of network analysis, we found the increasing of complexity but decreasing of stability in prokaryotic communities when salinity exceeded the change point. Moreover, prokaryotic communities became more deterministic when salinity exceeded the change point due to the niche adaptation of halophilic species. Our study showed that substantial variations in seawater prokaryotic communities along an extremely wide salinity gradient, and also explored the underlying mechanisms regulating these changes. [ABSTRACT FROM AUTHOR]

Bioassay-guided fractionation of the ethanolic extract of the stem bark of Albizia julibrissin led to the isolation of ten new oleanane-type triterpenoid saponins, julibrosides J 37 –J 46 ( 1 – 10 ), along with six known analogues ( 11 – 16 ). In addition, 11 prosapogenins ( 17 – 27 ) were prepared by mild or strong alkaline hydrolysis of the total saponin. The structures of 1 − 27 were determined by spectroscopic and chemical means, and their cytotoxicities against four human cancer cell lines, BGC-823, A549, HCT-116, and HepG2 were evaluated. Compounds 5 – 16 exhibited significant inhibitory activity with IC 50 values ranging from 2.59 to 9.30 μM, and 8 turned out to be the most active compound with all IC 50 values < 5 μM. A preliminary structure-activity relationship of these saponins clearly indicated that the outer monoterpenoid moiety (MT′) is a crucial substituent for cytotoxicity, and the linkage sites of the MT′ unit greatly influenced the activity. It could also be inferred that the existence of 16-OH of the aglycone almost has no effect on cytotoxicity and the N -acetyl-glucosamine moiety at C-3 seems to enhance activity. [ABSTRACT FROM AUTHOR]

The sea cucumber Apostichopus japonicus is one of the most dominant and economically important aquaculture species in China. Saponin, which possesses notable biological and pharmacological properties, is a key determinant of the nutritional and health value of A. japonicus. In the present study, we amplified the full-length cDNA of a phosphomevalonate kinase (PMK) gene (named AjPMK) using rapid amplification of cDNA ends (RACE). Subsequently, we engineered a recombinant AjPMK (rAjPMK) protein and assessed its enzymatic activity by enzyme-linked immunosorbent assay (ELISA). Proteins that interact with rAjPMK were screened and identified via pull-down assay combined with liquid chromatography with tandem mass spectrometry (LC-MS/MS). We found that the full-length cDNA of AjPMK contained 1354 bp and an open reading frame (ORF) of 612 bp. The AjPMK protein was predicted not to contain a signal peptide but to contain a phosphonolate kinase domain seen in higher eukaryotes and a P-loop with a relatively conserved nucleoside triphosphate hydrolase domain. The molecular weight of the AjPMK protein was estimated to be 23.81 kDa, and its isoelectric point was predicted to be 8.72. Phylogenetic analysis showed that AjPMK had a closer evolutionary relationship with genes from starfish than with those of other selected species. Besides, we found that rAjPMK synthesized mevalonate-5-diphosphate, interacted either directly or indirectly with crucial pattern recognition receptors (PRRs) and was regulated by immune-related processes, including antioxidative reactions, stress resistance responses and enzyme hydrolysis. Moreover, AjPMK also interacted with farnesyl pyrophosphate synthase, an enzyme reported to be involved in saponin biosynthesis. Together, our findings implied that AjPMK may be directly involved in saponin biosynthesis and the regulation of various innate immune processes. • A phosphomevalonate kinase (PMK) gene was identified in sea cucumber Apostichopus japonicus. • AjPMK is involved in sea cucumber saponin biosynthesis. • AjPMK might be regulated by multiple immune processes. [ABSTRACT FROM AUTHOR]

Summary: Nowadays, the true economic and nutritional value of food is underpinned by both origin and quality traits, more often expressed as increased quality benefits derived from the origin source. Gut microbiota contribute to food metabolism and host health, therefore, it may be suitable as a qualifying indicator of origin and quality of economic species. Here, we investigated relationships between the gut microbiota of the sea cucumber (Apostichopus japonicus), a valuable aquaculture species in Asia, with their origins and quality metrics. Based on data from 287 intestinal samples, we generated the first biogeographical patterns for A. japonicus gut microbiota from origins across China. Importantly, A. japonicus origins were predicted using the random forest model that was constructed using 20 key gut bacterial genera, with 97.6% accuracy. Furthermore, quality traits such as saponin, fat and taurine were also successfully predicted by random forest models based on gut microbiota, with approximately 80% consistency between predicted and true values. We showed that substantial variations existed in the gut microbiota and quality variables in A. japonicus across different origins, and we also demonstrated the great potential of gut microbiota to track A. japonicus origins and predict their quality traits. [ABSTRACT FROM AUTHOR]

Peptidoglycan recognition proteins (PGRPs) comprise a family of pattern recognition receptors (PRRs) with an important role in innate immunity. Here, we amplified the full-length cDNA of a novel PGRP from the sea cucumber A. japonicus (named AjPGRP-S1) using RACE. Subsequently, we prepared a codon-optimized recombinant AjPGRP-S1 (rAjPGRP-S1) protein and raised a polyclonal antibody against rAjPGRP-S1 by immunizing rabbits. At the transcriptional level, the tissue expression pattern of AjPGRP-S1 was determined by in situ hybridization and RT-qPCR, while the gene expression of AjPGRP-S1 after microbial polysaccharide challenge was also evaluated by RT-qPCR. Amidase activity was measured using the microplate method; the pathogen recognition characteristics were determined by ELISA and indirect immunofluorescence assay; and the immune factors that interact with AjPGRP-S1 were screened and identified via pull-down assay combined with LC-MS/MS. The AjPGRP-S1 protein was predicted to contain a signal peptide, a PGRP domain, and a molecular mass of 24.6 kDa, but lacked a cysteine residue that is indispensable for the formation of a Zn2+-binding site and amidase activity. Indeed, no amidase activity was detected from rAjPGRP-S1. These results indicated that AjPGRP-S1 might be a secretory, short-type, and recognition-type PGRP. AjPGRP-S1 transcripts were relatively highly abundant in coelomocytes and were markedly induced by challenge with diaminopimelic acid (DAP)-type peptidoglycan (PGN), suggesting that AjPGRP-S1 is mainly expressed by coelomocytes and might play a crucial role in the defense against Gram-negative bacteria. rAjPGRP-S1 was determined to be capable of binding to DAP-type PGN, lysine (Lys)-type PGN, β-1,3-glucan, Vibrio splendidus , Pseudoalteromonas nigrifaciens , Shewanella baltica , Bacillus cereus , Escherichia coli , and Staphylococcus aureus , but not lipopolysaccharide or mannan, implying that AjPGRP-S1 may have a broad-spectrum pathogen recognition ability. Additionally, rAjPGRP-S1 was found to interact either directly or indirectly with multiple soluble and insoluble PRRs and diverse antioxidation-, antistress-, complement system-, bacteria lysis-, and immune response-related factors, as well as several potential immunomodulatory factors, indicating that complete pathogen recognition by the A. japonicus immune system likely requires the synergistic activity of AjPGRP-S1 and other PRRs. These results further implied that AjPGRP-S1 might transduce the immune signal generated following pathogen recognition to multiple immune effectors, thereby inducing both pathogen-attack-oriented and self-protection-oriented immune reactions, as well as to potential immunomodulatory factors so as to adjust the response of the A. japonicus immune system. • AjPGRP-S1 is a secretory and recognition-type PGRP. • AjPGRP-S1 was mainly expressed by coelomocytes. • AjPGRP-S1 showed notable response to DAP-type PGN challenge. • AjPGRP-S1 has broad-spectrum pathogen recognition ability. • AjPGRP-S1 showed direct or indirect interaction with multiple immune factors. [ABSTRACT FROM AUTHOR]

Two undescribed oleanane-type saponins, julibrosides K–L, along with three undescribed oleanane-type prosapogenins, julibrosides M–O, were isolated from the stem bark of Albizia julibrissin Durazz. and the mild alkaline hydrolysate of the total saponin, respectively. Their structures were established by extensive analysis of 1D and 2D NMR experiments (COSY, TOCSY, HSQC, HMBC, and HSQC-TOCSY) and mass spectrometry. Furthermore, the cytotoxic activities of the isolated compounds against BGC-823, A549, HCT-116, and HepG2 cell lines were evaluated, and julibroside L showed significant cytotoxic activities against the four cancer cell lines with IC 50 values of 5.77, 4.80, 4.26, and 4.93 μ M, respectively. Five undescribed oleanane-type saponins, julibrosides K–O were isolated from the stem bark of Albizia julibrissin Durazz. Julibroside L showed significant cytotoxic activities against several cancer cell lines. [Display omitted] • Five undescribed oleanane-type saponins, julibrosides K–O, were isolated from the stem bark of Albizia julibrissin. • Julibroside L showed significant cytotoxic activities against BGC-823, A549, HCT-116, and HepG2 cell lines. [ABSTRACT FROM AUTHOR]

Abstract: D–A–π–A indoline dyes have exhibited an especially excellent performance and are regarded as one of the most promising classes of arylamine organic sensitizers. Two new D–A–π–A indoline dyes (XS45 and XS46) with different additional donor as well as a reference D–π–A indoline dye (XS47) have been synthesized to investigate the influence of donor and bridge structure in indoline dyes on the photovoltaic properties of dye-sensitized solar cells employing iodine/cobalt electrolyte. The incorporation of bulky dipropylfluorene unit in the donor part significantly increases the light harvesting ability and notably retards the charge recombination at the titania/electrolyte interface. On the other hand, the introduction of benzothiadiazole (BTD) in spacer not only evokes a large responsive range of wavelengths into NIR region, but also decreases the molar absorption coefficients of indoline dyes. DSCs incorporating Co(II/III)tris(1,10-phenanthroline)-based redox electrolyte/iodine electrolyte and three synthesized organic dyes as photosensitizers are described. The results confirm that using D–A–π–A indoline dyes as sensitizers for cobalt cells is feasible. [Copyright &y& Elsevier]

The sea cucumber Apostichopus japonicus is an important aquaculture species in China because of its high nutritional and medicinal values. Gender, as a factor affecting the physiology of organisms, is always considered when improving the breeding efficiency of economically important animals. In the present study, protein expression profiles of the gonads and tube feet of male and female A. japonicus were investigated using a comparative proteomics approach. A set of 7499 proteins were identified, which covered a broad range of functions based on function annotations. A significant difference in protein expression profiles was observed between the gonads and tube feet of A. japonicus ; gonads showed more apparent gender differences than tube feet. Moreover, the findings revealed that male A. japonicus had more specific functions and most of these functions were associated with energy consumption. Further analyses suggested that the regulation of ERK activity and the capacity of tyrosine production and virus immunity might be more powerful in male and female A. japonicus , respectively. Some candidate proteins were also recognized as potential targets for gender identification of A. japonicus. Overall, our study provides new insights into the understanding of molecular mechanisms underlying gender-based physiological differences in A. japonicus. The current study aimed to reveal gender differences in the physiological characteristics of gonads and tube feet of the sea cucumber A. japonicus. To the best of our knowledge, this is the first proteomics study to analyze the differences in the protein expression profiles of external organs between male and female A. japonicus. The analysis revealed gender differences in the protein expression profiles of both gonads and tube feet of A. japonicus , and the gender differences in gonads were quite apparent. Moreover, according to the recognition of differentially expressed proteins and the enrichment analyses based on Kyoto Encyclopedia of Genes and Genomes, a draft view of how the physiological functions of A. japonicus were affected by gender was obtained. Male A. japonicus could have more specific functions related to energy consumption than females. The regulation of ERK activity and virus immunity might be more robust in male and female A. japonicus , respectively. Some candidate proteins were also recognized as potential targets for gender identification of A. japonicus. The findings presented here will improve the understanding of researchers about the molecular mechanisms underlying gender-based differences in A. japonicus and contribute to the meticulous breeding of A. japonicus. [Display omitted] • Gender-based physiological differences in sea cucumbers were investigated. • Gonads showed more apparent gender differences than tube feet in sea cucumber. • The regulation of ERK activity might be more robust in male sea cucumbers. • Tyrosine production and virus immunity might be more robust in female sea cucumbers. • Some candidate gender identification targets were recognized from male tube feet. [ABSTRACT FROM AUTHOR]

Due to the importance of characteristics associated with the immunity and physiology of organisms, gender is always taken into account when improving the breeding efficiency of economically important animals. Protein variations in the cell-free ceolomic fluid (CCF) of male and female Apostichopus japonicus before and after spawning were investigated using a comparative proteomic approach, for the purpose of understanding the influence of gender and gender associated reproductive processes on humoral immunity and physiological characteristics of the sea cucumber, A. japonicus. A total of 6839 peptides were obtained and a set of 1466 proteins were identified in the CCF of male and female A. japonicus before and after spawning. Partial least squares discrimination analysis indicated that protein expression profiles in the CCF of A. japonicus were significantly affected by both gender and reproductive processes. In addition, the differentially expressed proteins (DEPs) in the CCF of different genders and reproductive stages of A. japonicus were determined and immune-related proteins in these DEPs were screened. Findings revealed that the alternative pathway of complement activation in both male and female A. japonicus before spawning might take precedence over that after spawning. Further KEGG enrichment analyses of DEPs suggested that the capacity of muscle contraction in A. japonicus females, and food digestion, nutrition absorption, epithelial differentiation as well as growth in A. japonicus males might be enhanced after spawning. Further, compared with A. japonicus females, males may have an advantage in growth in the stages following spawning. Besides, according to KEGG annotation related to metabolism, arginine biosynthesis and purine metabolism were dominant in the CCF of male and female A. japonicus , respectively, suggesting notable metabolic differences in female and male A. japonicus. Overall, our study provides new insight into the understanding of molecular mechanisms underlying gender-determined immune and physiological differences in A. japonicus. The current study aimed to reveal the gender differences in humoral immunity and physiological characteristics associated with reproduction in the sea cucumber Apostichopus japonicus. To the best of our knowledge, this is the first proteomic study analyzing the differences in protein profile between male and female A. japonicus. By analyzing the expression differences of the proteome via label-free proteomic technology, we revealed that both gender and reproduction could alter the protein composition and abundance in the cell-free colemic fluid (CCF) of A. japonicus. Based on the recognition of differentially expressed proteins (DEPs) related to immune function among the CCFs, shifts in humoral immunity of male and female A. japonicus that underwent reproduction were obtained. Moreover, according to the enrichment analyses of DEPs based on Kyoto Encyclopedia of Genes and Genomes, a draft view of how the male and female A. japonicus affected by reproduction physiologically was drawn. The results suggested that the alternative pathway of complement activation in both male and female A. japonicus were weakened after spawning. In addition, after reproduction, the capacity of muscle contraction might be enhanced in female A. japonicus , and the nutrients consumption, epithelial differentiation and growth might be strengthened in males. Further, ipath analysis indicated that A. japonicus with different genders also had notable differences in metabolism that related to arginine biosynthesis and purine metabolism. The findings presented here will improve the cognition of researchers in the molecular mechanism underlying the gender-determined immune and phyisological differences of A. japonicus and contribute for the meticulous breeding of A. japonicus. Unlabelled Image • Both gender and reproduction affected Apostichopus japonicus immunity and physiology. • A. japonicus alternative complement pathway was depressed after spawning. • The muscle contraction capacity in females might be enhanced after spawning. • The nutrients consumption and growth might be boosted in males after spawning. • The males might have advantage over females in growth after sapwning. [ABSTRACT FROM AUTHOR]