Personal mastery and quality of life in patients with atrial fibrillation after radiofrequency ablation: The mediating role of health promoting behavior.

BACKGROUND: Improving quality of life is vital for patients with atrial fibrillation (AF) after radiofrequency ablation. Quality of life can be affected not only by personal mastery but also by health promoting behavior as previously studied. However, it remains unclear whether health promoting behavior mediates the relationship between personal mastery and quality of life. OBJECTIVES: To explore whether health promoting behavior mediates the relationship between personal mastery and quality of life in patients with AF after radiofrequency ablation. METHODS: A cross-sectional design and convenience sampling were conducted at a tertiary hospital in China. Self-reported questionnaires were used to assess personal mastery, health promoting behavior and quality of life. SPSS and AMOS software were used for statistical analysis. RESULTS: A total of 202 patients with AF after radiofrequency ablation were enrolled (mean age 58.28 ± 12.70 years). The scores for personal mastery and quality of life were 22.52 ± 2.53 points and 62.58 ± 8.59 points, respectively, indicating a limited level. The health promoting behavior exhibited a moderate level, with scores averaging 103.82 ± 8.47 points. There was a positive correlation between the three variables (all P < 0.05). Health promoting behavior played a partial mediating role in the relationship between personal mastery and quality of life in patients with AF after radiofrequency ablation, accounting for 44.79 % of the total effect. CONCLUSIONS: In order to improve quality of life and prognosis, it is necessary to consider enhancing personal mastery and increasing patient compliance with health promoting behavior, which are important ways to improve their quality of life.

Larval biomass production from the co-digestion of mushroom root waste and soybean curd residues by black soldier fly larvae (Hermetia illucens L.).

People are increasingly using black soldier fly larvae (BSFL) as a sustainable waste management solution. They are high in protein and other essential nutrients, making them an ideal food source for livestock, poultry, and fish. Prior laboratory studies with BSFL developed on pure mushroom root waste (MRW) showed poor conversion efficiency compared to a regular artificial diet. Therefore, we mixed the nutrient-rich soybean curd residues (SCR) with MRW in different ratios (M2-M5). Pure mushroom root waste (M1, MRW 100%) had the lowest survival rate (86.2%), but it increased up to 96.9% with the SCR percentage increasing. M1 had the longest developmental period (31.1 days) and the lowest BSFL weight (7.4 g). However, the addition of SCR reduced the development time to 22.0 and 21.5 days in M4 (MRW 40%, SCR 60%) and M5 (MRW 20%, SCR 80%), respectively, and improved the larval weight to 10.9 g in M4 and 11.8 g in M5. Other groups did not have as much feed conversion ratio (FCR) (8.4 for M4 and M5), bioconversion (M4 5.4%; M5 5.9%), or lipid content (M4 25.2%; M5 24.3%). These mixtures did. Compare this to M1. We observed better results, with no significant differences between the M4 and M5 groups and their parameters. In the present study, our main target was to utilize more MRW. Therefore, we preferred the M4 group in our nutritional and safety investigation and further compared it with the artificial diet (M7). The heavy metals and essential amino acids (histidine 3.6%, methionine 2.7%, and threonine 3.8%) required for human consumption compared to WHO/FAO levels showed satisfactory levels. Furthermore, fatty acids (capric acid 1.9%, palmitic acid 15.3%, oleic acid 17.3%, and arachidonic acid 0.3%) also showed higher levels in M4 than M7. The SEM images and FT-IR spectra from the residues showed that the BSFL in group M4 changed the structure of the compact fiber to crack and remove fibers, which made the co-conversion mixture better.

Characteristics of gut bacterial microbiota of black soldier fly (Diptera: Stratiomyidae) larvae effected by typical antibiotics.

As agents in an emerging technology, Hermetia illucens (Linnaeus, 1758) (Diptera: Stratiomyidae) larvae, black soldier fly, have shown exciting potential for degrading antibiotics in organic solid waste, a process for which gut microorganisms play an important role. This study investigated the characteristics of larval gut bacterial communities effected by typical antibiotics. Initially, antibiotics significantly reduced the diversity of gut bacterial species. After 8 days, diversity recovered to similar to that of the control group in the chlortetracycline, tylosin, and sulfamethoxazole groups. Proteobacteria, Firmicutes, and Actinobacteriota were the dominant phyla at the initial BSFL gut. However, after 4 days treatment, the proportion of Actinobacteriota significantly decreased, but Bacteroidota notably increased. During the conversion process, 18, 18, 17, 21, and 19 core genera were present in the chlortetracycline, sulfamethoxazole, tylosin, norfloxacin, and gentamicin groups, respectively. Pseudomonas, Actinomyces, Morganella, Providencia and Klebsiella might be the important genera with extraordinary resistance and degradation to antibiotics. Statistical analyses of COGs showed that antibiotics changed the microbial community functions of BSFL gut. Compared with the control group, (i) the chlortetracycline, sulfamethoxazole, and tylosin groups showed significant increase in the classification functions of transcription, RNA processing and modification，and so on, (ii) the norfloxacin and gentamicin groups showed significant increase in defense mechanisms and other functions. Note that we categorized the response mechanisms of these classification functions to antibiotics into resistance and degradation. This provides a new perspective to deeply understand the joint biodegradation behavior of antibiotics in environments, and serves as an important reference for further development and utilization of microorganisms-assisted larvae for efficient degradation of antibiotics.

Insights into the reduction of antibiotic-resistant bacteria and mobile antibiotic resistance genes by black soldier fly larvae in chicken manure.

The increasing prevalence of antibiotic-resistant bacteria (ARB) from animal manure has raised concerns about the potential threats to public health. The bioconversion of animal manure with insect larvae, such as the black soldier fly larvae (BSFL, Hermetia illucens [L.]), is a promising technology for quickly attenuating ARB while also recycling waste. In this study, we investigated BSFL conversion systems for chicken manure. Using metagenomic analysis, we tracked ARB and evaluated the resistome dissemination risk by investigating the co-occurrence of antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and bacterial taxa in a genetic context. Our results indicated that BSFL treatment effectively mitigated the relative abundance of ARB, ARGs, and MGEs by 34.9%, 53.3%, and 37.9%, respectively, within 28 days. Notably, the transferable ARGs decreased by 30.9%, indicating that BSFL treatment could mitigate the likelihood of ARG horizontal transfer and thus reduce the risk of ARB occurrence. In addition, the significantly positive correlation links between antimicrobial concentration and relative abundance of ARB reduced by 44.4%. Moreover, using variance partition analysis (VPA), we identified other bacteria as the most important factor influencing ARB, explaining 20.6% of the ARB patterns. Further analysis suggested that antagonism of other bacteria on ARB increased by 1.4 times, while nutrient competition on both total nitrogen and crude fat increased by 2.8 times. Overall, these findings provide insight into the mechanistic understanding of ARB reduction during BSFL treatment of chicken manure and provide a strategy for rapidly mitigating ARB in animal manure.

Cellulose-degrading bacteria improve conversion efficiency in the co-digestion of dairy and chicken manure by black soldier fly larvae.

Black soldier fly larvae (BSFL) have potential utility in converting livestock manure into larval biomass as a protein source for livestock feed. However, BSFL have limited ability to convert dairy manure (DM) rich in lignocellulose. Our previous research demonstrated that feeding BSFL with mixtures of 40% dairy manure and 60% chicken manure (DM40) provides a novel strategy for significantly improving their efficiency in converting DM. However, the mechanisms underlying the efficient conversion of DM40 by BSFL are unclear. In this study, we conducted a holistic study on the taxonomic stucture and potential functions of microbiota in the larval gut and manure during the DM and DM40 conversion by BSFL, as well as the effects of BSFL on cellulosic biodegradation and biomass production. Results showed that BSFL can consume cellulose and other nutrients more effectively and harvest more biomass in a shorter conversion cycle in the DM40 system. The larval gut in the DM40 system yielded a higher microbiota complexity. Bacillus and Amphibacillus in the BSFL gut were strongly correlated with the larval cellulose degradation capacity. Furthermore, in vitro screening results for culturable cellulolytic microbes from the larval guts showed that the DM40 system isolated more cellulolytic microbes. A key bacterial strain (DM40L-LB110; Bacillus subtilis) with high cellulase activity from the larval gut of DM40 was validated for potential industrial applications. Therefore, mixing an appropriate proportion of chicken manure into DM increased the abundance of intestinal bacteria (Bacillus and Amphibacillus) producing cellulase and improved the digestion ability (particularly cellulose degradation) of BSFL to cellulose-rich manure through changes in microbial communities composition in intestine. This study reveals the microecological mechanisms underlying the high-efficiency conversion of cellulose-rich manure by BSFL and provide potential applications for the large-scale cellulose-rich wastes conversion by intestinal microbes combined with BSFL.

Single Component Organic Photosensitizer with NIR-I Emission Realizing Type-I Photodynamic and GSH-Depletion Caused Ferroptosis Synergistic Theranostics.

Phototheranostic agents have thrived as prominent tools for tumor luminescence imaging and therapies. Herein, a series of organic photosensitizers (PSs) with donor-acceptors (D-A) are elaborately designed and synthesized. In particular, PPR-2CN exhibits stable near infrared-I (NIR-I) emission, excellent free radicals generation and phototoxicity. Experimental analysis and calculations imply that a small singlet-triplet energy gap (ΔES1-T1 ) and large spin-orbit coupling (SOC) constant boost the intersystem crossing (ISC), leading to type-I photodynamic therapy (PDT). Additionally, the specific glutamate (Glu) and glutathione (GSH) consumption abilities of PPR-2CN inhibit the intracellular biosynthesis of GSH, resulting in redox dyshomeostasis and GSH-depletion causing ferroptosis. This work first realizes that single component organic PS could be simultaneously used as a type-I photodynamic agent and metal-free ferroptosis inducer for NIR-I imaging-guided multimodal synergistic therapy.

Isolated and identified pathogenic bacteria from black soldier fly larvae with "soft rot" reared in mass production facilities and its incidence characteristics.

The black soldier fly larvae (BSFL) can transform organic waste into high-end proteins, lipids, chitin, biodiesel, and melanin at an industrial scale. But scaling up of its production capacity has also posed health risks to the insect itself. In this investigation, larval "soft rot" which is occurring in mass production facilities that cause larval developmental inhibition and a certain degree of death was reported. Responsible pathogen GX6 was isolated from BSFL with "soft rot" and identified to be Paenibacillus thiaminolyticus. No obvious impact on larval growth was observed when treated with GX6 spores, whereas mortality of 6-day-old BSFL increased up to 29.33% ± 2.05% when GX6 vegetative cells (1 × 106 cfu/g) were inoculated into the medium. Moreover, higher temperature further enhanced the BSFL mortality and suppressed larval development, but increasing substrate moisture showed the opposite effect. The middle intestine of infected larvae became swollen and transparent after dissection and examination. Transmission electron microscopy (TEM) observation indicated that GX6 had destroyed the peritrophic matrix and intestinal microvilli and damaged epithelial cells of larval gut. Furthermore, 16S rRNA gene sequencing analysis of intestinal samples revealed that gut microflora composition was significantly altered by GX6 infection as well. It can be noticed that Dysgonomonas, Morganella, Myroides, and Providencia bacteria became more numerous in the intestines of GX6-infected BSFL as compared to controls. This study will lay foundations for efficient control of "soft rot" and promote healthy development of the BSFL industry to contribute to organic waste management and circular economy.

Mitigation of antibiotic resistome in swine manure by black soldier fly larval conversion combined with composting.

The increasing prevalence of antibiotic resistance genes (ARGs) in animal manure has attracted considerable attention because of their potential contribution to the development of multidrug resistance worldwide. Insect technology may be a promising alternative for the rapid attenuation of ARGs in manure; however, the underlying mechanism remains unclear. This study aimed to evaluate the effects of black soldier fly (BSF, Hermetia illucens [L.]) larvae conversion combined with composting on ARGs dynamics in swine manure and to uncover the mechanisms through metagenomic analysis. Compared to natural composting (i.e. without BSF), BSFL conversion combined with composting reduced the absolute abundance of ARGs by 93.2 % within 28 days. The rapid degradation of antibiotics and nutrient reformulation during BSFL conversion combined with composting indirectly altered manure bacterial communities, resulting in a lower abundance and richness of ARGs. The number of main antibiotic-resistant bacteria (e.g., Prevotella, Ruminococcus) decreased by 74.9 %, while their potential antagonistic bacteria (e.g., Bacillus, Pseudomonas) increased by 128.7 %. The number of antibiotic-resistant pathogenic bacteria (e.g., Selenomonas, Paenalcaligenes) decreased by 88.3 %, and the average number of ARGs carried by each human pathogenic bacterial genus declined by 55.8 %. BSF larvae gut microbiota (e.g., Clostridium butyricum, C. bornimense) could help reduce the risk of multidrug-resistant pathogens. These results provide insight into a novel approach to mitigate multidrug resistance from the animal industry in the environment by using insect technology combined with composting, in particular in light of the global "One Health" requirements.

Activating Octahedral Center in Co-Doped NiFe2 O4 via Bridging Amorphous MoSx for Electrocatalytic Water Oxidation: A Case for eg Orbital Regulation in Spinel Oxide.

Moderate eg filling for octahedral metal cations (MOh ) is strongly correlated with the electrocatalytic water oxidation performance in the oxides system. Here, the eg fillings of NiOh and FeOh in NiFe2 O4 -based spinel are controllably regulated by introducing an external radical of catalytically inactive MoSx as an electron acceptor via a novel ultrasonic anchored pyrolysis strategy. The electron occupied in eg orbit of MOh emigrates with the amount of MoS hanging on the apical of octahedral sites, and results in a salutary transition from high to medium eg occupancy state, as confirmed by the X-ray absorption spectroscopy and X-ray photoelectron spectroscopy. In addition, benefiting from the abundant unsaturated S atoms in amorphous MoSx , the MOh at the surface furthest activates and consequently shows a superior water oxidation performance. Density functional theory also reveals that the eg fillings of Ni and Fe decrease to 1.4 and 1.2 after MoSx modification, which can effectively reduce the free energy of the OOH* intermediates in the oxygen evolution reaction process. This work opens an avenue for further releasing the electrocatalytic activity of octahedral sites through bridging external phases with rational electron-capturing/donating capability.

Tripartite motif 72 inhibits apoptosis and mitochondrial dysfunction in neural stem cells induced by anesthetic sevoflurane by activating PI3K/AKT pathway.

Anesthetics exposure induces neurocognitive deficits during brain development and impairs self-renewal and differentiation of neural stem cells (NSCs). Tripartite motif 72 (TRIM72, also known as mitsugumin 53, MG53) is involved in tissue repair and plasma membrane damage repair. The neuroprotective effect of TRIM72 against sevoflurane-induced neurotoxicity of NSCs was investigated in this study. First, human NSCs were exposed to different concentrations of sevoflurane. Results showed that TRIM72 was downregulated in sevoflurane-treated NSCs. Exposure to sevoflurane reduced cell viability in NSCs. Second, sevoflurane-treated NSCs were stimulated with recombinant human TRIM72 (rhTRIM72). Treatment with rhTRIM72 enhanced the cell viability in sevoflurane-treated NSCs. Moreover, treatment with a rhTRIM72-attenuated sevoflurane-induced increase in caspase-3 activity in NSCs. Third, JC-1 aggregates were deceased and JC-1 monomer was increased in sevoflurane-treated NSCs, which were reversed by rhTRIM72. Furthermore, rhTRIM72 also weakened sevoflurane-induced decrease in superoxide dismutase and glutathione peroxidase and increase in malondialdehyde and reactive oxygen species in NSCs. Finally, reduced phosphorylation levels of protein kinase B (AKT) and phosphatidylinositol 3-kinase (PI3K) in sevoflurane-treated NSCs were upregulated by rhTRIM72. In conclusion, TRIM72 inhibited cell apoptosis and reduced the mitochondria membrane potential of sevoflurane-treated NSCs through activation of the PI3K/AKT pathway.

Multiple Receptors Contribute to the Attractive Response of Caenorhabditis elegans to Pathogenic Bacteria.

Nematodes feed mainly on bacteria and sense volatile signals through their chemosensory system to distinguish food from pathogens. Although nematodes recognizing bacteria by volatile metabolites are ubiquitous, little is known of the associated molecular mechanism. Here, we show that the antinematode bacterium Paenibacillus polymyxa KM2501-1 exhibits an attractive effect on Caenorhabditis elegans via volatile metabolites, of which furfural acetone (FAc) acts as a broad-spectrum nematode attractant. We show that the attractive response toward FAc requires both the G-protein-coupled receptors STR-2 in AWC neurons and SRA-13 in AWA and AWC neurons. In the downstream olfactory signaling cascades, both the transient receptor potential vanilloid channel and the cyclic nucleotide-gated channel are necessary for FAc sensation. These results indicate that multiple receptors and subsequent signaling cascades contribute to the attractive response of C. elegans to FAc, and FAc is the first reported ligand of SRA-13. Our current work discovers that P. polymyxa KM2501-1 exhibits an attractive effect on nematodes by secreting volatile metabolites, especially FAc and 2-heptanone, broadening our understanding of the interactions between bacterial pathogens and nematodes. IMPORTANCE Nematodes feed on nontoxic bacteria as a food resource and avoid toxic bacteria; they distinguish them through their volatile metabolites. However, the mechanism of how nematodes recognize bacteria by volatile metabolites is not fully understood. Here, the antinematode bacterium Paenibacillus polymyxa KM2501-1 is found to exhibit an attractive effect on Caenorhabditis elegans via volatile metabolites, including FAc. We further reveal that the attractive response of C. elegans toward FAc requires multiple G-protein-coupled receptors and downstream olfactory signaling cascades in AWA and AWC neurons. This study highlights the important role of volatile metabolites in the interaction between nematodes and bacteria and confirms that multiple G-protein-coupled receptors on different olfactory neurons of C. elegans can jointly sense bacterial volatile signals.

Transformation mechanism of methylphosphonate to methane by Burkholderia sp: Insight from multi-labeled water isotope probing and transcriptomic.

Methylphosphonate (MPn), has been identified as a likely source of methane in aerobic ocean and may be responsible for the "ocean methane paradox", that is oversaturation of dissolved methane in oxic sea waters. However, the mechanism underlying the cleavage of C-P bonds during microbial degradation is not well understood. Using multi-labeled water isotope probing (MLWIP) and transcriptome analysis, we investigated the phosphate oxygen isotope systematics and mechanisms of microbial-mediated degradation of MPn in this study. In the aerobic culture containing MPn as the only phosphorus source, there was a significant release of inorganic phosphate (149.4 µmol/L) and free methane (268.3 mg/L). The oxygen isotopic composition of inorganic phosphorus (δ18OP) of accumulated released phosphate was 4.50‰, 23.96‰, and 40.88‰, respectively, in the corresponding 18O-labeled waters of -10.3‰, 9.9‰, and 30.6‰, and the slope obtained in plots of δ18OP versus the oxygen isotopic composition of water (δ18OW) was 0.89. Consequently, 89% of the oxygen atoms (Os) in phosphate (PO4) were exchanged with 18O-labeled waters in the medium, while the rest were exchanged with intracellular metabolic water. It has been confirmed that the C-P bond cleavage of MPn occurs in the cell with both ambient and metabolic water participation. Moreover, phn gene clusters play significant roles to cleave the C-P bond of MPn for Burkholderia sp. HQL1813, in which phnJ, phnM and phnI genes are significantly up-regulated during MPn decomposition to methane. In conclusion, the aerobic biotransformation of MPn to free methane by Burkholderia sp. HQL1813 has been elucidated, providing new insights into the mechanism that bio-cleaves C-P bonds to produce methane aerobically in aqueous environments for representative phosphonates.

Formation and Stabilization of NiOOH by Introducing α-FeOOH in LDH: Composite Electrocatalyst for Oxygen Evolution and Urea Oxidation Reactions.

NiOOH is considered as the most active intermediate during electrochemical oxidation reaction, however, it is hard to directly synthesize due to high oxidation energy. Herein, theoretical calculations predict that α-FeOOH enables a decline in formation energy and an improvement in stabilization of NiOOH in NiFe-based layered double hydroxide (LDH). Inspiringly, a composite composed of α-FeOOH and LDH is well-designed and successfully fabricated in hydrothermal treatment by adding extra Fe3+ resource, and stable NiOOH is obtained by the following electro-oxidation method. Benefiting from strong electron-capturing capability of α-FeOOH, it efficiently promotes charge redistribution around the Ni/Fe sites and activates Ni atoms of LDH, verified by X-ray photoelectron spectra (XPS) and X-ray absorption spectra (XAS). The d-band center is optimized that balances the absorption and desorption energy, and thus Gibbs free energy barrier is lowered dramatically toward oxygen evolution reaction (OER) and urea oxidation reaction (UOR), and finally showing an outstanding overpotential of 195 mV and a potential of 1.35 V at 10 mA cm-2 , respectively. This study provides a novel strategy to construct highly efficient catalysts via the introduction of a new phase for complex multiple-electron reactions.

Synergistic bioconversion of organic waste by black soldier fly (Hermetia illucens) larvae and thermophilic cellulose-degrading bacteria.

Introduction: This study examines the optimum conversion of Wuzhishan pig manure by Black Soldier Fly Larvae (BSFL) at various phases of development, as well as the impact of gut microbiota on conversion efficiency. Method and results: In terms of conversion efficiency, BSFL outperformed the growing pig stage (GP) group, with significantly higher survival rates (96.75%), fresh weight (0.23 g), and larval conversion rate (19.96%) compared to the other groups. Notably, the GP group showed significant dry matter reductions (43.27%) and improved feed conversion rates (2.17). Nutritional composition varied, with the GP group having a lower organic carbon content. High throughput 16S rRNA sequencing revealed unique profiles, with the GP group exhibiting an excess of Lactobacillus and Clostridium. Promising cellulose-degrading bacteria in pig manure and BSFL intestines, including Bacillus cereus and Bacillus subtilis, showed superior cellulose degradation capabilities. The synergy of these thermophilic bacteria with BSFL greatly increased conversion efficiency. The BSFL1-10 group demonstrated high growth and conversion efficiency under specific conditions, with remarkable larval moisture content (71.11%), residual moisture content (63.20%), and waste reduction rate (42.28%). Discussion: This study sheds light on the optimal stages for BSFL conversion of pig manure, gut microbiota dynamics, promising thermophilic cellulose-degrading bacteria, and the significant enhancement of efficiency through synergistic interactions. These findings hold great potential for sustainable waste management and efficient biomass conversion, contributing to environmental preservation and resource recovery.

MFG-E8 Exerts Neuroprotection in Neural Stem Cells Induced by Anesthetic Sevoflurane via Regulating the PI3K/AKT Pathways.

MFG-E8 has shown tissue protection effects in various models of organ injury. In this study, the function of MFG-E8 in SEV-induced neural stem cells (NSCs) was studied. The cell viability and apoptosis affected by rhMFG-E8 were tested by MTT and flow cytometry analysis, respectively. Then, the mRNA expression of MFG-E8 was detected by qRT-PCR. The expression of SOD, GSF-Px, and MDA was assessed using ELISA assay. Western blot analysis was applied for assessing the expression of MFG-E8, BCL2, BAX, cleaved caspase-3, GRP-78, XBP-1, ATF-6, ATF-4, CHOP, p-PI3K, PI3K, p-AKT, and AKT. The pharmacological experiments suggested that both mRNA and protein expression of MFG-E8 were significantly decreased after 24 h, 48 h, and 72 h treatment with SEV, and the Western blot results displayed that 50 and 100 µg/ml rhMFG-E8 could evidently promote the expression of MFG-E8 in NSCs induced by SEV. Next, rhMFG-E8 reduced the apoptosis of NSCs induced by SEV through upregulating Bcl-2 and cleaved caspase-3 and downregulating Bax. Moreover, rhMFG-E8 alleviated the endoplasmic reticulum pressure of NSCs induced by SEV through decreasing the expression of GRP-78, XBP-1, ATF-6, ATF-4, and CHOP. In addition, the rhMFG-E8 could promote the expression of SOD and GSH-Px and inhibit the expression of MDA and LDH detected by the ELISA assay and LDH kit. Moreover, rhMFG-E8 elevated the expression of p-PI3K/PI3K and p-AKT/AKT, which were inhibited by SEV in NSCs. The results of this project supported that rhMFG-E8 protects neural activity in neural stem cells induced by anesthetic sevoflurane via regulating the PI3K/AKT pathways.

Hermetia illucens L. larvae-associated intestinal microbes reduce the transmission risk of zoonotic pathogens in pig manure.

Black soldier fly (BSF) larvae are considered a promising biological reactor to convert organic waste and reduce the impact of zoonotic pathogens on the environment. We analysed the effects of BSF larvae on Staphylococcus aureus and Salmonella spp. populations in pig manure (PM), which showed that BSF larvae can significantly reduce the counts of the associated S. aureus and Salmonella spp. Then, using a sterile BSF larval system, we validated the function of BSF larval intestinal microbiota in vivo to suppress pathogens, and lastly, we isolated eight bacterial strains from the BSF larval gut that inhibit S. aureus. Results indicated that functional microbes are essential for BSF larvae to antagonise S. aureus. Moreover, the analysis results of the relationship between the intestinal microbiota and S. aureus and Salmonella spp. showed that Myroides, Tissierella, Oblitimonas, Paenalcalignes, Terrisporobacter, Clostridium, Fastidiosipila, Pseudomonas, Ignatzschineria, Savagea, Moheibacter and Sphingobacterium were negatively correlated with S. aureus and Salmonella. Overall, these results suggested that the potential ability of BSF larvae to inhibit S. aureus and Salmonella spp. present in PM is accomplished primarily by gut-associated microorganisms.

Morphometric Characteristic of Black Soldier Fly (Hermetia illucens) · Wuhan Strain and Its Egg Production Improved by Selectively Inbreeding.

The use of black soldier fly (BSF) larvae to recycle various organic materials while producing biomass for use as feed is well established. Variety selection is important from the perspective of application. In the current study, morphometric and life-history traits of a Wuhan-domesticated BSF colony (Wuhan strain) were compared to those of a 'selectively inbred' population (inbred strain, inbred for 10 generations). In terms of morphological characteristics, the results showed that both strains had dichoptic compound eyes, club-shaped antennae, blue halters, and blue-green metallic luster wings with a hexagon discal cell. In both strains, the body and wing length of female adults were slightly larger than those of male adults. The first four larval stages of the BSF occurred rapidly (1-12 days) with transitions across stages resulting in doubling of size for both populations. Selective inbreeding did not alter the life-history traits of the larval exuviate stage in terms of age, size, weight, and feed reduction rate. Overall egg production for the inbred strain was significantly higher (1.5 times greater) than the Wuhan strain. This is explained by increased adult emergence and individual oviposition performance. It was speculated that inbreeding improved the reproductive success of inbred adult female offspring and selection process steadied it. The findings indicate that selective inbreeding could enhance overall oviposition performance and provide a strategy to selectively breed BSF with high egg production for future applications.

Reproductive Toxicity of Furfural Acetone in Meloidogyne incognita and Caenorhabditis elegans.

Furfural acetone (FAc) is a promising alternative to currently available nematicides, and it exhibits equivalent control efficiency on root-knot nematodes with avermectin in fields. However, its effect on the reproduction of root-knot nematode is poorly understood. In this study, the natural metabolite FAc was found to exhibit reproductive toxicity on Meloidogyne incognita and Caenorhabditis elegans. The number of germ cells of C. elegans was observed to decrease after exposure to FAc, with a reduction of 59.9% at a dose of 200 mg/L. FAc in various concentrations induced the germ-cell apoptosis of C. elegans, with an increase over six-fold in the number of apoptotic germ cells at 200 mg/L. These findings suggested that FAc decreased the brood size of nematode by inducing germ-cell apoptosis. Moreover, FAc-induced germ-cell apoptosis was suppressed by the mutation of gene hus-1, clk-2, cep-1, egl-1, ced-3, ced-4, or ced-9. The expression of genes spo-11, cep-1, and egl-1 in C. elegans was increased significantly after FAc treatment. Taken together, these results indicate that nematode exposure to FAc might inflict DNA damage through protein SPO-11, activate CEP-1 and EGL-1, and induce the core apoptosis pathway to cause germ-cell apoptosis, resulting in decreased brood size of C. elegans.

Inhibition of Zoonotic Pathogens Naturally Found in Pig Manure by Black Soldier Fly Larvae and Their Intestine Bacteria.

Black soldier fly (BSF) larvae are often exposed to organic waste which harbors abundant zoonotic pathogens. We investigated the ability of BSF larvae to inhibit the zoonotic pathogens naturally found in pig manure. The zoonotic pathogens populations were detected by using selective medium during the conversion. Results showed that the viability of the zoonotic pathogens in pig manure was significantly affected. After eight days of conversion, the Coliform populations were undetected, and Staphylococcus aureus and Salmonella spp. decreased significantly on the eighth day. Antimicrobial assays of the purified recombinant defensin-like peptide 4 (DLP4) showed that this peptide exhibits inhibitory activity against S. aureus, Salmonella enterica serovar typhimurium, and Escherichia coli in vitro. Bacteria BSF-CL and BSF-F were isolated from the larvae gut, and both inhibited the growth of S. aureus and E. coli, but Salmonella spp. was sensitive to the BSF-CL strain (but not to the BSF-F strain). The results from our experiments indicate that BSF larvae are capable of functionally inhibiting potential zoonotic pathogens in pig manure through a variety of mechanisms including antimicrobial peptides expression and the gut associate microorganisms. This study provides a theoretical basis for further study on the combined mechanism of BSF larvae immunity and its gut microbes against the zoonotic pathogens in pig manure.

Characteristics and mechanisms of ciprofloxacin degradation by black soldier fly larvae combined with associated intestinal microorganisms.

Antibiotics are challenging to degrade and are excreted by livestock which results in environmental pollution. In this paper, we demonstrated that environmentally friendly manure bioremediation performed by black soldier fly larvae (BSFL) is a wise alternative, which could effectively degrade ciprofloxacin (CIP) by approached 85.48% in artificial diet and 84.22% in poultry manure within 12 days. They are up to 2.5-4.0 fold more than that achieved by natural fermentation. The five CIP-degrading strains were isolated from the larval gut, two of which, named by Klebsiella pneumoniae BSFLG-CIP1 and Proteus mirabilis BSFLG-CIP5, could degraded CIP by nearly 98.22% and 97.83% in vitro, respectively. When the intestinal isolates were re-inoculated to sterile BSFL system, the degradation level significantly increased up to 82.38%, comparing with the sterile BSFL system (21.76%). It is proved that the larvae intestinal microbiota might carry out this highly-efficient CIP-degradation. Furthermore, seven possible metabolites were identified for CIP-degradation in vitro, and they were referring three main potential degrading mechanisms of hydroxylize, piperazine ring substitute and cleavage, and quinoline ring cleavage. In conclusion, the present study may provide a strategy to reduce antibiotics pollution in animal waste through bioremediation with BSFL and adjusted intestinal microbes.