Antifungal effects and biocontrol potential of lipopeptide-producing Streptomyces against banana Fusarium wilt fungus Fusarium oxysporum f. sp. cubense

Fusarium wilt of banana (FWB), caused by Fusarium oxysporum f. sp. cubense (Foc), especially tropical race 4 (TR4), presents the foremost menace to the global banana production. Extensive efforts have been made to search for efficient biological control agents for disease management. Our previous study showed that Streptomyces sp. XY006 exhibited a strong inhibitory activity against several phytopathogenic fungi, including F. oxysporum. Here, the corresponding antifungal metabolites were purified and determined to be two cyclic lipopeptide homologs, lipopeptin A and lipopeptin B. Combined treatment with lipopeptin complex antagonized Foc TR4 by inhibiting mycelial growth and conidial sporulation, suppressing the synthesis of ergosterol and fatty acids and lowering the production of fusaric acid. Electron microscopy observation showed that lipopeptide treatment induced a severe disruption of the plasma membrane, leading to cell leakage. Lipopeptin A displayed a more pronounced antifungal activity against Foc TR4 than lipopeptin B. In pot experiments, strain XY006 successfully colonized banana plantlets and suppressed the incidence of FWB, with a biocontrol efficacy of up to 87.7%. Additionally, XY006 fermentation culture application improved plant growth parameters and induced peroxidase activity in treated plantlets, suggesting a possible role in induced resistance. Our findings highlight the potential of strain XY006 as a biological agent for FWB, and further research is needed to enhance its efficacy and mode of action in planta

Design of Selective TPV Thermal Emitters Based on Bayesian Optimization Nesting Simulated Annealing

It is vital to further improve the design of TPV thermal emitters since the energy efficiency of thermophotovoltaic (TPV) systems is still not adequately high. In this paper, we propose a novel evaluator for the optimization of TPV thermal emitters, namely the percentage of effective figure (PEF) to replace the figure of merit (FOM). The associated algorithm, Bayesian optimization nesting simulated annealing (BOnSA), is developed to achieve better performance. By searching throughout the whole parameter space and then optimizing in a reduced space, BOnSA can lead to a satisfactory solution numerically for GaSb photovoltaic (PV) cells. When designing the emitter, the aperiodic material structure with an anti-reflection substructure and Fabry–Perot etalon is constructed from the material candidates. In particular, one of the optimal structures determined by BOnSA is {SiO2, ZnS, Ge, MgF2, W, Si, SiO2, W} with the value of PEF=0.822, which is better than the previous work by comparison. Moreover, by applying BOnSA to various structures, we have obtained higher values of PEF with less time cost, which thus verifies the efficiency and scalability of BOnSA. The results of our paper show that BOnSA provides an effective approach to the thickness optimization problem and that BOnSA is applicable in other relevant scenarios

Dietary supplementation with fermented Mao-tai lees beneficially affects gut microbiota structure and function in pigs

Gut microbiota positively contribute to livestock nutrition and metabolism. The manipulation of these microbes may improve animal health. Some feed additives improve livestock health and metabolism by regulating gut microbiota composition and activity. We fed hybrid pigs diets supplemented with 0% (control), 5% (treat 1), 10% (treat 2), or 15% (treat 3) fermented Mao-tai lees (FML) for 90days. Short-chain fatty acids (SCFAs), bioamines, and microbial communities found in colonic contents were analyzed to investigate microbiota composition and metabolic profiles. Concentrations of straight-chain fatty acids (e.g., acetate, propionate, and butyrate) and tyramine increased with FML supplementation content. Contrary to the minor effects of 5% and 10% FML on gut microbiota, 15% FML influenced beta diversity (Jaccard or Bray-Curtis dissimilarity) but not alpha diversity (number of operational taxonomic units and Shannon diversity) of pig gut microbial communities compared to the control group. Notably, 15% FML animals were characterized by a higher abundance of potentially beneficial bacteria (Lactobacillus and Akkermansia) but lower abundances of potential pathogens (Escherichia). Numerous genes associated with metabolism (e.g., starch, sucrose, and sulfur-compounds metabolism) showed a higher relative abundance in the 15% FML than in the control group. Additionally, most Phascolarctobacterium, Treponema, Prevotella, and Faecalibacterium bacterial markers in the 15% FML group were positively correlated with straight-chain fatty acid concentrations, suggesting that these bacteria are likely associated with SCFA production. Taken together, our findings demonstrate the beneficial effects of 15% FML on fermentation of undigested compounds and gut microbiota composition in the colon. Thus, 15% FML supplementation in pig feed may possibly represent a way to optimize pig colon health for livestock farming

Fetal Huanjiang mini-pigs exhibit differences in nutrient composition according to body weight and gestational period.

Low birth weight may negatively affect energy storage and nutrient metabolism, and impair fetal growth and development. We analyzed effects of body weight (BW) and gestational period on nutrient composition in fetal Huanjiang mini-pigs. Fetuses with the lowest BW (LBW), middle BW (MBW), and highest BW (HBW) were collected at days 45, 75, and 110 of gestation. Crude protein (CP), crude fat, amino acid (AA), and fatty acid (FA) concentrations were determined. The BW gain, carcass weight, fat percentage, and uterus weight of sows increased as gestation progressed, as did litter weight, average individual fetal weight, fetal body weight, and dry matter (DM). The concentrations of Ala, Arg, crude fat, Gly, Pro, Tyr, C14:0, C16:0, C16:1, C18:1n9c, C18:2n6c, C18:3n3, C18:3n6, C20:0, C20:3n6, saturated FA (SFA), and monounsaturated FA (MUFA) increased significantly as gestation progressed. The percentage of skeleton, and the ratio of the liver, lung, and stomach to BW decreased as gestation progressed. There were also significant reductions in the concentrations of CP, Asp, Glu, His, Ile, Leu, Lys, Phe, Ser, Thr, essential AA (EAA), acidic AA, C17:0, C20:4n6, C22:6n3, unsaturated FA (UFA), polyunsaturated FA (PUFA), n-3PUFA, n-6PUFA as gestation progressed, and reductions in EAA/total AA (TAA), PUFA/SFA, and n-3/n-6 PUFA. The LBW fetuses exhibited the lowest BW and crude fat, C14:0, C16:1, C17:0, C18:2n6c, and MUFA concentrations at days 75 and 110 of gestation. They also exhibited lower Tyr concentration at day 45 of gestation and lower Glu concentration at day 75 of gestation than HBW fetuses. These findings suggest that LBW fetuses exhibit lower amounts of crude fat and several FAs during mid-gestation and late-gestation, which may in turn affect adaptability, growth, and development

Toughness control of boron carbide obtained by spark plasma sintering in nitrogen atmosphere

Boron carbide ceramic was prepared by reactive Spark Plasma Sintering under N2-atmosphere and for different heating times and maximum pressure regimes. Split-Hopkinson Pressure Bar (SHPB), indentation, XRD and microscopy measurements were performed for samples characterization. It is shown that SHPB toughness control depending on SPS regime is possible and the main reason is introduction of nitrogen into B4C ceramic. Complex relationships between processing conditions, sintering mechanism, material's specifics, static and dynamic mechanical properties are discussed. Improvement of dynamic toughness is through mechanisms resembling those working for static load conditions such as cracks deflection and pull out, but there are also significant differences

Tough and dense boron carbide obtained by high-pressure (300 MPa) and low-temperature (1600°C) spark plasma sintering

Dense boron carbide (above 95%) was achieved through high pressure (300 MPa) and low temperature (1600°C) Spark Plasma Sintering (SPS). This approach resulted in improvement of fracture toughness and of dynamic toughness when compared to corresponding toughness values of the sample sintered by conventional SPS (2100°C, 50 MPa). Dynamic toughness was extracted from Split Hopkinson Pressure Bar measurements. Results are understood based on microstructure and on very different behaviour of the samples in respect to residual B2O3 and carbon available in the raw B4C powder

Composition of fatty acid of fetal pigs with LBW, MBW, and HBW at different gestation period (%; n = 8).

<p>Composition of fatty acid of fetal pigs with LBW, MBW, and HBW at different gestation period (%; n = 8).</p