Florfenicol (FF) is widely used in animal husbandry due to its broad-spectrum bactericidal activity, while there is little research focused on its toxic effects on the silkworm(Bombyx mori L.), a model organism. It was demonstrated in this paper that high-concentration florfenicol exposure significantly inhibited the activities of digestive and antioxidant enzymes, reduced the body weight and cocooning ability of silkworms, prolonged the instar duration, and simultaneously led to organelle swelling and vacuolization in the midgut, a large number of autophagosomes, and nuclear condensation. Meanwhile, it was found that exposure to FF reduced the α diversity and richness of the midgut flora, leading to a severe loss of core microbiota. The results of this study also indicated that Bacillus velezensis LY5, as a functional bacterium, effectively mitigated the toxic effects of FF on silkworm larvae. This strain significantly improved the body weight and cocoon quality of silkworms exposed to FF, promoted the repair of midgut tissue damage, and restored the structure of the midgut core flora. Furthermore, B. velezensis LY5 treatment increased the relative abundance of potentially beneficial bacteria while suppressing the abnormal proliferation of opportunistic pathogens. This study reveals the toxicological mechanism by which high concentrations of antibiotics (FF) disrupt the midgut microbiota balance in silkworms, induce tissue damage, and subsequently impede their growth and development. It also demonstrates for the first time that functional probiotics Bacillus velezensis LY5 effectively reverse this damage by restoring the silkworm midgut microbiota and intestinal tissue.

As important silkworm varieties reared on artificial diet, Youshi No. 1 (YS) and Guangshi No. 1 (GS) showed remarkable differences in physiological characteristics. GS had significantly better performance than YS in body weight, cocooning ability, food intake, feed utilization efficiency, and digestive enzyme activities. We further performed metabolomics and 16S rRNA high-throughput sequencing to analyze their metabolic profiles and midgut microbiota. More than 40 differential metabolites were screened out, and four metabolic pathways related to feeding divergence were determined via KEGG enrichment, among which L-valine was enriched in multiple pathways. Significant structural differences were also observed in midgut microbiota, and Bacillus was positively correlated with pantothenic acid and valine metabolism. These correlational results disclosed that differential metabolites and gut microbiota might underlie the phenotypic variations between the two varieties. Integrated analysis combined with functional verification experiments demonstrated that supplementation of 1% L-valine or specific Bacillus strains in an artificial diet was associated with the improvement of the growth performance, cocoon quality, and feed utilization efficiency of the YS silkworm variety.

Homologous regions (hrs) are repetitive DNA sequences widely distributed in baculovirus genomes, and are known to function as transcriptional enhancers. In this study, we systematically characterized the seven hrs (hr1, hr2L, hr2R, hr3, hr4L, hr4R, and hr5) from a novel isolate of Bombyx mori nucleopolyhedrovirus (strain BmNPV-YT). The seven hrs range from 390 to 880 bp in length and consist of 1–7 repeat units of approximately 72 bp, each containing a 30 bp palindrome with an EcoRI site. Structural diversity among the hrs includes variable numbers of stem–loop motifs, major late transcription factor (MLTF) sites, cAMP response elements (CRE-like), and 12-O-tetradecanoylphorbol 13-acetate (TPA)-response elements (TRE-like). Functional assays using luciferase reporter plasmids revealed that all seven hrs function as potent transcriptional enhancers for both homologous and heterologous promoters in vitro and in vivo. In BmN cells and fifth-instar silkworm larvae, the hrs enhanced the homologous ie1 promoter 11–1258-fold and 43–1545-fold, respectively, with hr2L showing the strongest activity (counts per minute: 4.82 × 108 in cells; 7.08 × 107 in larvae) and hr4R the weakest. Similarly, when driving the heterologous AcMNPV ie1 promoter in Sf21 cells and larvae, enhancement ranged from 19- to 1023-fold and 13- to 449-fold, respectively, again with hr2L and hr3 showing maximal effects and hr4R minimal enhancement. Notably, all the hrs, except hr4R, also stimulated the homologous late p10 promoter, with activation levels of up to 37.7-fold in vitro and 79.2-fold in vivo, significantly above baseline. However, hr4R showed negligible or no enhancement (0.84–1.05-fold). Among all the active hrs, hr5 emerged as the most potent enhancer of the p10 promoter. Spearman’s correlation analyses demonstrated that enhancer efficiency for all three promoters (homologous ie1, heterologous ie1, and homologous p10) correlated significantly with the number of palindromic sequences, the combined count of CRE and TRE motifs, and the total number of characteristic sequences (r = 0.873–0.982, p < 0.05 or p < 0.01). Collectively, our findings clarify the structural features of hrs from the newly isolated strain BmNPV-YT, systematically identify their promoter preferences and host adaptability as transcriptional enhancers, and establish their structure–function relationships. These findings provide novel insights into the transcriptional regulation of baculoviruses and offer valuable tools for optimizing baculovirus expression vector systems.

In the published publication [...]

There remains a significant gap in production performance and disease resistance between silkworms reared on artificial diets and those reared on mulberry leaves. This study aims to identify key differential proteins through proteomic analysis of the midgut of silkworms fed artificial diets compared to those fed mulberry leaves. Utilizing molecular docking technology, three anti-nutritional factors that consistently bind to the UGT40B4, UGT340C2, and UGT40A1 proteins were selected, and the differential expression of these UGT genes in response to various anti-nutritional factors was examined. The findings indicate that variations in feed significantly influence the expression of digestive, metabolic, and immune-related proteins within the silkworm midgut. Notably, the expression levels of the UGT40B4, UGT340C2, and UGT40A1 genes vary across different silkworm organs and developmental stages, reflecting their respective physiological roles. Furthermore, the effects of soybean isoflavone, tannic acid, and arabinoxylan on silkworm growth and cocoon quality were found to differ when these substances were incorporated into semi-synthetic feed. This research is anticipated to provide valuable insights for future studies on the role of UGT genes in the silkworm midgut and the formulation of artificial diets for silkworms.

In recent years, the use of artificial diet to rear silkworm Bombyx mori (L.) (Lepidoptera: Bombycidae) has advanced rapidly in China. However, significant differences are found in the production and performance of silk from silkworms reared on artificial diet and mulberry leaves, thereby affecting the development of artificial diet usage in sericulture. To understand the reasons for these differences, we tested the following 3 rearing methods: all-instar mulberry leaf rearing (Mul), all-instar artificial diet rearing (Diet), and instars 1-3 reared on artificial diet followed by instars 4-5 reared on mulberry leaf (Mix). The results showed that the silk production was significantly lower under Diet than Mix and Mul. Electron microscopy images revealed that the protein synthesis and energy supply were decreased under Dier and Mix compared with Mul. Subsequent strength analysis indicated that the relative strength of silk was highest under Mix, followed by Mul, and weakest under Diet. However, no significant differences in elongation were observed among treatments. The beta-sheet content of silk was significantly higher under Mix than Diet and Mul, and a similar trend was observed for the crystallinity. Furthermore, the elevated expression of BmChiNAG and the reduced expression of BmTpn genes may be a significant factor for the notable disparities in cocoon silk fineness and strength among the threes. These findings provide deep insights into the differences in silk produced by silkworms reared on mulberry leaves and artificial diet, as well as providing a reference for improving artificial diet for rearing silkworms.

Bombyx mori nucleopolyhedrovirus (BmNPV) is highly contagious and poses a serious threat to sericulture production. Because there are currently no effective treatments for BmNPV, a rapid and simple detection method is urgently needed. This paper describes an electrochemical immunosensor for the detection of BmNPV. The immunosensor was fabricated by covalently immobilizing anti-BmNPV, a biorecognition element, onto the surface of the working gold electrode via 11-mercaptoundecanoic acid (MUA)/beta-mercaptoethanol (ME) hybrid self-assembled monolayers. Electrochemical impedance spectroscopy (EIS) and atomic force microscopy (AFM) were used to characterize the electrochemical performance and morphology of the immunosensor, respectively. Under optimum conditions, the developed immunosensor exhibited a linear response to BmNPV polyhedrin in the range of 1 x 102-1 x 108 fg/mL, with a low detection limit of 14.54 fg/mL. The immunosensor also exhibited remarkable repeatability, reproducibility, specificity, accuracy, and regeneration. Normal silkworm blood was mixed with BmNPV polyhedrin and analyzed quantitatively using this sensor, and the recovery was 92.31 %- 100.61 %. Additionally, the sensor was used to analyze silkworm blood samples at different time points after BmNPV infection, and an obvious antigen signal was detected at 12 h post infection. Although this result agreed with that provided by the conventional polymerase chain reaction (PCR) method, the electroanalysis method established in this study was simpler, shorter in detection period, and lower in material cost. Furthermore, this innovative electrochemical immunosensor, developed for the ultra-sensitive and rapid detection of BmNPV, can be used for the early detection of virus-infected silkworms.

Herein, we report the successful development of a highly selective molecularly imprinted gel (MIG)-based electrochemical sensor for the simultaneous detection of vanillin (VAN) and tartrazine (TZ) in foods. A glassy carbon electrode (GCE) was first modified with conductive CuS@COOH-MWCNTs, after which the obtained CuS@COOH-MWCNTs/GCE was further functionalized by deposition of a molecularly imprinted chitosan-based gel crosslinked and stabilized using benzidine. The MIG allowed specific recognition of VAN and TZ, whilst the CuS@COOH-MWCNTs component was used for signal amplification. Under optimized testing conditions, the developed MIG-CuS@COOH-MWCNTs/GCE sensor allowed simultaneous detection of VAN and TZ, showing a linear response over the concentration range 0.03-125 mu M. Limits of detection were 0.006 mu M and 0.005 mu M, respectively. Analysis of liqueur and white vinegar samples spiked with VAN and TZ using the developed sensor afforded excellent recoveries (92.2%-109.7%). Further, the sensor was successfully applied to analyze the content of VAN and TZ in two kinds of vanilla ice cream, with results consistent with analyses performed using a national standard method.

Herein, a molecularly imprinted surface-enhanced Raman spectroscopy (SERS) sensor was developed for the selective capture and sensitive detection of tryptamine in foods. The SERS sensor exploited silver nanoparticle-decorated TiO2 (TiO2@Ag) substrates for Raman signal enhancement via synergistic effect of electromagnetic enhancement and photoinduced charge-transfer, whilst surface functionalization with the molecularly imprinted polymer ensured selective tryptamine capture. The SERS spectrum of tryptamine on the sensor closely matched that predicted by density functional simulations. The SERS intensity for tryptamine on the developed TiO2@Ag@MIP sensor increased linearly with the logarithm of the tryptamine concentration over the range of 10-6-10-2 mol L-1, with a LOD of 4.85 × 10-7 mol L-1. Tryptamine was detected in a spiked white vinegar sample, and its recoveries were in the range of 92.00%-111.40%. The SERS sensor could be used for the detection of tryptamine in actual samples.

微酸性电解水作为一种安全、高效、广谱的新型消毒剂,具有制备简单、成本低、使用后无残留、对人体无毒无害等优点.研究微酸性电解水对家蚕黑胸败血芽孢杆菌的杀灭效果及其杀菌机制,为其在蚕桑生产中的应用奠定基础.体外抑菌试验结果表明,有效氯质量浓度为40 mg/L、pH5.5、氧化还原电位(ORP)为1100 mV的微酸性电解水处理5 min即可全部杀灭家蚕黑胸败血芽孢杆菌.生物学试验结果表明,该电解水对家蚕黑胸败血芽孢杆菌处理5 min后,家蚕黑胸败血芽孢杆菌的灭活率达到90％;处理15 min时,灭活率为100％.经微酸性电解水处理后,家蚕黑胸败血芽孢杆菌的外部形态发生改变,菌体膨胀、逐渐伸长,之后出现孔洞,最后菌体破裂、死亡;胞外电导率、可溶性蛋白含量和可溶性糖含量逐渐增加;菌体DNA发生降解.试验结果表明微酸性电解水主要通过破坏家蚕黑胸败血芽孢杆菌细胞外部形态,改变细胞膜通透性,导致细胞内容物外渗,DNA结构受到破坏,达到杀菌目的 .

在充分调研齐河古晏农庄区位优势与自然资源等现状基础上,制定了该园区的总体发展规划,提出了以桑基鱼塘循环农业为主导,以传承“一带一路”蚕桑丝绸文化为骨架,以蚕桑绿色有机产品为突破口,将农庄建设成为集蚕桑生产、科普教育、科技示范、休闲康养于一体的零污染循环农业型蚕桑生态园的总体定位.将整个农庄按照“一带(滨水生态景观带)、两心(游客服务中心和蚕桑产品研发中心)、两馆(养蚕技术馆和丝绸博览馆)、三区(桑基鱼塘生态区、桑树种植区、葡萄种植区)”进行规划与建设,并提出了各分区建设内容和功能分区设计方案.

为探讨非杂交桑品种嫁接苗采用高密度草本式栽培的丰产性能和养蚕效果,利用发条能力较强的农桑14号嫁接桑进行了高密度草本式栽培建立桑园(简称农桑14号草本桑,90 000株/hm2)的试验,以桂桑优12号杂交桑草本式栽培建立桑园(简称桂桑优12号草本桑,105 000株/hm2)和育71-1嫁接桑普通栽植低干养成建立桑园(简称育71-1普栽桑,24 000株/hm2)为对照,调查了3种桑园第1～5年的产叶量指标,并进行了养蚕鉴定.结果 表明,建桑园第1～3年,试验区农桑14号草本桑的片叶产量比对照区桂桑优12号草本桑低10.42％ ～ 14.87％,但第4年和第5年,农桑14号草本桑的片叶产量分别比桂桑优12号草本桑提高8.81％和5.18％,5年单株总产叶量农桑14号草本桑比桂桑优12号草本桑高16.04％,5年合计经济系数(片叶质量与条叶总质量之比)农桑14号草本桑比桂桑优12号草本桑高8.87％.无论是农桑14号草本桑还是桂桑优12号草本桑,各年度产叶量均高于育71-1普栽桑.建园第1年(2013年)秋蚕期和建园第2年(2014年)春蚕期的养蚕试验结果表明,农桑14号草本桑条桑育成绩均优于桂桑优12号草本桑,与育71-1普栽桑片叶育的效果相当.本试验结果说明,利用耐剪伐的嫁接桑品种,采用高密度草本式栽培可以实现速生丰产和桑叶优质.

In this work, a molecularly imprinted sensor employing copper sulfide (CuS) as a novel signal probe was successfully developed for ultrasensitive and selective determination of sulfathiazole (STZ). The reduction signals of Cu2+ produced in the process of electron transfer of CuS containing large amounts of Cu2+ are easy to be captured, which provide high electrochemical signals. Moreover, gold nanoparticles@covalent organic framework with excellent conductivity was introduced on the electrode surface for signal amplification and facilitating electron transfer processes of CuS. Under optimized testing conditions, the proposed sensor offered a linear DPV response to STZ over a very wide concentration range (1.0 x 10(-4) to 1.0 x 10(-11) mol L-1), with a limit of detection of 4.3 x 10(-12) mol L-1. Fodder and mutton samples spiked with STZ were analyzed using this sensor, and the satisfactory recoveries ranging from 83.0% to 107.2% were obtained. In addition, the proposed sensor was used to determine the concentration of STZ in chicken liver and pork liver, with quantification results being near identical to those determined by high-performance liquid chromatography.

盐酸左旋氧氟沙星是第3代喹诺酮类药物氧氟沙星的左旋体,抗菌活性高.5龄第2天健康及感染黑胸败血芽孢杆菌(Bacillus bombysepticus,Bb)家蚕幼虫用500 μg/mL盐酸左旋氧氟沙星药液浸渍的桑叶添食处理后,采用超高效液相色谱测定健康家蚕和感病家蚕血淋巴中的药物浓度,用DAS 2.0处理软件分析得到药物动力学参数,为生产上合理使用该药物防治家蚕细菌病提供科学依据.结果 表明健康家蚕和感染Bb的家蚕添食盐酸左旋氧氟沙星后的血药经时过程均符合一级吸收一室开放式模型,健康家蚕的药动学参数吸收速率常数(Ka)为(0.507±0.032) h-1,吸收半衰期(T1/2K)为(1.425±0.017)h,最高血药浓度(Cmax)为(5.352±0.155) μg/mL,说明蚕体对盐酸左旋氧氟沙星吸收良好,血药浓度高;与健康家蚕相比,感染Bb家蚕的Ka由0.507 h-1降至0.386 h-1,T1/2Ka由1.425 h延长至1.798 h,药-时曲线下面积(AUC)从38.770μg/(mL·h)降为35.909 μg/(mL·h),分布半衰期(T11/2α)由1.679 h缩短为1.483 h,消除半衰期(T1/2β)由4.922 h降为2.450 h,说明Bb感染家蚕后导致药物在蚕体内的吸收减慢,吸收能力下降,代谢和消除加快.建议生产上用盐酸左旋氧氟沙星防治Bb感染引发的家蚕细菌病时,可适当提高药物剂量和增加给药次数,使蚕体内药物浓度维持在较高水平,保证良好的防治效果.

In this study, we used 2-(diethexyphosphoryl)acetic acid as a common template molecule and Fe3O4@SiO2 as support material to prepare a superparamagnetic core/shell molecular imprinting polymer (MIP), Fe3O4@SiO2@MIP, which has multiple recognition sites and increased adsorption capacity. Then, a biomimetic fluorescence immunoassay method was developed for the simultaneous determination of methyl parathion, chlorpyrifos, and trichlorfon using the Fe3O4@SiO2@MIP as biomimetic antibody and quantum dots as label. The factors that influenced the performance of this method were optimized. Under optimal conditions the limits of detection of the method were 0.21 ± 0.021, 0.44 ± 0.069 and 0.32 ± 0.033 μg/L for methyl parathion, chlorpyrifos, and trichlorfon, respectively. To evaluate the accuracy of the method, apple and orange samples spiked with methyl parathion, chlorpyrifos, and trichlorfon were analysed, and the recoveries ranged from 73.1% to 119.3%. Finally, this method was applied to detect three pesticides in pear, carrot, kiwifruit, and banana samples, and the results indicated a good correlation with those obtained from gas chromatography method.

The insecticide acetamiprid is widely used in controlling agricultural pests.The acute toxicity and chronic toxicity of acetamiprid to silkworm (Bombyx moii) were tested by using food intake method.Results of acute toxicity bioassay showed that 96 h median lethal concentration (LC50) of acetamiprid to the 3rd,the 4th and the 5th instar were 0.361,0.692 and 1.339 mg/L,respectively,indicating that acetamiprid is a high-risk or ultra-high-risk grade poison to silkworm.After treating the 3rd instar newly exuviated silkworm larvae continuously with low concentration of acetamiprid,the duration of each instar was prolonged,and the body weight of moulting or matured larvae,cocoon weight,cocoon shell weight and cocoon shell rate were all adversely affected.In addition,when the 3rd instar newly exuviated larvae were treated with acetamiprid of ≥ 0.011 mg/L,the superoxide dismutase (SOD) activity in larval midgut of day 6 of the 5th instar larvae was significantly activated (P ＜ 0.05),while the catalase (CAT) activity was markedly inhibited (P＜0.05).The activity of glutathione peroxidase (GSH-Px) was improved by low concentration (0.005-0.022 mg/L) of acetamiprid but was inhibited by high concentration (0.045 and O.090 mg/L) of acetamiprid.The results indicate that acetamiprid has extremely high risk to sericultural production and should be used in sericultural areas with caution Under high concentration,although SOD activity of silkworm larvae was activiated,but CAT and GSH-Px activities of silkworm larvae were both inhibited.This is the reason that acetamiprid can do harm to silkworm growth and development and to cocoon production.

使用胶体金免疫法原理的吡虫啉速测卡对桑叶吡虫啉农药残留进行检测,具有快速高效、灵敏度高、环境要求低、易于操作等优点.试验结果表明,吡虫啉速测卡可以检测出桑叶中96 h内的微量吡虫啉农药残留,检测浓度可达0.05 m g/L;经过家蚕生物鉴定和高效液相色谱检测,确定了吡虫啉速测卡检出结果的可靠性,明确了吡虫啉农药快速检测卡可以有效且快速的检测出桑树中的吡虫啉农药残留,服务于蚕业生产.

Imidacloprid, a widely used neonicotinoid insecticide, is toxic to silkworm (Bombyx mori). To explore whether N-acetyl-l-cysteine (NAC) has an effect on preventing silkworm (B. mori) from toxification caused by imidacloprid, we fed the fifth-instar larvae with mulberry leaves dipped in 200 mg/L NAC solution before exposing in imidacloprid, and investigated the silkworm growth, survival rate, feed efficiency, cocoon quality, and the activities of antioxidant enzymes in midgut. The results showed that addition of NAC could significantly increase body weight, survival rate, and feed efficiency of imidacloprid poisoned silkworm larvae (P < 0.05), as well as cocoon mass, cocoon shell mass, and the ratio of cocoon shell (P < 0.05). Furthermore, it could significantly promote the activities of the antioxidant enzymes including superoxide dismutase, catalase, and glutathione peroxide in the midgut of fifth-instar larvae under imidacloprid exposure at the late stage of treatment. In addition, it also could downregulate the malondialdehyde content. The results of our findings proved that the added NAC may have some beneficial effects on protection or restoration of antioxidant balance in imidacloprid exposed larvae.

The type Ⅱ diabetic model rats were consecutively treated with polysaccharide MLPⅡ extracted from mulberry leaves for 5 weeks.The ultrastructure of pancreatic β-cells was observed under electron microscope.The changes of nuclear transcription factor KB (NF-κB) was detected by immunohistochemistry.Meanwhile,the changes on protein expression level and gene transcription level of tumor necrosis factor α (TNF-ω and insulin 2 (INS-2) were detected by Western blotting and semi-quantitative RT-PCR.Compared with the rats of diabetic model control group,the injury to ultrastructure of pancreatic β-cells in MLPⅡ treated rats was obviously alleviated,the expression of NF-κB in pancreatic β-cells was obviously reduced,the expression of TNF-α protein and transcription of TNF-α mRNA in pancreatic tissue were significantly decreased (P＜0.01),whilst the expression of INS-2 protein and transcription of INS-2 mRNA in pancreatic tissue were significantly increased (P＜0.01).The results show that mulberry leaf polysaccharide MLPⅡ could obviously ameliorate the oxidative stress injury to pancreas of diabetic rats possibly through a mechanism related with decreasing the expressions of NF-κB and TNF-α in pancreas.

There is potential risk to silkworm (Bombyx mori) health due to pesticide residues in mulberry field through enrichment by mulberry.A bacterial strain H2,which can degrade acetamiprid that is extremely hazardous to silkworm,was isolated from mulberry field with long-term pollution of pesticides using enrichment culture and streak plate method.Based on the morphological,physiological and biochemical characteristics and the phylogenetic analysis to 16S rDNA sequence,this bacterial strain was identified as Pseudomonas alcaligenes.The maximum tolerant concentration of this bacterium to acetamiprid was 1 200 mg/L.Cultivated in inorganic salt medium with 300 mg/L acetamiprid,the bacterial growth had a lag phase at 0-1 d,a log phase at 1-4 d,a stationary phase at 4-6 d,and a decline phase after 6 d.After 9 d culture in inorganic salt medium with initial acetamiprid concentration of 300 mg/L,the degradation rate of acetamiprid was 62.7％ It was also found that this bacterium could grow in inorganic medium containing 1 000 mg/L imidacloprid,1 000 mg/L nitenpyram,1 000 mg/L thiacloprid and 500 mg/L phoxim respectively,demonstrating its effectiveness in degrading various neonicotinoid and organophosphorus pesticides.Therefore,it is promising to further develop this bacterium into microbial degradation agents against neonicotinoid and organophosphorus pesticides in mulberry field.