In this study, we investigated the protective effects of CPP-C3M4 against Salmonella-induced hepatic injury in lambs. Thirty 72-day-old Hu sheep were randomly divided into five groups: the control group (CON), the Salmonella-infected group (ST), and three CPP-C3M4 pretreatment groups at low, medium and high doses (CPP-C3M4-L, CPP-C3M4-M, and CPP-C3M4-H). The results showed that administration of CPP-C3M4 via duodenal fistula significantly alleviated liver enlargement and histopathological damage caused by Salmonella infection. CPP-C3M4 improved liver function by reducing alanine aminotransferase (ALT), aspartate aminotransferase (AST), and triglyceride (TG) levels. It enhanced the liver antioxidant capacity by increasing glutathione peroxidase (GSH-Px), catalase (CAT), and superoxide dismutase (SOD) activities. It also alleviated inflammatory responses by downregulating the mRNA expression of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-2 (IL-2), toll-like receptor 2 (TLR2), and toll-like receptor 9 (TLR9). Transcriptomic Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis further confirmed that CPP-C3M4 exerts its protective effects by suppressing multiple inflammatory pathways, with the interleukin-17 (IL-17) signaling axis being a key target of regulation. These results indicate that CPP-C3M4 is a promising alternative antimicrobial substance for preventing and alleviating Salmonella-induced liver injury in lambs.

The aim of this study was to investigate the effects of sodium butyrate on the morphology, antioxidant capacity, mitochondrial integrity, and transcriptome in the jejunum of early weaned lambs. Ten 21-day-old healthy weaned lambs with an average weight of (6.53 ± 0.17) kg were selected for the experiment and randomly divided into a control group (CON) and a sodium butyrate group (NaB). The experimental lambs were fed with basic diet (CON) and experimental diet (NaB, supplement with 3 g/kg of coated sodium butyrate in the basic feed) for 21 days. The results showed that the addition of sodium butyrate significantly increased villus height (p < 0.05) and total antioxidant capacity (p < 0.05) in the jejunum of lambs, significantly reduced malondialdehyde content (p < 0.05) and the accumulation of reactive oxygen species (p < 0.05) in jejunum tissue, and maintained the integrity of mitochondrial structure. The transcriptome analysis of jejunal tissue showed that the addition of sodium butyrate into weaned lambs’ diets significantly altered the expression of genes and pathways related to jejunal metabolism (p < 0.05). In summary, the addition of sodium butyrate improved the intestinal health of early weaned lambs and maintained intestinal metabolic function. The research results provide a foundation for the application of sodium butyrate to improve intestinal health of lambs during early weaning phase.

Weaning is an important period in the growth and development of lambs. Thus, effectively reducing the occurrence of weaning stress is critical for maintaining lamb production. Coated sodium butyrate has been shown to reduce inflammation, promote intestinal health, and maintain homeostasis. However, the application and potential mechanism of coated sodium butyrate in alleviating weaning stress in lambs are still unclear. To evaluate the effects of coated sodium butyrate on the growth performance, antioxidant capacity, and gut microbiota of weaned lambs, 10 weaned lambs of 21-day-old were randomly divided into two groups: the CON group (basal diet) and the NaB group (basal diet +3 g/kg of coated sodium butyrate). The trial lasted 21 days. The experimental results showed that compared to the CON group, coated sodium butyrate supplementation in the diet significantly increased the average daily weight gain and daily feed intake of lambs (p < 0.05). In addition, compared to the CON group, the addition of coated sodium butyrate also significantly decreased the serum MDA level of lambs (p < 0.05). Notably, the addition of coated sodium butyrate did not have a significant effect on the cecal microbiota, while increasing the diversity of colonic microbiota and promoting the abundance of Lachnospiraceae, Verrucomicrobiota, Akkermansia, Roseburia, and Sinobacteraceae, which are associated with the nutrient absorption of lambs (p < 0.05). These results indicate that dietary supplementation with coated sodium butyrate could promote the growth and antioxidant capacity of weaned lambs and alleviate weaning stress.

Cr(VI) is a common hazardous heavy metal contaminant that seriously endangers human and aquatic animal health. GPX4 was the key enzyme that reduces heavy metal toxicity through inhibiting ferroptosis pathway. Astaxanthin was GPX4 activator that can weaken biological toxicity induced by Cr(VI) exposure. The present study was conducted to evaluate the major role of GPX4 in astaxanthin protects Cr(VI)-induced oxidative damage, blood-brain barrier injury and neurotoxicity in brain-liver axis through inhibiting ferroptosis pathway. In the current study, astaxanthin intervention can effectively alleviate Cr(VI)-induced oxidative stress, blood-brain barrier damage, and neurotoxicity. GPX4 plays a major role in mediating astaxanthin nutritional intervention to reduce ROS and liver non-heme iron accumulation, which would contribute to the reduction of ferroptosis. Meanwhile, astaxanthin maintains the stability of transport receptors and protein macromolecules such as TMEM163, SLC7A11, SLC3A2, FPN1 and GLUT1 in the brain liver axis, promoting substance exchange and energy supply. Moreover, astaxanthin alleviates Cr(VI)-induced neurotoxicity by promoting tight protein expression and reducing blood-brain barrier permeability.

为解决抗菌药物不能穿透细胞膜杀伤胞内致病菌的问题,本试验以羊小肠(空肠段)上皮细胞为靶细胞,利用噬菌体展示技术4轮体外生物淘洗,系统地筛选羊小肠上皮细胞的特异性穿透肽,将其作为抗菌肽的载体从而提高抗菌肽的穿透能力.试验采用噬菌体展示技术,经过4轮体外生物淘洗,得到了能与羊小肠上皮细胞结合的多肽;4轮减数筛选后,噬菌体的回收率逐渐提高,特异性的噬菌体克隆得到了有效富集,酶联免疫吸附法(ELISA)测定单克隆噬菌体对羊小肠上皮细胞的亲和力,亲和力≥2的为阳性,筛选阳性噬菌体克隆,提取DNA进行测序,选择高重复率序列,合成细胞穿透肽,同时合成与细胞穿透肽的氨基酸序列及结构相同但组合顺序不同的对照多肽,并与异硫氰酸荧光素(FITC)标签连接.用细胞增殖/毒性检测试剂盒(CCK8)测定细胞穿透肽和对照肽对细胞活力的影响,用荧光显微镜初步观察穿透肽的穿透性,用激光共聚焦显微镜及流式细胞仪检测穿透肽在胞内的定位及穿透强度.结果表明:经4轮体外减数筛选噬菌体的回收率增长了 226倍,随着第1轮至第4轮筛选轮次增加,与羊小肠上皮细胞结合的噬菌体依次增加;使用ELISA进行检测,结果显示,在随机挑选的30个单克隆噬菌体中,22个检测为阳性克隆(亲合力≥2);提取阳性克隆噬菌体进行DNA测序分析后,得到2条重复率高的氨基酸序列,VLNSLID命名为SCPP1,HSTTAQF命名为SCPP2;细胞活力结果表明,在浓度低于256 μmoVmL时2条细胞穿透肽及其对照多肽的细胞活力仍在90％以上,表明对细胞无毒;荧光显微镜下观察及激光共聚焦结果表明,SCPP1和SCPP2可以特异性穿透羊小肠上皮细胞膜,且SCPP1可以穿透细胞核表现出比SCPP2更强的穿透性,2条对照多肽无穿透能力;流式细胞仪结果显示,SCPP1的胞内平均荧光强度明显高于SCPP2,且呈时间剂量依赖.本试验筛选出了安全可特异性穿透羊小肠上皮细胞的穿透肽(SCPP1),可作为治疗羊肠道胞内菌的抗菌肽的载体.

为辅助抗菌药物进入动物细胞杀伤胞内致病菌,本试验利用噬菌体展示技术筛选猪小肠上皮细胞的穿透肽.通过噬菌体展示技术进行 4 轮体外生物淘洗,得到与猪小肠上皮细胞结合的多肽;经过 4 轮减数筛选,噬菌体回收率逐渐提高,酶联免疫吸附法(ELISA)测定单克隆噬菌体对猪小肠上皮细胞的亲和力,亲和力≥2 的为阳性,将阳性噬菌体克隆提取DNA,将高重复率序列合成细胞穿透肽,同时合成与其氨基酸序列及结构相同但组合顺序不同的对照多肽,荧光FITC标签连接.检测多肽的抑菌活性、溶血活性和细胞毒性,荧光显微镜观察穿透肽的穿透性、激光共聚焦显微镜及流式细胞仪检测穿透肽在胞内的定位及强度.结果表明:4 轮筛选噬菌体的回收率增长 283 倍;ELISA检测显示,随机挑选 30 个单克隆噬菌体,17 个为阳性克隆;DNA测序得到 2 条高重复序列,SAYKMMA命名ICPP1 和SSSISGL命名ICPP2;穿透肽及对照多肽无抑菌活性,溶血性较好,安全无毒对细胞活力无影响;荧光显微镜观察及激光共聚焦结果表明,ICPP1 和ICPP2 可穿透猪小肠上皮细胞膜,且ICPP1 表现出更强的穿透性;流式细胞仪结果显示,ICPP1 的胞内平均荧光强度明显高于ICPP2,且呈时间剂量依赖,有较好的热稳定性和较低的血清稳定性.本试验筛选出了安全可穿透猪小肠上皮细胞的穿透肽(ICPP1),可作为治疗猪肠道胞内菌的抗菌肽的载体.

Antimicrobial peptides (AMPs) are attracting attention in the fields of medicine, food, and agriculture because of their broad-spectrum antibacterial properties, low resistance, and low-residue in the body. However, the low yield and instability of the prepared AMP drugs limit their application. In this study, we designed a tetramer of the AMP CC34, constructed and transfected two recombinant expression vectors with pGAPZαA containing a haploid CC34 and tetraploid CC34 (CC34-4js) into Pichia pastoris to explore the effect of biosynthesized peptides. The results showed that CC34 and CC34-4js expression levels were 648.2 and 1105.3 mg/L, respectively, in the fermentation supernatant of P. pastoris. The CC34-4js tetramer showed no antibacterial activity, could be cleaved to the monomer using formic acid, and the hemolytic rate of the polyploid was slightly lower than that of monomeric CC34. The average daily gain, average daily feed intake, feed conversion ratio and immune organ index of rats fed CC34 and CC34-4js showed no differences. In conclusion, CC34-4js exhibited a higher yield and lower hemolysis in P. pastoris than those of CC34. Finally, CC34 and CC34-4js enterokinase lysates showed similar antibacterial activity and both expressed peptides potentially improved the growth performance and organ indices of rats.

试验旨在研究添加发酵玉米蛋白粉(FCGM)替代豆粕对育肥羊生长性能、屠宰性能及瘤胃发酵的影响.选取48只体重(33.81±0.46)kg的健康小尾寒羊×澳洲白绵羊F1 代雄性杂交绵羊.随机分为4组,每组12只.对照组饲喂基础日粮,试验组分别用FCGM替代试验饲粮中 25％、50％、75％的豆粕.饲养全期饲粮精粗比为 7:3.试验期 70 d,其中预试期 10 d,正试期 60 d.结果表明:1～60 d,25％组平均日增重(ADG)高于对照组(P＜0.05);各试验组全期耗料增重比(F/G)均低于对照组;25％组胴体重和屠宰率最高(P＜0.05);75％组瘤胃液pH高于其他各组(P＜0.05),25％组和 50％组瘤胃液氨态氮高于 75％组(P＜0.05),50％和75％组丁酸浓度低于 25％组和对照组(P＜0.05).可见,FCGM替代日粮中的豆粕可以提高育肥羊的生长性能和屠宰性能,促进瘤胃发酵,用 25％替代量效果最佳.

Background: Industrial production is increasingly reliant upon recombinant microorganisms across sectors. Therefore, it is of great importance for long-term operational viability that care be taken in optimizing the preparation of operationally key organisms. In electrotransformations, low-frequency electric field pulses increase yeast cell viability but decreases their transmembrane of recombinant DNA vectors. Herein, we investigated the optimal parameters for transforming pGAPZ alpha A-CecMd3cs into Pichia pastoris GS115 and obtaining the efficient production of recombinant cells of interest. Results: For an initial experiment, we utilized a single-factor experimental design to perform the electroporation and measure the vector transformation efficiency in triplicate, identified three out of five voltages (250-350 V), pulse durations (9-17 ms), and pulse frequencies (1-5 pulses) as candidate values for further analysis. Based on this data, we obtained the optimal value for each parameter by utilizing Box-Behnken of response surface methodology statistical modelling. We found that under a fixed voltage, the primary factors affecting electrotransformation efficiency were pulse duration and frequency. Furthermore, we identified synergistic interactions between pulse length and voltage and between pulse length and frequency. Conclusions: The optimal parameters for electroporation are 275 V and 3 pulses of a 15-ms duration. We bioinformatically determined the optimal transformation parameters. (c) 2022 Pontificia Universidad Catolica de Valparaiso. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Rumen protected amino acids are supplements that can enhance ruminal performance, yet the coating designed to protect the amino acids might also lead to different effects. Methionine is an essential methyl donor to synthesize protein, and little data exists on the effects of coating materials on its bioavailability. The purpose of this study was to estimate the effect of rumen-protected methionine (RPM) coatings with different ratios of acrylic resin IV (AR), ethyl cellulose (EC), and a mixture of AR and EC (AREC). Fifteen RPMs were prepared according to a single factor design, with 5 proportions each of AR, EC, and AREC to DL-methionine (DL-Met). Twelve hybrid small-tailed Han sheep with rumen fistula were utilized to evaluate in situ escape of RPMs, followed by in vitro abomasum-intestinal release of the RPMs. The results showed a regular variation in both ruminal disappearance and gastrointestinal release of RPMs with different coating prototypes and retention time. The RPMs that were EC and AREC coated presented high bioavailability compared to those with AR. Bioavailability of RPMs was optimal with the 2:20 AREC: DL-Met ratio, when the proportion of AR:EC is 1:1. Additionally, RPMs with a 1:3 ratio of AR:EC confirmed the optimum effect for the RPM of 2:20 AREC: DL-Met. In conclusion, an RPM with a lower AREC ratio coating can achieve better bioavailability and is synergistic to those with EC and AR.

[目的]利用响应面分析法优化含活性肽CC34毕赤酵母重组菌的冻干营养保护剂组合配方.[方法]通过单因素试验,筛选脱脂乳粉、海藻糖、山梨醇和谷氨酸钠提高毕赤酵母重组菌存活率的最佳范围;利用Box-Behnken法建立毕赤酵母重组菌存活率回归方程,分析3种保护剂组合对菌体存活率的效应关系.[结果]脱脂乳粉浓度为10％时毕赤酵母重组菌冻干存活率最高,达到51.23％;海藻糖浓度为15％时冻干存活率最高,达到67.50％;山梨醇浓度为20％时冻干存活率最高,达到52.19％;谷氨酸钠浓度为3％时冻干存活率最高,达到36.92％.通过响应面法获得含活性肽CC34毕赤酵母重组菌冻干保护剂组合中脱脂乳粉、海藻糖、山梨醇的浓度分别为10.75％、15.70％、20.19％,通过最优模型预测毕赤酵母重组菌的存活率为77.00％,应用此最优保护剂组合进行冻干试验,菌体冻干存活率为78.98％.[结论]本试验通过响应面法优化了毕赤酵母重组菌复合冻干保护剂配方,在脱脂乳粉浓度为10.75％、海藻糖浓度为15.70％、山梨醇浓度为20.19％条件下,可获得较高的菌体冻干存活率(78.98％).该复合冻干保护剂可用于含活性肽CC34毕赤酵母重组菌的保存和后续试验研究.

Taraxacum mongolicum polysaccharide (TMP) is a highly effective anti-inflammatory and antioxidant agent, but it has not been studied in aquatic feed. Here, the objective of this study was to evaluate the effects of dietary TMP on the growth, digestive enzyme activity, immune response, antioxidant status, and the NF-KB, Nrf2 and TOR signalling pathway-related genes in Jian carp. The juvenile fish were randomly distributed into four groups according to the TMP concentrations (0, 0.5, 1.0 and 2.0 g/kg) for 56 days. Our results indicated that the growth, enzyme activity and immune factors in fish increased in a concentration-dependent manner, and the dietary supplementation with TMP (1.0 g/kg) increased the WG, SGR, PER, amylase, lipase and protease activity. Meanwhile, the serum immune response (except for ACP) and hepatopancreas antioxidant enzyme activity were positively regulated by TMP. However, MDA, PC, COR and LDH contents were negatively correlated with the dietary supplementation with TMP. Furthermore, the trend in the expression of genes related to the NF-KB, Nrf2 and TOR signalling pathways were similar to that of the enzyme activity, which increased with the increase in dietary supplementation with TMP (except for proinflammatory factors, tgf-beta and keap1). Among them, il-10, il-2, ho-1, nrf2, sod-(Cu-Zn) and gpx showed sharp increases. These results elucidate that dietary supplementation with TMP may greatly ameliorate the growth, digestive enzyme activity, immune response and antioxidant status and regulate the expression of NF-KB, Nrf2 and TOR signalling pathway-related genes in Jian carp.

In recent years, hexavalent chromium [Cr (VI)]has been widely used in the electrochemical industry, posing potential threat to aquatic animals The objective of this study was to investigate the toxic effects of waterborne Cr (VI) on hematology, digestive enzyme, redox state, and apoptosis in Cyprinus carpio. In this study, 300 C. carpio were randomly divided into four groups and exposure to 0 (Control), 0.5, 1 and 2 mg/L Cr (VI) for 28 days, respectively. The result showed that Cr (VI) exposure exerted significant toxic effects by reducing in the levels of hematology parameters (hemoglobin, erythrocytes) and serum calcium, increasing serum biochemistry (glucose, cholesterol and ALT), decreasing digestive enzyme (lipase and amylase). The waterborne Cr (VI) exposure significantly increased oxidative stress levels by increasing the levels of MDA, ROS and PC, interfering with the enzyme activities of antioxidant system (SOD, CAT, AHR, GSH, GSH-Px, GR and GST) and finally breaking the redox state in C. carpio. Additionally, our study found that waterborne Cr (VI) exposure induced intestinal and liver apoptosis in different ways was mainly related to death receptor pathway and mitochondrial pathway, respectively. Our results suggest that exposed to waterborne Cr (VI) above 0.5 mg/L has potential toxic effects in C. carpio. (c) 2022 Elsevier B.V. All rights reserved.

为探讨饲料中添加不同复合酶制剂对罗斯肉鸡血液理化指标、免疫器官指数及肠道菌群的影响.本研究用单因素设计,选390只零日龄健康罗斯肉鸡,随机分为5组,每组设6个重复,每个重复设13只鸡进行为期6周试验,设3段日粮.对照组饲喂基础日粮(代谢能依次为13.87、14.44、15.17 MJ/kg),试验I、II、III、IV组日粮添加复合酶量均为0.2 g/kg.结果表明:3周龄时,酶制剂IV组日粮鸡平均日采食量(ADFI)均高于其他酶制剂组(P<0.05),其日增重(ADG)高于酶制剂I、II组(P<0.05),与对照组无显著差异;6周龄时,相比对照组,酶制剂III组和IV组均提高肉鸡ADFI和ADG(P<0.05),II、III组鸡耗料重增比(F/G)降低(P<0.05);全试验期,采食IV组日粮鸡血清总蛋白(TP)、白蛋白(ALB)、磷(P)、血糖(GLU)含量均高于对照组(P<0.05),尿酸(UA)含量降低(P<0.05),3周龄采食IV组日粮鸡血清钙(Ca)含量最高;3周龄只有采食IV组日粮鸡的肝脏和胸腺指数高于对照组(P<0.05),其他各组间无显著差异;6周龄鸡胸腺指数变化与3周龄相同(P<0.05),采食酶制剂组日粮鸡的法氏囊和脾脏指数均高于对照组(P<0.05);在回肠和盲肠中,各酶制剂组相比对照组鸡的大肠杆菌菌落数均有所减少(P<0.05),乳酸杆菌和双歧杆菌菌落数均有所增加(P<0.05).可见,添加不同活性复合酶制剂均能提高肉鸡生长性能及血清蛋白、Ca、P等营养指标,提高免疫指数和有益菌数量;酶制剂IV组饲喂效果最佳,其次是酶制剂III组.

In this study, we aimed to assess the effects of probiotic administration on the digestibility characteristics and growth performance of finishing beef cattle fed a total mixed ration (TMR) containing different levels of corn stover. One hundred and sixty Simmental × Continental crossbred bulls were randomly allocated to two animal houses (80 bulls each) and randomly assigned four TMR differing in the level of corn stover-high (HCT) and low (LCT)-with or without probiotics in each animal house. Feeding HCT supplemented with probiotics increased (P < 0.05) the apparent digestibility of crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), and acid detergent fiber (ADF). Regardless of probiotic supplementation, the nitrogen intake and fecal nitrogen levels of animals fed HCT were lower than those fed LCT (P < 0.05). Additionally, feeding probiotics increased (P < 0.05) the efficiency of ruminal fermentation, final body weight, and average daily gain (ADG) of animals, with this effect being stronger in animals fed HCT. In conclusion, supplementing probiotics with HCT has a positive effect on the growth of finishing beef cattle, thereby providing economic benefits.

本试验旨在研究包膜丁酸钠(CSB)对脂多糖(LPS)刺激下断奶羔羊血清炎性细胞因子、肠道通透性及肠道组织形态的影响.试验选取(42±1)日龄、平均体重为(11.79±0.54)kg的断奶羔羊24只,按体重相近原则随机分为4组:空白组(CON组)、LPS组、CSB2L组、CSB3L组,其中CON和LPS组饲喂基础饲粮,CSB2L和CSB3L组在基础饲粮中分别添加2和3 g/kg CSB,每组6个重复,每个重复1只羊.在试验第28天每组选取3只羔羊进行屠宰,LPS、CSB2L和CSB3L组在屠宰前3 h腹腔注射100μg/kg BW LPS,CON组腹腔注射等量无菌生理盐水.结果表明:1)与CON组相比,饲粮中添加CSB可显著提高断奶羔羊的平均日采食量(ADFI)(P<0.05),CSB3L组的平均日增重(ADG)显著高于CON和LPS组(P<0.05).2)与CON组相比,LPS组断奶羔羊血清中肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)和白细胞介素-8(IL-8)含量显著升高(P<0.05).CSB2L和CSB3L组血清TNF-α 和IL-1β 含量均低于LPS组(P<0.05),血清TNF-α含量显著高于CON组(P<0.05).CSB3L组血清IL-8含量显著低于LPS组(P<0.05).CSB2L和CSB3L组血清白细胞介素-10(IL-10)含量显著高于LPS组(P<0.05).3)断奶羔羊血清中D-乳酸(DLA)含量和二胺氧化酶(DAO)活性在LPS刺激下显著升高(P<0.05).CSB2L和CSB3L组可显著降低LPS注射后的血清DLA含量和DAO活性(P<0.05).4)CON组肠黏膜形态结构完整且绒毛排列整齐.注射LPS后,空肠和回肠绒毛排列紊乱,高矮不一,绒毛肿胀脱落.CSB2L和CSB3L组空肠和回肠绒毛形态较完整且排列整齐,肿胀程度降低,上皮轻度脱落.LPS组盲肠部分肠绒毛上皮脱落,腺体排列紊乱,结肠绒毛略微脱落.CSB2L组盲肠和结肠有轻微水肿,CSB3L组盲肠和结肠绒毛上皮未见明显脱落和水肿.LPS刺激显著降低了空肠和回肠绒毛高度和绒毛高度/隐窝深度(P<0.05).CSB2L和CSB3L组空肠和回肠绒毛高度降低和绒毛高度/隐窝深度降低均得到缓解.CSB2L和CSB3L组十二指肠绒毛高度显著高于CON和LPS组(P<0.05),CSB3L组回肠绒毛高度和绒毛高度/隐窝深度显著高于CON组(P<0.05).由此可见,饲粮中添加CSB可以提高断奶羔羊的生长性能并能缓解LPS刺激引起的断奶羔羊应激,抑制血清促炎性细胞因子水平升高和肠道通透性增加,从而在一定程度上改善肠道组织形态,维护肠道健康.

玉米蛋白粉是一种优质的植物性蛋白质饲料,但其含有较多的不可溶性蛋白和抗营养因子,且氨基酸含量不平衡,动物不易吸收.微生物发酵可以改善玉米蛋白粉的营养价值,经过发酵可以降解玉米蛋白粉内的抗营养因子,提高氨基酸和可溶性蛋白的含量.文章综述了玉米蛋白粉发酵过程中的菌种选择、发酵工艺、发酵后的营养价值及其在动物生产中的应用.以期为发酵玉米蛋白粉在动物生产中的应用提供参考.

The objective of this study was to evaluate the toxic effects of Cr6+ on bioaccumulation, digestion, immunity, oxidative stress, apoptosis and inflammation-related genes in Channa asiatica. The fish was exposed to waterborne Cr6+ concentrations (0, 0.5, 1.0 and 2.0 mg/L) for 28 and 56 days. Our results demonstrated that the accumulation of Cr6+ in tissues increased in a concentration-dependent manner, and the content in tissue was liver > gill > gut > muscle. Meanwhile, Cr6+ exposure led to a remarkable suppression of digestion, immunity and antioxidant capacity in C. asiatica. Inversely, MDA and PC content were positively correlated with Cr6+ exposure concentration. Furthermore, the expression of genes went up with the increase of waterborne Cr6+ concentration. Among them, HSP90, NF-κB and TNF-α have a sharp increase. These results elucidate that waterborne Cr6+ exposure may induce bioaccumulation, inhibit digestion and immunity, promote oxidative stress and up-regulate the expression of apoptosis and inflammation-related genes in C. asiatica.

为研究含抗菌肽CC31毕赤酵母工程菌固态发酵生产高功能性蛋白质饲料工艺的优化,采用单因素试验设计筛选豆粕和麦麸最佳粒度;在最佳粒度的前提下利用DPS软件中均匀设计模型,拟合小分子蛋白浓度(Y)与接种量(X1)、含水量(X2)相关曲线.发酵结束测定小分子蛋白浓度并与预测值进行比较.同时对发酵饲料的营养成分进行分析.结果表明:最佳发酵粒度为40～60目,小分子蛋白浓度拟合曲线:Y=113.8745+0.9155 X1+1.1952 X2-0.0465 X1·X1-0.1167 X2·X2,R2=0.99,通过拟合曲线预测得出当接种量X1为9.85％,含水量X2为51.22％,小分子蛋白浓度(Y)的含量最高为148.99 mg·L-1.依据拟合曲线的最优接种量和含水量,设置接种量X1为10％,含水量X2为50％,试验得出小分子蛋白浓度为156.23 mg·L-1.与模拟曲线预测比较相对误差仅为4.63％.对其常规营养成分分析,发现能有效的增加粗蛋白含量,但对纤维的分解效果不明显.

昆虫抗菌肽是昆虫体内经诱导而产生的一类小分子碱性多肽物质,是昆虫先天免疫的重要效应分子,它具有不易形成耐药性、广谱抗菌、分子质量小等特点,并且对病毒、细菌、真菌、癌细胞具有杀伤作用.目前,在半翅目、鞘翅目、双翅目、膜翅目和鳞翅目等昆虫中都分离到了具有不同抗菌活性的抗菌肽.本文就昆虫抗菌肽的特点和种类、免疫机制、作用机制以及提高昆虫抗菌肽稳定性的策略进行综述,以期对昆虫抗菌肽的进一步研究和应用具有指导作用.