外源酶对家禽内源消化酶活性影响的研究进展

自从 2 0世纪中叶抗生素在饲料工业中应用以来 ,它们对畜牧业的发展起了巨大的推动作用 ;但其负面效应也日益明显 ,如产生抗药性和耐药性等。因此 ,研制和开发新的绿色饲料添加剂势在必行 ,酶制剂便为其中极为重要的一种 ,并且应用越来越广泛 ,国外甚至已将酶作为家禽日粮的常用成分。目前外源酶的添加效果及作用机理尚未完全确定 ,试验结果差异也较大。即使酶的添加对家禽生产性能仅起到较小的改善作用 ,但在大规模的集约化生产中 ,也会产生可观的经济效益和社会效益。现在的研究不仅局限于酶对家禽生产性能所产生的影响 ,而对它产生这种影…     

测定加酶日粮氨基酸表观消化率的Sibbald"TME"法比较研究

试验选用15羽伊莎成年公鸡,随机分成3组,采用添加和不添加酶制剂的加酶与常规对照两种日粮,按Sibbald“TME”法测定氨基酸表现消化率的要求,设计成常规日粮预试和强饲、常规日粮预试和加酶日粮强饲、加酶日粮预试和强饲3种程序,研究比较酶制剂及不同的测定程序对氨基酸测定结果的影响,并确定Ssibbald“TME”法测定加醇日粮氨基酸表现消化率的合理程序。研究结果表明：(1)预试常规日粮并强饲加酶日粮与强饲常规日粮相比较,提高了大部分氨基酸的表现消化率,总必需氨基酸及总氨基酸消化率分别提高了0．63％和1．70％;(2)预试并强饲加酶日粮与预试并强饲常规日粮相比较,可使绝大部分氨基酸的表观消化率均有所提高,总必需氨基酸及总氨基酸消化率分剐提高了2．49％和4．0l％;与预试常规日粮并强饲加酶日粮组相比,总必需氨基酸及总氨基酸消化率分剐提高了1．85％和2．28％。(3)采用Sibbald“TME”法测定家禽加酶日粮氨基酸消化率时预试采用加酶日粮为宜。     

饲用酸化剂防治家禽弯曲菌病的研究进展

弯曲菌作为全球腹泻病主要诱因之一,是一种以家禽为天然宿主的食源性病原菌。随着食品安全意识的提升及抗生素耐药性的逐年攀升,在养殖环节对家禽弯曲菌病的防治逐渐得到人们重视。而饲用酸化剂表现出提高饲料利用率、减少疾病发生、无污染、无残留等优势,已成为与益生素、酶制剂和微生物制剂等并列的重要绿色环保型添加剂,有利于减少抗生素的滥用。本文介绍了饲用酸化剂的分类、作用机制、及在防治家禽弯曲菌病的应用进展,并就饲用酸化剂的发展趋势进行了综述。     

谷朊粉酶解物对小鼠免疫功能的影响

研究了酶解谷朊粉小肽对小鼠免疫功能的影响.空白组饲粮中不添加谷朊粉或谷朊粉酶解物,对照组饲粮中添加未酶解的谷朊粉1 000 mg/(kg饲粮·d);Ⅲ、Ⅳ、Ⅴ组为试验组,饲粮中分别添加酶解谷朊粉500、750和1 000 mg/(kg饲粮·d),饲喂28 d后进行免疫指标测定.结果表明:Ⅳ组与其它各组相比,小鼠的SOD、GSH-PX、GLU、GPT、IgG、IgM、IL-2和IGF-I均提高显著,但IgA降低显著.添加酶解谷朊粉750 mg/(kg饲粮·d)对提高小鼠的免疫功能效果最佳.     

饲料用植酸酶制剂

植酸具有抗营养作用,单胃动物不能在消化过程中降解植酸。添加外源性植酸酶后,植酸得到降解,不权能显著地提高植酸中磷的利用率,还可减少动物粪便中磷对环境的污染。综述了饲用植物酶的性质、制备及其在饲料中的应用。     

饲用酶及处理方法

饲用酶及处理方法国内贸易部武汉科研设计院（４３００７０）程启芬饲料工业广泛应用高温预处理方法和添加酶来提高饲料的营养价值。目前试验证实综合使用上述两种方法能得到明显的协调作用。然而，在使用急剧饲料预处理技术如膨化工序时应特别注意对酶稳定性的影响。１饲...     

饲用酶应用进展

饲料中添加酶可帮助动物对饲料养分的消化吸收,大幅提高饲为产效率,促进动物生长。综术字木聚糖酶、β－葡聚糖酶,纤维素酶和植酸酶在饲料工业中的应用。     

家禽饲粮电解质平衡的研究与应用

概述了动物饲粮中的电解质平衡原理及其计算方法,国内外有关饲粮电解质平衡对营养物质的吸收和代谢、家禽体内的酸碱平衡、肉鸡生长和蛋鸡产蛋性能以及家禽产品质量的影响,饲粮电解质平衡与家禽代谢性疾病、抗热应激等方面的关系;介绍了家禽生产实践中饲粮电解质平衡的重要性及电解质平衡值的适宜范围.     

饲粮中添加非淀粉多糖酶对断奶仔猪生长性能和血清生化指标的影响

研究玉米型饲粮和小麦型饲粮中分别添加不同水平的非淀粉多糖酶（NSP酶、木聚糖酶和β-甘露聚糖酶）对断奶仔猪生长性能和血清生化指标的影响。结果表明：玉米型基础饲粮中添加NSP酶对仔猪的生长性能和血清生化指标无显著影响(P＞0.05）;小麦型基础饲粮中添加NSP酶,显著提高了断奶仔猪的平均日增重和血清中的总蛋白、球蛋白和磷的含量(P＜0.05）,显著降低了谷草转氨酶的活性(P＜0.05）。     

几种饲用酶制剂的添加效应

几种饲用酶制剂的添加效应湖南省益阳县农业局（４１３００２）熊谱成酶是具有生理活性的蛋白质，是一种生物催化剂，生物体内的各种生物化学反应几乎都是在酶的催化下进行的。在饲料中添加酶制剂，可强化消化力，增强动物体质，特别是对幼龄畜禽，可提高饲料营养成分的吸...     

Microbial enzymes for bioconversion of poultry waste into added-value products

The continuous growth of poultry industry results in an increased amount of waste provided from both production facilities and processing plants. The processing of poultry meat results in massive quantities of solid waste as feathers, viscera, bones, and dead on arrival. The use of enzymes for bioconversion of such byproducts into materials with increased value is an interesting strategy. Enzymes can be useful to convert poultry waste into feed and fertilizers. The hydrolysis of animal byproducts can also generate bioactive peptides, which are important molecules that may exert physiological effects in vivo, as antioxidant, angiotensin-I converting enzyme (ACE)-inhibitory and dipeptidyl peptidase-IV (DPP-IV)-inhibitory activities. Thus, poultry byproduct hydrolysates show potential for use as functional ingredients. This review presents an overview on useful microbial enzymes for bioconversion of poultry waste, such as proteases, lipases, combined enzyme preparations and, especially, keratinases for bioconversion of feathers. A discussion about production, purification and properties of keratinases is presented. Main areas for further studies are large scale production and purification of keratinases, and development of effective processes for production of bioactive molecules from poultry waste.     

Hydrolysis of galactooligosaccharides by commercial preparations of α-galactosidase and β-fruetofuranosidase: Potential for use as dietary additives

In vitro and in vivo studies were conducted with six commercial enzyme preparations (SP249, Energex, Rohament CW, Novozyme 230 and crude α -galactosidase) to determine their effectiveness in hydrolysing galactooligosaccharides from soya bean and canola meal in the gastrointestinal tract of poultry. The use of the enzyme invertase to enhance galactoside hydrolysis was also studied. A wide range of α -galactosidase activity was observed in vitro, with crude α-galactosidase from Mortirella vinacea and Novozyme 230 preparation showing the highest activity values of 4.3 and 1.5 nkat mg^?1, respectively. All preparations with the exception of crude α-galactosidase showed invertase activity which is known to convert raffinose and stachyose to the corresponding di-and trisaccharide, melibiose and manninotriose. Although the activity of invertase was highest on sucrose, the Novozyme 230 preparation showed activity values of 4.2 and 2.3 nkat mg^?1 toward raffinose and stachyose substrates, respectively. De novo synthesis of raffinose was observed when soya bean meal, canola meal or pure sucrose and galactose were incubated with certain enzyme preparations (ie Energex). In general, preparations possessing hydrolytic activity towards galactooligosaccharides showed very little synthesis of raffinose while preparations capable of generating raffinose were very weak in the hydrolysis of galactooligosaccharides. The best result in terms of galactooligosaccharide in vitro hydrolysis of canola and soya bean meal was obtained with a combination of α-galactosidase and invertase. In the in vivo study with caecectomised hens, hydrolysis of galactooligosaccharides averaged 88% when crude α-galactosidase (2 g kg^?1) and invertase (1 g kg^?1) were added to laying, hen diet containing 200 g soya bean meal per kilogram. A problem identified in the current study was that minerals such as calcium phosphate and calcium carbonate common in poultry diets inhibit the hydrolysis activity of α-galactosidase, indicating that high levels of activity would be required to yield a response in practical poultry feeding.     

酶制剂抗菌活性检测标准菌株的药敏性分析

即将正式颁布的国家标准《食品加工用酶制剂通用卫生标准》首次将酶制剂的抗菌活性列入检验指标,并采用了国际标准检验方法。研究针对国际标准方法中规定的6株酶制剂抗菌活性检验标准菌,选择了9大类40种常用抗生素,采用Kirby-Bauer法进行药敏性测定与分析。结果显示,6株标准菌对不同类的抗生素表现为不同的敏感性,但这一菌株组合对全部40种抗生素均为敏感。因此,此菌株组合具有较为广谱的药物敏感性,能较为全面的检测酶制剂中的抗菌物质;且标准菌株的药敏性图谱可为今后进一步分析酶制剂中抗菌活性物质的种类提供参考。     

In vitro susceptibility of Enterococcus faecium isolated from food to growth-promoting and therapeutic antibiotics

A total of 76 E. faecium strains, isolated at retail level from raw poultry meat, cheese, raw pork, and preparations of cheese and raw pork, were tested for their susceptibility and resistance to growth-promoting antibacterials used in animals and antibiotics used therapeutically in humans. All strains were uniformly susceptible to the growth promoters bambermycin and avilamycin. Resistance against bacitracin, virginiamycin and narasin was high among strains from poultry meat. With tylosin, a macrolide antibiotic used therapeutically and for growth promotion, resistance was mainly detected in strains originating from poultry meat, though also in some strains from pork and from pork and cheese preparations. The therapeutic antibiotic dalfopristin/quinupristin did not show full cross-resistance with the growth-promoting antibiotic virginiamycin. With dalfopristin/quinupristin two different levels of resistance were found. Only one E. faecium strain isolated from poultry was resistant to the glycopeptides avoparcin and vancomycin. Only one poultry meat strain was highly resistant to ampicillin. However, nearly all poultry meat strains showed decreased sensitivity. Only 3 out of 24 poultry strains were susceptible to minocycline, while all strains from other origins were susceptible to this tetracycline antibiotic. High-level streptomycin resistance was seen in strains of all origins, though infrequently. High-level gentamicin resistance was not found.     

屠宰过程中改良畜禽肉品质的研究进展

肉品质是人们对肉类多种质量特性的综合评价,要改良畜禽肉品质必须从多方面考虑.在屠宰过程中,作好临宰前的准备工作,改善畜禽的击晕方法,改进放血技术和烫毛方式,采用多种方法降低胴体污染,这些措施都能有效地改良畜禽肉的品质.     

Effects of different maceration enzymes on yield,clarity and anthocyanin and other polyphenol contents in blackberry juice

Enzymatic maceration of blackberries was conducted with eight different pectinolytic enzyme preparations. Juice yields were increased greatly when macerated blackberries were treated with enzyme preparations (P < 0.05), but no significant difference in yield was found among different enzymes (P > 0.05). The amounts of anthocyanins and polyphenols in the juices as well as clarity of the juices were greatly varied because of different enzyme treatment. Juice prepared with Klerzyme 150 showed better clarity and greater amount of anthocyanins than the juices prepared with other enzyme preparations (P < 0.05). Studies on the uniform design for Klerzyme 150 enzyme revealed that the optimum conditions were 0.063% (v/w), 44 °C and 110 min for enzyme dosage, reaction temperature and reaction time, respectively.     

Evaluation of pectolytic activities of enological interest in industrial enzyme preparations

 The purpose of this research was to determine the activity of several pectolytic enzymes, such as pectin methyl esterase, endopolymethylgalacturonase, endopolygalacturonase, exopolymethylgalacturonase, endopolygalacturonase, pectin transeliminase and pectic acid transeliminase, from within preparations that are available on the Portuguese market. The selected preparations were as follows: 15 pectolytic enzyme preparations, one hemicellulolytic preparation and one glucanase preparation. The measurements of enzyme activity were carried out using model solutions with 50 mg·l^–1 SO₂, pH 3.2, 25°C, with and without 12% ethanol (v/v), and a 24-h incubation period. Quantitatively, the results proved to be heterogeneous, significantly varying from preparation to preparation: all pectolytic enzyme activities in the 17 preparations analysed in this study were significantly different. The presence of ethanol reduced the enzymatic activity, apart from that of endopolymethylgalacturonase, and, in general, an increase of enzyme concentration raised the pectolytic enzyme activity. Received: 17 March 1997 / Revised version: 11 June 1997     

Evaluation of pectolytic activities of enological interest in industrial enzyme preparations

 The purpose of this research was to determine the activity of several pectolytic enzymes, such as pectin methyl esterase, endopolymethylgalacturonase, endopolygalacturonase, exopolymethylgalacturonase, endopolygalacturonase, pectin transeliminase and pectic acid transeliminase, from within preparations that are available on the Portuguese market. The selected preparations were as follows: 15 pectolytic enzyme preparations, one hemicellulolytic preparation and one glucanase preparation. The measurements of enzyme activity were carried out using model solutions with 50 mg·l^–1 SO₂, pH 3.2, 25°C, with and without 12% ethanol (v/v), and a 24-h incubation period. Quantitatively, the results proved to be heterogeneous, significantly varying from preparation to preparation: all pectolytic enzyme activities in the 17 preparations analysed in this study were significantly different. The presence of ethanol reduced the enzymatic activity, apart from that of endopolymethylgalacturonase, and, in general, an increase of enzyme concentration raised the pectolytic enzyme activity. Received: 17 March 1997 / Revised version: 11 June 1997     

酶制剂在肉鸭日粮中的应用研究

选用１１日龄健康樱桃谷鸭３００羽，随机分为三组，一组为对照，另两组在对照组日粮基础上添加０．０５％两种不同类型的酶制剂，以研究酶制剂在肉鸭日粮中的应用效果。从经济效益考虑，酶制剂的使用提高了肉鸭的经济效益，对充分开发利用一些非常规饲料原有重要意义。     

The effect of proteolytic enzymes on the thermostability of egg-white

The effect of proteolytic enzyme preparations such as Proteopol PB (bacterial origin), ficin, and pancreatin on the thermostability of egg-white proteins during pasteurization was investigated. Proteolytic activities of each enzyme were measured at three different doses which were calculated by the ANSON method. The degree of white protein degradation was evaluated by the determination of amino-nitrogen. Effectiveness in reducing the coagulation of egg-white proteins varied, depending on the type and dose of enzyme used. Proteopol PB showed only little effect, ficin demonstrated the best anticoagulation properties at the lowest dose, while for pancreatin the middle dose proved to be the most effective. It was concluded that moderate proteolysis is useful for improving the thermostability of egg-white proteins during pasteurization. Total bacterial counts increased considerably after incubation of egg-white with enzyme preparations, but after pasteurization the number of bacteria decreased to levels which were compatible with bacteriological standards for egg-white products.