Effects of dietary coated protease on growth performance,feed utilization,nutrient apparent digestibility,intestinal and hepatopancreas structure in juvenile Gibel carp (Carassius auratus gibelio)          下载免费PDF全文

Z. Li  Z.Y. Duan  H. Wen 《Aquaculture Nutrition》2018,24(1):47-55

This study was conducted to investigate the effects of dietary protease on growth performance, feed utilization, whole‐body proximate composition, nutrient digestibility, intestinal and hepatopancreas structure of juvenile Gibel carp, Carassius auratus gibelio (mean weight 8.08 ± 0.18 g). Six diets were prepared, including a positive control diet (dietary protein 350 g/kg, PC), one negative control diet (dietary protein 33 g/kg, NC) and four protease supplementations diets, which were 75, 150, 300 and 600 mg/kg protease NC diet. After 12 weeks of diet feeding in indoor recycle aquarium tanks, no significant difference (p > .05) was found on growth performance between fish fed diet with 75–600 mg/kg protease and the PC group. Compared with the fish fed the NC diet, the specific growth rate of fish fed 300 mg/kg protease increased significantly (p < .05), as well as protein efficiency ratios (p < .05), while feed conversion was the opposite (p < .05). The nutrient digestibility of crude protein and lipid was higher (p < .05) in fish fed 150 mg/kg protease diet than the PC diet. Whole‐body proximate composition of fish was not affected (p > .05) by the dietary treatment. Serum alkaline phosphatase and albumin were significantly affected by dietary protease (p < .05), while the content of total protein, glucose, triglyceride, total cholesterol, aspartate aminotransferase and alanine aminotransferase activities in serum was not affected (p > .05). Foregut muscular thickness was thinner (p < .05), when the fish fed diets supplementation of protease in 150 or 600 mg/kg diet than the NC diet. Protease activities in hepatopancreas and foregut were higher (p < .05), in the fish fed 150 or 300 mg/kg protease diet than the fish fed the PC diet, but those in the mid‐ and hindgut were not significantly affected (p > .05) by the dietary treatments. Based on the regression analysis of weight gain rate, the optimal dietary inclusion level of protease was 400 mg/kg in the diet for juvenile Carassius auratus gibelio.  相似文献   

重寄生真菌盾壳霉胞外蛋白酶产生条件及酶活影响因子          下载免费PDF全文

谢晓莉  杨龙  吴明德  张静  李国庆 《中国生物防治学报》2016,32(3):406-413

重寄生真菌盾壳霉Coniothyrium minitans是核盘菌Sclerotinia sclerotiorum的重要生防菌。为了探讨盾壳霉胞外蛋白酶在寄生核盘菌过程中的作用,采用明胶平板法对盾壳霉寄生核盘菌菌核产生的蛋白酶活性进行了检测,并进一步采用福林酚法定量测定蛋白酶活性,研究盾壳霉产生胞外蛋白酶的培养条件及影响蛋白酶活性的因子。试验结果表明,在被盾壳霉寄生的核盘菌菌核中检测到蛋白酶活性,表明蛋白酶可能参与盾壳霉重寄生作用。发现核盘菌菌核浸出液培养基适合盾壳霉产生胞外蛋白酶,摇培(20℃、200r/min)5d时蛋白酶活性最高,达到0.22U/mL。盾壳霉胞外蛋白酶酶促反应的最适温度为60℃,最适pH7.0。当温度不高于40℃时,蛋白酶酶活较稳定。5mmol/L的金属离子Mg²⁺、Zn²⁺、Ca²⁺、Cu²⁺、Mn²⁺、Li⁺和K⁺等对蛋白酶酶活没有显著影响(P>0.05),而Fe²⁺(5mmol/L)显著(P<0.05)提高了蛋白酶活性。盾壳霉蛋白酶对苯甲基磺酰氟(PMSF)敏感,说明盾壳霉产生的胞外蛋白酶可能主要是丝氨酸蛋白酶。这些结果为盾壳霉胞外蛋白酶的分离纯化和功能研究奠定了基础。  相似文献   

Detection of protease genes in field soil applied with liquid livestock feces and speculation on their function and origin     

Katsuji WATANABE 《Soil Science and Plant Nutrition》2009,55(1):42-52

The origin of soil protease in field soil was estimated using culture-dependent and independent approaches. Overall soil protease activity was much higher in field soils with an annual application of liquid livestock feces (120 t ha⁻¹ year⁻¹ and 600 t ha⁻¹ year⁻¹) compared with the activity recorded in other field soils, and the character of the soil proteases became highly homogeneous (approximately 70% metalloprotease in a 600 t field). Selective incubation studies suggested that bacteria were the most important source of soil protease. There were significantly higher correlations between serratial metalloprotease and the overall soil protease in both feces-applied fields in terms of the effect of inhibitors, and the bacteria, which produced serratial metalloprotease, were suggested to proliferate in both the 120 t and 600 t fields. The gene homologous to serratial metalloprotease gene was amplified in directly extracted DNA from field soils using selective DNA primer and proteolytic Serratia marcescens was certified to be one source of soil protease in these field soils. Proteolytic S. marcescens and its metalloprotease gene have occasionally been isolated and detected in field soils applied with raw feces, and have rarely been isolated or detected from other field soils. Proteolytic S. marcescens is believed to be introduced in the raw feces and subsequently colonizes the field soil and replaces the indigenous bacteria in the soil.  相似文献   

Exogenous protease supplementation of poultry by‐product meal‐based diets for broilers: Effects on growth,carcass characteristics and nutrient digestibility          下载免费PDF全文

T. Mahmood  M. A. Mirza  H. Nawaz  M. Shahid 《Journal of animal physiology and animal nutrition》2018,102(1):e233-e241

An experiment was conducted to investigate the effects of three levels (0%, 3% and 6%) of poultry by‐product meal (PBM) with or without protease on broiler growth, carcass characteristics and nutrient digestibility from 1 to 35 days. Two hundred and forty birds (n = 240) were fed equi‐caloric and equi‐nitrogenous (ME 2850 kcal/kg; CP 20%) diets throughout the experiment. The enzyme supplementation increased feed intake (p < .01) and body weight gain (p < .01), but feed:gain remained unaffected (p > .05) from 1 to 21 days. Increasing level of PBM decreased feed intake (p < .05), but body weight gain was improved (p < .05) at 3% PBM level during 1 to 21 days. The feed:gain was improved (p < .05) in birds fed diets containing 3% PBM. The feed:gain was also improved in birds fed diets containing 3% PBM from 1 to 35 days. However, feed intake and body weight gain in birds fed diets containing PBM remained unaffected. An interaction (p < .01) on feed intake between enzyme and PBM was noticed during 1 to 21 days. However, no interaction was recorded for body weight gain and feed:gain. The per cent carcass yield improved (p < .01) in birds fed diets supplemented with enzyme. The per cent breast meat yield was depressed (p < .005) in birds fed diets containing PBM. Apparent metabolizable energy (p < .001), nitrogen retention (p < .01), apparent metabolizable energy corrected for nitrogen (p < .001), and apparent digestibility coefficient for nitrogen (p < .01) improved in birds fed diets containing enzyme; however, a reverse was noticed in those fed diets containing only PBM. In conclusion, inclusion of 3% PBM along with supplementation of exogenous protease improved performance and nutrient digestibility in broilers.  相似文献   

苜蓿草粉对禾花鲤蛋白酶和淀粉酶活性影响的研究     

张春梅  施传信  王成章  何云  刘圈炜 《草业科学》2009,26(5):128-134

选取来源一致、规格整齐的2龄禾花鲤1 200尾,采用单因子完全随机设计,分为5个处理,每处理3个重复,每重复80尾鱼,分置于15个试验池中。各处理苜蓿Medicago sativa草粉的添加量分别为0（对照组）、40（试验Ⅰ组）、80（试验Ⅱ组）、120（试验Ⅲ组）和160 g/kg（试验Ⅳ组）,正试期50 d,观测苜蓿草粉对禾花鲤前、中、后肠及肝胰脏蛋白酶和淀粉酶活性的影响。结果表明：1）添加苜蓿草粉对前肠蛋白酶活性有显著影响 (P<0.05),其中试验II组显著高于对照组和试验Ⅳ组,但和试验Ⅰ、Ⅲ组差异不显著 (P>0.05)。添加苜蓿草粉对中、后肠及肝胰脏蛋白酶活性均无显著影响 (P>0.05),但它们有相同的变化趋势,即试验Ⅰ、Ⅱ、Ⅲ组鱼的蛋白酶活性均高于对照组。2）鲤鱼的前肠、中肠、后肠蛋白酶活性依次减弱,而肝胰脏的蛋白酶活性远低于肠道。3）添加苜蓿草粉后前肠及中肠淀粉酶活性比较,试验II组显著高于对照组 (P<0.05),其余各组与对照组差异不显著 (P>0.05),后肠淀粉酶活性与对照组无显著差异 (P>0.05)。添加苜蓿草粉能提高鲤鱼肝胰脏淀粉酶活性,其中试验Ⅱ组显著高于对照组 (P<0.05),其余试验组与对照组无显著差异 (P>0.05)。4）禾花鲤前、中、后肠及肝胰脏4部分淀粉酶的活性有较大的不同,肝胰脏>后肠>中肠>前肠。  相似文献   

3种微生态制剂的氨基酸组成及对鲤鱼消化酶活性的影响^*     

杜宣  周国勤  茆健强 《云南农业大学学报(自然科学版)》2006,21(3):351-354

 采用HPLC法分析了枯草芽孢杆菌、纳豆芽孢杆菌和复合微生态制剂的氨基酸含量,这3种不同的微生态制剂的氨基酸含量分别为53.2g/100g干基,56.4g/100g干基,59.5g/100g干基。在统一饵料的基础上,分别按0.1%,0.2%和0.5%添加纳豆芽孢杆菌、枯草芽孢杆菌和复合微生态制剂养殖鲤鱼45d,分析了鲤鱼肠道和肝胰脏中蛋白酶和淀粉酶的活性。结果表明,添加纳豆芽孢杆菌0.1%~0.5%的试验组能显著地提高鲤鱼肠道蛋白酶的活性,0.1%和0.2%剂量组可显著地提高鲤鱼肝胰脏蛋白酶的活性,0.1%剂量组可较显著地提高鲤鱼肠道和肝胰脏的淀粉酶的活性。枯草芽孢杆菌对鱼类消化酶的影响作用与纳豆芽孢杆菌不尽相同,其0.1%~0.5%试验组对鲤鱼肠道蛋白酶和淀粉酶均有较显著的提高作用,但对鱼类肝胰脏的消化酶活力影响不大。相对于蛋白酶而言,枯草芽孢杆菌对鲤鱼肠道淀粉酶活力的提高更为有效。复合微生态制剂0.1%~0.5%的各试验组能显著地提高鲤鱼肠道和肝胰脏的蛋白酶和淀粉酶的活力,其对鲤鱼肠道和肝胰脏的蛋白酶和淀粉酶的活力的提高率要优于单一菌种的微生态制剂。复合微生态制剂作为水产养殖生物的饵料添加剂使用,应根据不同食性的鱼类和不同的饵料组成加以选择和组配,合理的添加量在0.1%~0.2%之间为宜。  相似文献   

芝麻蛋白酶水解条件的研究   总被引：1，自引：0，他引：1  

肖扬  段玉峰  丁红军 《农产品加工．学刊》2009,(6)

对芝麻蛋白的酶水解工艺进行了初步研究,结果为:①通过比较,选用木瓜蛋白酶为酶解芝麻蛋白制备功能性短肽的专用酶,其工艺参数为:底物质量浓度9.0 g/L,酶添加量20.0%,pH值6.5,温度50℃,时间6 h,在此工艺下得到的酶解产物的抗氧化活性最高,对邻苯三酚自氧化的抑制率为35.6%;②酶解前的热处理可以提高酶水解的效果,最佳的热处理条件是将蛋白溶液在90℃下加热10 min。  相似文献   

海洋细菌L_1-9菌株产蛋白酶发酵条件的优化     

夏振强  暴增海  王增池  马桂珍 《湖北农业科学》2009,48(5)

海洋细菌L1-9是一株对多种植物病原真菌有强抑制作用并能产生蛋白酶、纤维素酶等细胞壁降解酶的优良菌株.采用比色法对该菌株产生蛋白酶的最适培养基和发酵条件进行了研究.结果表明,该菌株产蛋白酶的最佳培养基为豆饼粉2.00%、麸皮3.00%、玉米粉4.00%、Na2HPO4·12H2O 0.40%、KH2PO4 0.03%、CaCl2 0.10%、NaCO3·10H2O 0.10%;最适发酵条件为500mL三角瓶装液量70mL,接种量5%,培养基起始pH值6.0或9.0,转速190 r·min-1,温度25℃,发酵时间42h.  相似文献   

菜籽粕蛋白肽制备工艺条件优化   总被引：1，自引：1，他引：0  

辛愿  肖志刚  肖睿  吴谋成 《东北农业大学学报》2009,40(12)

试验改进了菜籽粕蛋白的酶解工艺,并对改进后的工艺条件进行了优化。采用2709碱性蛋白酶水解菜籽粕蛋白,分别考察了pH值、酶用量、酶解时间、温度、底物浓度对蛋白回收率的影响规律,在此基础上,利用响应面分析法对菜籽粕蛋白的酶解条件进行了优化。结果表明,2709碱性蛋白酶水解菜籽粕蛋白的较优条件为pH11.5、温度50℃、底物浓度4%、水解时间173min、酶用量5778U·g-1,此时蛋白回收率可达87.18%。  相似文献   

深海芽孢杆菌B1394的鉴定及其产蛋白酶酶学性质   总被引：2，自引：0，他引：2  

王雪梅  胡江春  王书锦 《吉林农业大学学报》2009,31(2)

从深3 200-3 600 m的南海海底沉积物中分离到185株深海细菌,从中筛选到1株产蛋白酶活力较强的菌株B1394,酶活高达873 U/mL.采用16S rDNA分子生物学鉴定,结合细菌常规鉴定方法鉴定其为枯草芽孢杆菌(Bacillus subtilis).对其粗酶性质进行研究发现:最适酶活温度60℃,最适pH 8.0,在低温30℃和40℃下也具有较高的酶活性,40-60℃热稳定性较好,显示出部分嗜热酶特性;Mn2+、Mg2+、ca2+对该蛋白酶有激活作用,Hg2+、Fe3+、Cu2+、Zn2+、Fe2+对该蛋白酶有抑制作用;PMSF几乎完全抑制蛋白酶活性,推断为丝氨酸蛋白酶.  相似文献