共查询到19条相似文献，搜索用时 265 毫秒
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为探讨罗非鱼碎鱼肉酶法制备蛋白胨的加工工艺,采用正交试验的方法,分别研究了木瓜蛋白酶、AS.1398中性蛋白酶、复合蛋白酶水解罗非鱼碎肉制备蛋白胨的工艺条件。结果表明:木瓜蛋白酶的最佳水解工艺条件为pH6.5,温度65℃,水解时间4h,加酶量1250 U/g,蛋白胨得率达12.63%;AS.1398中性蛋白酶最佳水解工艺条件为pH 7.5,温度55℃,水解时间4 h,加酶量750 U/g,蛋白胨得率达13.25%;复合蛋白酶的最佳水解工艺条件为pH 7.0,温度50℃,水解时间4.5 h,加酶量850 U/g,蛋白胨得率达11.43%。 相似文献
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以罗非鱼（Oreochromis spp.）下脚料为原料,采用高温热水抽提法提取其蛋白质作为乳酸菌发酵L-乳酸的氮源。以酵母膏作为对照,探讨了保加利亚乳杆菌（Lactobacillus bulgaricus）、嗜热链球菌（Streptococcus thermophi-lus）和鼠李糖乳杆菌（L.rhamnosus）在罗非鱼下脚料水解液培养基中的生长情况及L-乳酸的产量。结果显示,3种乳酸菌在2种培养基中均能良好地生长,pH下降明显;L-乳酸产量随乳酸菌菌种不同而异,其中鼠李糖乳杆菌在罗非鱼下脚料水解液培养基中发酵10 h后,L-乳酸净产量为3.38 g.L-1,与以酵母膏作为氮源的产酸水平相当。可见罗非鱼下脚料水解液可以替代酵母膏作为L-乳酸发酵的一种低成本氮源。 相似文献
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酶解罗非鱼鱼皮胶制备降血压肽的研究 总被引：2，自引：1，他引：1
为探讨罗非鱼鱼皮胶制备降血压肽的酶解工艺,研究选用Neutrase中性蛋白酶、Alcalase碱性内切蛋白酶、胰蛋白酶、木瓜蛋白酶和复合蛋白酶分别对罗非鱼鱼皮胶进行酶解,对其酶解液的水解度进行比较。结果表明复合蛋白酶的酶解效果最好。对复合蛋白酶的酶解工艺进行单因素优化,确定其最佳酶解工艺为:温度50℃、pH值7.0、料液比1∶5、酶量为底物量的1.5%。在此条件下水解6h时,水解度为60%,酶解产物对血管紧张素转化酶(ACE)的抑制率最高,达到78.96%。 相似文献
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以缢蛏为试验材料,采用羟自由基清除率为评价指标,从胰蛋白酶、胃蛋白酶、木瓜蛋白酶、碱性蛋白酶和中性蛋白酶5种蛋白酶中筛选最适水解用酶,在单因素试验基础上使用响应面法优化酶解工艺条件,考察缢蛏蛋白肽的羟自由基清除能力并通过Sephadex G-15凝胶层析测定其分子质量分布。结果表明,碱性蛋白酶酶解制备的缢蛏蛋白肽清除羟自由基能力明显强于其他蛋白酶,优化后的碱性蛋白酶水解缢蛏蛋白工艺条件为底物浓度6mg/ml、加酶量3%、pH8.0、温度55℃、酶解时间4h,蛋白肽的羟自由基清除率为76.60%,IC50值为1.89mg/ml,蛋白肽中80%以上是分子质量小于1500Da的小分子肽。 相似文献
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以缢蛏为试验材料,采用羟自由基清除率为评价指标,从胰蛋白酶、胃蛋白酶、木瓜蛋白酶、碱性蛋白酶和中性蛋白酶5种蛋白酶中筛选最适水解用酶,在单因素试验基础上使用响应面法优化酶解工艺条件,考察缢蛏蛋白肽的羟自由基清除能力并通过SephadexG-15凝胶层析测定其分子质量分布.结果表明,碱性蛋白酶酶解制备的缢蛏蛋白肽清除羟自由基能力明显强于其他蛋白酶,优化后的碱性蛋白酶水解缢蛏蛋白工艺条件为底物浓度6 mg/ml、加酶量3％、pH8.0、温度55℃、酶解时间4h,蛋白肽的羟自由基清除率为76.60％,IC50值为1.89 mg/ml,蛋白肽中80％以上是分子质量小于1500 Da的小分子肽. 相似文献
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复合酶提取牡蛎抗氧化肽的工艺研究 总被引：1，自引：0，他引：1
以牡蛎为原料,首先从木瓜蛋白酶、中性蛋白酶、碱性蛋白酶、胃蛋白酶、胰蛋白酶中筛选出胰蛋白酶为内切酶,以水解度为指标,得到最佳的酶解工艺条件:时间4h,温度50℃,pH8.0,料水比1∶2,加酶量3％(7 500 U/g),水解度为49.50％;同时以水解度为指标,得到外切酶风味蛋白酶的最佳酶解工艺:时间5h,温度50℃,pH8.0,料水比1∶2,加酶量3％ (450 U/g),实际水解度50.95％.最后,以清除羟自由基能力和水解度为指标,探讨内切酶(胰蛋白酶)和外切酶(风味蛋白酶)不同复合酶解方式的抗氧化能力.最终确定,复合酶解制备牡蛎抗氧化肽效果最好,其酶解条件为胰蛋白酶为3％(7 500 U/g)、风味蛋白酶加酶量为3％ (450 U/g),pH8.0,时间5h,料水比1∶2,温度50℃时,水解度高达53.94％,体外清除·OH的EC50为0.56 mg/mL. 相似文献
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丁香酚在罗非鱼体内的药物代谢动力学研究 总被引：1，自引：0，他引：1
为了解丁香酚在罗非鱼体内的代谢动力学特征,利用高效液相色谱法(HPLC)检测经丁香酚麻醉后苏醒的吉富罗非鱼(Oreochromis niloticus)血浆、肝脏及肌肉中丁香酚的质量浓度变化。试验结果:采用30 mg/L丁香酚药浴后,罗非鱼血浆、肝和肌肉中的药时数据均符合非房室模型;丁香酚在罗非鱼血浆、肝脏和肌肉中的药代动力学参数显示,峰值浓度(Cmax)分别为8 257.52μg/m L、88.62μg/kg和73.78μg/kg,达峰时间(Tmax)分别为0.5、1和2 h,消除半衰期(t1/2)分别为11.267 3、75.616 1和24.147 4 h,药时曲线下面积(AUC0~∞)分别为83 738.054 3 h·μg/m L、1 466.467 7 h·μg/kg和1 131.101 7 h·μg/kg,0~∞平均滞留时间(MRT0~∞)分别为11.498 2、85.284 4和39.388 7 h,表观分布容积(Vz)分别为1.941 2m L/kg、743.903 0 kg/kg和307.994 9 kg/kg。结果表明,丁香酚在罗非鱼体内分布广泛、消除慢、停留时间长。本研究可为罗非鱼活体运输中麻醉剂的安全使用提供参考。 相似文献
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《水产科学》2015,(7)
超声波和蛋白酶可以破坏蛋白质结构,提高短肽的得率。本试验以近江牡蛎为原料,在适度水解、控制挥发性盐基氮在合理范围的前提下,以短肽含量为主要目标,首先通过研究超声波功率、时间对牡蛎自溶酶解的影响,优化超声波辅助酶解工艺,然后采用单因素试验研究碱性蛋白酶对超声波—自溶酶解液酶解效果的影响。结果显示,440 W超声波处理牡蛎10min后自溶酶解,短肽含量为(88.75±1.16)mg/mL,是对照组的2.12倍;水解度为(30.38±0.05)%;挥发性盐基氮为(79±2)μg/g。采用碱性蛋白酶对超声波-自溶酶解液进行进一步酶解,优化的酶解条件是:加酶量5kU/g,酶解温度55℃,酶解时间4h,此时短肽含量达到100mg/mL以上,水解度为(35.95±0.05)%;挥发性盐基氮为(178±6)μg/g,处在可接受范围。试验结果表明,超声波预处理后自溶,再进行外源蛋白酶酶解可显著提高酶解效率。 相似文献
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2种水温条件下罗非鱼体内氟苯尼考的药物动力学比较 总被引：3，自引：0，他引：3
采用药饵给药，药物剂量为10mg·kg^-1，比较研究了22和28℃水温条件下奥尼罗非鱼（Oreochromis niloticus×O．aureus）体内氟苯尼考的药物动力学。结果得出，22℃组和28℃组罗非鱼血浆的峰药浓度（Cmax）分别为4．46和3．90μg·mL^-1，达峰时间（Tmax）均为12h，消除半衰期（T1/2β）分别为10．03和8．12h，药-时曲线下面积（AUC）分别为86．68和72．44h·μg·mL^-1。相应条件下的肌肉Cmax分别为6．88和4．59μg·g^-1，Tmax均为12h，T1／2β分别为10．97和8．03h，AUC分别为112．71和73．66h·μg·g^-1。低温组罗非鱼血浆和肌肉中药物的T1／2β均长于高温组，前者分别比后者长1．91和2．96h，表明低温组罗非鱼体内药物的消除速度慢于高温组。虽然2个水温组血浆和肌肉中药物的Tmax相同，但低温组血浆、肌肉的Cmax和AUC均明显高于高温组，表明低温组罗非鱼吸收利用药物程度高于高温组。 相似文献
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为研究敌百虫对奥尼罗非鱼幼鱼的急性毒性效应,采用96 h半静水式生物毒性试验方法,在水温(23.5±2.0)℃,溶解氧>5 mg/L的条件下,分别检测在曝气自来水(pH为6.5)和池塘水(pH为8.5)中敌百虫对奥尼罗非鱼幼鱼的急性毒性效应。结果显示:在曝气自来水中,敌百虫对奥尼罗非鱼幼鱼24、48、72、96 h的半致死质量浓度分别为3.68、3.31、2.05、1.57 mg/L,安全质量浓度为0.157 mg/L;在池塘水中,敌百虫对奥尼罗非鱼幼鱼24、48、72、96 h的半致死质量浓度分别为0.35、0.29、0.17、0.13 mg/L,安全质量浓度为0.013 mg/L。试验结果表明,在池塘水中敌百虫对奥尼罗非鱼幼鱼的毒性比在曝气自来水条件下强。 相似文献
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The effects of periphyton substrate and fish stocking density on water quality, phytoplankton, periphyton and fish growth 总被引：4，自引：0，他引：4
M E Azim M C J Verdegem M Singh A A van Dam & M C M Beveridge 《Aquaculture Research》2003,34(9):685-695
The objectives of this study were to determine how periphyton and phytoplankton biomass vary with grazing pressure by tilapia Oreochromis niloticus, to evaluate the growth performance of fish when substrate is introduced and to calculate the efficiency of nitrogen utilization in substrate and non‐substrate systems. Ten circular 1000‐L plastic tanks were filled with 15 cm of loamy soil bottom and water. Five different treatments were applied: eight tilapias with substrate (treatment 8T/S), eight tilapias without substrate (treatment 8T), four tilapias with substrate (treatment 4T/S), four tilapias without substrate (treatment 4T) and no tilapia with substrate (treatment 0T/S). Each week, 2 g of NaNO3 and 3.5 g of single superphosphate (SSP) were applied to each tank. Sixteen glass slides (1 m×4 cm×4 mm) were installed vertically in the tank bottom, one portion extending above the water surface and equally spaced within the water column in all substrate tanks. Periphyton and phytoplankton quantity and quality, water quality, fish growth and proximate fish composition were measured. Because of grazing, phytoplankton and periphyton biomass decreased after the introduction of fish to the tanks. The periphyton biomass was higher in non‐fish tanks (treatment 0T/S) throughout the experiment than that in tanks with fish (treatments 8T/S and 4T/S). The periphyton biomass was similar in the 4T/S and 8T/S treatments, suggesting that the grazing pressure on periphyton biomass reached threshold levels. Fish ate 25–36% of the total standing biomass every day. Tilapia growth was significantly higher in treatments with substrate. Nitrogen retention was double in substrate ponds compared with in control ponds. There were no significant effects of periphyton substrate or fish density on body composition of fish. 相似文献
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自吉富罗非鱼养殖池塘水体、底泥和鱼体肠道中筛选无乳链球菌拮抗株。对其中1株抑菌能力最强的菌株LT3-1进行溶血性、形态、生理生化、16S rRNA基因序列测定,并进一步对其抑菌活性与发酵时间的关系、抑菌物质对温度的耐受性、产酶性能、降解亚硝酸盐性能、药物敏感性、安全性试验、攻毒试验进行研究。鉴定结果表明,菌株LT3-1为枯草芽孢杆菌,无溶血性。液体发酵16 h时,抑菌活性最强,抑菌圈平均直径为(25.30±0.57) mm。随温度的升高抑菌活性下降,但仍然存在,说明抑菌物质有耐高温特性。枯草芽孢杆菌LT3-1具有水解蛋白、淀粉和纤维素的能力。亚硝酸盐降解试验表明,枯草芽孢杆菌LT3-1菌液密度为10^5 cfu/mL时,6 h即可将亚硝酸盐质量浓度由2.5 mg/L降至0.03 mg/L,降解率达98.8%( P <0.05)。枯草芽孢杆菌LT3-1对检测的9种抗生素均敏感,罗非鱼接种密度为10^7 cfu/mL的枯草芽孢杆菌LT3-1菌液200 μL后,仍然存活且未有异常表现。动物攻毒试验表明,添加0.05%枯草芽孢杆菌LT3-1菌粉的试验组罗非鱼存活率提高20%,显著高于对照组( P < 0.05 )。综上所述,筛选自吉富罗非鱼肠道的枯草芽孢杆菌LT3-1能有效拮抗罗非鱼无乳链球菌,可以作为防治当地罗非鱼无乳链球菌病的良好菌种资源。 相似文献
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Steven J. Gabel James W. Avault Robert P. Romaire 《Journal of the World Aquaculture Society》1981,12(2):153-162
Channel catfish (Ictalurus punctatus) (x? = 0.8 g) and all-male hybrid tilapia fingerlings (Sarotherodon mossambica ♂ × S. hornorum ♀) (x? = 35.0 g) were stocked in 0.04 ha replicated ponds in Baton Rouge, Louisiana, in March and July 1981, respectively. The ponds were stocked at densities of 11,110 catfish per ha, 11,110 catfish with 5,550 tilapia per ha, 7,400 catfish per ha, and 7,400 catfish with 3,700 tilapia per ha. The fish were fed daily at 4% of estimated catfish biomass and were harvested in November 1981. There were no differences in dissolved oxygen or water temperature among the four culture systems (P > 0.05). The presence of tilapia, however, significantly increased water turbidity, pH and chlorophyll a concentrations (P < 0.05). Tilapia did not improve water quality and may have deteriorated it. Tilapia did not affect channel catfish growth or production (P > 0.05), but the presence of tilapia did significantly increase total fish yield (P < 0.05) by 13.5 and 32.2% at low and high catfish densities, respectively. Channel catfish and tilapia averaged 390 and 245 g at harvest, respectively. Overall catfish survival averaged 61%. Tilapia survival was 72% and 61% at low and high densities, respectively. 相似文献
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ABSTRACT Fish cage culture is an intensive, continuous-flow fish farming system, allowing intensive exploitation of water bodies with relatively low capital investment. This study aimed to determine the production function of Nile tilapia, Oreochromis niloticus, in cages; the profit-maximizing biomass at 300–400 and 500–600 fish per m3 for cages of different volumes; and the influence of water body conditions in fish performance. Feed intake, survival rate, and water temperature were monitored daily; dissolved oxygen, pH, and transparency of water were monitored each 15 days. Caged tilapia were fed daily on commercial, floating pellets (32% crude protein) at 0900, 1300, and 1700, and feeding rate was adjusted based on weight gain and survival rate. Data were analyzed statistically by ANOVA (P = 0.05) and regression analysis; the Mitscherlich function was chosen to represent the production function. Carrying capacity of both stocking densities reached 200 kg/m3 and no differences were found (P > 0.05) regarding accumulated biomass and individual average weight over time. The larger stocking density yielded larger accumulated biomass and had better feeding efficiency and no differences between individual average weights of fish at both densities were observed (P > 0.05). Profit-maximizing biomass at 500–600 fish/m3 was 145 kg/m3 and at 300–400 fish/m3 was 121 kg/m3. Cage farming of Nile tilapia at 500–600 fish/m3, individual average weight 283 g, presented many advantages: optimization of space and production time, better feed efficiency, higher fish production per unit volume of cages, and increased profitability. 相似文献
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纳豆菌抗菌肽APNT-6对凡纳滨对虾的低温保鲜效果 总被引：3，自引：0，他引：3
为了解决因凡纳滨对虾货架期短而滥用化学保鲜剂等问题,实验通过微生物发酵,柱状色谱纯化得到一种新型生物保鲜剂——纳豆菌抗菌肽APNT-6,采用牛津杯法测定了其对凡纳滨对虾腐败菌的抑菌效果,并用浸保鲜剂方式将抗菌肽应用于凡纳滨对虾保鲜,通过测定对照组和保鲜剂组在(4±1)℃贮藏过程中的pH、挥发性盐基氮(TVB-N)、细菌总数、感官评分等鲜度指标的变化规律,评价了抗菌肽对凡纳滨对虾在(4±1)℃贮藏条件下保鲜效果。结果表明,纳豆菌抗菌肽APNT-6对凡纳滨对虾中Pseudomonas、Shewanella等8株腐败菌有良好的抑菌效果,经0.5 mg/mL抗菌肽保鲜剂处理后,保鲜剂组在(4±1)℃贮藏过程中pH、挥发性盐基氮(TVB-N)和细菌总数增加缓慢,货架期延长了2～3 d。 相似文献
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土霉素在奥尼罗非鱼体内的药动学研究 总被引：2，自引：0，他引：2
在(21±1)℃的水温条件下,以50 mg/kg的单剂量,分别给奥尼罗非鱼(Oreochromis aureus×O.niloticus)水剂口灌和混饲口灌土霉素,用高效液相色谱法(HPLC)检测给药后各个时间点的血药浓度。结果显示:最低检测限为0.005μg/mL,线性范围为0.005~4μg/mL。水剂口灌组和混饲口灌组的药时数据均符合具时滞的二室开放动力学模型,水剂口灌组的动力学方程为:Ct=0.231e-0.028(t-0.010)+0.353e-0.011(t-0.010)-0.584e-0.468(t-0.010),混饲口灌组动力学方程:Ct=0.839e-0.057(t-0.459)+0.442e-0.013(t-0.459)-1.281e-0.282(t-0.459)。水剂口灌组及混饲口灌组主要药动学参数分别为:吸收半衰期(t1/2ka)为1.481 h,2.458 h;分布半衰期(t1/2α)为24.834 h,12.193 h;消除半衰期(t1/2β)为60.312 h,51.533 h;达峰时间(Tmax)为7.230 h,8.221 h;最大血药浓度(Cmax)为0.494μg/mL,0.796μg/mL;血药浓度-时间曲线下面积(AUC)=37.74μg.h/mL,43.075μg.h/mL。这些参数表明,水剂口灌比混饲口灌吸收快,分布和消除慢,在血液中达到峰浓度的时间更短,但峰浓度值比混饲口灌低。 相似文献
19.
Abstract. Effects of stocking density on water quality and on the growth, survival and food conversion of Oreochromis niloticus (Linnaeus) were evaluated. Fingerlings of tilapia (average weight 40.25 ± 94 g) were stocked in six 3.75-m3 concrete tanks at 16, 32 and 42.6/m3 and reared for 164 days. A water flow rate of 1 l/min/kg fish biomass was maintained in all the tanks. The growth rate was inversely related to stocking density with mean weights of 337.25g, 327.0g and 323.5g at the low, medium and high densities respectively. At harvest, standing crop biomass averaged 5.36 kg, 10.44kg and 13.24kg for the three densities. The respective food conversion ratios (FCR) were 1.85, 1.88 and 1.95, while the survival rates were 99.2, 99.6 and 95.9%. However, the survival rate, growth rate and food conversion efficiencies were not significantly different at the three stocking densities. Water quality did not deteriorate in different tanks as the oxygen was continuously replenished and metabolites and waste products removed by the water flowing through the tanks. These data suggest that culture of tilapia at a density of 42.6/m3 and production of 13.24 kg/m3 in 164 days with a production of 18–20 kg/m3 in a growing season (April-October) of 210 days is possible using the drainage water in flow-through water systems. 相似文献