枯草芽孢杆菌培养液水解鱼蛋白质制备蛋白胨的初步研究

对枯草芽孢杆菌胞外蛋白酶的产生条件及其培养液水解鱼蛋白质制备蛋白胨进行了初步研究.结果表明,适宜枯草芽孢杆菌产蛋白酶的培养基初始pH值7.0、培养温度30℃、250 mL三角瓶中的装液量为60 mL,培养时间为24 h;用枯草芽孢杆菌培养液为蛋白酶源水解蛋白质时,应控制反应体系的温度为55℃,pH 9.0,加入低浓度的Mg2+、Ca2+并去除Cu2+、Fe3+、Pb2+和Ag+,对枯草芽孢杆菌产酶有促进作用.用枯草芽孢杆菌培养液分别水解鳕鱼粉和罗非鱼,蛋白质制备蛋白胨的得率分别为13.95%和14.96%,与目前的工业水平基本相当.

酶解鲐鱼废弃物制取鱼蛋白质水解物的研究

本文提出了用木瓜蛋白酶酶解鲐鱼加工废弃物制取水溶性鱼蛋白质水解物的技术，并确定其最佳水解条件为：温度６０℃，ｐＨ值６５，底物浓度为固液比５：８。在加酶量为鱼糜中蛋白质含量的１２５％，反应时间为６ｈ时，氮利用率可达７１％，蛋白质水解物中粗蛋白含量为８２４８％，必需氨基酸含量占氨基酸的３９８％，富含镁，是理想的食物蛋白添加剂。

无盐鱼蛋白质水解物的制备

鱼或鱼废料经蛋白水解酶,碱及酸处理可以制备鱼蛋白质水解物和鱼蛋白质分离物。由于酸碱的中和作用,终产品中常含有大量的盐分。高盐分影响了产品的产率和理化性质。本文提出了一种制备无盐鱼蛋白质水解物的方法,用木瓜蛋白酶及碱处理黑线鳕骨架,使其液化,然后用酸性酪蛋白代替盐酸中和水解液中的碱。这样制备的鱼蛋白质产品不含由于酸碱中和产生的额外盐分,称为无盐鱼蛋白质水解物。产品产率为16.1％,蛋白质含量为85.96％,可溶性蛋白质含量为61—62％。该产品可作为加工食品的蛋白质添加剂或奶粉的代用品。

鱼蛋白质混合剂保存供者肝脏

据美国伯克利加利福尼亚大学生物医学工程师Boris Rubinsky报道,防止冷水鱼冻结的一种蛋白质可延长待移植供者器官的寿命。 Rubinsky在伯克利工业联络规划大会上报告说,他及其合作者将纽芬兰海的大头鱼的蛋白质加入到“保护能力最差的保护溶液”中,并用这种混合剂保存冷冻的大鼠肝脏达24小时之久,肝脏没有受到严重损伤。研究人员发现,用鱼蛋白质保存的肝脏所发挥的作用是未经鱼蛋白质处理肝脏的3倍。

动物蛋白酶1058水解鱼是鱼可溶性蛋白质

研究了动物蛋白酶 1 0 58水解鱼是鱼蛋白时 ,酶量、温度、作用时间对鱼是鱼蛋白质水解率和苦味的影响。结果表明 :酶浓度的提高 ,水解时间的延长 ,均使鱼是鱼蛋白水解率明显提高。最适水解温度为 50℃ ,当温度高于 50℃时 ,水解率逐渐下降 ,蛋白酶开始失活。苦味值随水解率提高而增加。用正交试验的方法 ,经综合分析和试验得出 ,该蛋白酶水解鱼是鱼的最佳条件是酶量与底物之比为 1 .5∶ 1 0 0 0 ;温度为 50℃ ;水解时间为 4h。

鱼血清蛋白质的微型双相电泳分析

本文采用改进的微型双相电泳系统，对兴国红鲤、草鱼及其杂交鱼血清蛋白质进行了分析，获得较清晰而稳定的结果，分析得出杂交鱼的血清蛋白质的组成更接近于父本草鱼。实验表明微型双相电泳是进行鱼类血清蛋白质分析的灵敏而有效的方法。

Comparative Study on Muscle Fiber Characteristics and Muscle Nutritional Quality between Two Groups of Yellow River Carps

The aim was to protect the Henan Yellow River carp germplasm resources and provide a scientific basis for the meat quality improvement of Yellow River carps. With artificially farmed and wild Henan Yellow River carps as the research objects, comparative study on muscle fiber diameter and density, routine nutritional composition, calcium and phosphorus contents and amino acids composition was conducted between the two groups of carps. The results showed that the moisture content was significantly higher （P 〈0.05）, the crude fat and crude protein contents were significantly lower （P〈0.05）, the essential amino acids and total amino acids contents were lower （P〉0.05）, the phosphorus content was higher （P 〉0.05）, and the calcium content was lower （P〉0.05） in the wild group compared with those in the farming group. The analysis of muscle fiber characteristics showed that there were significant differences in the average muscle fiber diameter （P〈0.05） and muscle fiber density （P〈0.01） between the two groups of Henan Yellow River carps.

α-Synuclein redistributed and aggregated in rotenone-induced Parkinson’s disease rats

Objective To observe the influence of rotenone on the distribution of α-synuclein （ASN） in rat model of Parkinson＇s disease （PD）. Methods Wistar rats were randomly divided into two groups and received 2 mg/kg rotenone （s.c.） or sunflower oil （as control group） for about 4 weeks. The hippocampus, substantia nigra and striatum of brain were observed. Hematoxylin and eosin stain were used to observe the Lewy body like inclusion. The expression of tyrosine hydroxylase （TH） or ASN protein was determined by anti-TH or anti-α-synuclein immunohistochemistry, respectively. Results In control rats, ASN protein distributed widely in brain, especially in hippocampus, cortex and striatum. Rotenone obviously increased TH positive neurons and fibers loss in substantia nigra and striatum （P 〈 0.05）. In rotenone treated rats, ASN positive cells increased in global brain but not distributed in an even manner. In substantia nigra, ASN positive stuff was found aggregate in both cytoplasm and nucleus, and some formed spherical inclusion; in striatum, ASN positive neurites end aggregated and agglomerated around neurons; and in hippocampus, few dot-like ASN were aggregated in cell body, and no notable change was found in nucleus. Conclusion In rotenone administrated PD rats, ASN protein aggregated in several brain regions but most obviously in striatum and substantia nigra, and the distribution region of ASN was changed from peri-synapse to the cytoplasm and nucleus of dopaminergic neuron.

美容新观念

用科学的方法让美丽经得起考验,这是领导潮流的美容观念之一。因而带动了美容化妆品的新潮迭起,美容技巧的日臻完善给人们的生活带来新的色彩。脑素肽——尽显风流脑素肽是从动物脑部或内脏器官中提取的一种流行性物质,它具有防皱、防秃。

孩子吃什么能长得高

日本川幽博士推荐的有助于身高增长的五大营养品是: 1、牛奶 一种“全营养品”,它含有丰富的蛋白质、氨基酸、钙、磷等,对增高极为有利。

Effects of Dietary Protein Level on Growth and Utilization of Protein and Energy by Juvenile Mangrove Red Snapper(Lutjanus argentimaculatus)

A feeding trial was conducted in a recirculating water system to investigatethe effects of dietary protein levels on growth, feed utilization, hepatosomatic index and liverlipid deposition of juvenile red snapper, Lutjanus argentimaculatus (average initial wet weight 8.0± 0.39 g and total length 3.14 ± 0.3 cm). In the experiment, six fishmeal-based diets wereformulated to contain various protein levels (20% to 45% in 5% increments), with dietary energyranging from 2210.7kJ100g to 2250.2 kJ 100g dry matter. The protein to energy ratios of diets rangedfrom 8.58 mg protein kJ^(-1) to 20.03 mg protein kJ^(-1). Diets were fed for 90 d to triplicategroups of fish stocked in 0.128 m^3 seawater tanks, 25 individuals each. The daily ration of 2% wetbody weight was offered to the fish thrice a day. The fish at the end of the study had more thanten-fold (77.0 g) increase in weight compared to the initial (8.0 g). Fish fed diets of 40% and 45%protein produced significantly (P【0.05) higher weight gain of 77.2 g and 76.5 g, and specific growthrate (SGR) of 2.65% and 2.62% than those of 67.0 g and 68.3 g, and 2.49% and 2.51% of the otherdiets. The broken-line regression of SGR against dietary protein level yielded an optimum dietaryprotein requirement of 42.6% (Y = - 1.6295 + 0.1114 X^2, P【0.05). Survival remained 100% amonggroups. Feed conversion ratio decreased from 0.45 for fish fed 20% dietary protein to 0.35 for fishfed 45% dietary protein. Nitrogen intake increased with an increase in dietary protein, which inturn resulted in an increase in nitrogen gain of fish whole body. Fish fed 40% and 45% protein dietsshowed higher (P【0.05) nitrogen gain (0.27g and 0.26g) than those (0.23g and 025g) fed all otherdiets. Gross energy intake (GEI) in fish fed 45% protein was lower (600.67kJ) than that (607.97 kJ)of 40% protein diet, though the differences were not statistically significant (P】0.05); GEI rangingfrom 677.31 kJ to 663.20 kJ at remaining four diets (20% to 35% protein) did not appear to differsignificantly (P】0.05). The highest energy gain of 518.33 kJ was obtained with fish fed 40% protein,resulting in the highest energy retention efficiency of 85.26%. The hepatosomatic index of fish feddiets of 20%, 25%, 30% and 35% protein were significantly (P【0.05) higher (2.09% to 2.57%) thanthose (1.44% and 1.41%) of fish fed diets containing 40% and 45% protein. Liver lipid contentsdecreased from 8.72% to 7.0% in fish fed dietary protein of 20% to 45% in 5% increments. Resultssuggest that the diet containing 40% to 42.6% protein with a P/E ratio of 17.6 mg protein kJ^(-1) isrequired for good growth of L. argentimaculatus weighing between 8.0 g and 85.2 g under the cultureconditions of the present study.

Cloning and sequence analysis of a full-length cDNA of SmPP1cb encoding turbot protein phosphatase 1 beta catalytic subunit

Reversible protein phosphorylation, catalyzed by protein kinases and phosphatases, is an important and versatile mechanism by which eukaryotic cells regulate almost all the signaling processes. Protein phosphatase 1 （PP1） is the first and well-characterized member of the protein serine/threonine phosphatase family. In the present study, a full-length cDNA encoding the beta isoform of the catalytic subunit of protein phosphatase l（PPlcb）, was for the first time isolated and sequenced from the skin tissue of flatfish turbot Scophthalmus maximus, designated SmPPlcb, by the rapid amplification of cDNA ends （RACE） technique. The cDNA sequence of SmPPlcb we obtained contains a 984 bp open reading frame （ORF）, flanked by a complete 39 bp 5＇ untranslated region and 462 bp 3＇ untranslated region. The ORF encodes a putative 327 amino acid protein, and the N-terminal section of this protein is highly acidic, Met-Ala-Glu-Gly-Glu-Leu-Asp-Val-Asp, a common feature for PP1 catalytic subunit but absent in protein phosphatase 2B （PP2B）. And its calculated molecular mass is 37 193 Da and pI 5.8. Sequence analysis indicated that, SmPPlcb is extremely conserved in both amino acid and nucleotide acid levels compared with the PPlcb of other vertebrates and invertebrates, and its Kozak motif contained in the 5＇UTR around ATG start codon is GXXAXXGXXATGG, which is different from mammalian in two positions A6 and G3, indicating the possibility of different initiation of translation in turbot, and also the 3＇UTR of SmPPlcb is highly diverse in the sequence similarity and length compared with other animals, especially zebraf＇lsh. The cloning and sequencing of SmPPlcb gene lays a good foundation for the future work on the biological functions of PP1 in the flatfish turbot.

Fish Protein Recovered Using pH Shifting Method and Its Physicochemical Properties

The solubility of meat protein of croaker and jack mackerel was significantly affected by pH shifting. The protein yield of alkali-aided processing is higher than those of conventional and acid-aided processing. The addition of sarcoplasmic protein increases the breaking force and deformation value. The breaking force of recovered protein gel from alkali-aided processing is decreased by the addition of NaCI. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE） revealed that fish protein of alkali is similar to that at pH7.0. Alkali-aided processing for recovering fish protein is a valuable method for increasing the utilization of frozen and pelagic fishes and for making kamaboko products.

Dietary Leucine Requirement of Juvenile Japanese Seabass(Lateolabrax Japonicus)

A 56-day feeding trial was conducted to examine the dietary leucine requirement of juvenile Japanese seabass in sea- water floating net cages （1.5 m × 1.5 m × 2.0 m）. Six isonitrogenous （crude protein 40%） and isoenergetic （gross energy 20 kJ g-1） diets were formulated to contain different concentrations of leucine （0.9%, 1.49%, 2.07%, 2.70%, 3.30% and 3.88% of dry matter）. Crys- talline L-amino acids were supplemented to simulate the whole body amino acid pattern of Japanese seabass except for leucine. Three groups （30 fish individuals each, 8.0g±0.20g in initial weight） were fed to apparent satiation at 5：00 and 17：30 every day. During the experimental period, the water temperature ranged from 26 to 32℃ and salinity from 26 to 30, and the dissolved oxygen was maintained at 7mgL-l. The results showed that weight gain （WG）, nitrogen retention （NR）, feed efficiency （FE） and protein efficiency ratio （PER） were significantly increased when dietary leucine was increased from 0.90% to 2.70% of dry matter, and then declined. WG was the highest when fish were fed D4 containing 2.70% of leucine. No significant differences were observed in body composition among dietary treatments （P 〉 0.05）. Considering the change of WG, the optimum dietary leucine requirement of juve- nile Japanese seabass was either 2.39% of dry matter or 5.68% of dietary protein.

Detection of the End Point Temperature of Thermal Denatured Protein in Fish and Chicken Meat Through SDS-PAGE Electrophoresis

Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was applied in the detection of the end point temperature (EPT) of thermal denatured protein in fish and meat in this study. It was also used in studying the thermal denatured temperature range of proteins in salmon and chicken meat. The results show that the temperature ranges of denatured proteins were from 65 ℃ to 75 ℃ , and these temperature ranges were influenced by the processing methods. Through SDS-PAGE, the features of repeated heating thermal denatured proteins under the same temperature and processing time were studied. The electrophoresis patterns of thermal denatured proteins determined through repeated heating at the same temperature did not exhibit any change. For the detection of cooked fish and meat samples, they were subjected to applying the SDS-PAGE method, which revealed an EPT ranging from 60 ℃ to 80 ℃ .

Protein-sparing effect of carbohydrate in diets for juvenile turbot Scophthalmus maximus reared at different salinities

The aim of the present study was to investigate the protein-sparing effect of carbohydrate in diets for juvenile turbot(Scophthalmus maximus) reared at five salinities(12,18,24,30,and 36).The fish were fed three isocaloric and isolipidic diets for 60 days.The results show that specific growth rate(SGR)and feed conversion efficiency(FCE) were higher in fish reared at salinities of 18 and 36,but lower at 12.Fish fed with diet C25P40(25%carbohydrate and 40%protein) had lower SGR and FCE values compared with those fed with the C5P52(5%carbohydrate and 52%protein) and C15P46(15%carbohydrate and 46%protein) diets;however,there was no statistical difference between diet C5P52 and C15P46.SGR and FCE values were unaffected by diet composition in fish reared at salinity 36.Hepatic lipogenic enzyme activities were higher in fish reared at 18 and 36,but lower at 12,while glucokinase(GK) activity was higher in fish reared at 12,and lower at 18 and 36.Dietary starch enhanced GK activity while depressing lipogenic enzyme activity.However,lipogenic enzyme activity increased with increasing dietary starch in fish reared at 36.It is recommended that salinity should be maintained > 12 in the farming of juvenile turbot.In addition,an increase in gelatinized starch from 5%to 15%could spare 6%dietary protein in fish reared at salinities of 18-30,while higher salinity(36) could improve dietary carbohydrate use and enhance the protein-sparing effect,which is linked with the induction of lipogenic capacities.

A Study on the Meat and Bone Meal or Poultry By-product Meal as Protein Substitutes of Fishmeal in Concentrated Diets for Paralichthys olivaceus

A study was conducted to evaluate the effects of meat and bone meal （MBM） and poultry by-product meal （PBM） as the replacement of fishmeal in the diets on the growth performance, survival and apparent digestibility coefficient （ADC） of Japanese flounder （Paralichthys olivaceus）. The experimental diets included 0%, 20%, 40%, 60% and 80% MBM or PBM replacement of total fishmeal respectively. All diets were iso-nitrogenous and isocaloric. The results showed that there are no significant differences （P 〉0.05） in growth performance among the treatments fed with 0% -60% MBM replacement of fishmeal, while the percent weight gain （WG, % ）, body length gain （BLG, % ） and ADC significantly decrease when fishmeal is replaced by 80% MBM. The result showed also that there are no significant differences （P 〉0.05） in growth performance and ADC among all treatments fed with the diets with 0% -80% replacements of fishmeal with PBM.

Characterization of defensin gene from abalone Haliotis discus hannai and its deduced protein

Defensin is one of preserved ancient host defensive materials formed in biological evolution. As a regulator and effector molecule, it is very important in animals＇ acquired immune system. This paper reports the defensin gene from the mixed liver and kidney cDNA library of abalone Haliotis discus hannai Ino. Sequence analysis shows that the gene sequence of full-length cDNA encodes 42 mature peptides （including six Cys）, molecular weight of 4 323 Da, and pI of 8.02. Amino acid sequence homology analysis shows that the peptides are highly similar （70% in common） to other insects defensin. Because of a typical insect-defensin structural character of mature peptide in the secondary structure, the polypeptide named Haliotis discus defensin （hd-def）, a novel of antimicrobial peptides, belongs to insects defensin subfamily. The RT-PCR result of Haliotis discus defensin shows that the gene can be expressed only in the hepatopancreas by Gram-negative and positive bacteria stimulation, which is ascribed to inducible expression. Therefore, it is revealed that the Haliotis discus defensin gene expression was related to the antibacterial infection of Haliotis discus hannai Ino.

Feasibility of Partial Replacement of Fishmeal with Proteins from Different Sources in Diets of Korean Rockfish(Sebastes schlegeli)

An 8-week feeding experiment was conducted in an indoor recirculation seawater system to investigate the effects of partial replacement of dietary fishmeal with proteins from five sources on the growth performance and feed utilization of Sebastes schlegeli. Six isonitrogenous and isoenergetic diets were formulated using fishmeal(FM, the control) as sole protein source, or proteins from five sources including poultry by-product meal(PBM), meat and bone meal(MBM), soybean meal(SBM), cottonseed meal(CSM) and canola meal(CNM). Fifteen percent of the crude protein provided by fish meal was replaced, respectively. The results showed that the differences in specific growth rate(SGR) and survival rate(SR) among fish fed PBM, MBM, SBM, CSM and whole FM diets were not significant. However, SGR and SR of fish fed CNM diet was significantly lower than that of other treatments. Feeding rate, feed conversion, nutrient retention showed similar patterns to that of growth. Fish fed CSM and CNM showed significantly lower apparent digestibility coefficient(ADC) of dry matter and gross energy than those fed others while fish fed CNM showed lower ADC of crude protein than those fed others(P<0.05). These results suggested that it was feasible to substitute 15% dietary protein provided by fishmeal with PBM, MBM, SBM and CSM, respectively, but not with CNM as the replacement with CNM reduced fish growth and feed utilization.