Preparation by enzymolysis and bioactivity of iron complex of fish protein hydrolysate (Fe-FPH) from low value fish

Preparation of Fe^2＋ chelate of fish protein hydrolysate （Fe-FPH） obtained from low value fish proteins was introduced and its bioactivity was studied by compound enzymolysis. The optimum conditions for hydrolysate chelating Fe^2＋ are DH （degree of hydrolysis） at 5%, pH 7.0, 20℃ and 15 min chelating time for FM （material not being defatted）. Four types of Fe-FPH including CA （deposit after chelating）, CB （deposit in 50% of absolute ethanol solution）, CC （suspended deposit in 80% of absolute ethanol solution）, and CD （bottom deposit in 80% of absolute ethanol solution） were fractionated with absolute ethanol from FM. Structural analysis through infra-red spectrum revealed that Fe^2＋ was combined strongly with amino-group and carboxyl-group in each chelate and each Fe^2＋ could form two five-member ring structures. All of the four chelates were shown more significant antioxidative activity and can be used as natural hydrophobic and hydrophilic antioxidant. Among all the chelates, the CB possesses the most effective antioxidative activity at 92% as high as that of a-tocopherol. Among all Fe-FPHs, only CD showed the most effective antibacterial activity against Escherichia coli, Staphylococcus aureus, Salmonella typhi, and Bacillus subtilis and can be used as natural antibacterial. It provides a more effective way for utilization of low value fish proteins and key information of Fe-FPH as additive in food industry.

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.

Improvement of Vitis amurensis Rupr.grape quality by using fish protein hydrolysates as fertilizer

High quality wine grape is the first factor to satisfy the wine-maker to produce superior quality wines.In this work,a fish protein hydrolysates derived from deep-sea salmon or cod,was used as fertilizer to improve Shuanghong(Vitis amurensis Rupr.)grape quality.Application of powder fish protein hydrolysates fertilizer by spraying directly to foliar(4.5 kg/ha),to root(4.5 kg/ha)or to the both foliar(4.5 kg/ha)and root(4.5 kg/ha)were carried out respectively,during the period from 2–3 weeks before flowering until 2–3 weeks before harvest.Grape sampling was made at both veraison and harvest.Different classes of phenolic compounds,including 10 phenolic acids and 11 proanthocyanidins in grape seeds and 10 anthocyanins in grape skins were determined by UHPLC or HPLC;total anthocyanins and total polyphenols in grape skins were determined by spectrophotometric method.Antioxidant activities of the phenolic compounds were evaluated by ABTS and FRAP methods.The results showed that the application of fish protein hydrolysates fertilizer to both root and foliar led to a significant improvement of berry quality at harvest/maturity,i.e.,increasing 12.13%total polyphenols(TP),8.3%total anthocyanins 11.03%ABTS and 45.81%FRAP compared with control.Besides,both root and foliar application resulted in the highest individual anthocyanins and proanthocyanidins in grapes.These results suggest that the both root and foliar application could be of great interest for the viticulturists to produce grapes with higher polyphenolic content and antioxidant activity.Although this work was experimented with Vitis amurensis Rupr.grapes,the proposed methods would also be applicable to other grape varieties for the purposes of increasing anthocyanin or polyphenol contents.

Effects of fish protein hydrolysate on growth performance and humoral immune response in large yellow croaker (Pseudosciaena crocea R.)

We investigated the effects of fish protein hydrolysate (FPH) on growth performance and humoral immune response of the large yellow croaker (Pseudosciaena crocea R.). One thousand and two hundred large yellow croakers [initial average weight: (162.75±23.85) g] were divided into four groups and reared in floating sea cages (3 m×3 m×3 m). The animals were fed with 4 diets: basal diet only (control) or diets supplemented with 5%, 10% and 15% (w/w) FPH. The results show that dietary FPH levels significantly influenced the growth and immunity of the large yellow croaker. Compared with the control group, total weight gain (TWG) in all treatment groups, relative weight gain (RWG) and specific growth rate (SGR) in fish fed with diets supplemented with 10% and 15% FPH were significantly increased (P<0.05). Similar results were observed in immune parameters [lysozyme activity, serum complements, immunoglobulin M (IgM)]. Lysozyme activity, complement C4 and IgM were also significantly increased (P<0.05) in fish fed with diets supplemented with 10% and 15% FPH, while complement C3 level was significantly increased (P<0.05) in all treatment groups. In general, with the supplementation of FPH, particularly at dose of 10%, the growth performance and immunity of the large yellow croaker can be improved effectively.

Identification of SNARE proteins in fish—Tilapia Oreochromis niloticus

SNARE proteins are a group of membrane-associated proteins involved in exocytosis, secretion and membrane trafficking events in eukaryotic cells. Research on SNARE protein biology has become a more attractive field in recent years, which is applied to marine biology specifically to the fish Tilapia （Oreochromis niloticus）. Plasma membrane fractions of different tissues of Tilapia, including brain, liver-pancreas, intestine, skin and muscle, were extracted, and immuno-decorated with isoform-specific antibodies to the SNARE families and associated proteins. The presence of Syntaxins - 1 A, 2 and 3, SNAP - 23 and SNAP - 25, VAMP - 2, Munc - 18 - 1 and Munc - 13 in the brain was identified, which were differentially distributed in the other organ tissues of the fish Tilapia. The distinct distribution of SNARE and associated proteins will serve as the basis for further investigation into their special secretory function in these tissues of the fish.

Amino acid fortified diets for weanling pigs replacing fish meal and whey protein concentrate:Effects on growth,immune status,and gut health

Background： Limited availability of fish meal and whey protein concentrate increases overall feed costs. Availability of increased number of supplemental amino acids including Lys, Met, Thr, Trp, Val, and lie allows replacing expensive protein supplements to reduce feed costs. This study was to evaluate the effect of replacing fish meal and/or whey protein concentrate in nursery diets with 6 supplemental amino acids on growth performance and gut health of post-weaning pigs. Treatments were 1） FM-WPC： diet with fish meal （FM） and whey protein concentrate （WPC）; 2） FM-AA： diet with FM and crystalline amino acids （L-Lys, L-Thr, L-Trp, DL-Met, L-Val, and L-lie）; 3） WPC-AA： diet with WPC and crystalline amino acid; and 4） AA： diet with crystalline amino acid. Results： Pigs in FM-AA, WPC-AA, and AA had greater （P 〈 0.0.5） ADG and gain：feed than pigs in FM-WPC during wk ] （phase 1）. Plasma insulin concentration of pigs in AA tended to be greater （P = 0.064） than that of FM-WPC at the end of wk 1 （phase 1）. Plasma concentrations of IgG in AA was lower （P 〈 0.05） compared with WPC-AA and FW, and FM-AA had lower （P 〈 0.05） IgG concentration than WPC-AA at the end of wk 1 （phase 1）. Concentration of acetate in cecum digesta in FM-AA tended to be greater （P = 0.054） than that of FM-WPC and WPC-AA. Concentration of isovalerate in cecum digesta of pigs in FM-AA was greater （P 〈 0.05） than that of FW and WPC-AA. Conclusions： This study indicates that use of 6 supplemental amino acids can replace fish meal and/or whey protein concentrate without adverse effects on growth performance, immune status, and gut health of pigs at d 21 to 49 of age. Positive response with the use of 6 supplemental amino acids in growth during the first week of post-weaning may due to increased plasma insulin potentially improving uptake of nutrients for protein synthesis and energy utilization. The replacement of fish meal and/or whey protein concentrate with 6 supplemental amino acids could decrease the crude protein level in nursery diets, and potentially lead to substantial cost savings in expensive nursery diets.

大口黑鲈饲料营养需求及鱼粉替代研究进展

水产养殖动物的精准营养需求参数对其配合饲料的优化或者开发至关重要。文章概述了大口黑鲈蛋白质、脂肪、矿物质、碳水化合物以及维生素等主要元素需求以及蛋白源替代研究,对大口黑鲈饲料配制和降低成本等有重要的指导意义。

Effects of Three Humic Acid Foliar Fertilizers on Quality and Photosynthetic Characteristics of Hawthorn

[Objectives]To investigate the effects of three foliar fertilizers on photosynthetic characteristics,fruit quality and yield of hawthorn.[Methods]Taking hawthorn foliar fertilization as the reference,the photosynthetic rate,transpiration rate,intercellular CO 2 concentration,stomatal conductance and single fruit weight of hawthorn leaves were measured under different concentrations of foliar fertilizer.[Results]The results showed that the photosynthetic rate,transpiration rate and stomatal conductance of hawthorn leaves increased significantly,while the intercellular CO 2 concentration decreased.Specifically,the fish protein peptide foliar fertilizer performed best,with net photosynthetic rate and transpiration rate increased by 57.22%and 57.51%,respectively.All the three foliar fertilizers significantly reduced the intercellular CO 2 concentration.In addition,fertilization significantly increased the single fruit weight of hawthorn,and the effect of fermented fulvic acid foliar fertilizer was the most significant,with the highest growth rate of 68.49%.[Conclusions]Spraying foliar fertilizer significantly increased the content of Vc,titratable acid,anthocyanin and soluble solids of hawthorn fruit,among which fermented fulvic acid foliar fertilizer had the optimal effect.

化肥减量配施鱼蛋白有机液肥对番茄产量和品质的影响

为探讨增施鱼蛋白有机液肥替代化肥的效果,以每667m^(2)施用高钾水溶肥5.0kg为对照,设置每667 m^(2)施用高钾水溶肥3.5 kg+鱼蛋白有机液肥5.0 L、高钾水溶肥2.0 kg+鱼蛋白有机液肥5.0 L、高钾水溶肥0.5kg+鱼蛋白有机液肥5.0L这3个化肥减量处理,比较分析化肥减量增施鱼蛋白有机液肥对番茄生长、产量和果实性状及可溶性固形物含量的影响。结果表明:在每667m^(2)施用5.0L鱼蛋白有机液肥的情况下,减少水溶肥用量会降低番茄的株高、叶长和叶宽,但促进了茎粗、果实纵横径的生长,其中不同处理的果实纵径差异不显著,果形指数和可溶性固形物含量随水溶肥用量的减少先升高再降低,以每667 m^(2)每次追施高钾水溶肥3.5 kg和2.0 kg的果形指数最大,但与其他处理没有显著差异。不同处理的平均单穗坐果数没有显著差异,单果质量和果实纵横径的变化趋势一致,每667 m^(2)每次追施高钾水溶肥0.5 kg的小区产量最大。因此,在追求产量的情况下,果实膨大至采收前以每667 m^(2)每次追施高钾水溶肥+0.5 kg鱼蛋白有机液肥5.0 L的肥料配比最适合生产;如果追求品质,每667 m^(2)每次追施高钾水溶肥2.0 kg+鱼蛋白有机液肥5.0 L的肥料配比有利于生产,比对照果实可溶性固形物含量可提高5.8%,667 m^(2)产量提高17.2%。

改进鱼类营养和饲料研究范式:从大口黑鲈和大黄鱼配合饲料在养殖生产中的应用谈起

鱼类营养和饲料研究起始于20世纪50年代,并借鉴对人类和畜、禽营养研究的经验建立了研究范式。在过去70年中,鱼类营养和饲料研究遵循已有的范式取得了大量的成果,这些研究成果推动了水产配合饲料技术的进步,为水产饲料产业从无到有、从小到大做出了贡献。然而,随着全球水产养殖规模的不断扩大,水产养殖产业面临的资源和环境压力日益增加,对水产饲料也提出了更多和更高的要求。养殖生产实践表明,根据一些肉食性鱼类营养和饲料研究结果设计配方生产的饲料不能取得预期的应用效果,这意味着遵循已有研究范式所得到的结果难以完全满足现代鱼类养殖生产的需要。本文总结了两种具有重要经济价值的肉食性鱼类(大口黑鲈和大黄鱼)配合饲料在养殖生产中应用的曲折历程,指出早期研究明显低估了饲料蛋白水平是导致配合饲料长期无法在养殖生产中成功应用的主要原因。早期研究报道大口黑鲈的饲料蛋白需求为400~440 g/kg,大黄鱼的饲料蛋白需求为450~470 g/kg,但投喂配合饲料的鱼的生长明显比投喂冰鲜鱼的鱼慢。重新评估发现大口黑鲈和大黄鱼饲料蛋白需求分别为480~510 g/kg和490~520 g/kg,投喂含适量蛋白的配合饲料时鱼生长与投喂冰鲜鱼时接近。对大口黑鲈和大黄鱼饲料蛋白需求的明显低估反映出已有鱼类营养和饲料研究范式中存在不足,其表现为:①强调食物对鱼类生长的影响,但忽视了鱼类遗传背景和食物外的其他环境条件对鱼类生长和摄食的作用;②强调鱼类个体生长可反映其营养需求和饲料质量,但忽视了鱼类个体生长并不能完全反映养殖产量和效益;③强调生长和饲料利用效率在评价水产养殖效益方面的重要性,但忽视了投饵养殖对自然资源和环境所产生的负面影响是限制水产养殖可持续发展的瓶颈;④基础饲料配方对评价营养需求或饲料质量的影响没有得到足够重视,因基础饲料组成不合理导致一些研究结果缺乏实际意义。针对上述问题,作者建议对已有范式的概念、理论和研究方法做如下改进:①重视鱼类遗传背景和食物以外的其它环境条件对鱼类生长的影响,明确鱼类生长潜力决定营养需求,而食物营养是实现生长潜力的条件;②重视食物中各种营养素之间的相互作用,明确不同饲料原料在配方的营养平衡中发挥不同的作用;③进行饲养实验时重视实验鱼种质和种群结构,重视对照组和处理组个体生长的差异幅度在判断处理效应方面的指示意义,重视饲料配方对自然资源和环境等制约水产养殖可持续发展的因素的影响。改进后的研究范式更符合现代水产养殖生产实际,遵循其开展研究获得的结果能够更好地指导饲料配方设计,所生产的配合饲料也能更好地应用于水产养殖生产。

油炸预制鱼冷冻复热过程中的品质变化

为解决新零售预制烤鱼经冷冻复热后口感下降的问题,选取草鱼为研究对象,以水分含量、持水力、水分分布及组成和微观结构等为指标,探究鱼肉油炸、冷冻、复热不同阶段的品质变化规律。结果表明,随冻融循环次数增加,鱼肉肌纤维破坏程度增加,水分含量显著降低(P<0.05),持水性变差,脂肪氧化和蛋白降解程度显著增加(P<0.05),风味发生改变。复热后,冻融1次鱼肉仍能保持较好口感,但冻融2次后鱼肉感官评分较低,且肌原纤维小片化指数、TBARS和TCA-可溶性肽含量较冷冻前样品分别增加了24.44%、225.84%和52.85%。综上,当油炸预制鱼产品在贮运流通过程中发生冻融次数超过2次时明显降低产品食用品质和消费者接受度。

棉籽蛋白替代鱼粉对斑点叉尾鮰生长性能、饲料利用和肠道组织结构的影响

试验旨在研究棉籽蛋白替代鱼粉对斑点叉尾鮰生长性能、饲料利用率和肠道组织结构的影响。设计鱼粉含量为100 g/kg的基础饲料,用棉籽蛋白分别替代基础饲料中0、20%、40%、60%、80%和100%的鱼粉配制成6组等蛋白饲料(D1、D2、D3、D4、D5组和D6组),饲养初始平均体重为(171±1)g的斑点叉尾鮰67 d。结果表明:与D1组相比,D5组和D6组的末均重和增重率显著降低,饲料系数显著增加(P<0.05);D3组、D5组和D6组的肝体比显著低于D1组(P<0.05);D6组肌肉粗蛋白含量显著高于D1组(P<0.05);各组斑点叉尾鮰存活率、肥满度、脏体比和肌肉的水分、粗脂肪和粗灰分含量均无显著差异(P>0.05);当棉籽蛋白100%替代鱼粉比例时,饲料的干物质表观消化率和蛋白质表观消化率显著下降(P<0.05),各组之间的脂肪表观消化率无显著差异(P>0.05);在肠道组织学中,棉籽蛋白替代鱼粉对肠道的绒毛高度和肌层厚度无显著差异(P>0.05)。综上所述,在鱼粉含量为100 g/kg的基础饲料中,棉籽蛋白可以有效替代60%的鱼粉不会影响斑点叉尾鮰的生长性能、饲料利用和肠道组织结构。

γ-聚谷氨酸和鱼蛋白水溶肥对松花菜生长和产量的影响

为明确γ-聚谷氨酸和鱼蛋白水溶肥在蔬菜生产上的作用,以松花菜为供试作物,设置常规施肥、γ-聚谷氨酸、鱼蛋白3个处理。试验结果表明,γ-聚谷氨酸处理和鱼蛋白处理都能显著提高松花菜的株高、茎粗,提升松花菜品质和产量,增加松花菜的经济效益,以鱼蛋白处理对松花菜增产增效效果更好。

杂粕饲粮中添加水解鱼蛋白肽对肉鸡生长性能、屠宰性能、肉品质及氨基酸表观回肠消化率的影响

本试验旨在研究杂粕饲粮中添加不同水平的水解鱼蛋白肽对肉鸡生长性能、屠宰性能、肉品质及氨基酸表观回肠消化率的影响。选用300只体重相近、体况良好的1日龄爱拔益加(AA)肉仔鸡,随机分为5组,每组6个重复,每个重复10只鸡。对照组饲喂玉米-杂粕型基础饲粮(4%菜籽粕+5%棉籽粕),试验组分别在杂粕饲粮中添加1%、2%、3%和4%水解鱼蛋白肽,并配制成等能等氮的全价饲料。试验期42 d。结果表明:1)与对照组相比,添加1%水解鱼蛋白肽显著提高肉鸡42日龄体重、22~42日龄平均日采食量以及1~42日龄平均日增重和平均日采食量(P<0.05)。2)与对照组相比,添加4%水解鱼蛋白肽显著提高肉鸡半净膛率和全净膛率(P<0.05),添加2%水解鱼蛋白肽显著提高全净膛率(P<0.05)。3)与对照组相比,添加1%水解鱼蛋白肽显著提高肉鸡胸肌红度(a)和黄度(b)值(P<0.05),显著降低胸肌pH 45 min和剪切力(P<0.05),显著降低腿肌pH 45 min和pH_(2)4 h(P<0.05)。4)与对照组相比,1%水解鱼蛋白肽组蛋氨酸、苏氨酸、缬氨酸、谷氨酸、甘氨酸、天冬氨酸和脯氨酸表观回肠消化率显著提高(P<0.05)。综上所述,肉鸡杂粕饲粮中添加1%水解鱼蛋白肽可提高其生长性能,改善肉品质,同时促进氨基酸的消化吸收。

酶解棉籽蛋白替代鱼粉及添加单宁酸对斑点叉尾鮰生长性能和肠道健康的影响

试验研究了酶解棉籽蛋白替代鱼粉及添加单宁酸对斑点叉尾鮰(Ictalurus punctatus)生长性能和肠道健康的影响。设计鱼粉含量为10%的基础饲料,用酶解棉籽蛋白分别替代基础饲料中33.3%、66.6%和100%的鱼粉,并在100%替代组的基础上添加0.5 g/kg和1 g/kg的单宁酸,配制成6组等蛋白饲料(D1、D2、D3、D4、D5组和D6组),饲养初始平均体重为(172.6±1.6)g的斑点叉尾鮰67 d。结果表明:D4、D5和D6组的末体重和增重率较D1组显著下降(P<0.05),D4和D6组的饵料系数较D1组显著增加(P<0.05)。各组斑点叉尾鮰存活率、肥满度、肝体比、脏体比和肌肉常规成分组成均无显著差异(P>0.05)。斑点叉尾鮰后肠肠道微生物群落的优势菌群包括厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidota)、变形菌门(Proteobacteria)和梭杆菌门(Fusobacteria)。对比不同处理组发现,D4组的拟杆菌门相对丰度显著低于D5组(P<0.05),D4组的变形菌门相对丰度显著高于D1、D2和D5组(P<0.05)。各组斑点叉尾鮰肠道的组织结构和微生物多样性无显著差异(P>0.05)。综上所述,在鱼粉含量为10%的基础饲料中,酶解棉籽蛋白可以有效替代66.6%的鱼粉而不会对斑点叉尾鮰的生长性能和肠道健康产生负面影响,0.5 g/kg单宁酸能有效改善无鱼粉组斑点叉尾鮰的肠道微生物群落组成,但对生长性能没有提升效果。

糖基化反应对鱼蛋白胶挥发性风味及凝胶性能的影响

为改善鱼蛋白胶风味,本文以鱼蛋白胶为原料,通过与葡萄糖构建糖基化反应体系,利用酶标仪、色度仪、质构仪、流变仪和气相色谱-质谱联用仪测定鱼蛋白胶的游离氨基、色泽、凝胶强度、胶融温度和挥发性风味物质变化,探究不同糖基化时间对挥发性风味物质及凝胶性能的影响。结果表明,糖基化反应时间从0 h增加到24 h,鱼蛋白胶黄度增加,游离氨基含量下降,糖基化程度逐渐增加(P<0.05),胶融温度无显著性差异(P>0.05)。糖基化反应6 h时,总醛相对含量最低为47.09%,产生不愉悦气味的化合物壬醛、癸醛、辛醛相对含量分别减少9.64%、7.88%、1.39%。葡萄糖的加入使得鱼蛋白胶的凝胶强度下降,随糖基化时间的增加,凝胶强度先增大后减小,糖基化反应6 h时,凝胶强度达最大值。因此,糖基化反应6 h能够有效改善鱼蛋白胶风味特性。本研究结果可为鱼蛋白胶的风味改善提供理论依据。

FISH和IHC检测HER2基因及蛋白在乳腺癌诊治中的应用

目的对比研究免疫组织化学（IHC）与荧光原位杂交（FISH）方法检测乳腺癌中C-erbB-2蛋白表达和HER2基因扩增,评估两种方法的实际应用价值。方法 IHC和FISH法分别检测58例乳腺癌组织中C-erbB-2蛋白表达和HER2基因扩增状况,并进行一致性分析。结果IHC检测蛋白阳性2＋和3＋共22例,占总病例的37.9%,58例乳腺癌中FISH检测出HER2基因扩增17例,占29.3%。IHC检测C-erbB-2蛋白3＋的12例中11例HER2基因扩增阳性,1例无扩增;C-erbB-2蛋白2＋者10例,其中5例可见HER2基因扩增;C-erbB-2蛋白1＋者11例HER2基因扩增仅1例。C-erbB-2蛋白阴性病例共25例均未检测到基因扩增。结果显示IHC检测C-erbB-2蛋白与FISH检测HER2基因扩增状态有较高的一致性（k=0.681,P〈0.01）,C-erbB-2蛋白阴性和3＋标本与HER2基因扩增阳性率比较差异无统计学意义（P〉0.05）;而C-erbB-2蛋白1＋和2＋病例与其HER2基因扩增差异具有统计学意义（P〈0.05）。结果 IHC检测C-erbB-2蛋白强阳性（3＋）和阴性（0）与HER2基因扩增有较高的一致性,可作为临床是否应用Herceptin治疗的依据,而C-erbB-2蛋白2＋和1＋病例必须进一步行HER2基因扩增检测。

市售鱼鳔氨基酸及蛋白质成分分析

目的 分析16批不同基原的市售鱼鳔中氨基酸及蛋白质成分。方法 建立一种6-氨基喹啉基-N-羟基琥珀酰亚胺基甲酸酯柱前衍生、高效液相色谱法,测定鱼鳔中17种氨基酸含量,并对不同基原鱼鳔中氨基酸类成分进行分析;采用十二烷基硫酸钠聚丙烯酰胺凝胶电泳分析鱼鳔中的蛋白质分子量分布,并采用蛋白质组学法鉴定鱼鳔中的蛋白质。结果 17种氨基酸在一定浓度范围内线性关系良好(R2≥0.998 0),平均加样回收率85.62%~109.60%,精密度、稳定性、重复性RSD均小于3.5%。16批鱼鳔氨基酸组成与含量存在差异,氨基酸总含量介于468.31~620.05 mg/g;从16批鱼鳔中共鉴定688种蛋白质,包括Ⅰ型在内的胶原蛋白多达11种,此外,鱼鳔中还含有较多分子质量52~95 kDa的低丰度蛋白。结论 该研究可为鱼鳔的质量评价和开发利用提供参考。

鱼类低温适应性机制与抗冻蛋白的研究进展

温度对调节鱼类的生物功能至关重要,长期生活在极端寒冷环境中的鱼类通过发生适应性进化而存活下来,抗冻蛋白的产生是其中最重要的适应性特征之一。为全面了解鱼类的低温适应性机制研究进展,首先从内分泌系统、代谢系统和免疫系统3个方面阐述了低温水环境对鱼类的基因表达和激素分泌的影响,以及对机体代谢过程的整体影响;其次,从鱼类的生理适应和进化适应两部分综述了鱼类的低温适应性机制;最后,详细阐述了抗冻蛋白的研究起源与结构特性、克隆与功能鉴定等方面的研究进展。相关研究现状表明,利用组学方法可以研究低温胁迫下鱼类的代谢途径和分子信号通路,在生物整体水平上分析低温适应机制;利用该方法,已经挖掘了多种低温耐受功能基因。由于不同鱼类及其温度适应性存在差异,未来还需要开展更多基础性研究工作。

两株菌协同发酵鱼下脚料制备功能性宠物饲料

为了提高有机废弃物在生产中的利用,探索新型功能性宠物饲料,以鱼下脚料为原料,通过单因素试验和正交试验探究最佳发酵条件,并添加猴头菇菌丝体和番茄渣制成功能性饲料。结果表明,最优发酵条件为枯草芽孢杆菌∶红酵母=2∶1,鱼下脚料添加量30%、接菌量5%(V/V)、发酵温度30℃,发酵基质中添加烘干的2%猴头菇菌丝体和1%番茄渣,可显著增加原料中蛋白质和氨基酸含量,粗蛋白质含量提升率为73.71%,总氨基酸含量提升率为24.97%,其中,谷氨酸含量增加最为明显,提升率为98.98%。小鼠急性毒理试验表明,对照组与试验组无显著性差异(P>0.05),说明此饲料可应用于功能性宠物饲料的生产。该研究为今后鱼下脚料的发酵工艺提供了理论基础,且为宠物饲料的发展提供了新方向。