藻胆蛋白提取方法研究进展

藻胆蛋白（Phycobiliprotein）是红藻和蓝藻特有的捕光色素蛋白,包括藻红蛋白、藻蓝蛋白和别藻蓝蛋白3类。藻胆蛋白本身为亮丽的天蓝色,在蓝紫光激发下能发出强烈的荧光,它含有人体必需的氨基酸,因此,藻胆蛋白用途极为广泛,既可以作为天然色素应用于食品、化妆品、染料等工业,又可制成荧光试剂,用于临床医学诊断和免疫化学等研究领域中,同时还是一种重要的生理活性物质,可制成保健品及药品等。     

藻胆蛋白的研究和应用

藻胆蛋白(Phycobiliproteins,PBP)是存在于蓝藻(Cyanophyceae)、红藻(Rhodophyceae)、隐藻(Cryptophyceae)和少数甲藻(Pyrrophyceae)中的一类色素复合蛋白,已知的藻胆蛋白主要可以分为4大类,即藻红蛋白(P h y c o c y a n i n s,P E)、藻蓝蛋白(Phycocvardn,PC)、藻红蓝蛋白(Ph     

坛紫菜不同色素突变体的初步研究

初步探讨了坛紫菜Porphyra haitanensis褐色、褐绿色、翠绿色、红棕色、棕褐色、桔红色和紫色7种色素突变体的子一代叶状体形态特征、生长及4种主要色素含量的变化.3～4cm长的不同色泽幼苗经20d培养后的结果显示:(1)各色素突变体从长度、宽度、鲜重量和细胞厚度方面较野生坛紫菜均具有显著优势;在培养时间内,各色素突变体的长度日增长量均显著高于野生型坛紫菜;褐绿色、棕褐色和红棕色突变体在鲜重日增重率上表现出明显的优势,在第11～15天所有色素突变体的平均日增重率均高于野生型;(2)红棕色、棕褐色和紫色突变体的总藻胆蛋白含量明显高于野生型.紫色突变体的藻红蛋白、藻蓝蛋白和别藻蓝蛋白含量均为最高,其中藻红蛋白、别藻蓝蛋白含量为野生型的3倍.叶绿素含量均无明显变化.本研究结果为有效利用坛紫菜的不同色素突变体进行种质改良奠定了良好基础.     

江苏盐城发现一海生隐藻

隐藻含有丰富的DHA、藻蓝蛋白和藻红蛋白,具有较高的开发利用价值.于江苏盐城射阳盐场发现1种海生隐藻,可以在含氯化钠80 g/L的盐度培养基中良好生存, 但它的形态特征与淡水森氏藻相似,该海生隐藻国内未见报道,因此具有重要价值.     

鱼腥藻藻蓝蛋白的提取

对鱼腥藻藻蓝蛋白的大规模提取方法进行了初步的探索。对实验室精细的小规模分离提取方法进行了简化。用0．01mol／L磷酸盐缓冲液浸提，经3次反复冰融渗透震荡处理，使细胞破碎，释放藻蓝蛋白，然后离心分离。用磷酸缓冲液反复提取至上清液透明。采用这种方法从鱼腥藻中提取藻蓝蛋白，可处理的样品规模大，藻蓝蛋白得率高达98．8％，并且操作方法简便，节约药品，成本低。     

Ni^2+对钝顶螺旋藻生长及藻胆蛋白含量的影响

为研究Ni^2+对螺旋藻生长的影响,采用室内培养法,在培养液中添加不同质量浓度的Ni^2+,对螺旋藻的生长曲线、生物量、吸收光谱以及藻胆蛋白含量进行了测定和分析。试验结果显示,当Ni^2+质量浓度为0~0.5μg/mL时,随着质量浓度的增加,藻胆蛋白含量增加,螺旋藻生长加快,累积的螺旋藻生物量增加;0.5μg/mL的Ni^2+对螺旋藻生长、生物量累积和藻胆蛋白含量具有最大促进作用;0.5μg/mL的Ni^2+处理,导致螺旋藻叶绿素a在蓝紫光区的吸收光谱发生明显变化,440 nm的吸收峰消失,而在430 nm和450 nm处分别出现一个吸收峰;Ni^2+对藻蓝蛋白和别藻蓝蛋白的吸收光谱没有显著影响。当Ni^2+质量浓度达到1.0μg/mL时,螺旋藻仍能正常生长。试验结果表明,0.5μg/mL的微量Ni^2+通过改变螺旋藻叶绿素a在蓝紫光区的吸收光谱,提高藻胆蛋白含量,从而促进螺旋藻的生长和生物量的累积,是促进螺旋藻生长的最佳Ni^2+质量浓度,为降低螺旋藻生产成本,以及利用螺旋藻治理水体镍污染提供科学依据。     

紫菜藻胆蛋白质的提取纯化与抗病毒研究

用溶胀法和反复冻融法粗提取紫菜中的藻胆蛋白,并经羟基磷灰石（HA）柱用不同浓度的磷酸缓冲液梯度洗脱,分离纯化出藻胆蛋白,研究其对感染病毒小鼠的抗病毒活性。结果表明：当纯度（A558nm＋A616nm）/A280nm〉4时,洗脱液离子强度为200mmol／L,收集液在280nm处有明显的吸收峰;感染病毒的小鼠注射藻胆蛋白后活动量比未注射时频繁,体重增加较明显。     

螺旋藻直线形变异藻株(Sp.-Dz)研究初报

从长期应用于研究与生产中的优良钝顶螺旋藻（Ｓｐｉｒｕｌｉｎａ ｐｌａｔｅｎｓｉｓ）藻株（Ｓｐ．－Ｄ）中分离出一株直线形变异藻株（Ｓｐ．－Ｄｚ）,对其生长特性及主要生化组分进行了初步研究,实验结果表明,这一直线形变异藻株具有生长快、上浮性好、藻胆蛋白含量高等优点,是一株值得进一步研究和利用的新藻株。     

蜈蚣藻和繁枝蜈蚣藻孢子发生类型的研究

本研究以我国厦门地区沿海产的蜈蚣藻和繁枝蜈蚣藻为对象，进行其发生的比较研究，其结果如下：1．蜈蚣藻的果孢子和四分孢子大小相似，直径约为15微米左右，孢子中央具有一个细胞核，色素体多集中于细胞中央，呈黄褐色。繁枝蜈蚣藻的果孢子和四分孢子略大，直径为17微米左右，其色素体呈棕褐色。2．蜈蚣藻和繁枝蜈蚣藻的孢子发生类型，均为间接盘状型，但其发生初期的发生形式，略有不同，表现出种间的差异性。     

侧孢短芽孢杆菌溶藻活性代谢产物对虾池颤藻的溶藻效果

为改善对虾养殖水环境,研究了不同阶段的侧孢短芽孢杆菌无菌滤液和颤藻对溶藻效果的影响.通过测定溶藻过程中藻体干重、叶绿素a含量以及藻蓝蛋白含量,探究了溶藻效果的最佳作用阶段及其作用机理.结果显示,稳定期和衰亡期的无菌滤液对颤藻的溶藻效果极为显著,7d后颤藻干重分别减少了51.77％、47.04％,叶绿素a含量分别降低了67.60％、59.13％,藻蓝蛋白含量分别增加了33.51％、30.97％;溶藻细菌无菌滤液对延滞期颤藻的溶藻效果极显著,7d后颤藻干重减少了63.90％,叶绿素a含量下降了69.72％,藻蓝蛋白含量升高了54.17％.结果表明,侧孢短芽孢杆菌培养至稳定期的无菌滤液对延滞期颤藻的溶藻效果最好.     

Rare serotype occurrence and PFGE genotypic diversity of Streptococcus agalactiae isolated from tilapia in China

Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China.     

Growth hormone (GH) and reproduction: a review

Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations.     

Purification and partial characterization of GtHs (cfLH and cfFSH) from Indian walking catfish (Clarias batrachus) (L.) and development of a homologous ELISA for cfLH

Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL^?1 (1.25 ng well^?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation.     

Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection

Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg^?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality).     

Evaluation of a Fast Method Based on the Presence of Two Restriction Sites in the Mitochondrial ND5 (mt ND5) Gene for the Identification of Scomber Species

The purpose of this work was to evaluate the suitability of a method based on the presence of two restriction sites (for Hae III and Hindf I) in the mitochondrial NADH dehydrogenase subunit 5 (mt ND5) gene to identify Scomber species. The evaluation was performed on 144 reference and market samples by sequencing of the entire 505-bp fragment of the mt ND5 gene and of a 464-bp fragment of the Kocher fragment of the cytochrome b gene (mt Cytb). Sequence analysis of any of the two fragments allows the identification of each of the four Scomber species, but S. japonicus and S. colias had the same restriction sites at the ND5 amplicon and would not have been differentiated by this analysis. Similarly, loss of the Hae III site in some S. scombrus individuals would have misidentified them as not being Scomber. All the market products were correctly labeled except one acquired in Spain labeled as originating in the Atlantic and containing S. japonicus.     

Imported ornamental fish are colonized with antibiotic‐resistant bacteria

There has been growing concern about the overuse of antibiotics in the ornamental fish industry and its possible effect on the increasing drug resistance in both commensal and pathogenic organisms in these fish. The aim of this study was to carry out an assessment of the diversity of bacteria, including pathogens, in ornamental fish species imported into North America and to assess their antibiotic resistance. Kidney samples were collected from 32 freshwater ornamental fish of various species, which arrived to an importing facility in Portland, Oregon from Colombia, Singapore and Florida. Sixty‐four unique bacterial colonies were isolated and identified by PCR using bacterial 16S primers and DNA sequencing. Multiple isolates were identified as bacteria with potential to cause disease in both fish and humans. The antibiotic resistance profile of each isolate was performed for nine different antibiotics. Among them, cefotaxime (16% resistance among isolates) was the antibiotic associated with more activity, while the least active was tetracycline (77% resistant). Knowing information about the diversity of bacteria in imported ornamental fish, as well as the resistance profiles for the bacteria will be useful in more effectively treating clinical infected fish, and also potential zoonoses in the future.     

Effect of iodophor disinfection of non‐hardened Salmo trutta eggs on their bacterial and fungus load

This study investigated the efficiency of iodophor disinfection (135 ppm active iodine for 15–30 min) of non‐hardened Salmo trutta eggs against different groups of bacteria and against fungus. Egg samples were taken from non‐disinfected and from disinfected eggs, microorganisms were cultured on specific nutrient media and their mass was measured by turbidimetric methods. Bacteria and fungus mass of non‐hardened eggs could be reduced but not eliminated by iodophor disinfection with 135 ppm active iodine for 15 min. The extent of reduction was 47–65% (Experiment 1). The efficiency of disinfection increased with disinfection time as the reduction in bacteria and fungus mass was 40–55% after 15 min and 58–74% after 30 min (Experiment 2). Disinfection efficiency of iodophor solution diluted in water (reduction 49–57%) and of iodophor solution diluted in sodium chloride solution iso‐osmolar to the oocytes (reduction 52–61%) was similar (Experiment 3). The reduction in bacteria and fungus mass was persistent as it was 39–72% lower in embryos deriving from disinfected eggs than in embryos deriving from non‐disinfected ones (Experiment 4). In conclusion, the tested disinfection method is inadequate to eliminate pathogens completely but it could positively influence immune defence of eggs and embryos.     

Nitrogenous waste excretion and accumulation of urea and ammonia inChalcalburnus tarichi (Cyprinidae), endemic to the extremely alkaline Lake Van (Eastern Turkey)

The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I^–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg^–1 fish·h^–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g^–1·ml^–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min^–1·g^–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min^–1·g^–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated.