Beneficial effects of high-pressure homogenization on the dispersion stability of aqueous hydrolysate from Mytilus edulis

Owing to the formation of aggregation and gelation during storage,certain proteins and peptides exhibit limited applications in aqueous protein food products.The purpose of this study was to investigate the influence of homogenization and xanthan gum addition on the dispersion stability of Mytilus edulis hydrolysate(PHM).High-pressure homogenization(HPH)at 360 and 40 bar in the first and second values,respectively,and adding xanthan gum at a concentration of 1 mg/mL showed significantly improvement on the stability of the PHM solution.PHM-xanthan gum solutions(PHMX)showed the highest polypeptide precipitation rate and turbidity retention rate compared with those of PHM.Moreover,the centrifugal precipitation rate of PHMX without HPH was higher than that of homogeneous PHMX.After HPH treatment at 400 bar,the percentage of smaller particles in PHM and PHMX was increased,the aqueous system became more uniform,and the fluorescence intensity reached its maximum.HPH pretreatment improved the polypeptide dispersion stability and turbidity retention rate of PHM and PHMX and reduced the fluorescence intensity.The interactions of xanthan gum and polypeptide render the network microstructure more uniform under the conditions of homogenization,thus improving the dispersion stability of PHMX solutions.Therefore,under the premise of adding xanthan gum,HPH can better enhance the dispersion stability of the polypeptide in PHM.

Relationship between oxygen concentration, respiration and filtration rate in blue mussel Mytilus edulis

The large water-pumping and particle-capturing gills of the filter-feeding blue mussel Mytilus edulis are oversized for respiratory purposes. Consequently, the oxygen uptake rate of the mussel has been suggested to be rather insensitive to decreasing oxygen concentrations in the ambient water, since the diff usion rate of oxygen from water flowing through the mussel determines oxygen uptake. We tested this hypothesis by measuring the oxygen uptake in mussels exposed to various oxygen concentrations. These concentrations were established via N2-bubbling of the water in a respiration chamber with mussels fed algal cells to stimulate fully opening of the valves. It was found that mussels exposed to oxygen concentrations decreasing from 9 to 2 mg O_2/L resulted in a slow but significant reduction in the respiration rate, while the filtration rate remained high and constant. Thus, a decrease of oxygen concentration by 78% only resulted in a 25% decrease in respiration rate. However, at oxygen concentrations below 2 mg O_2/L M. edulis responded by gradually closing its valves, resulting in a rapid decrease of filtration rate, concurrent with a rapid reduction of respiration rate. These observations indicated that M.edulis is no longer able to maintain its normal aerobic metabolism at oxygen concentration below 2 mg O 2/L, and there seems to be an energy-saving mechanism in bivalve molluscs to strongly reduce their activity when exposed to low oxygen conditions.

紫贻贝(Mytilus edulis Linnaeus)大量死亡原因的初步研究

从发病紫贻贝(Mytilusedulis)的内脏团内分离出一株菌SS1,通过人工感染试验,证实其为致病菌。经形态、生理生化等几项指标鉴定,该菌株性状与溶藻弧菌基本相符。药物敏感试验结果表明羧苄青霉、万古霉素、克林霉素、氨苄青霉素、阿莫西林等9种药物对该菌株均有明显的抑制作用。

Effect of Salinity on Growth of Mussels,Mytilus edulis,with Special Reference to Great Belt(Denmark)

The effects of salinities between 10 and 30 psu on the growth of blue mussels, Mytilus edulis, were studied in laboratory feeding experiments and compared to the growth of mussels suspended in net-bags in the brackish water Great Belt, Denmark. In the laboratory, 3 series of growth experiments were conducted: in Series #1, groups of mussels were exposed to 10, 15, 25 and 30 psu, in Series #2, two groups of mussels were exposed to 10 and 30 psu, respectively, for 15 days (first period) where upon the mussels were exposed to the reversed salinities for another 15 days (second period). In Series #3, two groups of mussels were initially exposed to 15 and 25 psu for 22 days whereupon the mussel groups were exposed to the reversed salinities for another 17 days. In the laboratory experiments there was a tendency towards reduced growth with decreasing salinity, reflected as reduced shell growth rate and decreasing weight specific growth rate with falling salinity. The shell growth rate was relatively low in the first feeding period compared to the second period, and mussels that were initially exposed to 10 psu, where the growth was low, exhibited fast growth when subsequently exposed to 30 psu, and reversed when 30 psu mussels were exposed to 10 psu. The study showed that mussels are able to adjust growth at changing salinities, and the observed effect of salinity could partly be explained by a temporary shell valve closure after a sudden change in salinity. The specific growth rate of mussels measured in laboratory experiments at salinities between 15 to 25 psu (4.2% to 4.8% d–1) were comparable to the growth of mussels in the field experiment (3.2% to 4.0% d–1) where the salinity varied between 24 and 13 psu during the growth period.

Environmental Factors and Seasonal Variation in Density of Mussel Larvae(Mytilus edulis) in Danish Waters

Mussel larval densities may fluctuate considerably on both small spatial and short temporal scales. So far, only few and scattered data on the occurrence of mussel larvae have been reported from Danish waters. However, seasonal variation in density of blue mussel (Mytilus edulis) larvae as related to environmental factors (temperature, salinity, phytoplankton biomass) is basic information of relevance for future line-mussel farming in Danish waters. Here we report on the density of mussel larvae in a number of potential farming sites in the inner Danish waters. The mussel larval density measured in Skive Fjord, an eutrophicated inner branch of Limfjorden, during a period of 20 years, from 1989 to 2009, along with corresponding temperatures and chlorophylla, makes up the most important series of data reported here. In most years, a pronounced spring density peak and a subsequently lower autumn peak could be seen in Skive Fjord, but most conspicuous in the period 1993 to 2002 where the mean maximum spring larval density was 319 ± 260 ind·l-1. Further, data on mussel larval densities have been recorded on 4 locations in the Great Belt region: Kerteminde Bay in 2008 to 2011, and in 2008 at 3 other locations: Musholm Bay, Svendborg Sund, and Horsens Fjord. The maximum spring densities in the studied waters were observed in Skive Fjord, typically in May, whereas 10 to 100 times lower peak densities were found at the other locations studied. The reported observations show that mussel larvae are omnipresent in the studied areas and it is suggested that the larval density is sufficient forrecruitment to future line-mussel farms.

Effect of Salinity-Changing Rates on Filtration Activity of Mussels from Two Sites within the Baltic Mytilus Hybrid Zone:The Brackish Great Belt(Denmark)and the Low Saline Central Baltic Sea

Mussels from two sites within the Baltic mussel (Mytilus edulis × M. trossulus) hybrid zone were used in a comparative study on the effects of salinity-changing rates on filtration activity. The acute effect of varying salinity-changing rates was found to be similar in M. edulis from the brackish Great Belt and in M. trossulus from the low saline Central Baltic Sea, and the relationships could be described by linear regression lines through 0.0 indicating that the acute effect of deteriorating conditions at decreasing salinities is the opposite as for improving conditions when the salinity is subsequently increased. Further, both M. edulis and M. trossulus acclimatized to 20 psu reacted to an acute salinity change to 6.5 psu by immediately closing their valves whereupon the filtration rate gradually increased during the following days, but only M. trossulus had completely acclimatized to 6.5 psu within 5 days which may be explained by different genotypes of M. edulis and M. trossulus which probably reflected an evolutionary adaptation of the latter to survive in the stable low-salinity Baltic Sea.

Study on Pollination Compatibility of Superior Lonicera caerulea Individuals

In order to solve the problems including low fruit-bearing rate and low yield caused by blind plantation in production, the medium formula for pollen germination of Lonicera caerulea L. var. edulis Turcz. ex Herd., its pollination habit, self-compatibility and open pollination compatibility between different superior individuals were investigated with superior individuals from superior wild individuals of L. caerulea in Changbai Mountains as experimental materials. Self-compatibility and open pollination compatibility among different fine plants provide theoretical basis for its further application and further selection of new varieties. The results showed the optimal medium for germination of L. caerulea pollen was 27.5% sucrose ＋ 100 PPM boric acid with a pH value of 6.0. On this medium, the superior individuals L1, L2 and L3 had the pollen germination rates of 53.4%, 50.9% and 51.6%, respectively. The three superior individuals had no significant differences in the quantity of germinated pollen tubes, which ranged from 1 to 4. The three excellent single plants were the most likely to germinate a single pollen tube, accounting for 83.3% of the pollen germinated and 89.6% of the pollen germinated. Therefore, in production, it is necessary to plant L1 with a certain amount of pollination trees or plant it together with multiple species, to improve its yield. On the contrary, L2 and L3 have no need for pollination trees theoretically, but whether the fruits obtained by self-pollination and outcrossing differ in quality still needs further study.

紫贻贝（Mytilus edulis L．）鳃的研究

用光镜和扫描电镜观察了紫贻贝鳃的组织学和表面结构。鳃丝上皮由六个区带的细胞组成：前纤毛柱状细胞、前侧纤毛柱状细胞、无纤毛柱状细胞、侧纤毛柱状细胞、立方或扁平细胞及后纤毛柱状细胞。各种柱状细胞的纤毛与食物的运输及水流的产生有关。立方或扁平细胞为呼吸上皮区，其组织学和表面结构有助于进行气体交换。

芝麻浸提液对毛竹种子萌发及幼苗生理特性的影响

以2019年9月份采自广西桂林市的毛竹(Phyllostachys edulis)种子为供试种子材料;以2019年10月份采自浙江省林业科学研究院竹类植物园的芝麻(Sesamum indicum L.)植株根、茎、叶为原料,制备不同质量浓度的水浸提液(25、50、75、100 g·L^(-1))为种子处理液;以蒸馏水为对照,在培养皿(直径15 cm)中分别加入不同质量浓度的芝麻根、茎、叶浸提液,每个培养皿中放入50粒毛竹种子,置于恒温恒湿箱(温度25℃、湿度90%)中进行发芽培养试验;发芽结束后,抽取幼苗10株,测定胚根的生理生化指标(超氧化物歧化酶活性、过氧化物酶活性、过氧化氢酶活性、可溶性蛋白质量分数、游离脯氨酸质量分数、丙二醛质量摩尔浓度);以毛竹种子发芽率、发芽指数、化感效应综合指数为评价指标,分析不同质量浓度芝麻根、茎、叶水浸提液对毛竹种子萌发、幼苗生长及生理特性的影响,探索芝麻对毛竹生长的潜在化感作用。结果表明:①随着芝麻根、茎、叶浸提液质量浓度的升高,毛竹种子的发芽率和发芽指数均呈降低趋势;芝麻根、茎、叶浸提液质量浓度为100 g·L^(-1)时,毛竹种子的发芽率和发芽指数均显著低于对照。芝麻叶浸提液处理的毛竹种子发芽率,在各质量浓度时均低于根、茎浸提液处理的毛竹种子发芽率。胚根和胚芽长度,均随芝麻浸提液质量浓度的升高而降低,而根芽比逐渐升高,但根芽比在芝麻浸提液质量浓度为75、100 g·L^(-1)处理间的差异不显著。②毛竹种子萌发的综合效应指数均小于0,但其绝对值均呈现升高趋势;同一芝麻器官浸提液,各芝麻浸提液质量浓度间的综合效应指数差异显著;同一质量浓度,芝麻叶浸提液的化感抑制作用,高于根、茎浸提液。③随着芝麻浸提液质量浓度的升高,毛竹幼苗抗氧化酶活性均呈现先升高后降低的趋势,但其达到峰值时的芝麻浸提液质量浓度不同;随着芝麻浸提液质量浓度的升高,可溶性蛋白质量分数逐渐降低,而游离脯氨酸质量分数、丙二醛质量摩尔浓度逐渐升高。④芝麻浸提液对毛竹种子萌发及幼苗生长具有明显的化感抑制作用,且高质量浓度的化感抑制作用高于低质量浓度,叶的化感抑制作用高于根、茎;环境变化影响毛竹幼苗的抗氧化酶活性、渗透调节物质质量分数。

三种典型POPs对紫贻贝不同组织DNA损伤的比较研究

采用彗星电泳技术,比较研究了Aroclor 1254、BaP、DDT三种典型POPs对紫贻贝(Mytilus edulis)鳃、性腺、消化腺细胞的DNA损伤效应的差异,以期为进一步评价这三种典型POPs遗传毒理机制及其预警监测提供科学依据。结果表明,Tail DNA%是评价DNA损伤的理想指标,另外,在急性毒性试验中,这三种POPs对紫贻贝鳃、性腺、消化腺细胞的DNA损伤作用均存在显著时间-剂量-效应关系,其中,BaP的DNA损伤作用最大,鳃和消化腺细胞对毒性作用较敏感。同时,对不同组织细胞的敏感性差异原因及其在环境监测中的应用进行了探讨。

化学物质诱导变态后紫贻贝稚贝的生长及存活

在以往实验的基础上,跟踪调查了筛选出的化学诱导物质对紫贻贝(Mytilus edulis)幼虫变态后的生长和成活率的影响,并比较了其与相同条件下自然诱导物、微生物膜诱导后的稚贝的生长和成活率。实验结果表明,肾上腺素、苯肾上腺素、可乐宁、KCl和NH4Cl 5种化学物质均成功地诱导了该种幼虫的变态,其变态后稚贝同微生物诱导变态后的稚贝以相同的速度生长,且在培育过程中无死亡稚贝出现。因此,这些化学物质可作为该种养殖以及海洋防污染研究中幼虫变态的有效人工诱导物。

贻贝多活素的药理学研究——Ⅰ 对实验性心肌缺血的保护作用及其机制的研究

用两种模型研究贻贝多活素((multibioactive substances of Mytilus edulis,MSM)对实验性心肌缺血的保护作用。在结扎冠脉致大鼠急性心肌梗死实验中,MSM(1.35、4.05、6.75g/kg)可明显降低缺血EKG中S-T段异常抬高的程度,ΣST分别为25.2、27.8和21.8mV,与NS对照组(62.9mV)差异非常显著(P<0.001),N-BT染色显示心肌梗死的范围明显缩小。MSM亦能减轻因快速静注垂体后叶素引起的大鼠EKG中缺血性损伤的变化,使心肌缺血阳性率明显降低。结果表明,MSM对实验性心肌缺血有保护作用,其作用机制可能与降低血中MDA浓度,提高CuZn-SOD、GSH-Px活性,防止心肌细胞脂质过氧化作用有关。

贻贝多活素的药理学研究——Ⅱ对大鼠实验性血栓形成及血小板聚集的影响

观察了贻贝多活素(MSM)对实验性血栓形成和血小板聚集的影响。大鼠经igMSM1.35、2.7和5.4g/(kg·d)连续28d后,对“旋转环法”所形成的大鼠实验性血栓有明显抑制作用,其血栓湿重分别为105.1、97.3和89.3mg,与生理盐水(NS)^-对照组的142.7mg相比较,差异非常显著(P<0.01);其血栓干重亦明显低于NS组(P<0.01)。同样的给药途径和剂量,MSM可抑制ADP诱导的大鼠血小板聚集,使其最大聚集率降低,聚集速度减慢,聚集抑制率分别为27％、33％和21％。MSM体外用药亦可降低胶原诱导的家兔血小板最大聚集率和聚集速度,抑制率分别为45％、58％和64％。结果表明,MSM可通过降低血小板的聚集功能从而抑制动脉血栓的形成。

蓝锭果忍冬干燥果实的营养成分及其评价

Nutritional components in dry fruits of Lonicera caerulea L.var.edulis Turcz.ex Herd.collected from Hulun Buir of Inner Mongolia have been analysed.The results show that dry fruits mainly contain sugar(243.40 mg·g-1),crude protein(87.49 mg·g-1),crude fat(86.30 mg·g-1),VB2(0.543 mg·g-1),VPP(2.809 mg·g-1),VA(4.66×10-3 mg·g-1),VE(3.188 mg·g-1),carotene(1.661 mg·g-1),essential microelements(0.852 mg·g-1) including Fe,Mn,Zn,Cu,Se and essential amino acids(22.97 mg·g-1).It also contains VC,VB1,K,Na,Ca,Mg,P and other nonessential amino acids.

兰靛果忍冬大小孢子发生与雌雄配子体的发育

综合运用光镜、扫描、透射电镜技术 ,观察兰靛果忍冬的大小孢子发生和雌雄配子体的发育过程。结果表明 ,花药壁发育属于基本型 ,变形绒毡层 ,四分体呈四面体型排列 ,小孢子母细胞的胞质分裂为同时型 ,3- c型花粉。柱头表面具大量乳突细胞 ;花柱细长 ,上部具明显的花柱道 ,下部实心 ,有发达的引导组织 ;子房下位 ,倒生胚珠 ,具珠被绒毡层 ,薄珠心 。

佳木斯地区野生蓝靛果引种及其栽培技术研究

2005年,对引自吉林和黑龙江省的6个样地的野生蓝靛果忍冬进行栽培试验,调查其在佳木斯的引种表现。结果表明:汪清、伊春2个样地苗木生长、开花、结果良好,平均单果重0.8 g,最大1.2 g以上,果实饱满,色泽鲜艳,口感极佳。4月上旬开花,6月初成熟,抗寒性强,且挂果时间长于其它4个样地的苗木,适宜在佳木斯地区栽培和推广。

加拿大蓝靛果忍冬在哈尔滨地区引种栽培的研究

蓝靛果忍冬是一种具有较高经济价值的寒地浆果之一,具有广阔的开发利用空间。主要介绍了2011年引进加拿大蓝靛果忍冬优良品种在哈尔滨地区引种栽培的表现情况,并初选出适宜哈尔滨地区栽培的品种,同时对其各品种进行了物候观测和播种育苗。较为全面地阐述了引进品种在试验地的综合表现,以及不同品种间的性状差异,为蓝靛果忍冬资源收集和优品筛选工作的顺利进行提供理论依据。

接骨木复合饮料的研究（Ⅰ）──蓝靛果忍冬果实的食用价值研究

药用植物蓝靛果忍冬是接骨木复合饮料的主要成分之一，它的成熟果实不仅是清热解毒的天然药，而且是味道鲜美的果品；研究确定了蓝靛果忍冬成熟果实的果汁加工工艺，并对所得果汁进行了较全面的分析。测出了果汁中含有缬氨酸、亮氨酸、赖氨酸等１８种氨基酸，维生素Ｃ，维生素Ｂ＿１，维生素Ｂ＿２，以及Ｋ、Ｃａ、Ｍｇ、Ｆｅ、Ｚｎ等１４种微量元素。对蓝靛果的食用价值进行了综合评价，并对合理开发这一有用资源提出了建议。

紫贻贝贝壳和脉红螺厣中色素的提取与鉴定

为了确定紫贻贝（Mytilus edulis）贝壳与脉红螺厣中的黑色物质是否为黑色素这一物质,作者实验选取紫贻贝贝壳和脉红螺（Rapana venosa）厣,清洗干净,之后分别对两份样品进行研磨粉碎、称量、盐酸浸泡、沸水浴加热、乙醚纯化等步骤后,将得到的黑色提取物质用0.01 ml/L氢氧化钠水溶液溶解,在190~500 nm的范围内测定紫外吸收光谱,发现两份样品最大吸收峰都在210~220 nm,随波长增加,其吸光值下降,与公认的黑色素紫外吸收光谱特征一致;另外将提取的两份黑色固体物质分别用溴化钾压片后进行傅里叶红外光谱扫描,其红外图谱都在3μm和6μm处分别有特征吸收峰,亦与公认的黑色素红外扫描图谱特征一致,从而首次确定紫贻贝贝壳和脉红螺厣中的黑色物质为黑色素,提示黑色素在贝类中可能是广泛存在的。

龙葵、蓝靛果复合饮料的研制

以龙葵果和蓝靛果为原料,经前期处理后先确定两种果汁的混合配比,经鉴定结果确定最佳配比为1:1。选择以混合果汁添加量、白砂糖添加量、柠檬酸添加量三个因素为单因素实验,以感官评价评分为实验数据,并且根据单因素实验结果进行L9(34)正交试验得出饮料的最佳配方。以黄原胶,卡拉胶,瓜豆胶三种稳定剂分别单独进行实验,并且测定沉淀量,经试验结果表明,龙葵、蓝靛果复合饮料的最佳配方为:混合果汁添加量为14%,白砂糖的添加量为10%,柠檬酸的添加量为0.06%,稳定剂的种类为黄原胶,添加量为0.2%。