硫酸软骨素酶高产菌株的筛选、鉴定和发酵培养条件的研究

通过透明圈法从土样中初筛到2株产硫酸软骨素酶能力较高的菌株,经复筛,28号菌株产酶能力更强,对该菌株的形态特征和生理生化特性考察,初步鉴定为少动鞘氨醇单胞菌(Sphingomonas paucimobilis)。该菌株的发酵产酶条件研究表明,其产酶最适培养基组分为(%,w/v):酵母粉1.0,硫酸软骨素0.5,NaCl 0.5,KH2PO40.03,MgSO4.7H2O0.5,起始pH=8.5,其余为水。其最适产酶条件为:250mL三角瓶装液量40mL,1%(v/v)接种量,25℃,100r/min培养36h。在最适产酶培养条件下,菌株发酵液中硫酸软骨素酶的活力可达1.2U/mL。本研究筛选出产硫酸软骨素酶高的菌株,并为发酵法制备硫酸软骨素酶提供一定的实验依据。     

双酶分步水解金枪鱼(Eleotridae)碎肉制备高F值酶解液的工艺研究

以金枪鱼碎肉为原料, 采用双酶分步水解法制备高F值酶解液, 通过Box-Behnken试验设计, 分别确定两步酶解的最佳条件, 酶解液经活性炭静态吸附去除游离芳香族氨基酸, 对脱芳后的酶解液进行氨基酸组成分析并测定F值。结果表明, 胃蛋白酶为第一步水解用酶, 酶解的最佳工艺条件为酶用量650U/g, 料水比1∶7(g/mL), 温度35.9℃; 风味蛋白酶为第二步水解用酶, 酶解的最佳工艺条件为酶用量50700U/g, pH 6.51, 温度51℃, 最终水解度达到36.87%±0.54%; 酶解液在pH 3.0, 温度35℃条件下, 经5%(质量体积分数)的活性炭吸附时间3h后, 脱芳率达到63.18%, F值为30.33, 符合高F值肽的要求。     

黄海西部沿岸冷水在夏季南黄海西部底层冷水形成和季节演变过程中作用的化学水文学分析

以金枪鱼碎肉为原料, 采用双酶分步水解法制备高F值酶解液, 通过Box-Behnken试验设计, 分别确定两步酶解的最佳条件, 酶解液经活性炭静态吸附去除游离芳香族氨基酸, 对脱芳后的酶解液进行氨基酸组成分析并测定F值。结果表明, 胃蛋白酶为第一步水解用酶, 酶解的最佳工艺条件为酶用量650U/g, 料水比1∶7(g/mL), 温度35.9℃; 风味蛋白酶为第二步水解用酶, 酶解的最佳工艺条件为酶用量50700U/g, pH 6.51, 温度51℃, 最终水解度达到36.87%±0.54%; 酶解液在pH 3.0, 温度35℃条件下, 经5%(质量体积分数)的活性炭吸附时间3h后, 脱芳率达到63.18%, F值为30.33, 符合高F值肽的要求。     

响应面法优化酶法制备藻蓝蛋白抗氧化肽的实验研究

为优化碱性蛋白酶酶解藻蓝蛋白制备抗氧化肽的工艺条件,采用响应面分析法,以超氧阴离子自由基清除率为响应值,研究了[E]/[S]、酶解温度和时间对制备抗氧化肽工艺的影响.结果表明,制备藻蓝蛋白肽的最佳酶解条件为:温度为44.9℃、时间为6.4 h和[E]/[S]为3.6%,此时对超氧阴离子自由基清除率达到75.39%.在该条件下制备的藻蓝蛋白酶解产物(0.5 g/L)还原能力的吸光度为1.03,并达到稳定.     

盐藻多糖提取工艺的研究

探讨盐藻D.peircei多糖的提取工艺.采用正交实验确定了提取盐藻粗多糖的最佳工艺条件,通过酶解方法脱除其蛋白.实验结果表明,提取盐藻粗多糖的最佳工艺条件为100℃,提取10h,固液比1∶16,pH=9,通过中性蛋白酶对其酶解,可脱除其部分蛋白,使糖含量达到29.01%,初步确定此多糖为含有硫酸基和己糖醛酸的蛋白多糖.     

海带废渣中提取岩藻聚糖硫酸酯的工艺研究

采用响应曲面分析法研究了氯化钙水提法从海带废渣中提取岩藻聚糖硫酸酯的制备技术.在单因素试验的基础上,根据Box-Behnken试验设计原理,通过建立数学模型对提取温度、提取时间、料液比等因素进行显著性和交互性分析研究,获得了最佳提取制备参数.结果表明,提取温度68℃,提取时间6h,料液比1:80时,可以获得3.95％的岩藻聚糖硫酸酯.其中岩藻糖含量为17.47％,硫酸根含量为37.14％.     

海参蒸煮废液多糖提取优化研究

从海参蒸煮废液有效利用出发,采用胃蛋白酶提取废液中海参多糖。在单因素实验基础上,选择酶解pH、酶解温度、酶用量为自变量,酶解后多糖质量浓度为响应值,利用Box-Benhnken中心组合实验及响应面分析法,研究各自变量交互作用对多糖提取的影响。确定最佳提取工艺条件为:酶解pH=1.50、酶解温度47.00℃、酶用量2.00%,在此条件下提取海参多糖质量浓度为2.31g/L。经体积分数为50%的乙醇沉淀后回收海参多糖,总回收率为39.5%。     

金枪鱼(Katsuwonus pelamis)碎肉蛋白降压肽的酶解制备及活性研究

以血管紧张素转换酶(ACE)抑制率为指标,通过正交试验L9(34)确定碱性蛋白酶(Alcalase)对金枪鱼(Katsuwonus pelamis)碎肉蛋白的最佳酶解条件,利用D101大孔树脂建立了酶解物的脱盐工艺,利用超滤、葡聚糖凝胶(G-25)色谱和反相-高效液相色谱(RP-HPLC)分离降压肽,并确定其纯度,利用氨基酸序列分析和ESI-MS鉴定纯化多肽的结构。结果表明,碱性蛋白酶酶解金枪鱼碎肉蛋白制备降压肽的最佳酶解条件是:pH 9.5,酶用量1.5%,酶解温度50°C,酶解时间5h;D101大孔吸附树脂脱盐工艺条件为:上样浓度10 mg/mL、上样流速1.5 BV/h、解吸剂为75%乙醇;酶解物经超滤和Sephadex G-25分离获得一个纯度较高的四肽,经氨基酸序列分析和ESI-MS鉴定结构为Phe-GlyGly-Val(FGGV),ESI-MS检测给出分子离子峰m/z 379.50([M+H]+)。利用碱性蛋白酶酶解并经超滤和色谱技术制备的金枪鱼碎肉蛋白降压肽具有良好的ACE抑制活性,可作为降压药物、保健食品或添加剂进行开发。     

废弃鱼骨中蛋白质的提取分离及酶解工艺研究

以蛋白提取率和多肽分子质量分布为评价指标,采用不同提取方法和不同蛋白酶对废弃鱼骨蛋白质的提取和酶解工艺进行了研究。结果表明,高压蒸煮法提取的鱼骨蛋白质中蛋白含量为86.15%,蛋白提取率为16.76%,明显高于恒温水浴和热回流提取法。中性蛋白酶酶解的多肽中蛋白含量为88.46%,多肽比例高达95%以上,明显高于其他三种酶。先利用高压提取法提取蛋白质,再利用中性蛋白酶酶解蛋白质制备多肽,可降低酶用量,该方法为多肽工业化生产提供参考及新思路。     

酶法制备低盐虾酱的研究

为了解决传统的自然发酵工艺制备虾酱带来的种种弊端，本选用小型毛虾经蛋白酶水解，采用甲醛滴定法对不同加酶量、酶解时间、温度和用盐量对FAM值的影响进行了测定，确定了碱性蛋白酶和中性蛋白酶的最适反应条件均为加酶量0.5％，酶解温度55℃，加盐量18％，而最适酶解时间分别为2h和1h，最适pH为7.0。酶法制备低盐虾酱使产品低盐，适合大众消费；高温酶解，风味品质更好；生产周期短，降低所需成本。酶解后毛虾的产品质量符合国家卫生标准。     

中国鱼类名录Ⅻ--鳚亚目、(鱼衔)亚目、喉盘鱼亚目、鰕虎鱼亚目、微体鱼亚目、刺尾鱼亚目、带鱼亚目、鲭亚目、鲳亚目、金枪鱼亚目、攀鲈亚目、刺鳅亚目

鳚亚目 4 科 33 属 95 种，鰕虎鱼亚目 5 科 98 属 259 种，刺尾鱼亚目 5 科 11 属 65 种，鲈形目 19亚目 104 科 535 属 1799 种。     

The distribution of Mn,Fe, Cu,Ni, Co,Ga, Cr,V, Ba,Sr, Sn,Zn, and Pb,in some soil-sized particulates from the lower troposphere over the world ocean

Soil-sized particulates have been collected on board ship by a mesh technique from the lower troposphere of the North, Equatorial and South Atlantic Ocean, northern and southern Indian Ocean, South and East China Sea and various coastal localities.Spectrographic analysis reveals that, on average, the particulates have concentrations of Mn, Ni, Co, Ga, Cr, V, Ba, and Sr which are of the same order of magnitude as those in average crustal material. In contrast, the average concentrations of Pb, Sn, and Zn are one order of magnitude higher than those in average crustal material.Within this “world-wide” average there are significant geographical variations in the distributions of Pb, Sn, and Zn which may be related to anthropogenic sources.On the basis of trace-element distributions lower tropospheric soil-sized marine particulates have been divided into four genetic components; local, zonal, inter-zonal, and global. The proportions of these components vary geographically, and each component may have both a natural and an anthropogenic fraction.     

Distribution, abundance, and growth of larval tautog, Tautoga onitis, in Buzzards Bay, Massachusetts, USA

Tautog, Tautoga onitis, is an abundant species of fish in estuaries of the northeastern United States. Planktonic tautog larvae are abundant in summer in these estuaries, but there is little information on rates of growth of tautog larvae feeding on natural assemblages of food in the plankton. We examined abundance and growth of larval tautog and environmental factors during weekly sampling at three sites along a nearshore‐to‐offshore transect in Buzzards Bay, Massachusetts, USA during summer 1994. This is the first study of a robust sample size (336 larvae) to estimate growth rates of field‐caught planktonic tautog larvae feeding on natural diets, using the otolith daily‐growth‐increment method. The study was over the entire summer period when tautog larvae were in the plankton. The sampling sites contrasted in several environmental variables including temperature, dissolved oxygen (DO), and chlorophyll a concentration. There was a temporal progression in the abundance of tautog larvae over the summer, in relation to location and temperature. Tautog larvae were first present nearshore, with a pronounced peak in abundance occurring at the nearshore sites during the last 2 weeks in June. Larvae were absent at this time further offshore. From late June through August, larval abundance progressively decreased nearshore, but increased offshore although never approaching the abundance levels observed at the nearshore sites. The distribution and abundance of tautog larvae appeared to be related to a nearshore‐to‐offshore seasonal warming trend and a nearshore decrease in DO. Otoliths from 336 larvae ranging from 2.3 to 7.7 mm standard length had otolith increment counts ranging from 0 to 19 increments. Growth of larval tautog was estimated at 0.23 mm·day^?1, and length of larvae prior to first increment formation was estimated at 2.8 mm indicating that first increment formation occurs 3–4 days after hatching at 2.2 mm. Despite spatial and temporal differences in environmental factors, there were no significant differences in growth rates at any of three given sites over time, or between sites. Because larval presence only occurred at a narrow range of temperature (17–23.5 °C) and DO (6.5–9.3 mg·l^?1), in situ differences in growth did not appear to be because of differences in larval distribution and abundance patterns relative to these parameters.     

Arsenic,barium, germanium,tin, dimethylsulfide and nutrient biogeochemistry in Charlotte Harbor,Florida, a phosphorus-enriched estuary

Concentrations of dissolved nutrients (NO₃, PO₄, Si), germanium species, arsenic species, tin, barium, dimethylsulfide and related parameters were measured along the salinity gradient in Charlotte Harbor. Phosphate enrichment from the phosphate industry on the Peace River promotes a productive diatom bloom near the river mouth where NO₃ and Si are completely consumed. Inorganic germanium is completely depleted in this bloom by uptake into biogenic opal. The $\text{Ge}\text{Si}$ ratio taken up by diatoms is about 0·7 × 10^?6, the same as that provided by the river flux, confirming that siliceous organisms incorporate germanium as an accidental trace replacement for silica. Monomethylgermanium and dimethylgermanium concentrations are undetectable in the Peace River, and increase linearly with increasing salinity to the seawater end of the bay, suggesting that these organogermanium species behave conservatively in estuaries, and are neither produced nor consumed during estuarine biogenic opal formation or dissolution. Inorganic arsenic displays slight removal in the bloom. Monomethylarsenic is produced both in the bloom and in mid-estuary, while dimethylarsenic is conservative in the bloom but produced in mid-estuary. The total production of methylarsenicals within the bay approximately balances the removal of inorganic arsenic, suggesting that most biological arsenic uptake in the estuary is biomethylated and released to the water column. Dimethylsulfide increases with increasing salinity in the estuary and shows evidence of removal, probably both by degassing and by microbial consumption. An input of DMS is observed in the central estuary. The behavior of total dissolvable tin shows no biological activity in the bloom or in mid-estuary, but does display a low-salinity input signal that parallels dissolved organic material, perhaps suggesting an association between tin and DOM. Barium displays dramatic input behavior at mid-salinities, probably due to slow release from clays deposited in the harbor after catastrophic phosphate slime spills into the Peace River.     

4-溴苯甲酸-2,3,4,5,6-五溴苯酯的合成(英文)

以苯酚和4—溴苯甲酸为原料,合成一种尚未见文献记载的新化合物——4—溴苯甲酸—2,3,4,5,6—五溴苯酯,用无水三氯化铝催化苯酚的全溴化。此产物可望在阻燃剂方面得到应用。     

Large amplitude, leaky, island-generated, internal waves around Palau, Micronesia

Three years of temperature data along two transects extending to 90 m depth, at Palau, Micronesia, show twice-a-day thermocline vertical displacements of commonly 50–100 m, and on one occasion 270 m. The internal wave occurred at a number of frequencies. There were a number of spectral peaks at diurnal and semi-diurnal frequencies, as well as intermediate and sub-inertial frequencies, less so at the inertial frequency. At Palau the waves generally did not travel around the island because there was no coherence between internal waves on either side of the island. The internal waves at a site 30 km offshore were out-of-phase with those on the island slopes, suggesting that the waves were generated on the island slope and then radiated away. Palau Island was thus a source of internal wave energy for the surrounding ocean. A numerical model suggests that the tidal and low-frequency currents flowing around the island form internal waves with maximum wave amplitude on the island slope and that these waves radiate away from the island. The model also suggests that the headland at the southern tip of Palau prevents the internal waves to rotate around the island. The large temperature fluctuations (commonly daily fluctuations ≈10 °C, peaking at 20 °C) appear responsible for generating a thermal stress responsible for a biologically depauperate biological community on the island slopes at depths between 60 and 120 m depth.