人工培养地木耳的群体显微结构及营养成分分析

以人工培养的地木耳 (Nostoc commune Vauch.) 为材料,测定其生化组成,并对培养的地木耳显微结构进行观察。结果表明：地木耳表层藻丝较中央藻丝排列更加紧密,中央藻丝有或无单独胶鞘包裹;人工培养的地木耳含16 种氨基酸,蛋白质含量为17.46%;脂肪含量为0.53%,低于野生地木耳中脂肪的含量;维生素含量较低;矿质元素含量远高于野生地木耳的含量;而砷、铅、汞、镉4 种重金属元素含量较低,符合国家食品卫生标准。     

10种不同来源桑黄中4种有效成分含量的对比研究

对比研究10种不同桑黄多糖、黄酮、三萜类化合物及总蛋白的含量。采用苯酚-硫酸、亚硝酸-硝酸铝、香草醛-冰醋酸和BCA法对其提取物中几种活性成分进行含量测定。结果表明,多糖含量最高为8年野生桑黄提取物(2.491%),含量最低的是7号人工桑黄(0.264%);黄酮含量最高和最低分别为4号(1.829%)和6号(0.179%),二者为人工桑黄;三萜含量最高为6号人工桑黄(0.306 8%),最低的为9号野生桑黄(0.068 3%);蛋白含量最高为7号人工桑黄(0.602 2%),最少的是9号野生品种(0.210 5%)。结果表明,野生桑黄中多糖含量较高,可能是野生桑黄生长年份较长,有利于一级代谢产物多糖的累积;人工桑黄中黄酮、三萜和蛋白含量较高,可能是优化培养条件,有利于此类活性成分的富集。     

发状念珠藻不同细胞破碎方法的研究

为了获得野生发状念珠藻和液态培养发状念珠藻细胞破碎和提取藻蓝蛋白的最佳方法,进行了发状念珠藻细胞破碎方法的研究.采用液氮研磨、反复冻融,超声破碎,高压均质和玻璃珠破碎这几种方法对野生和液态培养发状念珠藻进行破碎研究.通过测定破碎率、藻蓝蛋白提取得率和纯度,对几种细胞破碎效果和藻蓝蛋白提取方法进行比较.结果表明,采用高压均质方法能获得最佳的破碎效果,当野生发状念珠藻和液态培养发状念珠藻细胞密度为10mg/mL时,破碎率分别达到96.45%和97.06%.反复冻融法为提取液态培养发状念珠藻藻蓝蛋白最理想的方法,其藻蓝蛋白的纯度和提取得率分别为0.468和1.28%;高压均质为提取藻蓝蛋白的最理想方法,其藻蓝蛋白纯度和提取得率分别为0.153和1.43%.     

地木耳细胞的破碎和藻蓝蛋白提取工艺的研究

以地木耳干粉为原料,比较研究了反复冻融法、超声波法及反复冻融结合超声波法地木耳细胞破碎的效果,得出最优细胞破碎方法,并对细胞破碎液利用超声波法进行提取工艺研究,经过单因素分析及正交试验得出超声波法提取的最佳工艺条件。结果表明,反复冻融结合超声波法的地木耳细胞破碎效果最好,破碎液中地木耳藻蓝蛋白的提取率为0.070 1%,是反复冻融法的3.8倍,是超声波法的1.1倍;超声波法提取地木耳藻蓝蛋白的最佳工艺条件为:超声时间25 min,超声功率600 W,提取溶剂pH 6.0,提取液中地木耳藻蓝蛋白的提取率为0.484 6%,是细胞破碎液中的1.8倍。     

野生与人工栽培地木耳营养成分的对比分析

对云南昆明松花坝野生地木耳与陕西秦岭地区人工栽培地木耳的基本营养成分(水分、灰分、蛋白质、还原糖、脂肪、总糖、VC、氨基酸和矿物质)、生物活性成分(多酚、多糖、皂苷、黄酮)进行对比分析。结果表明,云南昆明松花坝野生地木耳蛋白质、还原糖、VC、总氨基酸、粗多糖、总皂苷、总黄酮含量高,分别为17.45 g/100 g、12.11 mg/g、81.37 mg/100 g、22.25%、179.91 mg/g,43.87 mg/g,6.51 mg/g;陕西秦岭人工栽培地木耳灰分、矿物质含量较高,灰分含量为23.84g/100g;野生地木耳和人工栽培地木耳水分、粗脂肪、总糖、总多酚含量差异不显著。     

重组巴斯德毕赤酵母工程菌发酵生产藻蓝蛋白的研究

探讨重组巴斯德毕赤酵母工程菌发酵生产藻蓝蛋白的特性,以期能够通过基因工程和发酵工程技术大规模的生产活性重组藻蓝蛋白。先用甘油作碳源培养重组巴斯德毕赤酵母工程菌,达到一定生物量后,再用甲醇诱导外源重组藻蓝蛋白基因的表达,并测定了甘油浓度、细胞干重、细胞光密度和藻蓝蛋白含量的变化。结果表明:所获得的细胞干重最高达41.93g/L,细胞光密度最高为182.77,藻蓝蛋白的最高产量为61.20mg/L,分泌到胞外的藻蓝蛋白的最高产量为24.32mg/L。该研究为实现藻蓝蛋白的产业化生产奠定了良好的基础。     

不同纯度藻蓝蛋白对A549和HCCLM3的抗癌活性比较

摘 要: 目的 比较5种不同纯度藻蓝蛋白的抗癌活性差异, 并分析其抗癌活性与蛋白质含量、色基含量和藻蓝蛋白纯度的关系。方法 测定了5种不同藻蓝蛋白对两种癌细胞: 人胞肺癌细胞(human pulmonary carcinoma cell, A549)和人高转移肝癌细胞(human highly metastatic liver cancer cell, HCCLM3)的抑制率、细胞体外迁移能力、细胞凋亡率。结果 5种藻蓝蛋白均可抑制两种癌细胞的增殖、迁移, 诱导癌细胞凋亡。除藻蓝蛋白B外, 其他4种藻蓝蛋白对癌细胞的抑制率具有明显的剂量效应和时间效应关系, 藻蓝蛋白C抑制癌细胞迁移效果显著(P<0.05)优于其他4种藻蓝蛋白, 25 mg/mL的藻蓝蛋白A、B、C、E、F对A549作用48 h的抑制率分别为84.29%±0.74%、41.81%±4.79%、79.61%±0.76%、58.66%±3.85%、71.39%±3.84%, 对HCCLM3的抑制率分别为93.21%±3.40%、37.64%±2.63%、91.02%±4.55%、57.71%±7.64%、83.01%±3.98%; 偏相关和热图分析发现藻蓝蛋白的抑癌活性与其色基及纯度成负相关, 与蛋白质含量呈正相关。结论 5种藻蓝蛋白抗癌活性存在一定差异, 其中藻蓝蛋白C抗癌活性更好。蛋白质部分可能是藻蓝蛋白的主要抑癌基团。     

葛仙米藻胆蛋白和藻蓝蛋白对S180荷瘤小鼠肿瘤生长的影响及其作用机制

目的:对人工养殖的葛仙米藻胆蛋白和藻蓝蛋白在S180荷瘤小鼠肿瘤生长的影响及作用机制研究。方法:通过考察S180荷瘤小鼠肿瘤体积、小鼠脏器指数和肿瘤组织切片观察,对葛仙米中藻胆蛋白、藻蓝蛋白的体内抗肿瘤活性进行评价,并初步研究了其作用机制。结果:体内抗肿瘤作用结果显示,葛仙米藻胆蛋白12.5、25、50 mg/kg剂量组对小鼠肉瘤S180的抑瘤率分别为11.19%、20.14%、37.65%。葛仙米藻蓝蛋白12.5、25、50 mg/kg剂量组对小鼠肉瘤S180的抑瘤率分别为19.74%、35.00%、52.06%。藻蓝蛋白能够明显促进抑癌蛋白P53和促凋亡蛋白Bax的表达,抑制凋亡抑制蛋白Bcl2的表达。结论:葛仙米藻蓝蛋白高剂量组可显著减少S180肉瘤细胞的增殖,葛仙米藻蓝蛋白低、中剂量和葛仙米藻胆蛋白高剂量也有一定的抑制作用,人工养殖的葛仙米中藻胆蛋白和藻蓝蛋白具有较好的体内抗肿瘤活性。     

不同比例杜仲叶渣对平菇栽培效果的影响

采用不同比例杜仲叶渣栽培平菇,考察其对平菇菌丝长势、满瓶时间、生长速度和总黄酮、蛋白质、脂肪以及相关微量元素含量的影响。结果表明:杜仲叶渣替代10%～40%棉籽壳时,菌丝满瓶时间最短、生长速度最快,且长势最好;替代100%棉籽壳时,总黄酮含量最高,为对照组的3.72倍;替代70%棉籽壳时,蛋白质含量最高,为对照组的1.04倍;替代40%棉籽壳时,脂肪含量最低,为对照组的0.660倍;替代60%棉籽壳时,Fe、Zn、Na、K含量最高,分别为对照组的2.47、1.82、1.85、1.27倍;替代90%棉籽壳时,Ca、Mg、Mn、Cu含量最高,分别为对照组的1.68、1.80、1.79、1.58倍。     

地木耳人工培养最适光温条件及功能性成分scytonemin的变化

以宁波产野生地木耳(Nostoc commune)为对象,研究地木耳人工培养的最适光温条件,并就光温条件以及紫外辐射对地木耳抗紫外活性物质Scytonemin产出量的影响进行探讨。结果表明：地木耳人工培养的最适光温条件是25℃,光照强度25μE/(m2 ·s)。同光照条件下,地木耳对较低的温度适应性比对较高的温度适应性好,而光照强度高低的影响差异并不明显。不同的光温条件对地木耳中Scytonemin产出量及其变化有显著影响：最适光温条件下,人工培养的地木耳中Scytonemin产出量最低(约150μg/g),增加光强而不是增加光照时间对Scytonemin产出量累积有利,光强增加1倍,产出量可增加近120%。适当的紫外照射能显著提高地木耳中Scytonemin的产出量。     

提高微绿球藻的生物量和油脂含量的研究

研究光照强度和硝酸钾质量浓度对微绿球藻生物量和油脂含量的影响,通过两步培养法培养微绿球藻提高其生物量和油脂含量。结果表明:在硝酸钾质量浓度100 mg/L条件下,当光照强度为1 940~2 060 lx时,培养12 d,微绿球藻的生物量和油脂含量最高,分别为0.68 g/L和16.28%;低光照强度(1 940~2 060 lx)下,在不添加硝酸钾时,微绿球藻的生物量最低,为0.39 g/L,油脂含量最高,为22.62%;随着硝酸钾质量浓度的增加,微绿球藻的生物量逐渐增加,而油脂含量逐渐下降;两步培养法可以促进微绿球藻的油脂合成,油脂含量和油脂产量分别达到30.50%和0.15 g/L。     

Bacterial control of plant diseases

This article focuses on the effective biocontrol of plant diseases by microorganisms, which is attracting attention as an alternative to chemical control methods. As most research has so far been concentrated on fluorescent Pseudomonas species, the use of Bacillus species which has been considered to be less effective compared to that of pseudomonads, has been mainly introduced to demonstrate the effectiveness of the bacteria.     

两步培养法提高栅藻的生物量及油脂含量

采用两步法培养栅藻,即在低光强-含氮条件下,培养栅藻至稳定期积累生物量,然后将栅藻转移至高光强-缺氮培养基中积累油脂。结果表明:在低光强-含氮培养基BG11(+N)条件下,适宜栅藻生长的低光强为2 000~2 400 lx,培养期为10 d;转高光强-缺氮培养基BG11(-N)条件下培养,适宜栅藻积累油脂的高光强为6 000~6 500 lx,培养期为6 d。利用两步法培养栅藻,其生物量可达(0.957±0.126)g/L,油脂含量可达(23.35±0.2)%。两步法培养栅藻的生物量和油脂含量分别比常规单步法培养(10 d)的提高了35.74%和近1倍。     

Continuous cultivation of <Emphasis Type="Italic">Dunaliella salina</Emphasis> in photobioreactor for the production of β-carotene

A helix tube photobioreactor with a volume of 10 L was designed and manufactured. The facade of the reactor was designed as three-layer frame. The illumination helixes units were 16, illumination area volume was 1.5 L, illuminate specific area was 95 m⁻¹. A marine micro-alga Dunaliella salina was used as a model organism in this study. Results showed that the optimum inoculum concentration was OD₆₃₀ = 0.15 and the optimum circulation rate of culture fluid was 630 mL/h for the bioreactor. In continuous cultivation, in order to determine the optimum collection of alga solution for the highest yield of β-carotene, three different alga solution collection and addition fresh culture medium volumes were applied: 0.8, 1.5, 2.0 L/day. The biomass and extraction of β-carotene were determined in different cultivation periods. The result suggested that the optimum daily harvest of alga solution was 1.5 L/day for the cultivation of D. salina to obtain the highest production of β-carotene.     

Utilization of shrimp shellfish waste as a substrate for solid-state cultivation of Aspergillus sp. S1-13: evaluation of a culture based on chitinase formation which is necessary for chitin-assimilation

The utilization of shrimp shellfish waste as a substrate for solid-state cultivation of a filamentous fungus, Aspergillus sp. S1-13, was investigated. The organism was selected from among 220 isolates based on the productivity of its chitinolytic enzyme (chitinase), which might reflect microbial growth. The enzyme was produced only when the organism was grown on medium containing the shellfish waste. The addition of 58-65% water (w/w) to the medium was effective in enhancing production, and a certain amount of enzyme was observed in media of higher water content (up to about 75%). The initial pH and nitrogen source (ammonium sulfate) of the solid-state medium also affected the amount of enzyme. The amount of enzyme increased 2-fold in an optimum solid-state medium: 5 g of shrimp shellfish waste and 3 ml of basal medium (pH 5) containing 0.1% (NH4)2SO4 was inoculated with 4 ml of spore suspension; static cultivation at room temperature. The amount increased further (1.5-fold) when the cultivation was carried out at 37 degrees C, with 1.85 units of the enzyme formed from 1 g of shrimp shellfish waste. An analysis by ion-exchange column chromatography suggested the presence of at least two colloidal chitin-hydrolyzing enzymes and one p-nitrophenyl beta-D-N-acetylglucosaminide-hydrolyzing enzyme in an extract of the solid-state culture. The elution profile was similar to that obtained with a liquid culture filtrate.     

A new model for the reconstruction of biomass history from carbon dioxide emission during batch cultivation of Geotrichum candidum

A non-structured model has been developed to describe the CO2 emission during growth of Geotrichum candidum on a lactate + peptone-based liquid medium. From the nitrogen and carbon mass balances, it was shown that about 50% of the total CO2 released was from the metabolism of the energy supply for biosynthesis, and the remaining from that for maintenance; thus, CO2 production was considered to be partially associated with growth. The model fitted the experimental data as long as a net growth was observed (0-50 h). The coefficients for growth- and non-growth-associated CO2 production were A = 0.646 (dimensionless) and B = 0.017 h(-1), respectively. From the coefficients of the model and the CO2 history data, the biomass kinetics has been reconstructed, and the calculated biomass concentrations agree fairly well with the experimental data. From this, measurement of the CO2 evolved may be used as an indirect and non-intrusive method of monitoring fungal growth during the first 50 h of cultivation.     

小球藻异养培养的研究

通过单因子试验，研究了椭圆小球藻L1藻株异养培养发酵的最佳条件分别为：葡萄糖10g/L，尿素0.2^1g/L的BG-11培养基，培养温度25℃～30℃，培养基起始pH为5.5～6.5,250mL三角瓶装液量为100mL，接种量10%，在此基础上，进行了2L发酵罐培养实验，获得了干重5.42g/L的生物量，约为自养培养获得生物量的20倍。对异养与自养灌细胞内主要营养成分的分析结果表明：异养小球藻总脂含量升高，蛋白质及灰分含量下降。     

Purification of Aspergillus sp. S1-13 chitinases and their role in saccharification of chitin in mash of solid-state culture with shellfish waste

In a suspension of solid-state culture of Aspergillus sp. S1-13 containing a lactic acid-treated crab shell as the substrate, the saccharification of chitin in the shell proceeded to form N-acetylglucosamine (GlcNAc): the culture was the source of chitin and chitinases. The analysis of chitinases in the water-extract of the solid-state culture indicated occurrence of an exochitinase (Exo, MW 73 kDa) and two endochitinases. The amounts of the endochitinases suggested that one of them (Endo-1, MW 45 kDa) might be the main species in the chitin-saccharification. The amount of GlcNAc released from the LA-treated crab shell by the combined action of isolated Exo and Endo-1 was very small, predicting participation in the saccharification of other enzyme species, which might be hardly extracted with water from the solid-state culture. The re-extraction of the solid-state culture using 2 M KCl, which was extracted with water beforehand, demonstrated another endochitinase (Endo-2, MW 51 kDa). Endo-2 isolated from the salt-extract can adsorb to chitin, and can hydrolyze the chitin in the adsorbed state. The roles of these chitinases in the chitin-saccharification based on their properties and combined action were discussed.     

Development of a novel method for feeding a mixture of -lactic acid and acetic acid in fed-batch culture of Ralstonia eutropha for poly- -3-hydroxybutyrate production

Fermentative production of poly- -3-hydroxybutyrate [P(3HB)] from a mixture of -lactic acid and acetic acid by Ralstonia eutropha was investigated. For fed-batch culture with cell density, it is necessary to control the concentration of these organic acids in the culture medium below the inhibitory level for cell growth. Therefore, a novel feeding method, termed the computer-controlled pH-stat substrate feeding method, was developed using the rate of increase of the pH (pH-increasing rate) of the culture medium as an indicator for feed control. The pH-increasing rate, which was calculated every minute by a pH meter-linked computer, represented secondary information regarding substrate consumption by cells. When the pH-increasing rate decreased to 5% of the maximum increasing rate, acidic substrate solution was fed into the fermentor until the pH was reduced to 7.00. Using this feeding strategy, the cell concentration and PHA content obtained in 42 h were 75.0 g/l and 73.1% (w/w), respectively, resulting in a high P(3HB) productivity of 1.30 g/l·h.     

富油微藻的选育及规模化培养研究进展

随着化石能源的逐年消耗,以可再生资源生产能源物质成为解决能源问题的重要途径之一,其中产油微藻制备生物柴油成为生物质能源领域的研究热点。介绍了微藻生物柴油的国内外发展概况以及其规模化培育过程中藻种的选育情况,探讨了藻种规模化培育过程中的关键技术环节以及存在的主要问题,并对微藻生物柴油的发展趋势和面临的挑战进行了评述。