温度对谷皮菱形藻生长及其理化成分的影响

考察了不同温度对谷皮菱形藻生长及其理化成分的影响。结果表明:温度在10℃或30℃条件下不利于细胞生长,同时也不利于胞内理化成分的积累。在20℃条件下细胞密度、叶绿素含量、胞内蛋白、胞外多糖及胞内多糖达到最大值。谷皮菱形藻的最适生长温度为20℃,10℃可以作为种质保存的温度。     

姬松茸胞内多糖碱提取工艺

为了进一步提高姬松茸胞内多糖得率,采用单因素实验和响应曲面法,对姬松茸菌丝体胞内多糖碱提取工艺进行了研究。结果表明优化的碱提取工艺为提取时间4．63h,碱液浓度1．03mol／L,提取温度60．90℃,液料比85．85mL／g,在此条件下胞内多糖的提取得率为（273．49±1．59）mg／g干菌体,明显高于水提取所得到的胞内多糖得率。这为姬松茸碱提胞内多糖理化性质、生理活性等方面进一步的研究提供切实可行的高效提取方法。     

蛹虫草多糖发酵工程研究

报道了蛹虫草(Gordyceps militaris)多糖发酵工程中的关键因子对菌丝体生物量和多糖产量影响的研究结果.对蛹虫草液体发酵培养基中的碳源、氮源和温度进行了正交试验,考察了三因子对蛹虫草生物量以及多糖的综合效应.实验结果表明:各因素不同水平间的组合对蛹虫草生物量、胞外多糖、胞内多糖以及总多糖的影响不同.其中.在6%的碳源和1%的氮源以及25℃的条件下.能获得蛹虫草的最大生物量以及总多糖和胞外多糖的最大产量;碳源为6%、氮源为1%、温度为22℃时.胞内多糖的产量达到最高.     

桦褐孔菌子实体多糖提取研究

目的:为了获得桦褐孔菌多糖最大量的多糖收率,研究了影响多糖提取的最佳条件.方法:对影响桦褐孔菌胞内水溶性多糖提取效果的6个因素进行了单一因素影响实验,并对多糖提取影响因子的3个因素进行正交试验,对多糖提取工艺参数进行了优化.结果:正交试验确定桦褐孔菌子实体多糖的最佳提取条件是:料水比为1∶40,温度80℃,提取1.5h,多糖收率达2.53％.结论:确立了桦褐孔菌子实体多糖提取工艺,建立了一套简便、高效的桦褐孔菌胞内多糖的提取方法.     

响应面法优化富硒荷叶离褶伞菌丝体胞内粗多糖发酵条件

为了优化富硒荷叶离褶伞菌丝体胞内粗多糖发酵条件,在单因素试验基础上,考察灭菌条件、培养时间、硒添加量和硒添加时间对富硒荷叶离褶伞菌丝体胞内粗多糖的影响,并通过Box-Benhnken实验设计和响应面分析法确定最优发酵条件。结果表明,在121℃、20min条件下对培养基和Na₂SeO₃溶液分别灭菌后混合,在发酵至第129h,发酵液中添加4µg/mL Na₂SeO₃,继续发酵至第244h,发酵产生的富硒荷叶离褶伞菌丝体胞内粗多糖含量为349.8mg/100mL。     

金顶侧耳胞内多糖生物活性研究

对金顶侧耳Pleurotus citrinopileatus胞内多糖的热水浸提工艺进行研究,并研究了该多糖的抑菌活性以及对超氧阴离子自由基和亚硝基的清除作用。结果表明,金顶侧耳胞内多糖的最佳提取工艺为:提取温度60℃,液料比100:1,时间4h,此条件下多糖提取率可达17.65%。该多糖对埃希氏大肠杆菌和金黄色葡萄球菌均有抑制作用且对超氧阴离子自由基和亚硝基有较强的清除作用,说明该多糖具有明显的生物活性。     

真菌激发子对桑黄胞内代谢产物积累的影响

利用前期通过大量预试验筛选获得的3种真菌多糖激发子,在桑黄Sanghuangporus sanghuang发酵液中进行添加,研究其对桑黄胞内黄酮、三萜及多糖等代谢产物积累的影响,并对激发效果好的激发子继续进行添加量和激发时间的优化。结果显示:参试的3种真菌多糖激发子在一定程度上均能促进桑黄胞内黄酮和胞内三萜类成分的积累,但对胞内多糖积累的影响不明显;来源菌株为薄多年卧孔菌Perenniporia tenuis的激发子表现最突出,激发效果显著且稳定性良好。激发条件优化的结果表明:在接种的同时按照50mg/L的终浓度进行激发子的添加,激发6d,桑黄胞内黄酮含量达最高值0.7%,比对照提高79.49%;在接种1d后,按照50mg/L的终浓度进行激发子的添加,激发5d,对桑黄胞内三萜类成分代谢的激发效果最显著,胞内三萜含量最高可达5.62%,是对照组的3.43倍。     

香菇液体发酵高产多糖菌株筛选

通过评价香菇野生菌株发酵产多糖性能,筛选高产香菇多糖菌株.以采自长白山野生香菇通过组织分离获得的6株菌株和2株人工栽培菌株为出发菌株,对不同发酵培养时间菌丝体生物量、胞内多糖含量、胞外多糖含量等进行测试分析,结果表明,8株菌株随着培养时间的延长,菌丝体生物量均有不同程度的增加,但胞内多糖含量和胞外多糖得率变化趋势不同,...     

利用扁桃斑鸠菊叶发酵高产粗毛纤孔菌胞外多糖的条件优化及其抗氧化活性研究

粗毛纤孔菌胞外多糖是粗毛纤孔菌液体发酵的重要活性代谢产物,但采用常规的发酵方法,粗毛纤孔菌胞外多糖的产量较低。为更好地获取粗毛纤孔菌胞外多糖,本文采用双向液体发酵的方法,通过向发酵培养基中添加适量的扁桃斑鸠菊叶粉末,来提高粗毛纤孔菌胞外多糖的产量,并对优化得到的胞外多糖抗氧化活性进行了研究。以发酵液中胞外多糖含量为指标,采用单因素实验和正交实验优化发酵条件;采用红外光谱对胞外多糖的结构特征进行分析;通过测定胞外多糖对ABTS、DPPH和羟基自由基的清除率来了解其抗氧化活性。结果表明,最优发酵条件为:扁桃斑鸠菊叶粉末添加量0.5g/L、发酵时间10d、pH 6.5、接种量5.0mL,在此条件下,粗毛纤孔菌胞外多糖的产量达到(2.34±0.25)mg/mL,与未添加扁桃斑鸠菊叶的空白组相比,其胞外多糖产量提高了约216.22%;红外分析与抗氧化活性实验结果表明,添加扁桃斑鸠菊叶后的胞外多糖与未添加扁桃斑鸠菊叶的胞外多糖红外主要吸收峰一致,并且对ABTS、DPPH以及羟基自由基清除能力相近。本研究结果表明扁桃斑鸠菊叶能够有效地提高粗毛纤孔菌胞外多糖的产量,为其他珍稀食药用菌胞外多糖的高效生产提供了新思路。     

药用昆虫蜣螂对灵芝多糖生物合成的影响

采用液体深层发酵方式,研究了几种药用昆虫对灵芝多糖生物合成的影响。结果表明,药用昆虫蜣螂在添加量为5g/L时能显著促进灵芝胞内多糖(IPS)和胞外多糖(EPS)的形成(P<0.05)。胞内多糖和胞外多糖的产量分别由对照的(1.93±0.09)g/L和(520.3±20.2)mg/L提高到(2.41±0.12)g/L和(608.9±20.2)mg/L。灵芝胞内多糖和胞外多糖在DEAE纤维素柱上都可分离得到5种主要组分,其中IPS-1和EPS-1分别为2类多糖的主要组分。进一步用凝胶柱分离显示,IPS-1由3个单个的组分组成,EPS-1由2个单个的组分组成。添加蜣螂发酵后,灵芝胞内多糖和胞外多糖中没有出现新的组分,且各组分的相对含量也没有显著变化(P>0.05),提示添加蜣螂发酵后,灵芝胞内多糖和胞外多糖主要组分的合成途径并未改变。     

Nicotine Production by Tobacco Callus Tissues and Effect of Plant Growth Regulators

Relationships between callus origin and the nicotine contents as well as conditions of nicotine production in tobacco tissue cultures were investigated. Nicotine contents of callus tissues were remarkably affected by plant growth regulators in the culture medium. Thus, nicotine production was promoted by the regulators at lower concentrations, but gradually inhibited when the concentrations increased over an optimal region which was different among several kinds of the regulators. The nicotine contents also considerably depended on conditions of the callus induction as well as organ from which they were derived, at least just after callus induction. The differences due to the induction conditions were considered to be gradually lost during successive cultures. Thus, the nicotine contents appeared gradually to change to a certain level which mainly depended on the concentration of the regulators added to the culture medium. When such stabilized callus tissues were transferred to a culture medium containing another regulator or different concentration of the regulator, their nicotine contents rapidly changed to a new level depending on the culture conditions during a few successive cultures. The stabilized callus tissues grown on a medium containing 0.1 ppm α-NAA contained 0.5% of nicotine or more, which was almost the same level in root of the intact plant.     

不同水肥和光照条件对水稻化感特性的影响

采用盆栽实验对水稻化感品种华航1号在不同水肥和光照条件下的化感潜力和化感物质进行了研究。结果表明,华航1号在较高水肥条件下化感潜力较强,而在较低水肥条件下化感潜力下降,进一步对华航1号的化感特征物质的含量测定表明,在较低水肥条件下其化感物质没有显著的变化,只是次生物质的种类有所增加,尤其是一些具有抗病功能的次生物质的含量有所增加,在弱光照条件下华航1号的化感特征物质含量比在较强光照条件下要低,而且具有抗病功能的次生物质含量则保持较高水平,结果还发现,不论水、肥或光照条件的变化,华航1号对非伴生杂草的化感潜力都比伴生杂草要强。     

Lipid compositions in diatom Conticribra weissflogii under static and aerated culture conditions

The diatom Conticribra weissflogii is a microalga with high nutrition value, rich in docosahexaenoic acids (DHA) and eicosapentaenoic acids (EPA). In order to study the effect of culture conditions on the changes of lipid compositions, the intact lipid structural profiles and fatty acids in C. weissflogii were monitored under static and aerated culture conditions. The results showed that, lipids identified in C. weissflogii were neutral lipid triacylglycerols (TAG), betaine lipid diacylglycerylcarboxy‐N‐hydroxymethyl‐choline (DGCC), phosphatidylcholine (PC) and four classes of photosynthetic glycerolipids. The profiles of lipid metabolites of C. weissflogii were different between two culture modes, with the following characteristics under aerated conditions: TAGs increased significantly, whereas the levels of sulfoquinovosyl diacylglycerol (SQDG), monogalactosyldiacylglycerol (MGDG), and DGCC decreased. Furthermore, higher contents of EPA‐rich TAG and EPA/DHA‐rich DGCC were detected at the end of stationary phase, while EPA/DHA‐rich PC, EPA‐rich MGDG and EPA‐rich digalactosyldiacylglycerol (DGDG) were obtained in the exponential phase under static conditions. Meanwhile, the contents of almost all classes of the essential fatty acids (EFAs)‐enriched lipids increased at onset of stationary phase under aerated conditions. Taken together, given that the high levels of EFAs are required for artificial rearing of marine organisms, aeration is critically important for increasing the production rate and the contents of EFA molecules and therefore increasing the nutritional value of the microalgae.     

Comparison of pigment and proximate compositions of <Emphasis Type="Italic">Tisochrysis lutea</Emphasis> in phototrophic and mixotrophic cultures

Pigment contents and proximate compositions are important traits to evaluate the nutritional value of microalgae. The environmental condition and nutrient availability in the culture medium are hypothesised to regulate algal colour, nutritional composition and production. This study aimed to compare the pigment and proximate compositions in Tisochrysis lutea under phototrophic and mixotrophic conditions in an attempt to improve algal product quality. Algae were grown in the phototrophic and mixotrophic conditions at 50 μmol photons m^?2 s^?1 for 12 h daily, but 50 mM glycerol was added as a carbon source in the mixotrophic culture. The pigment contents in algae significantly increased in the mixotrophic condition, and the contents of chlorophylls a and c and carotenoids increased nearly 60 % compared with those in the phototrophic condition. The contents of saturated and polyunsaturated fatty acids in algae were significantly higher while the content of monounsaturated fatty acids was significantly lower in the mixotrophic condition than those in the phototrophic condition. Although the contents of protein, lipid and carbohydrate in T. lutea were not different, their overall production was significantly enhanced in the mixotrophic condition compared to the phototrophic condition. This study indicates that mixotrophic culture promotes pigment and proximate production and the change of fatty acid profile in algae depends on the addition of organic carbon to the culture medium.     

Differences in the carbohydrate composition between the yeastlike and mycelial cells of Mucor hiemalis

The use of sporangiospores from a 20-day culture for inoculation enabled us to obtain yeastlike cells of strain Mucor hiemalis F-1431 (for which capacity for dimorphic growth was not previously studied) by cultivation in liquid medium under aerobic conditions. The carbohydrate composition of the fat-free biomass of the mycelial and yeastlike forms grown in the same culture under aerobic conditions was studied. In the fat-free biomass consisting of yeastlike cells, as compared to the mycelium, the contents of chitin and glucose decreased from 25 and 30.9% of dry biomass to 14 and 17.5% of dry biomass, respectively. We failed to detect any changes in the contents of fucose, galactose, mannose, and uronic acids among the heteropolysaccharide monomers of fungal cells of different morphotypes, which is probably due to the aerobic cultivation conditions. It was suggested that the composition of heteropolysaccharide monomers does not play such a significant role in the formation of yeastlike cells in the culture grown under aerobic conditions as the content of chitin, the main supporting biopolymer.     

Effect of culture medium and light conditions on the morphological characteristics and carbohydrate contents of Medicago strasseri calli

Using 6 culture media (12, 12D, 12G, 11, A and B) made up of MS medium (Murashige-Skoog, 1962) supplemented or not with glycerine, with different cytokinins, and/or 2,4-D, the morphological characteristics and contents in total carbohydrates, reducing sugars, sucrose and starch were studied in calli induced from explants (cotyledon, petiole, hypocotyl and leaf) obtained from Medicago strasseri seedlings. Callus formation was induced under photoperiod (16h light/8h darkness) conditions or in the absence of light. Considerable variability in the calli was observed, depending on the explants and media used. Under photoperiod conditions, medium A with KIN (1 mg/l) and 2,4-D (3 mg/l) induced many calli with the highest contents in total carbohydrates (886.1–889.3 mg/g DW), sucrose (132.1–188.2 mg/g DW) and starch (125.2–247.6 mg/g DW) and the lowest contents in reducing sugars (118.4–173.3 mg/g DW). In media 11, A and B, under conditions of darkness, calli degenerated at the start of culture. Calli developed in darkness generally had dry weights and total carbohydrate and starch contents lower than those cultured under photoperiod conditions. However, sucrose contents were greater in calli formed in darkness. At these cultures times, differentiation, in the form of organogenesis, was only seen using medium B with cotyledons, petioles and leaves as explants. It was also observed when petioles were cultured in medium A but with a less pronounced organogenic response.     

不同营养元素限制对圆红冬胞酵母油脂生产的影响

以产油酵母圆红冬胞酵母（Rhodosporidium toruloides）作为研究对象,系统地研究了氮、磷、硫限制对其油脂积累的影响,并在3L生物反应器上考察了R.toruloides在C/P摩尔比为1 133.3时初始葡萄糖浓度对油脂生产的影响。结果表明：氮、磷、硫中任意一种营养元素受限,均能促使R.toruloides在胞内积累高于自身干重60%的油脂;通过改变培养基的组成,可以调节油脂中脂肪酸的构成,使油脂中饱和脂肪酸比例高于70%或不饱和脂肪酸比例高于60%。就油脂生产强度及转化效率而言,磷限制优于氮限制或硫限制。当C/P摩尔比相同时,初始葡萄糖浓度越低越有利于油脂生产。对采用不同原料生产微生物油脂的技术有一定指导意义。     

水稻根分泌激素调节生长速度

植物激素是植物体内合成的一类重要小分子物质,其含量可因外界条件变化而改变,并作为信号物质调控植物生长发育和适应环境。水培所用介质体积过小会造成植物生长受限、植株矮小,通常认为是小体积生长介质中营养成分不足所致。研究表明,在不同体积且不含任何营养物质的纯水中培养的水稻(Oryza sativa)亦表现出不同的生长速度,幼...     

Selection and optimization of a high-producing tissue culture of <Emphasis Type="Italic">Panax ginseng</Emphasis> C. A. Meyer

Biomass growth, ginsenoside and polysaccharide production in different ginseng tissue cultures, including callus culture, adventitious root culture and hairy root culture, were studied, and the active component contents were compared with that of native ginseng roots. The adventitious root culture was confirmed to be a very nice system, which grew fast and contained a rather high content of ginsenosides. Then, the culture conditions of adventitious root culture were optimized. The results showed that salt strength, various sucrose concentrations, ammonia/nitrate ratios and phosphate concentrations had significant influences on adventitious roots growth, secondary metabolite and polysaccharide synthesis in ginseng. The best culture conditions for ginsenoside production seemed to be 0.75 salt strength Murashige and Skoog medium, 4% sucrose, 9 mM ammonia to 36 mM nitrate, and 1.25 mM phosphate, while the optimization for polysaccharide accumulation seemed to be 0.75 salt strength, 6% sucrose, 9 mM ammonia to 36 mM nitrate and 3.75 mM phosphate source. Appropriate conditions allowed for a maximum ginsenoside yield of up to 132.90 mg/L and polysaccharide yield of 407.63 mg/L to be obtained after 4 weeks of culture.     

蛹虫草液体培养条件优化及有效成分含量分析

为优化蛹虫草菌的液体培养条件,对蛹虫草菌丝体进行液体摇瓶培养。以干菌丝体得率为指标,对影响发酵产量的重要因子设计正交试验,得出最佳培养条件。在最优条件下扩大培养,检测此时菌丝体中虫草素及虫草多糖含量。结果表明:蛹虫草菌丝体液体发酵的最适条件为:接种量10 % (v/v) ,发酵初始pH7 0 ,发酵温度2 7℃,发酵时间96h。扩大培养后,测得菌丝体中虫草素的含量为5 1 785mg/10 0g ,虫草精多糖含量为1 92g/10 0g。