热带普通小球藻生长过程中色素质量浓度和颜色值变化及相关性分析

该文基于CIE-L*a*b*颜色分析系统,采用全自动分光测色仪对热带普通小球藻(Chlorella vulgaris)生长过程中的颜色值变化进行监测,同时测定其细胞密度及色素的质量浓度变化并进行相关分析。结果显示,热带普通小球藻生长过程中细胞密度分为接种期、快速生长期、稳定期和衰亡期4个阶段,绿色素和黄色素质量浓度和颜色参数值黄度值(b*)、色差值(△E)和饱和度(C)均呈增加趋势,而颜色参数值明度值(L*)、红度值(a*)、相角(H°)呈降低趋势;颜色参数值与细胞密度、色素质量浓度具有较强的相关性,线性回归模型拟合度较高,在快速生长期尤为显著,其中b*和△E可作为较佳的指示指标。通过量化热带普通小球藻生长过程中的颜色参数变化,建立非接触性数量及质量动态变化预测模型,可快速准确预测,为提高养殖过程中精细操作及效率提供理论基础。     

Fe~(3+)对鳗池中铜绿微囊藻和小球藻生长的影响

以铜绿微囊藻(Microcystis aeruginosa)和小球藻(Chlorella vulgaris)为研究对象,分别测定了初始Fe3+摩尔浓度为0、1、10、15、20、25、50、100μmol·L-1时铜绿微囊藻和小球藻的生长曲线和叶绿素a含量。结果表明,2株藻均存在铁限制,其中缺铁对铜绿微囊藻生长的限制较为显著,当初始Fe3+浓度为0,1μmol·L-1时,其生长曲线呈现出负增长的趋势;铜绿微囊藻的μmax出现在25μmol·L-1,小球藻的μmax则出现在20μmol·L-1;当浓度为100μmol·L-1时,2株藻的生长均受到了一定的抑制,但此时的生长速度仍高于低Fe3+组。     

营养元素和pH对若夫小球藻生长和油脂积累的影响

以若夫小球藻（Chlorella zofingiensis）为研究对象,考察了不同的营养方式（自养、混养、异养）,不同的氮源、磷（P）质量浓度和pH对其生长和油脂积累的影响.结果表明,若夫小球藻在混合营养方式下藻体质量浓度及油脂质量分数明显高于自养与异养方式,以蔗糖为碳源的混合营养方式下若夫小球藻总脂质量浓度最高（3.14g·L^-1）,分别是自养和异养的4.6和5.0倍.以尿素为氮源时若夫小球藻总脂质量浓度最高（0.79 g·L^-1）.在一定范围内增加P质量浓度能提高若夫小球藻总脂质量浓度,其最适P质量浓度为7.0 ～ 14.0 mg·L^-1.人为改变培养液的pH对若夫小球藻细胞生长影响较大,若夫小球藻能够在pH4.5 ～9.5范围内生长,超出此范围时细胞很快裂解死亡.     

稀土元素铕(Eu)对小球藻生长和叶绿素含量的影响

将淡水小球藻在含有不同浓度稀土元素铕的培养基中培养 ,每天用分光光度计检测培养液在662nm和 632nm的吸光度值 ,计算小球藻叶绿素的含量变化。研究结果表明 ,小球藻叶绿素在可见光范围内有 2个吸收峰 ,分别在波长 661 8纳米和 431 6纳米 ;稀土元素Eu在低浓度 (0 5mg/L)时 ,对淡水小球藻的增殖有短期的促进作用 ,浓度大于或等于 1 0mg/L时 ,迅速抑制藻体生长     

蛋白核小球藻与水蕹菜调控对南美白对虾养殖水体及其生长影响的初步研究

为了解接种蛋白核小球藻(Chlorella vulgaris)和种植水蕹菜(Ipomoea Aquatica)对南美白对虾(Penaeus vannamei)养殖的影响,在南美白对虾养殖水体中设置空白对照组、单纯接种蛋白核小球藻、种植水蕹菜及二者联合的4个处理组,定期监测各处理组中水质理化指标、生长特性及免疫相关酶活性的变化情况。结果显示:与对照组相比,三个处理组均能有效去除南美白对虾养殖水体中的NO~-_2-N、NH~+_4-N、TN和TP,其中接种蛋白核小球藻处理组对NO~-_2-N的去除率达到51.27%;种植水蕹菜处理组对NO~-_2-N、NH~+_4-N和TP去除效果最好,去除率分别为55.19%、70.06%和74.76%;联合处理组对水体TN去除率为49.66%,去除TN效果最佳。三个处理组均能提高南美白对虾的特定生长率和提高其成活率,其中联合处理组效果最佳,分别较对照组提高了0.66%和27.27%,水雍菜处理组分别增加了8.14%和9.10%,蛋白核小球藻处理组分别增加了4.41%和2.28%,同时联合处理组的增重率显著高于其他三组。种植水蕹菜处理组能显著增加南美白对虾CAT、GST活性和GSH含量,分别较对照组增加了128.84%、235.39%和426.26%;联合处理组对南美白对虾肝胰腺的SOD活性和GSH含量促进效果最佳且达到显著水平,分别较对照组增加了52.75%和1 376.69%。综上可见,接种蛋白核小球藻和种植水蕹菜均能不同程度地促进南美白对虾生长及免疫活性,且以联合处理的综合效果最佳。     

Using Chlorella vulgaris and iron oxide nanoparticles in a designed bioreactor for aquaculture effluents purification

Aquaculture operations produce high volumes of wastewater containing suspended solids and nutrients such as phosphorus and nitrogen. Treatment of water effluent from fish production ponds is essential for sustain environment. So, the present study was conducted to evaluate simultaneous use of microalgae and iron oxide nanoparticles (NPs) to purify aquaculture effluents within a designed bioreactor. For designing experiment, effluent samples were collected from fish farms in Sari, Iran. Iron oxide nanoparticles were prepared from Iranian Nano Pishgaman Company. Chlorella vulgaris was captured from the environment, then purified and cultured in the laboratory. After that, NP and microalgae were transferred to the reactor space. TSS (total suspended solid), TDS (total dissolved solid), BOD (biological oxygen demand), pH (power of hydrogen), EC (electrical conductivity), NO₃ (nitrates), NO₂ (nitrite), NH₄, (ammonium) and PO₄ (phosphates) were measured during the experiment period which NH₄ (93.67 %), NO₃ (92.23 %), NO₂ (89.3 %), and PO₄ (89.25 %) showed the highest reduction percentage, respectively. Also, significant differences among the calculated parameters (except for pH) were observed during the experiment (P < 0.05). Based on the obtained results, it is concluded that the simultaneous use of microalgae and nanoparticles is desirable for purification of aquaculture wastewaters.     

营养元素对小球藻生长及胞内蛋白质和多糖含量的影响

在24～26℃、自然光照的条件下,首先考察小球藻生长与胞内蛋白质和多糖积累的关系,其次利用正交设计实验考察不同浓度的营养元素对小球藻生长及胞内蛋白质和多糖含量的影响。结果表明,小球藻中蛋白质和多糖的合成与积累主要发生在生长过程的平衡期。实验的目标不同,所需要的营养元素浓度及其优化组合不同。利于小球藻生长、胞内蛋白质和多糖积累的营养元素的优化组合分别为:C6H12O6:2g/L;KNO3:0.8g/L;NaH2PO4:0.2 g/L;C6H12O6:10 g/L;KNO3:1.6 g/L;NaH2PO4:0.2 g/L;C6H12O6:6 g/L;KNO3:1.6g/L;NaH2PO4:0.1g/L。与之对应的细胞密度、蛋白质和总糖含量分别为:6.46×107个细胞/L,655.4 mg/g,168.1mg/g。     

太空搭载小球藻（Chlorella vulgaris）子代群体新品系的筛选、培养及其营养组成分析

本文以经过太空搭载返回地面后保存的小球藻（Chlorella vulgaris）藻种T0为实验材料,从提高小球藻生长速度和促进小球藻油脂富集两个方面考虑,对小球藻生长的环境因子和培养基成分进行探讨和研究;最终经过两次筛选获得速长-油脂高产的株系TY31.实验结果表明,小球藻在140 μmol·m-2·s-1光照强度、23℃培养温度、以3.75 mmol/L的NH2 CONH2为氮源、以0.12 mmol/L的K2HPO4为磷源的最佳培养条件下,细胞生长速度加快,生长期变长,蛋白、脂肪及脂肪酸含量增加.研究发现,以第一次筛选的小球藻藻株T9为出发株,采用改良的BG-11培养基进一步选育的速长-油脂高产株系TY31,其最终细胞密度增加11.06×106 mL-1,脂肪含量增加6.50％,脂肪酸含量增加3.76％,具有应用于生物能源研究的潜力,为海洋微藻的开发利用奠定了基础.     

电磁场对小球藻生理特性的影响及其机理分析

采用稳恒电磁场的循环磁处理方式培养小球藻,对其生长、色素和元素积累量等变化进行研究,同时探讨了小球藻电磁场效应的可能机理。研究发现不同的电磁场强度对小球藻生长的作用不同,磁处理对小球藻细胞的色素组成没有影响,只是改变其含量;藻细胞官能团没有发生变化;磁处理对于小球藻中的微量元素积累会产生较大程度的影响,尤其是金属离子。电磁场的生物效应可能来源于离子吸收过程的改变。     

不同浓度漂白粉处理对水体中小球藻和原生动物的影响

以小球藻为研究对象,利用小球藻比原生动物耐受氧化剂能力强的特点,往被原生动物污染的藻液中添加7组不同浓度的漂白粉,探讨漂白粉处理小球藻液的最适浓度.结果显示:在温度为25℃、光照为2 500 lx、盐度为26的条件下,以均匀泼洒全池后水体漂白粉浓度为15 mg/L时最利于小球藻生长,且能够有效杀除小球藻中的原生动物,藻细胞在2d内逐渐恢复,显微镜观察未发现原生动物,小球藻生长速度显著升高,达到了常规培养的藻细胞浓度.     

补充CO2对光生物反应器培养小球藻生长和光合作用的影响

试验结果表明,补充1000 μl/L CO2,可促进小球藻的生长,藻细胞密度和生物量显著高于对照组(350 μl/L).补充CO2能够延长指数生长期,并且指数生长期(培养8 d)的最大光合速率、光合作用效率和光合作用饱和光照度均显著提高.但补充CO2降低了小球藻蛋白含量,这可能与Rubisco含量下降有关.     

基于荧光效应和调色板均衡化的小球藻自动计数方法研究

为实现藻类的自动计数,以小球藻为对象,提出一种基于荧光效应和调色板均衡化的小球藻自动计数方法。首先对小球藻荧光显微图像进行预处理,将真彩色小球藻荧光图像转换为256色图像,再采用调色板均衡化算法增强小球藻荧光图像对比度,并利用基于调色板的阈值分割算法将目标藻类与背景进行分割,同时进行计数。结果表明,该计数方法能够避免杂质影响,直接对藻类彩色图像进行图像增强和阈值分割,可以增强图像对比度,避免彩色图像灰度化过程中图像信息损失;采用连通区域标记方法结合连通区域的大小识别低重叠度藻类,可降低重叠藻类对计数结果的影响,从而提高小球藻的计算准确度。研究表明,该方法实现了针对藻类彩色图像的自动计数,且对小球藻的计数精度准确率达到95%以上,高于只使用灰度图像计数的方法。     

Effects of crude extracellular protein and crude intracellular polysaccharides of Vibrio alginolyticus on the growth,energy metabolism regulation and WSSV resistance of Litopenaeus vannamei

This study aimed to investigate the effects of adding crude extracts of the extracellular protein (Ex‐Pro) and intracellular polysaccharides (In‐Poly) of Vibrio alginolyticus to diets, at a dosage of 10 g/kg, on the growth, energy metabolism and WSSV (White Spot Syndrome Virus) resistance of Litopenaeus vannamei (initial weight, 0.88 ± 0.04 g/shrimp). Growth and survival rate were not significantly affected by the crude extracts (p > 0.05). Shrimp fed Ex‐Pro crude extracts showed higher succinate dehydrogenase (SDH) activity in the hepatopancreas and muscle but lower lactate dehydrogenase (LDH) activity in the muscle (p < 0.05). The activities of hexokinase (HK), pyruvate kinase (PK), LDH and SDH in the hepatopancreas and the activity of SDH in the muscle were significantly increased by feeding In‐Poly crude extracts (p < 0.05). In contrast, the content of fatty acid synthase (FAS) in the muscle was significantly reduced by the crude extracts (p < 0.05). The contents of glucose and triglyceride and the activity of the electron transport system in the hepatopancreas were significantly increased by the crude extracts (p < 0.05), and the WSSV resistance of the shrimp was increased. These results indicated that the Ex‐Pro and In‐Poly crude extracts of V. alginolyticus could affect energy metabolism, and there was a correlation between WSSV resistance and energy metabolism in L. vannamei.     

Effect of light intensity and photoperiod on biomass and fatty acid composition of the microalgae, Chlorella vulgaris

The effects of irradiance and photoperiod on the biomass and fatty acid (FA) composition of Chlorella vulgaris were examined in the exponential growth phase. Results indicated significant differences in biomass and FA at different intensities and photoperiods. Maximum biomass (2.05 ± 0.1 g l⁻¹) was at 62.5 μmol photons m⁻² s⁻¹ and 16:8 h light/dark photoperiod. FA composition changed considerably in different light regimes; the maximum percentage of total saturated (SFA) (33.38%) was recorded at 100 μmol photons m⁻² s⁻¹ and 16:8 h photoperiod, while monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids decreased with increasing irradiance and light duration. The maximum percentage of total MUFA (15.93%) and PUFA (27.40%) was recorded at 37.5 μmol photons m⁻² s⁻¹ and 8:16 h photoperiod.     

Seaweed-based biostimulant improves photosynthesis and effectively enhances growth and biofuel potential of a green microalga Chlorella variabilis

Aquaculture International - The main aim of the present study was to determine the effects of a seaweed-based biostimulant’s supplementation on the growth of Chlorella variabilis. A liquid...     

Chlorella vulgaris meal improved growth performance,digestive enzyme activities,fatty acid composition and tolerance of hypoxia and ammonia stress in juvenile Pacific white shrimp Litopenaeus vannamei

This study was conducted to investigate the effectiveness of fish meal substitution by Chlorella vulgaris meal in the diet of Pacific white shrimp, Litopenaeus vannamei. Experimental diets contained varying levels of fish meal (400, 300, 200, 100 and 0 g/kg) which was replaced by increasing levels of C. vulgaris (0, 97.2, 194.4, 291.6 and 388.8 g/kg). After 8 weeks of feeding trial, shrimp fed diet with 97.2 g/kg C. vulgaris showed significantly improved growth compared to other treatments including control. Similarly, shrimp fed diet with 97.2 g/kg C. vulgaris showed significantly higher amount of trypsin and amylase activities compared to other treatments. The contents of long‐chain polyunsaturated fatty acids including eicosapentaenoic acid, docosahexaenoic acid and arachidonic acid were significantly higher in the whole body of L. vannamei fed with different levels of C. vulgaris compared to those of control group. After exposure to hypoxia, the survival rate of shrimp fed diets contained different levels of C. vulgaris was higher than that of control group, while no significant differences were observed in ammonia tolerance among treatments. In conclusion, this study indicated that fish meal can be completely replaced with C. vulgaris in the diet of juvenile L. vannamei with no adverse effects on the performance of shrimp.     

Use of Chlorella vulgaris as a carotenoid source for rainbow trout: effect of dietary lipid content on pigmentation, digestibility and retention in the muscle tissue

Apparent digestibility, deposition and retention of carotenoids in the muscle of rainbow trout, Oncorhynchus mykiss, were investigated comparing the feeding of pigments from Chlorella vulgaris against commercially available pigments at two different total lipid contents (15% and 20% lipid). Algal biomass (ALG) was included in rainbow trout diets and muscle pigmentation was compared to that obtained in trout fed diets containing a 5:3 mixture of canthaxanthin and astaxanthin (MIX) (reflecting the relative concentrations of these carotenoids in the dry alga) or those fed a diet containing astaxanthin only (AST). Apparent digestibilities of pigments and nutrients were determined by the indirect method, using Cr2 O3 as indicator, and the colour intensity and pigment concentration were assessed in the muscle, using the Roche colour card for salmonids and UV-vis spectrophotometry. After 6 weeks feeding, colour intensity was similar for the various pigment sources, achieving levels 12 to 13, yet significantly higher in fish fed the diet with the higher lipid content ( 20%) (p<0.05). Pigment concentration in the muscle was also higher in the fish fed the high-fat diet. Muscle pigment concentrations were similar for fish fed diets ALG and MIX, and over 1.5 times higher than for diet AST (p<0.05) after 6 weeks. Apparent digestibility of dry matter, crude protein, lipid, total energy and specific carotenoid concentrations were also measured. Increased dietary fat content was shown to increase the deposition and the retention of carotenoids in muscle, and the difference increased with time (deposition increase of 10–20% at week 3 and 30–40% at week 6 and retention increase of 10–15% at week 3 and 30% at week 6). Pigment digestibility also apparently increases (10–20%) under those conditions despite the fact that no significant effects in terms of apparent digestibility increase were found for dry matter, protein, lipids or energy. © Rapid Science Ltd. 1998     

0#柴油和原油的水溶性成分对小球藻(Chlorella vulgaris)生长的影响

采用室内培养方法,研究了不同浓度0#柴油和原油的水溶性成分(Water accommodated fraction,WAF)对小球藻(Chlorella vulgaris)的生长影响及其差异.结果显示,低浓度的0#柴油WAF(0.30、0.10 mg/L)和原油WAF(1.17、0.58 mg/L)能够促进小球藻的生长,且0#柴油WAF的0.10 mg/L实验组和原油WAF的0.58 mg/L实验组在96h时,小球藻细胞密度显著高于对照组(P＜0.05);而高浓度的0#柴油WAF(8.10、2.70、0.90 mg/L)和原油WAF(9.36、4.68、2.34 mg/L)会抑制小球藻的生长.0#柴油和原油WAF对小球藻的96 h-EC50分别为3.34、6.54 mg/L,NOEC分别为0.30、1.71 mg/L,LOEC分别为0.90、2.34 mg/L.0#柴油WAF的毒性高于原油WAF,0#柴油和原油水溶性成分的组分差异是影响二者毒性强弱的主要因素.     

Assessment of Bioactive Potential of Aqueous Protein Extracts from Diatoms Nitzschia laevis,Spirulina platensis,and Chlorella vulgaris

The bioactivities of protein extracts from Nitzschia laevis, Spirulina platensis, and Chlorella vulgaris were evaluated in vitro. Free radical scavenging potential, reducing power, oxygen radical absorbance capacity, superoxide anion radical, xanthine oxidase inhibition, and potential to inhibit angiotensin 1-converting enzyme (ACE) and acetylcholinesterase enzyme (AChE) were studied. Nitzschia protein extracts showed the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities, reducing power, and ACE inhibitory activity. Spirulina’s proteins showed the highest 2,2′-Azino-bis (3 ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging activity, xanthine oxidase, and AChE inhibition activities. Aqueous protein extracts from Nitzschia, Spirulina, and Chlorella showed in vitro antioxidant, anti-ACE, and anti-AChE activities, suggesting possible new sources of bioactive proteins of different phyla with nutraceutical and pharmaceutical potentials.