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71.
Valeria Barone Ferdinando Fragalà Piergiorgio Stevanato Andrea Baglieri 《Archives of Agronomy and Soil Science》2019,65(5):712-726
The enzymatic activity of the soil and potential plant growth can both be affected by the addition of different substances, such as biostimulants. The final objective of this work was to evaluate the effect of Chlorella vulgaris, Scenedesmus quadricauda or their extracts applied directly into the soil, by monitoring the complex soil-microorganism-plant system. Experiments were conducted in pots using agricultural soil and tomato plants in a growth chamber at 25 ± 2 °C illuminated by artificial light with a 16-h photoperiod. The soil biological activity was analyzed by monitoring fluorescein diacetate hydrolysis, dehydrogenases, acid and alkaline phosphomonoesterase and urease activities. Dry weight and chlorophyll index values of tomato plants were also investigated. Results showed that both the microalgae and their extracts positively affected soil biological activity by increasing values of the biochemical index of potential soil fertility (Mw) both in cultivated and uncultivated soils. The highest Mw value was reached in cultivated soil treated for 11 days with the lower concentration of S. quadricauda extract (Mw 9.47). All treatments significantly increased the growth of tomato plants with respect to untreated soil. These results are very promising with a view to improving soil biological activity as well as increasing plant growth. 相似文献
72.
在受控实验条件下,模拟了重金属铜、铅、镉在海水-小球藻-菲律宾蛤仔食物链中的累积和传递,测定了小球藻、菲律宾蛤仔对铜、铅、镉的富集系数以及铜、铅、镉在小球藻-菲律宾蛤仔食物链上的传递系数。结果显示,随着海水中重金属浓度的增加,小球藻、菲律宾蛤仔体内的重金属含量逐渐增大,小球藻对铜、铅、镉离子的富集系数变化范围分别为1626~3161、3295~7799、5438~9313;蛤仔对Cu、Pb、Cd的富集系数变化范围分别为364~821、1089~1936、245~736;生物传递因子变化范围分别为0.22~0.26、0.25~0.46、0.03~0.14。在本实验条件下,小球藻对Cu、Pb、Cd的富集系数远大于菲律宾蛤仔,Cu、Pb、Cd在小球藻-菲律宾蛤仔食物链上没有明显的生物放大效应。 相似文献
73.
为探究典型溴化阻燃剂六溴环十二烷(HBCD)和重金属Cu2+对海水小球藻(Chlorella salina)的毒性作用,本研究测定HBCD和Cu2+单独和联合暴露96 h后小球藻的细胞密度、Chla含量和叶绿素荧光的变化情况。结果表明:单独暴露下,HBCD处理组藻细胞密度与对照组相比显著下降,其中500μg·L-1 HBCD处理组抑制率最高(32.99%),Chl a含量和Fv/Fm则与对照组无显著差异;Cu2+处理组中,96 h-EC50分别为637μg·L-1(细胞密度)和541μg·L-1(Chl a含量),Chl a含量对Cu2+的敏感性高于细胞密度,海水小球藻的生长受到明显抑制且呈剂量-效应关系,1 260μg·L-1和2 000μg·L-1 Cu2+处理组中Fv/Fm分别显著降低24.24%和32.32%;HBCD和Cu2+<... 相似文献
74.
75.
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。 相似文献
76.
单胞藻的生产性培养技术 总被引:3,自引:0,他引:3
单胞藻类具有营养丰富,生长繁殖迅速,对环境适应性强和易培养的特点,是水产动物特别是贝类、甲壳类幼体的优质适口饵料。但由于天津地区海水透明度低,有机质含量、浮游动物、浮游植物丰富,进行藻类生产性培养困难很大,为此,2004年笔者以球等鞭金藻(Isochrysis galbana)、小球藻( Chlorellasp.)、牟氏角毛藻( Chaetoceros miiellerilemmermann)、湛江叉鞭金藻(Dicrateria zhanjiangensis)、亚心形扁藻(Platymonas subcordiformis)为试验藻种,研究了海水单胞藻类一级培养(保种)、二级培养(中继培养)、三级培养(生产性培养)的操作规程。探讨… 相似文献
77.
Fishmeal can be totally replaced by a mixture of rapeseed meal and Chlorella meal in diets for crucian carp (Carassius auratus gibelio) 下载免费PDF全文
Xi Shi Feng Chen Guang‐Hui Chen Ya‐Xiong Pan Xiao‐Ming Zhu Xu Liu Zhi Luo 《Aquaculture Research》2017,48(11):5481-5489
This study was conducted to investigate the effects of dietary fishmeal (FM) replacement by a mixture of rapeseed meal and Chlorella meal (RCM) on growth performance, apparent digestibility coefficients (ADCs), digestive enzymatic activities and intestinal histology of crucian carp Carassius auratus gibelioi. Five isonitrogenous diets were formulated to replace 0% (RCM0), 25% (RCM25), 50% (RCM50), 75% (RCM75), and 100% (RCM100) of protein from fishmeal with RCM respectively. Each experimental diet was randomly assigned to triplicate groups with 25 juvenile fish (initial body weight: 1.77 ± 0.04 g) per fibreglass tank for 6 weeks. With increasing substitution levels, weight gain rate, specific growth rate, feed intake and protein efficiency ratio increased, but feed conversion rate decreased. Dietary RCM substitution improved lipid content of muscle, but had no significant effect on other proximate composition of muscle and liver. ADCs of dry matter, protein, lipid, energy and the majority of amino acids increased with increasing substitution level, and digestive enzyme activities (amylase, trypsin and lipase) in intestine showed the similar trend with ADCs. Dietary RCM substitution had no significant adverse effect on intestinal histology. This study indicated that FM protein could be completely replaced by mixed protein sources (RCM) in crucian carp diets. 相似文献
78.
为探究微生物还原五价钒[V(Ⅴ)]的机理,从钒污染土壤中筛选出一株V(Ⅴ)还原菌,经鉴定为神户肠杆菌(Enterobacter kobei NC1-2),研究不同电子传递抑制剂和电子穿梭体对菌株NC1-2还原V(Ⅴ)的电子传递过程的影响,以及V(Ⅴ)微生物还原前后的毒性变化及其对藻类生长的影响。结果表明,当V(Ⅴ)初始浓度20 mg·L-1,培养3 d时菌株NC1-2对V(Ⅴ)的还原率为90.3%。扫描电镜(SEM)结果显示菌株表面附着无定形物质,结合能量散射X射线谱(EDS)分析证实无定形物质中含有钒元素;X射线光电子能谱(XPS)分析表明菌株NC1-2将V(Ⅴ)还原为V(Ⅳ)。电子传递抑制剂辣椒素、奎那克林和氯化铜能抑制菌株NC1-2对V(Ⅴ)的还原;核黄素作为电子穿梭体可缩短电子传递距离,促进胞外电子传递,有利于V(Ⅴ)的还原,进而加快菌株NC1-2对V(Ⅴ)的还原。V(Ⅴ)还原成V(Ⅳ)后毒性降低,减少了对小球藻Chlorella pyrenoidosa和斜生栅藻Scenedesmus obliquus的生长胁迫,两种藻生长96 h时的藻密度显著增加,且叶绿素a含量均有所提高,... 相似文献
79.
三嗪类农药复合污染物对蛋白核小球藻的联合毒性作用评估 总被引:3,自引:2,他引:1
为探讨复合污染的三嗪类农药对非靶标生物的联合毒性作用,以苯嗪草酮(Metamitron, Met)、草净津(Bladex, Bla)和特丁通(Terbumeton, Ter)为目标污染物,以蛋白核小球藻(Chlorella pyrenoidosa, C. pyrenoidosa)为指示生物,分别应用直接均分射线法和均匀设计射线法设计二元及三元混合物体系,采用微板毒性分析法系统测定3种农药及其混合污染物对C. pyrenoidosa的时间-浓度-效应数据,应用浓度加和(Concentration addition, CA)为标准参考模型分析混合物毒性相互作用,应用二维和三维等效图表征混合物联合毒性作用规律,并同步分析C. pyrenoidosa中叶绿素a含量变化,进一步评价农药及其混合物对小球藻的毒性效应。结果表明:农药及其混合物对C. pyrenoidosa的毒性数据可用Logit函数较好拟合,3种农药的毒性顺序为BlaTerMet;依据CA模型,二元混合物的毒性相互作用整体上呈现为加和作用向协同作用的转变,二维等效图显示3组二元混合物体系在半数效应浓度均具有较强的协同作用;农药三元混合物体系的5条射线均呈现加和作用,且不随暴露时间延长发生改变,三维等效图法与CA模型的分析结果基本一致;叶绿素a含量减少率与其浓度-效应曲线变化趋势基本一致。 相似文献
80.
Culture performance beyond metamorphosis of larval loach (Misgurnus anguillicaudatus) was examined in a feeding experiment of the early development stage (20 days after hatch; DAH). Total length, dry weight,
length- and weight-specific growth rate (SGR) and survival were monitored in different diet regimes. During 20 days, diet
treatments included: microparticle diets (A); live daphnia (Moina micrura) (B); live daphnia plus live chlorella (Chlorella pyrenoidosa) (C); and live daphnia plus microparticle diets (D). Fish survival rates during 20 days were 21.23 ± 4.2% (A), 73.19 ± 2.8%
(B), 90.76 ± 3% (C) and 91.46 ± 3.1% (D), respectively. Length- and weight-specific growth rate after 20 DAH (final mean SGR;
% day−1) were 5.36 ± 0.44 and 15.75 ± 1.52 (A), 9.29 ± 1.25 and 23.47 ± 2.23 (B), 9.42 ± 1.55 and 24.88 ± 2.9 (C) and 9.55 ± 1.23
and 24.40 ± 2.75 (D), respectively. Fish in treatments B, C and D displayed higher growth rates and were significantly longer
and heavier than fish in treatment A by the end of the experiment (Ρ < 0.05). Fish in treatment A had highly significant greater (Ρ < 0.001) mortalities than in treatments B, C and D. There were no significant differences in any growth parameter between
fish in treatments B, C and D, but the survivals in treatments C and D (90.76% and 91.46%) were significantly higher than
in treatment B (73.19%, Ρ < 0.05). The results demonstrated that enriched prey and co-feeding may serve as a potential feeding strategy for loach larvae,
and the form of co-feeding reduces the costs and dependence on live foods to a certain extent. We concluded that larval loach
should be reared over metamorphosis using either of the following methods: feed with live daphnia supplemented with microparticle
diets or with live chlorella. However, a prolonged rearing period of loach larvae is needed to detect nutritional problems
and observe remote effects of co-feeding on weaning in the future. 相似文献