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排序方式: 共有292条查询结果,搜索用时 31 毫秒
111.
温度对两种海洋微藻生长与多糖含量的影响 总被引:2,自引:0,他引:2
通过对不同温度条件下的海洋微藻的生物量和多糖含量的研究,探索海洋微藻在不同温度下生长和多糖含量的变化规律,提高海洋微藻多糖的产量,增加其饵料价值。实验结果:20~25℃有利于微藻的生长,10~15℃则有利于微藻多糖的积累。不同的温度对微藻生长及体内多糖含量的变化有重要的影响。 相似文献
112.
V. Kiron W. Phromkunthong M. Huntley I. Archibald G. De Scheemaker 《Aquaculture Nutrition》2012,18(5):521-531
Two marine algal products MAP3 and MAP8 were examined for their suitability as fishmeal protein substitutes in feeds of three prominent farmed species, through short‐term feeding studies. Algal meals were tested at 5 and 10% protein replacement levels for Atlantic salmon and at 25 and 40% for common carp and whiteleg shrimp. At the end of the 12‐week period, the growth and feed performance of the two fish species did not reveal any significant difference between those fish offered the algae‐based feed and those offered the control feed. The whole body proximate compositions of Atlantic salmon fed the control and algae‐based feeds were not significantly different. In common carp, the lipid content in the fish fed higher level of MAP3 was significantly lower than that of the fish fed the control feed. In whiteleg shrimp, at the end of the 9‐week feeding period, growth performance and feed utilization did not differ between the treatment groups. Protein content in the shrimp fed the higher level of MAP8 was significantly lower than that of shrimp on the control feed. The three species could accept the algal meals in their feeds at the tested levels, though there were some noticeable effects on body composition at higher inclusion levels. 相似文献
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合浦珠母贝对不同种类及浓度的单胞藻摄食与消化效果研究 总被引:2,自引:0,他引:2
从单胞藻粒径大小、表面结构、生化组成及饵料浓度等角度开展了合浦珠母贝(Pinctada fucata)对不同种类及浓度的单胞藻摄食与消化效果研究。投喂粒径大小相近的牟氏角毛藻(Chaetoceros muelleri)和湛江叉鞭金藻(Dicrateria zhanjiangensis)混合藻,粒径大小不同的亚心形扁藻(Platymonas subcordiformis)和海水小球藻(Marine chlorella)混合藻,用细胞计数法检测剩余混合藻中各单胞藻浓度。分别投喂以上4种不同浓度梯度的单胞藻,观察比较粪便中单胞藻消化状况。结果显示,合浦珠母贝对粒径大小相近的单胞藻没有表现出明显的选择性摄食(P0.05),对粒径较大的单胞藻摄食率明显高于粒径较小的单胞藻(P0.05);随着投喂单胞藻浓度的升高,合浦珠母贝对单胞藻的消化程度降低。 相似文献
115.
Cline Laroche 《Marine drugs》2022,20(5)
Microalgae and cyanobacteria are photosynthetic organisms that can produce/accumulate biomolecules with industrial interest. Among these molecules, EPSs are macromolecular polysaccharidic compounds that present biological activities and physico-chemical properties, allowing to consider their valorization in diverse commercial markets, such as cosmetic, therapeutic, nutraceutic, or hydrocolloids areas. The number of microalgae and cyanobacteria strains described to produce such EPSs has increased in recent years as, among the 256 producing strains gathered in this review, 86 were published in the last 10 years (~33%). Moreover, with the rise of research on microalgae EPSs, a variety of monosaccharides compositions have been discovered, highlighting the versatility of these organisms. If some production strategies can be applied to increase EPS production yields, it appears that case by case studies are needed to promote EPS synthesis by a strain, as many responses exist. This paper proposes an up-to-date state of the art of the diversity of microalgae and cyanobacteria EPS-producing strains, associated to the variability of compositions. The strategies for the production and extraction of the polymers are also discussed. Finally, an overview of the biological activities and physico-chemical properties allow one to consider their use on several commercial markets. 相似文献
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118.
Martin Olofsson Teresa Lamela Emmelie Nilsson Jean-Pascal Bergé Victória del Pino Pauliina Uronen Catherine Legrand 《Marine drugs》2014,12(4):1891-1910
Instead of sole nutrient starvation to boost algal lipid production, we addressed nutrient limitation at two different seasons (autumn and spring) during outdoor cultivation in flat panel photobioreactors. Lipid accumulation, biomass and lipid productivity and changes in fatty acid composition of Nannochloropsis oculata were investigated under nitrogen (N) limitation (nitrate:phosphate N:P 5, N:P 2.5 molar ratio). N. oculata was able to maintain a high biomass productivity under N-limitation compared to N-sufficiency (N:P 20) at both seasons, which in spring resulted in nearly double lipid productivity under N-limited conditions (0.21 g L−1 day−1) compared to N-sufficiency (0.11 g L−1 day−1). Saturated and monounsaturated fatty acids increased from 76% to nearly 90% of total fatty acids in N-limited cultures. Higher biomass and lipid productivity in spring could, partly, be explained by higher irradiance, partly by greater harvesting rate (~30%). Our results indicate the potential for the production of algal high value products (i.e., polyunsaturated fatty acids) during both N-sufficiency and N-limitation. To meet the sustainability challenges of algal biomass production, we propose a dual-system process: Closed photobioreactors producing biomass for high value products and inoculum for larger raceway ponds recycling waste/exhaust streams to produce bulk chemicals for fuel, feed and industrial material. 相似文献
119.
探究浮游细菌群落结构以及微生物与环境因子的相关性,可为湖泊环境评价和生态治理提供理论依据。选取湖北境内的梁子湖和后官湖,于2018年4月分别设置10个和5个采样点,进行浮游细菌与水体理化指标采样调查;通过16S rRNA基因高通量测序,分析比较浮游细菌群落结构及其多样性的差异,并通过冗余分析(RDA)探讨环境因子与浮游细菌群落结构的关系。结果表明,梁子湖和后官湖均有较高的浮游细菌群落多样性,其Shannon指数分别为3.974~4.743和3.924~4.500;梁子湖与后官湖的浮游细菌群落结构有所差异,梁子湖菌群隶属于放线菌门(Actinomycetes)、变形菌门(Proteobacteria)、拟杆菌门(Bacteroides)、蓝细菌门(Cyanobacteria)、疣微菌门(Verrucomicrobia)、绿菌门(Chlorobi)、绿弯菌门(Chloroflexi)、装甲菌门(Armatimonadetes)、厚壁菌门(Firmicutes)和硝化螺旋菌门(Nitrospirae);后官湖菌群隶属于放线菌门、蓝细菌门、变形菌门、拟杆菌门、疣微菌门、芽单胞菌门(Gemmatimonadetes)、绿弯菌门、绿菌门、浮霉菌门(Planctomycetes)、装甲菌门和螺旋体菌门(Saccharibacteria);其中,梁子湖的优势菌群为放线菌门(20.09%~43.23%)和变形菌门(21.35%~35.28%),而后官湖的优势菌群为放线菌门(20.70%~42.69%)和蓝细菌门(14.40%~45.77%)。RDA分析表明,总氮(TN)、pH、总磷(TP)是影响微生物群落结构的主要环境因子。 相似文献
120.
为研究3种不同藻类对池蝶蚌幼蚌的摄食率和生长的影响,进行了普通小球藻、斜生栅藻、舟形藻为影响因素,以养殖产量和相对(体重)生长率为评价指标的正交试验。结果表明:池蝶蚌幼蚌的摄食量在5 h内随着藻类浓度的增加而增加,实验组3、7、9的摄食量明显高于其他实验组;相对生长率(壳长、壳高、壳宽和蚌重)、绝对生长率和养殖产量在9组实验中均变化明显;在试验所设定的水平范围内,舟形藻对养殖产量和相对(体重)生长率影响最大,3种藻类的最佳水平组合是:普通小球藻为250个/mL,斜生栅藻为2.5×104个/mL,舟形藻2.5×104个/mL。 相似文献