961 resultados para CTX-M-15-PRODUCING STRAINS
Resumo:
本文在本实验室提供的愈伤组织高产系A1,的基础上,进行了单细胞水平的高产系筛选,并获得几个具有较高生长速率和色素含量的高产细胞系:对两种水平的筛选系进行了比较,结果表明在单细胞水平上筛选可以获得更加优良的细胞系。 愈伤组织系A1和A5在生长培养基中具有不同的性状。A1系为红色,而A5系则呈白色;二者同时显示出不同的PAL活性变化以及不同的可溶性蛋白质的种类和酯酶同工酶、过氧化物同工酶谱带。当转入生产培养基中,这种差异消失。 本文还报道了在固体和液体培养条件下,培养物在生长培养基中的生长动态,在生产培养基中的色素形成动态,并分析了不同种龄对色素形成的影响。结果表明,在固体培养基中第27天是最佳的由生长培养基转入生产培养基的时问,在液体悬浮培莽基中则第9天是最佳的转接时问。
Resumo:
Benthic food webs often derive a significant fraction of their nutrient inputs from phytoplankton in the overlying waters. If the phytoplankton include harmful algal species like Pseudo-nitzschia australis, a diatom capable of producing the neurotoxin domoic acid (DA), the benthic food web can become a depository for phycotoxins. We tested the general hypothesis that DA contaminates benthic organisms during local blooms of P. australis, a widespread toxin producer along the US west coast. To test for trophic transfer and uptake of DA into the benthic food web, we sampled 8 benthic species comprising 4 feeding groups: filter feeders (Emerita analoga and Urechis caupo); a predator (Citharichthys sordidus); scavengers (Nassarius fossatus and Pagurus samuelis) and deposit feeders (Neotrypaea californiensis, Dendraster excentricus and Olivella biplicata). Sampling occurred before, during and after blooms of P. australis in Monterey Bay, CA, USA during 2000 and 2001. DA was detected in all 8 species, with contamination persisting over variable time scales. Maximum DA levels in N. fossatus (674 ppm), E. analoga (278 ppm), C. sordidus (515 ppm), N. californiensis (145 ppm), P. samuelis (56 ppm), D. excentricus (15 ppm) and O. biplicata (3 ppm) coincided with P. australis blooms, while DA levels in U. caupo remained above 200 ppm (max. = 751 ppm) throughout the study period. DA in 6 species exceeded levels thought to be safe for higher level consumers (i.e. ≥20 ppm) and thus is likely to have deleterious effects on marine birds, sea lions and the endangered California sea otter, known to prey upon these benthic species.
Resumo:
On July 12-15, 2008, researchers and resource managers met in Jupiter, Florida to discuss and review the state of knowledge regarding mesophotic coral ecosystems, develop a working definition for these ecosystems, identify critical resource management information needs, and develop a Mesophotic Coral Ecosystems Research Strategy to assist the U.S. National Oceanic and Atmospheric Administration (NOAA) and other agencies and institutions in their research prioritization and strategic planning for mesophotic coral ecosystems. Workshop participants included representatives from international, Federal, and state governments; academia; and nongovernmental organizations. The Mesophotic Coral Ecosystems Workshop was hosted by the Perry Institute for Marine Science (PIMS) and organized by NOAA and the U.S. Geological Survey (USGS). The workshop goals, objectives, schedule, and products were governed by a Steering Committee consisting of members from NOAA (National Centers for Coastal Ocean Science’s Center for Sponsored Coastal Ocean Research, the Office of Ocean Exploration and Research’s NOAA Undersea Research Program, and the National Marine Fisheries Service), USGS, PIMS, the Caribbean Coral Reef Institute, and the Bishop Museum.