Перегляд вихідного коду сторінки 11 Onalespib Speech Ideas

These non-corrin Co-containing enzymes have been isolated and characterized but further research is needed to fully understand their biological functions. Aside from its role in the enzymes mentioned, Co may also substitute for Zn in carbonic anhydrase under Zn-limited conditions for some eukaryotic phytoplankton (Sunda and Huntsman, 1995). Moreover, a Co-containing alkaline phosphatase has been identified in bacteria isolated from a hot spring although alkaline phosphatase normally contains Zn as a metal cofactor (Gong et al., 2005). The  role of Co in phosphorus acquisition has been demonstrated in a culture study by Jakuba et al. (2008) using the coccolithopore E. huxleyi and they found that low Co treatments resulted in low alkaline phosphatase activity. All treatments in our culture study were supplemented with 12.5 pmol L-1 Zn�� but the observed trends suggest that Co was not replaced with Zn. The existence of various enzymes that require Co warrants further studies to comprehensively understand biochemical processes involving Co and identify which of these may be important in Trichodesmium. B12 and other B-vitamins may come from biological production and other sources including allochthonous sources, such as influxes from rivers and streams, and regenerated vitamins from phytoplankton  cell death or lysis (Gobler et al., 2007). These sources lead to B12 concentrations that are higher in coastal waters than in the open ocean and which generally reflects abundance of total Co concentration (Panzeca et al., 2008). Low B12 concentrations are typical in  the tropical and subtropical oceans characterized by intense light and high temperatures explaining the relatively short half-life of B12 in the field (Carlucci et al., 1969). The highest B12 concentration we used in this work (400 pmol L-1 B12) is approximately equivalent to the suggested B12 level in YBC-II medium widely used to cultivate Trichodesmium in the laboratory. Trichodesmium has been shown to harbor various bacteria especially when present in colonies (Sheridan et al., 2002; Roe et al., 2012). The strain used in this work is non-axenic, thus it may contain bacteria taken along with it since it was isolated and subsequently cultivated in the laboratory. Bacteria and other organisms associated with Trichodesmium are both particle attached or free-living and were found to be specific, indicating a certain degree of relationship between host and associated bacteria (Sheridan et al., 2002). B12 synthesis is a feature unique to some prokaryotic organisms and some of the associated bacteria in Trichodesmium may be capable of B12 synthesis, thus this association is [http://en.wikipedia.org/wiki/Cisplatin Cisplatin] possibly related to B12 cycling. The genome of Trichodesmium shows that it contains genes necessary for B12 synthesis (Sa?udo-Wilhelmy et al., 2014).