Improving Accuracy and Availability of Productivity Methods for a Keystone Functional Group of Microbes

提高微生物关键功能群生产力方法的准确性和可用性

• 批准号: 0234357
• 负责人: Steven Newell
• 金额: $ 11.22万
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2005-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0234357&HistoricalAwards=false
• 关键词: Improving; Accuracy; Availability; Productivity; Methods

ABSTRACTProposal: Improving Accuracy and Availability of Productivity Methods for a Keystone Functional Group of MicrobesSalt marsh plants exceedingly productive, as also are the ascomycetes (fungi) that are secondary microbial producers utilizing marsh plant organic matter as an energy source. The combination of marsh grass-marsh fungal high production is likely to be one of the basic factors underlying the high output of marine animals from salt marsh ecosystems. Because fungi in the standing-decaying marsh grass systems grow almost exclusively within the opaque solid dead plant mass, monitoring their productivity and biomass accumulation are technically difficult. This problem has been surmounted by development of biochemical analytical methods that make use of fungal-proxy molecules. The best of these has proven to be ergosterol, a cell-membrane component nearly unique to fungal cells. Ergosterol is an indicator molecule for living fungal mass and is Ergosterol relatively easily extracted from naturally decaying materials and measured by HPLC (high-performance liquid chromatography). Rates of fungal synthesis (= fungal productivity) can be measured as rates of incorporation of C14 into ergosterol, where the rate of increase in radioactivity in ergosterol parallels the rate at which the fungus is growing. It is herein proposed to seek two basic improvements to the fungal-productivity method.The acetate-to-ergosterol method has only recently become available and there remains much to be done regarding refinement of the method. One very basic item that needs attention is the conversion factor for calculating the rate of fungal organic-mass production from the rate of acetate incorporation into ergosterol. There are values available for this factor, but they range widely, and no one of the five or six investigators currently working in the field of fungal productivity has concentrated experimental efforts on this specific problem. It is proposed herein to do so, testing a range of environmental conditions and a range of target fungal species. Such a method, using the well-known dansyl fluorophore, has appeared in the drug-testing literature that is directly analogous to the acetate-to-ergosterol method. It is proposed herein to test whether this method can be used to measure fungal productivity in naturally decaying marsh grass leaves. If it can be so used, the ability to measure fungal productivity in ecosystems would become available in a wider range of laboratories (as opposed to its current restriction to those licensed for handling of radioisotopes). Broader Impacts: The research proposed would improve the utility of the methods now available for monitoring fungal production. This would provide better tools for investigators working at the edges of coastal oceans, marine sites that are currently in urgent need of attention due to their susceptibility to anthropogenic damage. More importantly, the new methodological information would also be of considerable value to forestry scientists, aquatic-ecosystem scientists, agricultural scientists, and industrial-fermentation scientists, because of the great importance of fungal activities in these fields.

摘要建议：提高微生物盐沼植物关键功能组生产力方法的准确性和可用性非常高产，子囊菌(真菌)也是如此，子囊菌是利用沼泽植物有机质作为能源的次级微生物生产者。沼泽草-沼泽真菌的高产组合可能是盐沼生态系统海洋动物产量高的基本因素之一。由于直立腐烂的沼泽草系统中的真菌几乎完全生长在不透明的固体死亡植物体内，因此监测它们的生产力和生物量积累在技术上是困难的。这个问题已经被利用真菌代理分子的生化分析方法的发展所克服。其中最好的是麦角甾醇，一种几乎是真菌细胞独有的细胞膜成分。麦角甾醇是活真菌群的指示分子，是相对容易从自然腐烂的材料中提取并通过高效液相色谱法测定的麦角甾醇。真菌合成的速率(=真菌生产力)可以用将C14并入麦角甾醇的速率来测量，其中麦角固醇放射性增加的速率与真菌生长的速率平行。本文建议对真菌产生法进行两个基本的改进。醋酸酯到麦角甾醇的方法是最近才出现的，在改进该方法方面仍有许多工作要做。需要注意的一个非常基本的事项是用于计算真菌有机大量生产率的换算系数，该换算系数是从醋酸酯并入麦角甾醇的速率计算出来的。这一因素有可利用的值，但它们的范围很大，目前在真菌生产力领域工作的五六名研究人员中，没有一个人将实验努力集中在这个特定的问题上。这里建议这样做，测试一系列环境条件和一系列目标真菌物种。这种方法，使用众所周知的丹磺酰基荧光团，已经出现在药物测试文献中，直接类似于醋酸酯到麦角甾醇的方法。本文建议测试这种方法是否可以用来测量自然腐烂的沼泽草叶片中的真菌生产力。如果它可以这样使用，那么测量生态系统中真菌生产力的能力将在更广泛的实验室中使用(而不是目前仅限于那些获得许可处理放射性同位素的实验室)。更广泛的影响：拟议的研究将提高目前可用于监测真菌生产的方法的实用性。这将为在沿海海洋边缘工作的调查人员提供更好的工具，这些海洋遗址目前由于容易受到人为破坏而迫切需要关注。更重要的是，新的方法信息对林业科学家、水生生态系统科学家、农业科学家和工业发酵科学家也有相当大的价值，因为真菌活动在这些领域非常重要。