Isotope-fluorescence activated cell sorting to allocate C utilization in the soil microbial black box

同位素荧光激活细胞分选分配土壤微生物黑匣子中的碳利用

• 批准号: BB/F000251/1
• 负责人: Elizabeth Shaw
• 金额: $ 45.27万
• 依托单位: University of Reading
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FF000251%2F1
• 关键词: Isotope; fluorescence; activated; cell; sorting

Photosynthesis fixes carbon dioxide (CO2) carbon (C) from the atmosphere and incorporates it into plant tissues. The C is then transferred to soil when plant parts die, and from the activities of living plant roots. The transfer of C from root to soil is called rhizodeposition. Rhizodeposits contain a diverse range of C compounds that serve as a food source for microbes living in the soil close to plant roots (the rhizosphere). When rhizosphere microbes consume rhizodeposits they convert some of the C into cells, some to soil organic matter and some to CO2. Out of the diverse microbial community living in the rhizosphere that could potentially be consuming rhizodeposit C, it is important to know the proportion of C consumption that a particular group is responsible for. This knowledge is important because: 1. The efficiency with which microbes consume rhizodeposit C determines how much C is stored in the soil and how much goes back to the atmosphere. It is estimated that release of CO2 through consumption of rhizodeposits by soil microorganisms is about ten times greater than CO2 release to the atmosphere due to the burning of fossil fuels. It is probable that the efficiency of conversion of C to CO2 and soil organic matter differs depending upon the microbial species responsible. Thus, the quantity of rhizodeposit C consumed by a given species has consequences for atmospheric CO2 concentrations and soil C storage. 2. The types of microbes living in the rhizosphere can affect plant growth differently, some are beneficial (e.g. they fix nitrogen), some are detrimental (e.g. they cause disease). Thus, which microbial species grow and increase their activity at the expense of rhizodeposits has consequences for plant nutrition and health. Assessing the amount of rhizodeposit C consumed by microbial groups under realistic soil conditions is difficult. Current methodology uses the stable isotope of C (13C) to trace the rhizodeposit C in to the DNA of rhizosphere microbes. The 13C DNA is separated and used as a basis for DNA fingerprinting to identify the consuming microbes. However, this method is not very sensitive and it is not quantitive; it tells you which microbial species are consuming the 13C, but not how much of the 13C they have consumed. Quantitative knowledge regarding the consumption of rhizodeposits by particular microbial species under defined environmental conditions is important as it will allow us to understand the ecology of the rhizosphere better and therefore, in agriculture, let us: (a) make better predictions regarding how the system will respond to the changing environment and the adoption of new crop production practices; (b) manipulate the rhizosphere for benefit, for example, in the improvement of the performance of beneficial microbes in the rhizosphere which will promote lower input, more sustainable agriculture. Therefore, the aim of the research project is to assess the potential of a new method to quantify the consumption of rhizodeposits by chosen microbial species. The new method brings together three well-established techniques: (i) use of C isotopes to trace microbial C consumption; (ii) labelling microbial cells belonging to a species or group of interest with a fluorescent dye; (iii) sorting the fluorescent cells and quantifying the C isotope content. The project will start off with simple experiments. These will involve the inoculation of a bacterial type to soil, which has the unusual ability to consume a particular chemical, which will also be added to the soil. Experiments will then progress to designs involving quantification of C consumption by both inoculated and native bacteria in set-ups which mimic rhizodeposition and those which contain real bean and wheat plants. When optimized, the new methodology will serve as a platform technology that can be applied broadly to enhance understanding and ask questions regarding the plant-soil system.

光合作用将大气中的二氧化碳（CO2）和碳（C）固定下来，并将其纳入植物组织。当植物部分死亡时，C被转移到土壤中，并且来自活植物根的活动。C从根到土壤的转移称为根沉积。根际沉积物含有多种C化合物，可作为生活在植物根部附近土壤（根际）中的微生物的食物来源。当根际微生物消耗根沉积物时，它们将一些C转化为细胞，一些转化为土壤有机质，一些转化为CO2。在可能消耗根际沉积物C的根际微生物群落中，重要的是要知道特定群体负责的C消耗比例。这些知识很重要，因为：1。微生物消耗根际沉积碳的效率决定了有多少碳储存在土壤中，有多少碳回到大气中。据估计，通过土壤微生物消耗根沉积物释放的CO2比由于燃烧化石燃料而释放到大气中的CO2大约10倍。C转化为CO2和土壤有机质的效率可能因微生物种类而异。因此，一个给定的物种所消耗的根沉积碳的数量对大气CO2浓度和土壤碳储量有影响。2.生活在根际的微生物类型可以不同地影响植物生长，有些是有益的（例如，它们固定氮），有些是有害的（例如，它们引起疾病）。因此，哪些微生物物种以根沉积物为代价生长并增加其活性对植物营养和健康具有影响。在实际土壤条件下，很难评估微生物群体消耗的根沉积碳量。目前的方法使用C（13 C）的稳定同位素来追踪根际微生物的DNA中的根沉积物C。13 C DNA被分离并用作DNA指纹的基础，以识别消耗微生物。然而，这种方法不是很灵敏，也不是定量的;它告诉你哪些微生物物种正在消耗13 C，但不能告诉你它们消耗了多少13 C。关于特定微生物物种在特定环境条件下消耗根际沉积物的定量知识是重要的，因为它将使我们能够更好地了解根际生态，因此，在农业中，让我们：（a）更好地预测系统将如何响应不断变化的环境和采用新的作物生产实践;（B）操纵根际以获得益处，例如改善根际中有益微生物的性能，这将促进低投入、更可持续的农业。因此，该研究项目的目的是评估一种新方法的潜力，以量化所选微生物物种对根际沉积物的消耗。新方法汇集了三种成熟的技术：（i）使用碳同位素追踪微生物碳消耗;（ii）用荧光染料标记属于感兴趣的物种或群体的微生物细胞;（iii）分选荧光细胞并定量碳同位素含量。该项目将从简单的实验开始。这将涉及到将一种细菌接种到土壤中，这种细菌具有消耗特定化学物质的不寻常能力，这种化学物质也将被添加到土壤中。然后，实验将进展到涉及在模拟根沉积的设置和包含真实的豆类和小麦植物的设置中量化接种细菌和本地细菌的碳消耗的设计。优化后，新方法将作为一种平台技术，可广泛应用于增强对植物-土壤系统的理解并提出有关问题。

项目成果

?Use of Fluorescence ? Activated Cell Sorting (FACS) to evaluate the specificity of an oligonucleotide probe designed to target the 16S rRNA of the genus Pseudomonas in soil bacterial extracts?

?利用荧光？

• 作者: Christos Gougoulias (Author)

?Dissecting the Carbon Cycle beneath our feet: Quantifying the role of microbial decomposers of plant litter inputs to soil?

剖析我们脚下的碳循环：量化植物凋落物进入土壤的微生物分解者的作用？

• 作者: Christos Gougoulias (Author)

Development of a novel methodology to track carbon flow through the microbial black box below ground

开发一种追踪地下微生物黑匣子碳流的新方法

• 作者: Christos Gougoulias (Author)

The role of soil microbes in the global carbon cycle: tracking the below-ground microbial processing of plant-derived carbon for manipulating carbon dynamics in agricultural systems.

• DOI: 10.1002/jsfa.6577
• 发表时间: 2014-09
• 期刊: JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
• 影响因子: 4.1
• 作者: Gougoulias, Christos;Clark, Joanna M.;Shaw, Liz J.
• 通讯作者: Shaw, Liz J.

Are pseudomonads below ground pseudomonads indeed? An application of Fluorescence-Activated Cell Sorting

地下假单胞菌真的是假单胞菌吗？

• 作者: Christos Gougoulias (Author)