Yakov Kuzyakov | |
---|---|
Born | 27 August 1963 Moscow, USSR |
Alma mater | Russian State Agrarian University, University of Halle |
Scientific career | |
Fields | Soil science, Ecology, Land use, Carbon, Nitrogen, Rhizosphere, Climate change |
Yakov Kuzyakov (born 27 August 1963) is a soil scientist professor. [1]
Kuzyakov graduated in 1986 from the Martin Luther University of Halle-Wittenberg in Halle. He defended his PhD at the Russian State Agrarian University – Moscow Timiryazev Agricultural Academy (Moscow) in 1990 under the supervision of Alexey Fokin. Then he headed the radioisotopic laboratory from 1990 to 1993 over there. Later in 1993 Kuzyakov continued his research at the Humboldt University of Berlin and the Leibniz Institute of Vegetable and Ornamental Crops. In 1997 he completed the habilitation at the University of Hohenheim under the supervision of Karl Stahr. In 2006 he took up a professorship at the department of Agroecosystem Research at the University of Bayreuth. Since 2011, he heads the department of Soil Science of Temperate Ecosystems and the department of Agricultural Soil Science at the University of Göttingen. [2] [3]
Kuzyakov is a highly cited researcher in the field of Agricultural Sciences for the 2015–2023, [4] [5] he was also included in the list of the most cited Russian scientists in 2017. [6] The H-index is 115 (Scopus database). Yakov has published more than 875 scientific papers, [7] [8] indexed by Web of Science and Scopus databases which include:
He developed new concepts of Priming effect, [11] [12] Microbial hotspots and hot moments in soil, [13] Transformation of low-molecular organic compounds in soil, Rhizosphere dynamics and stationarity, [14] Root exudation and its localization, Visualization of enzyme activity in soil, [15] Competition between microorganisms and roots for nutrients, [16] Pedogenic carbonates, [17] Agropedogenesis, [18] Partitioning and quantification of CO2 sources, [19] Biochar stability [20] etc. These concepts were investigated in the frame of global climate change conditions: global warming, elevated СО2 in the atmosphere, drought, N deposition and soil degradation. He is the first to use position specific isotope labelling, 14СО2 and 13СО2 plant labelling combined with autoradiography and zymography coupling with biomarkers. The concepts, ideas and methodical approaches developed by Yakov Kuzyakov group stimulated many research directions worldwide. [21]
Kuzyakov specialises in soil ecology and soil biogeochemistry (lipids, low molecular organic substances), agriculture, land use, agroecology, C and N cycles, priming effects, soil-plant interactions (rhizosphere processes), in-depth study of rhizodeposition, partitioning of CO2 fluxes from soil and application of radioactive and stable isotope labelling approaches in soil science. [22] He has conducted research in all climatic zones including cold deserts, tropical areas and in various ecosystems (agricultural lands, forests, mountains, pastures, etc). [23] [24] [25] The collaboration includes the projects with other research groups from Europe (Germany, Italy, France, Denmark, Russia, UK), Asia (China, South Korea, Indonesia), North and South America (USA, Chile), Africa (Tanzania) and Australia. [26]
In classical soil science, humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter. It is a kind of soil organic matter. It is rich in nutrients and retains moisture in the soil. Humus is the Latin word for "earth" or "ground".
Organic matter, organic material, or natural organic matter refers to the large source of carbon-based compounds found within natural and engineered, terrestrial, and aquatic environments. It is matter composed of organic compounds that have come from the feces and remains of organisms such as plants and animals. Organic molecules can also be made by chemical reactions that do not involve life. Basic structures are created from cellulose, tannin, cutin, and lignin, along with other various proteins, lipids, and carbohydrates. Organic matter is very important in the movement of nutrients in the environment and plays a role in water retention on the surface of the planet.
The rhizosphere is the narrow region of soil or substrate that is directly influenced by root secretions and associated soil microorganisms known as the root microbiome. Soil pores in the rhizosphere can contain many bacteria and other microorganisms that feed on sloughed-off plant cells, termed rhizodeposition, and the proteins and sugars released by roots, termed root exudates. This symbiosis leads to more complex interactions, influencing plant growth and competition for resources. Much of the nutrient cycling and disease suppression by antibiotics required by plants occurs immediately adjacent to roots due to root exudates and metabolic products of symbiotic and pathogenic communities of microorganisms. The rhizosphere also provides space to produce allelochemicals to control neighbours and relatives.
Soil ecology studies interactions among soil organisms, and their environment. It is particularly concerned with the cycling of nutrients, soil aggregate formation and soil biodiversity.
The microbial loop describes a trophic pathway where, in aquatic systems, dissolved organic carbon (DOC) is returned to higher trophic levels via its incorporation into bacterial biomass, and then coupled with the classic food chain formed by phytoplankton-zooplankton-nekton. In soil systems, the microbial loop refers to soil carbon. The term microbial loop was coined by Farooq Azam, Tom Fenchel et al. in 1983 to include the role played by bacteria in the carbon and nutrient cycles of the marine environment.
Phospholipid-derived fatty acids (PLFAs) are widely used in microbial ecology as chemotaxonomic markers of bacteria and other organisms. Phospholipids are the primary lipids composing cellular membranes. Phospholipids can be saponified, which releases the fatty acids contained in their diglyceride tail. Once the phospholipids of an unknown sample are saponified, the composition of the resulting PLFA can be compared to the PLFA of known organisms to determine the identity of the sample organism. PLFA analysis may be combined with other techniques, such as stable isotope probing to determine which microbes are metabolically active in a sample. PLFA analysis was pioneered by D.C. White at the University of Tennessee, in the early to mid 1980s.
Endomyxa is a group of eukaryotic organisms in the supergroup Rhizaria. They were initially a subphylum of Cercozoa and later a subphylum of Retaria, but several analyses have proven they are a phylogenetically separate lineage, and Endomyxa is currently regarded as its own phylum.
A microbial consortium or microbial community, is two or more bacterial or microbial groups living symbiotically. Consortiums can be endosymbiotic or ectosymbiotic, or occasionally may be both. The protist Mixotricha paradoxa, itself an endosymbiont of the Mastotermes darwiniensis termite, is always found as a consortium of at least one endosymbiotic coccus, multiple ectosymbiotic species of flagellate or ciliate bacteria, and at least one species of helical Treponema bacteria that forms the basis of Mixotricha protists' locomotion.
Extracellular enzymes or exoenzymes are synthesized inside the cell and then secreted outside the cell, where their function is to break down complex macromolecules into smaller units to be taken up by the cell for growth and assimilation. These enzymes degrade complex organic matter such as cellulose and hemicellulose into simple sugars that enzyme-producing organisms use as a source of carbon, energy, and nutrients. Grouped as hydrolases, lyases, oxidoreductases and transferases, these extracellular enzymes control soil enzyme activity through efficient degradation of biopolymers.
The plastisphere is a human-made ecosystem consisting of organisms able to live on plastic waste. Plastic marine debris, most notably microplastics, accumulates in aquatic environments and serves as a habitat for various types of microorganisms, including bacteria and fungi. As of 2022, an estimated 51 trillion microplastics are floating in the surface water of the world's oceans. A single 5mm piece of plastic can host 1,000s of different microbial species. Some marine bacteria can break down plastic polymers and use the carbon as a source of energy.
The root microbiome is the dynamic community of microorganisms associated with plant roots. Because they are rich in a variety of carbon compounds, plant roots provide unique environments for a diverse assemblage of soil microorganisms, including bacteria, fungi, and archaea. The microbial communities inside the root and in the rhizosphere are distinct from each other, and from the microbial communities of bulk soil, although there is some overlap in species composition.
Priming or a "priming effect" is said to occur when something that is added to soil or compost affects the rate of decomposition occurring on the soil organic matter (SOM), either positively or negatively. Organic matter is made up mostly of carbon and nitrogen, so adding a substrate containing certain ratios of these nutrients to soil may affect the microbes that are mineralizing SOM. Fertilizers, plant litter, detritus, and carbohydrate exudates from living roots, can potentially positively or negatively prime SOM decomposition.
Root mucilage is made of plant-specific polysaccharides or long chains of sugar molecules. This polysaccharide secretion of root exudate forms a gelatinous substance that sticks to the caps of roots. Root mucilage is known to play a role in forming relationships with soil-dwelling life forms. Just how this root mucilage is secreted is debated, but there is growing evidence that mucilage derives from ruptured cells. As roots penetrate through the soil, many of the cells surrounding the caps of roots are continually shed and replaced. These ruptured or lysed cells release their component parts, which include the polysaccharides that form root mucilage. These polysaccharides come from the Golgi apparatus and plant cell wall, which are rich in plant-specific polysaccharides. Unlike animal cells, plant cells have a cell wall that acts as a barrier surrounding the cell providing strength, which supports plants just like a skeleton.
Nitrogen-15 (15N) tracing is a technique to study the nitrogen cycle using the heavier, stable nitrogen isotope 15N. Despite the different weights, 15N is involved in the same chemical reactions as the more abundant 14N and is therefore used to trace and quantify conversions of one nitrogen compound to another. 15N tracing is applied in biogeochemistry, soil science, environmental science, environmental microbiology and small molecule activation research.
Kornelia Smalla is a chemist and biotechnologist at the Julius Kuehn Institute (JKI) in Braunschweig and a university lecturer in microbiology at the Technical University of Braunschweig.
Ellen Kandeler is a German biologist and agricultural scientist specialising in soil biology at University of Hohenheim. She also heads the Soil Biology area in the EU Biofector project.
Caroline Masiello is a biogeochemist who develops tools to better understand the cycling and fate of globally relevant elemental cycles. She is a professor at Rice University in the Department of Earth, Environmental and Planetary Sciences and holds joint appointments in the Chemistry and Biochemistry Departments. Masiello was elected as a Fellow of the Geological Society of America in 2017. She currently leads an interdisciplinary team of scientists who are developing microbial sensors for earth system science.
The plant microbiome, also known as the phytomicrobiome, plays roles in plant health and productivity and has received significant attention in recent years. The microbiome has been defined as "a characteristic microbial community occupying a reasonably well-defined habitat which has distinct physio-chemical properties. The term thus not only refers to the microorganisms involved but also encompasses their theatre of activity".
Paraburkholderia madseniana is a Gram-negative bacterium belonging to the genus Paraburkholderia. The type strain is P. madseniana RP11T, which was isolated from forest soil near Ithaca, NY, in 2016. The species was named in honor of Gene Madsen, a Professor at Cornell University, in recognition of his contributions to the field of environmental microbiology. The species is notable for its capacity to degrade phenolic compounds and its involvement in the priming effect.
Limnofila is a genus of heterotrophic protists that live in freshwater habitats and feed on bacteria. They are also present in the soil ecosystem, where they play an important role as predators of bacteria. They are classified as a single family Limnofilidae and order Limnofilida.