Organic Matter
Michael J. Kennish in Ecology of Estuaries Physical and Chemical Aspects, 2019
In order to examine the production and biotic transformation of POC in estuaries, it is necessary to briefly review the trophic structure and energy flow of these systems. The estuarine ecosystem consists of biotic communities of organisms and an abiotic environment that are interactive. The flow of energy is such that trophic structure, biotic diversity, and material cycles (i.e., the exchange of materials between living and nonliving components) can be defined within the system.64 Based on Lindemannian theory,65 estuarine organisms can be assigned to specific trophic (feeding) levels, which contain groups of organisms that share a common method of obtaining their energy supply.66 Autotrophs occupy the initial trophic level, transforming inorganic compounds into organic material and serving as an energy base for heterotrophic organisms on the remaining trophic levels. Thus, the second trophic level comprises herbivorous animals which consume plants and bacteria; these herbivores are primary consumers or secondary producers. Secondary and tertiary consumers are carnivorous animals found on the third and fourth trophic levels, respectively, with secondary consumers ingesting primary consumers and tertiary consumers feeding on secondary consumers.
Changing Circumstances and Diets
Christopher Cumo in Ancestral Diets and Nutrition, 2020
Heterotrophs may be classified by what they eat, with the range of foods determining degree of specialization. Herbivores eat only plants. This category includes specialists like the panda (Ailuropoda melanoleuca), which derives almost all its nourishment from bamboo (species in subfamily Bambusoideae) leaves, stems, and shoots. Such narrowness poses risks because the staple’s endangerment causes hunger and starvation. Eradication of that food triggers extinction. At the other end of the spectrum are herbivores that eat many species. Elephants (Elephas maximus and Loxodonta africana), for example, consume several plants’ bark, branches, roots, leaves, and fruits. Herbivores feed carnivores. Lions (Panthera leo), for example, target the African savanna’s herbivores. Not necessarily restricted to herbivores, carnivores may also eat other carnivores and omnivores. Carnivory is not unique to animals because the Venus flytrap (Dionaea muscipula) and allied plants consume insects. Such organisms are both autotroph and heterotroph.
The Evolutionary Significance of Drug Toxicity Over Reward
Hanna Pickard, Serge H. Ahmed in The Routledge Handbook of Philosophy and Science of Addiction, 2019
All living organisms, including all humans, are the latest members of unbroken lineages of organisms extending back to the origin of life, over 3 billion years ago. Today, almost all organisms acquire their energy directly or indirectly from oxygenic photosynthesis, which uses sunlight to reduce carbon dioxide to organic carbon, and stores chemical energy in the form of sugars and other carbohydrates. These then provide the building blocks and fuel for the growth and reproduction of the photosynthetic organisms, termed autotrophs. The first single-celled oxygenic photosynthetic autotrophs evolved about 2.4 billion years ago (Hohmann-Marriott and Blankenship 2011).
Blautia—a new functional genus with potential probiotic properties?
Published in Gut Microbes, 2021
Xuemei Liu, Bingyong Mao, Jiayu Gu, Jiaying Wu, Shumao Cui, Gang Wang, Jianxin Zhao, Hao Zhang, Wei Chen
Blautia species are strictly anaerobic, non-motile, 1.0–1.5 × 1.0–3.0 μm in size, usually spherical or oval, and appear in pairs or strands, with most strains being sporeless. The optimum temperature and pH for most Blautia strains are 37°C and 7.0, respectively.11 Some species such as B. producta possess both heterotrophic and autotrophic properties and can use CO, H2/CO2, and carbohydrates as energy sources.34 Carbohydrate utilization experiments have shown that all Blautia strains can use glucose, but different strains showed different abilities to use sucrose, fructose, lactose, maltose, rhamnose, and raffinose (Table 2). The final products of glucose fermentation by Blautia are acetic acid, succinic acid, lactic acid, and ethanol, and the main biochemical tests have revealed negative results for lecithin, lipase, catalase, and indole. The long-chain fatty acids produced by Blautia strains are classified into linearly saturated and monounsaturated types, with C14:0, C16:0, and C16:00 dimethyl acetal fatty acids as the main species. The GC content of Blautia DNA is 37–47 mol%, and the type species of this genus is B. coccoides.11
Direct and indirect targets of carboxyatractyloside, including overlooked toxicity toward nucleoside diphosphate kinase (NDPK) and mitochondrial H+ leak
Published in Pharmaceutical Biology, 2023
Andrzej M. Woyda-Ploszczyca
Similarly, cyanide, such as hydrogen cyanide (HCN), an inhibitor of a terminal oxidase in the mitochondrial electron transport chain, known as complex IV, that affects mitochondrial respiration, may regulate, i.e., inhibit or stimulate, germinability in a concentration-dependent manner (Esashi et al. 1991; Siegień and Bogatek 2006). HCN is produced in certain plant species, including Xanthium spp., during processes, such as the catabolism of cyanogenic glycosides and cyanogenic lipids. Accordingly, in the rhizomes of A. gummifera, the ATR content is increased during the winter (Daniele et al. 2005), which likely helps maintain the plant in a resting state until spring. Therefore, compounds that are extremely toxic to animals and humans have crucial modulatory functions in the ontogenesis of many eukaryotic autotrophs. In addition to ATR/CATR and HCN, the expression level of the delay of germination 1 (dog1) gene, which protein product, among others, indirectly influences the cell wall properties, and some respiration-associated genes, which protein products are indirectly responsible for a potentially high level of energy (ATP) production and, thus, biosynthesis (Nemati et al. 2020, 2022), a burial depth of achenes or seeds, where 15–18 cm may constitute a critical suppression threshold with no seedling emergence, and the amount of mulch (Amini et al. 2020; Saeed et al. 2020) affect the prolonged dormancy or its lack in dimorphic seeds of X. strumarium.
The effect of different carbon sources on biofouling in membrane fouling simulators: microbial community and implications
Published in Biofouling, 2022
Johny Cabrera, Hao-yu Guo, Jia-long Yao, Xiao-mao Wang
The water used in the experiment was tap water from Tsinghua University’s School of Environment’s laboratory, which has a low organic content and no chemical disinfectants added. A peristaltic pump (Masterflex precision pump) and Pharmed tubing were used to pump the water. Another peristaltic pump was used to dose carbon from a carbon stock solution. The flow in the pumps was calibrated using an electronic scale (Mettler Toledo). The carbon stock solution was prepared to have a concentration of 24 mg L−1. A 1 mol L−1 NaOH solution was used to set the pH of the carbon stock solution to 11, because the carbon stock-flow was too low compared to the MFS inlet flow (100 to 1), increasing the pH to 11 did not affect the pH of the water coming into the MFS. The pH was modified to avoid bacterial growth in the carbon-containing solution. The nitrogen supply was potassium nitrate (KNO3), and the phosphorus source was sodium phosphate monobasic dihydrate (NaH2PO4·2H2O) to achieve a carbon, nitrogen, and phosphorus concentration ratio of 100:20:10, as in previous studies (Vrouwenvelder, Graf von der Schulenburg et al. 2009; Vrouwenvelder et al. 2011; Siddiqui 2016, 2017; Haaksman et al. 2017). The MFSs were covered with aluminum foil to avoid the effect of sunlight on biofilm growth (growth of autotrophs). The pressure of the MFSs was recorded daily, and the temperature was recorded at the MFS inlet.
Related Knowledge Centers
- Carbon Dioxide
- Chemosynthesis
- Heterotroph
- Organic Compound
- Photosynthesis
- Protein
- Carbohydrate
- Fat
- Carbon
- Redox