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Bacteria
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Some bacteria have the capability of synthesizing all of their cellular carbon compounds from carbon dioxide or carbonate and their other nutritional requirements from nonorganic sources, using energy to do so derived either from (A) the oxidation of one of the following nonorganic chemicals: ferrous iron, ammonium, methane, or inorganic sulfur (these organisms are called chemoautotrophs or autotrophs), or (B) light (these organisms are called photoautotrophs or phototrophs).
Components of Nutrition
Published in Christopher Cumo, Ancestral Diets and Nutrition, 2020
Humans and other animals must consume food for energy because, Chapter 3 emphasizes, they are heterotrophs, organism that cannot manufacture energy and nutrients, except for vitamin D in the presence of sunlight. Heterotrophs contrast with autotrophs—plants, algae, and photosynthetic bacteria—which use sunlight for energy. Heterotrophs use food to fuel the chemical reactions that sustain life. Absent food’s energy, cessation of these reactions causes death. The fact that life requires energy raises the issue of quantification: How much energy does the body need for maintenance, growth, and reproduction? This question is difficult to answer given that several factors influence requirements.
Organic Matter
Published in Michael J. Kennish, 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.
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.
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
Reliability of antioxidant potential and in vivo compatibility with extremophilic actinobacterial-mediated magnesium oxide nanoparticle synthesis
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Kavitha Kandiah, Thenmozhi Jeevanantham, Balagurunathan Ramasamy
Salem magnesite reserves are unique for their cryptocrystalline structure, which is best suited for manufacturing refractory bricks. Magnesite of the Salem region is relatively low in calcium oxide and high in silica content [12]. The mineral composition of magnesite mine contains magnesite-rich ultra-basic and low concentration of silicon oxide (SiO2), 2.38%; aluminium oxide (Al2O3), 0.10%; ferric oxide (Fe2O3), 0.08%; ferrous oxide (FeO), 0.06%;calcium oxide (CaO), 0.42%; and MgO, 46.35%. Magnesite deposits cover an area of ∼5000 km; the pH of the soil is alkaline; and the temperature is high and dry in plains. In addition, the microorganism existing in the magnesite soil has special abilities to survive in the extremophilic environment. Among them, actinobacteria reside in a unique state due to their high G + C content and their ability to produce a variety of bioactive secondary metabolites [12–14]. The extremophilic actinobacteria show several adaptive strategies such as antibiosis, switching between different metabolic modes (i.e. autotrophy, heterotrophy and saprobes), and production of specific enzymes to survive under unfavourable environmental conditions. Actinobacteria are an ecologically important group and widely found in terrestrial and aquatic ecosystems that play an important role in several biological processes such as biogeochemical cycles, bioremediation [14,15], bioweathering and plant growth promotion [16]. Many researchers have synthesized silver and gold NPs using actinobacteria [14–17].