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Vitamins and Nutrition
Published in Richard J. Sundberg, The Chemical Century, 2017
Pantothenic acid, sometimes called vitamin B5, was isolated from yeast and a variety of other sources by Roger J. Williams, a biochemist at the University of Texas in Austin. It is a structural component of coenzyme A, which is a critical component in metabolism of fatty acids, carbohydrates, and amino acids. Pantothenic is widely distributed in foods and is therefore not associated with any particular deficiency disease.
Potential methanogenic and degradation of nonylphenol ethoxylate from domestic sewage: unravelling the essential roles of nutritional conditions and microbial community
Published in Environmental Technology, 2023
Jeny Ventura, Franciele Pereira Camargo, Isabel Kimiko Sakamoto, Edson Luiz Silva, Maria Bernadete Amâncio Varesche
Regarding the NPEO addition, its –OH groups can be removed by the action of an alcohol dehydrogenase (adh) enzyme, besides the alkan-1-ol dehydrogenase (peg-dh), an oxidoreductase which acts mainly on the C3-C16 linear-chain of saturated primary alcohols, and also on C4-C7 of aldehydes and on non-ionic surfactants, being worth mentioning that the last previously listed enzyme was already described as related to nonylphenol degradation, as ethoxy (EO) chain nonylphenol dehydrogenase (NPEO-DH) [68]. The aldehydes generated in this step can be used as substrate for the acetaldehyde dehydrogenase (acetylating) enzyme (dmpfg), being then converted to ethanol or used with Coenzyme A (CoA), reducing the NAD+ to NADH, H+ and Acetyl-CoA, a key compound for acidogenesis. On other hand, it is known that nonylphenol recalcitrance can increase as the number of ethoxylated groups decreases [69,70], resulting in more toxic, persistent and bioaccumulative metabolites, such as nonylphenol (4-NF) and nonylphenol monoethoxylated (NP1EO), which may explain the lower microbial diversity in S4 assays (NPEO = 5.00 mg L−1) in comparison to S5 assays (NPEO = 2.50 mg L−1) (Chao1 = 910.48 and 986.37, respectively), besides lower CH4 production (134.45 and 336.04 NmL g−¹ CODremoved, respectively).
Effect of 2,4-dichlorophenol on the production of methane from anaerobic granular sludge during anaerobic digestion through spectroscopy analysis
Published in Environmental Technology, 2022
Mingrun Li, Fei Han, Zhaoran Zhang, Huiping Zeng, Dong Li, Jie Zhang
Figure 1B showed the activities of three functional enzymes (NADH, F420 and Acetyl-CoA) involved in methanogenesis during anaerobic digestion. The activities of the three functional enzymes were inhibited to varying degrees in the presence of 2,4-DCP. Among them, the activity of coenzyme F420 was more susceptible to the toxicity of 2,4-DCP than that of Acetyl-CoA and NADH, which might be due to the fact that it was a functional enzyme mainly involved in methane production. The activity of coenzyme F420 was only 35.0% of the control group at 100 mg/L 2,4-DCP. The activity of coenzyme NADH were 92.0, 81.5 and 55.0% of the control group at 20, 50 and 100 mg/L 2,4-DCP, respectively. The activity of Acetyl-CoA was 49.4% of that of the control group at 100 mg/L 2,4-DCP, suggesting that the inhibitory effect of 2,4-DCP on acetyl CoA was weaker than that on coenzyme F420. These data suggested that the reduction ability of microorganisms to convert key precursors of methane production into methane, rather than a lack of key precursor for methanogenesis. The acid production stage could still provide key precursors for methane production in the presence of 2,4-DCP, but the large reduction in the activity of F420 did not allow conversion of the produced key precursors to methane. This conclusion showed that the inhibitory effect of 2,4-DCP on methane production during anaerobic digestion was much greater than that on acid production.
Application of nutrient stress conditions for hydrocarbon and oil production by Botryococcus braunii
Published in Biofuels, 2019
Tanisha Manchanda, Rashmi Tyagi, Durlubh Kumar Sharma
A rich source of hydrocarbons and lipids, the green alga Botryococcus braunii, found in different types of natural water bodies, has been reported to accumulate about 30–70% of hydrocarbons under various conditions of growth.[11, 12, 13] Main hydrocarbons synthesized by different strains of B. braunii are n-alkadienes and trienes, triterpenoid botryococcenes, methylated squalenes, or the tetraterpenoid, lycopadiene, etc. Some strains of the alga are also reported to produce ether lipids which are closely related to hydrocarbons.[14–16] Among different types of lipids found in algae, triglycerides are the main ones to serve the biodiesel purpose. Main steps in the formation of triglycerides involve: (1) synthesis of acetyl coenzyme-A in the cytoplasm by withdrawing glyceraldehydes phosphate from Calvin cycle in the chloroplast, (2) elongation and desaturation of fatty acid carbon chains mainly by acetyl coenzyme-A carboxylase enzyme and fatty acid synthase with malonyl coenzyme as substrate, and (3) the formation of the triglycerides. Normally C14–C18 fatty acids are the main components of biodiesel. Elongation and desaturation of fatty acid carbon chains to form C18 and further elongation of carbon chains give rise to hydrocarbons in some specific algae like Botryococcus.[17]