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Propanediol Production from Glycerol
Published in Ozcan Konur, Biodiesel Fuels, 2021
Schutz and Radler (1984) study the production of 1,3-PD from glycerol by Lactobacillus brevis and Lactobacillus buchneri in a paper with 129 citations. Three strains of Lactobacillus brevis and one strain of Lactobacillus buchneri grew very poorly on glucose. They observed good growth on glucose plus glycerol, while glucose was fermented to acetate or ethanol, lactate and CO2, glycerol which was dehydrated to 3-hydroxypropanal and subsequently reduced to 1,3-PD. Cell extracts of L. brevis and L. buchneri grown on glucose plus glycerol contained a B12-dependent glycerol dehydratase and a 1,3-PD dehydrogenase. Glycerol was not metabolized when used as the only substrate. Fructose as sole carbon source was partially reduced to mannitol. The joint fermentation of fructose and glycerol yielded 1,3-PD from glycerol. Ribose was fermented but did not support glycerol fermentation. Extracts from ribose grown cells did not contain glycerol dehydratase or 1,3-PD dehydrogenase. Besides glycerol the following diols were metabolized as cosubstrates with glucose: 1,2-PD, ethylene glycol, and butanediol-2.3, yielding propanol-1, ethanol, and butanol-2, respectively. Washed cells of two L. brevis strains, B18 and B20, formed 1,3-PD and 1,2-PD from glycerol, the third strain B 22 formed only 1,2-PD from glycerol in the absence of glucose.
Explosive terrorism characteristics of explosives and explosions
Published in Robert A. Burke, Counter-Terrorism for Emergency Responders, 2017
Physically, it is a powdery solid at normal temperature ranges, with density 1.6 g/cc. The chemical name is hexanitromannitol and it is also known by nitromannite, MHN, nitromannitol, nitranitol, or mannitrin. It is less stable than nitroglycerin, and it is used in detonators. Mannitol hexanitrate is a secondary explosive formed by the nitration of mannitol, a sugar alcohol. The productmannitol, a sugar alcohol. The product is used in medicine as a vasodilator and an explosive in blasting caps. Its sensitivity is considerably high, particularly at high temperatures >167°F (>75°C) where it is more sensitive than nitroglycerine. It has the highest brisance of any known conventional explosive, even more than nitroglycerine.
Under-utilized wild fruit Lepisanthes rubiginosa (Roxb.) Leenh: A discovery of novel lycopene and anthocyanin source and bioactive compound profile changes associated with drying conditions
Published in Drying Technology, 2023
Theeraphan Chumroenphat, Apichaya Bunyatratchata, Sirithon Siriamornpun
Sugars are important components contributing to the sensory properties of fruits. Generally, the individual sugars found in fruits are sucrose, glucose, and fructose. These sugars are also the principal sources of perceived sweetness. Fructose was the most predominant sugar in all drying methods, followed by glucose, mannitol, sucrose, and sorbitol (Table 3). The highest fructose content was found in fresh LRL (2344 mg/g db), which is much higher than that found in Pithecellabium dulce (193 mg/g).[9] Additionally, d(+) raffinose, d(+) maltose, d(−) mannitol, and d(−) sorbitol were found as minor constituents in the fruits. This study identified sugar alcohols, including mannitol and sorbitol. Mannitol can be metabolized in plants.[41] The proposed pathway demonstrated that fructose 6-phosphate could be converted to mannitol and during catabolism, mannitol can also be converted to fructose 6-phosphate.[41] All drying methods reduced the contents of sucrose, glucose, and fructose, as shown in Table 3. The stability of sugars is influenced by various factors including temperature and pH.[42,43] Several studies have reported the decreased in glucose and fructose levels following drying process.[44,45] For instance, fructose content decreased by approximately 23% and glucose levels were reduced by around 11% under the hot air drying process (60 °C).[45] Another study also reported a reduction in glucose levels with hot air drying compared to freeze drying.[44] However, HD and FD increased the mannitol content by 13 and 11 times, respectively, compared to fresh samples (Table 3). The possible explanation for the increase in mannitol content is that the rise in temperature during the sample preparation and the progress of FD and HD lead to the activation of enzymes that stimulate the metabolism of macromolecule sugars.[46] Whilst, the mannitol content of SD samples slightly decreased compared to the fresh samples in our present study. Fructose can be hydrogenated to mannitol[47] as shown in the pathway presented in Supplementary data (Figure S1). Therefore, the high content of mannitol in HD might be attributed to the conversion of fructose into mannitol.