Methanol, fermentation

Various other bacterial strains and processes have been studied by academic groups for the production of poly(3HB) or poly(3HB-co-3HV), several of which are presented here. Some methylotrophic and methanotrophic bacteria are interesting for poly(3HB) production purposes. Methanol is an inexpensive substrate and there is considerable experience in methanol fermentation techno-... 

In Japan, Mitsubishi Gas Chemical [MGC] has made an in-depth development study of the production of PHB from methanol fermentation [trade name BioGreen]. 

Chemicals have long been manufactured from biomass, especially wood (sHvichemicals), by many different fermentation and thermochemical methods. For example, continuous pyrolysis of wood was used by the Ford Motor Co. in 1929 for the manufacture of various chemicals (Table 20) (47). Wood alcohol (methanol) was manufactured on a large scale by destmctive distillation of wood for many years until the 1930s and early 1940s, when the economics became more favorable for methanol manufacture from fossil fuel-derived synthesis gas. 

Capacity Limitations and Biofuels Markets. Large biofuels markets exist (130—133), eg, production of fermentation ethanol for use as a gasoline extender (see Alcohol fuels). Even with existing (1987) and planned additions to ethanol plant capacities, less than 10% of gasoline sales could be satisfied with ethanol—gasoline blends of 10 vol % ethanol the maximum volumetric displacement of gasoline possible is about 1%. The same condition apphes to methanol and alcohol derivatives, ie, methyl-/-butyl ether [1634-04-4] and ethyl-/-butyl ether. 

Acetic Acid. Methanol carbonylation has become the process of choice for production of this staple of the organic chemical industry, which is used in the manufacture of acetate fibers, acetic anhydride [108-24-7] and terephthaUc acid, and for fermentation (see Acetic acid and derivatives). 

Recovery and Purification. The dalbaheptides are present in both the fermentation broth and the mycelial mass, from which they can be extracted with acetone or methanol, or by raising the pH of the harvested material, eg, to a pH of 10.5—11 for A47934 (16) (44) and A41030 (41) and actaplanin (Table 2) (28). A detailed review on the isolation of dalbaheptides has been written (14). Recovery from aqueous solution is made by ion pair (avoparcin) or butanol (teicoplanin) extraction. The described isolation schemes use ion-exchange matrices such as Dowex and Amberlite IR, acidic alumina, cross-linked polymeric adsorbents such as Diaion HP and Amberlite XAD, cation-exchange dextran gel (Sephadex), and polyamides in various sequences. Reverse-phase hplc, ion-exchange, or affinity resins may be used for further purification (14,89). 

As noted above, all vitamin is produced by microbial fermentation. A partial Hst of microorganisms that synthesize vitamin B 2 under appropriate conditions follows. Most strains, in their wild state, produce less than 10 mg/L vitamin although a few approach 40 mg/L. The organisms are both aerobes and anaerobes. The carbon requirements in the fermentations are satisfied from sources as wide ranging as hydrocarbons, methanol, and glucose. 

Respiratory, or oxidative, metaboHsm produces more energy than fermentation. Complete oxidation of one mol of glucose to carbon dioxide and water may produce up to 36 mol ATP in the tricarboxyHc acid (TCA) cycle or related oxidative pathways. More substrates can be respired than fermented, including pentoses (eg, by Candida species), ethanol (eg, by Saccharomjces), methanol (eg, by Hansenu/a species), and alkanes (eg, by Saccharomjces lipoljticd). 

Polyethers are usually found in both the filtrate and the mycelial fraction, but in high yielding fermentations they are mosdy in the mycelium because of their low water-solubiUty (162). The high lipophilicity of both the free acid and the salt forms of the polyether antibiotics lends these compounds to efficient organic solvent extraction and chromatography (qv) on adsorbents such as siUca gel and alumina. Many of the production procedures utilize the separation of the mycelium followed by extraction using solvents such as methanol or acetone. A number of the polyethers can be readily crystallized, either as the free acid or as the sodium or potassium salt, after only minimal purification. 

Nature produces a tremendous amount of methyl aleohol, simply by the fermentation of wood, grass, and other materials made to some degree of eellulose. In faet, methyl aleohol is known as wood aleohol, along with names sueh as wood spirits and methanol (its proper name the proper names of all aleohols end in -ol). Methyl aleohol is a eolorless liquid with a eharaeteristie aleohol odor. It has a flash point of 54°F, and is highly toxie. It has too many eommereial uses to list here, but among them are as a denaturant for ethyl alcohol (the addition of the toxie ehemieal methyl aleohol to ethyl aleohol in order to form denatured aleohol), antifreezes, gasoline additives, and solvents. No further substitution of hydroxyl radieals is performed on methyl aleohol. 

A culture of Bacillus polymyxa in a tube with Trypticase soybean broth was incubated overnight at 25°C. 5 ml of this culture was transferred to 100 ml of the tank medium in a 500 ml Erlenmeyer flask which was incubated for 48 hours at room temperature. This 100 ml culture served as inoculum for one tank. During the course of fermentation the medium was aerated at the rate of 0.3 volume of air per volume of mash per minute. The temperature was maintained at about 27 C. Samples of mash were taken every 8 hours in order to determine pH and the presence of contaminants and spores. After 88 hours of fermentation the pH was about 6.3 and an assay using Escherichia coll showed the presence of 1,200 units of polymyxin per cubic centimeter. The polymyxin was extracted and purified by removing the mycelia, adsorbing the active principle on charcoal and eluting with acidic methanol. 

The production-scale fermentation unit, with a projected annual capacity of over50,000 tonnes was fully commissioned in 1980. The bioreactor (Figure 4.8) is 60 m high, with a 7 m base diameter and working volume 1,500 m3. There are two downcomers and cooling bundles at the base. Initial sterilisation is with saturated steam at 140°C followed by displacement with heat sterilised water. Air and ammonia are filter sterilised as a mixture, methanol filter sterilised and other nutrients heat sterilised. Methanol is added through many nozzles, placed two per square metre. For start-up, 20 litres of inoculum is used and the system is operated as a batch culture for about 30 h. After this time the system is operated as a chemostat continuous culture, with methanol limitation, at 37°C and pH 6.7. Run lengths are normally 100 days, with contamination the usual cause of failure. 

Polar organic solvents readily precipitate exopolysaccharides from solution. The solvents commonly used are acetone, methanol, ethanol and propan-2-ol. Cation concentration of the fermentation liquor influences the amount of solvent required for efficient product recovery. In the case of propan-2-ol, increasing the cation concentration can lead to a four-fold reduction in die volume of solvent required to precipitate xanthan gum. Salts such as calcium nitrate and potassium chloride are added to fermentation broths for this purpose. 

Cyclic peptide from 11 amino acids. Preparation by fermentation of Tolypocladium inflatum Gams with addition of DL-a-aminobutyric acid to the fermentation medium. Isolation by homogenization of mycelium, extraction with 90 % methanol and column chromatographic purification. 

Choi and Won (1999) have reported a very u.seful strategy of recovering relatively nonvolatile lactic acid (e.g. from fermentation of carbohydrates) as volatile methyl lactate using a cationic ion-exchange resin as the catalyst. In another column reactor the methyl lactate is hydrolysed, using a cationic ion-exchange resin as the catalyst, to lactic acid and methanol, and the latter is recycled. 

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