Bacteria, alkanes

The tables that follow give the costs of various SCP production processes in comparative rather than in actual form. To see what this means examine Table 4.9. The production cost of raw materials for yeasts grown on n-alkanes is given as 58.5. This means that tire cost of raw materials accounts for 58.5% of the total production costs of this process. The same cost for bacteria grown on methanol is 73.8. This means that in this case 73.8% of the total production cost is accounted for by raw materials. This does not mean that the actual cost of raw materials for tire methanol process is more titan that for the n-alkanes process, as the total costs of the two processes are not necessarily similar. 

Yeast, n-alkanes Bacteria, Methanol Yeast, Ethanol Fungus, Sulphite waste liquor... 

Considerable interest arose during the 1970 s and 1980 s in the use of micro-organisms to produce useful fatty adds and related compounds from hydrocarbons derived from the petroleum industry. During this period, a large number of patents were granted in Europe, USA and Japan protecting processes leading to the production of alkanols, alkyl oxides, ketones, alkanoic adds, alkane dioic acids and surfactants from hydrocarbons. Many of these processes involved the use of bacteria and yeasts associated with hydrocarbon catabolism. 

Aeckersberg F, FA Rainey, F Widdel (1998) Growth, natural relationships, cellular fatty acids and metabolic adaptation of sulfate-reducing bacteria that utilize long-chain alkanes under anoxic conditions. Arch Microbiol 170 361-369. 

Smits THM, SB Balada, B Witholt, JB van Beilen (2002) Eunctional analysis of alkane hydroxylases from Gram-negative and Gram-positive bacteria. J Bacterial 184 1733-1742. 

Suzuki T, K Tanaka, I Matsubara, S Kinoshita (1969) Trehalose lipid and alpha-branched-beta-hydroxy fatty acid formed by bacteria grown on -alkanes. Agric Biol Chem 33 1619-1627. 

The operation of cytochrome P450 in alkane oxidation has been reported both in bacteria and in yeasts. It has been shown that alkane hydroxylases of CHYP 153 are widespread both in Gram-negative and Gram-positive bacteria that lack the integral membrane alkane hydroxylase (van Beilin et al. 2006). 

The degradation of alkynes has been the subject of sporadic interest during many years, and the pathway has been clearly delineated. It is quite distinct from those used for alkanes and alkenes, and is a reflection of the enhanced nucleophilic character of the alkyne C C bond. The initial step is hydration of the triple bond followed by ketonization of the initially formed enol. This reaction operates during the degradation of acetylene itself (de Bont and Peck 1980), acetylene carboxylic acids (Yamada and Jakoby 1959), and more complex alkynes (Figure 7.18) (Van den Tweel and de Bont 1985). It is also appropriate to note that the degradation of acetylene by anaerobic bacteria proceeds by the same pathway (Schink 1985b). 

Monooxygenation is distributed among a variety of bacteria and several have been examined for their potential to degrade fluorinated alkanes ... 

Many bacteria produce surfactants in response to exposure to hydrocarbons, and these have been demonstrated both for those that degrade alkanes and PAHs (Deziel et al. 1996). The positive effect of adding surfactants is, however, equivocal (Deschenes et al. 1996). 

Paraffins may not only be additive in PE but can also be regarded as the low molecular coimter part of S3mthetic polyolefins. Several groups have performed studies on the biodegradation of alkanes. Jen-Hao and Schwartz (12) were probably the first to claim that the number of bacteria that PE was able to support was dependent on the molecular weight of the pol3nner. 

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