Solid carbon source

Fig. 12 Methods of growing diamondlike materials using solid carbon source.

The first direct-counting C determination on an archaeologically related sample was published in 1978 (39). In a literal sense, direct counting is currently in an early part of its own solid carbon phase, in that all currently operational systems utilize solid carbon sources and, in general, each measurement still requires a considerable degree of special attention and a relatively large commitment of manpower and resources. If the... 

Contrary to other methods, the laser ablation of solid carbon sources is not suitable to a large-scale synthesis of MWNT. The process cannot be conducted continuously, and the amounts of energy required render it uneconomic. Hence laser ablation apparatus are most likely to remain reserved to MWNT-synthesis in the laboratory. 

To overcome transport limitations associated with using a solid carbon source, ethylene was adopted as both the carbon source and fluidizing gas in several experiments. Metal powders in these experiments were either tungsten or molybdenum. 

Figure 3.7 shows the growth of R. rubrum in a batch fermentation process using a gaseous carbon source (CO). The data shown follow the logistic model as fitted by (3.14.2.11) with the solid lines, which also represent an unstructured rate model without any lag phase. The software Sigma Plot was used to fit model (3.14.2.11) to the experimental data. An increase in concentration of acetate in the prepared culture media did not improve the cell dry weight at values of 2.5 and 3 gT-1 acetate, as shown in Figure 3.7. However, the exponential growth rates were clearly observed with acetate concentrations of 0.5-2 g-F1 hi the culture media.

Among the five different species of Azospirillurn, only A. irakeme shows clearly pectinolytic activity on solid and in liquid medium. Moreover, this species can grow under non-diazotrophic as well as diazotrophic conditions when pectin is the sole carbon source (Khammas and Kaiser, 1991). Khammas and Kaiser (1991) analysed the pectinolytic activity of seven A. irakense isolates, and gave evidence for the presence of two types of pectinolytic enzymes. All strains tested have inducible Ca dependent pectate lyase activity. Six strains, showed also pectin methylesterase activity. So far, none of the corresponding enzymes have been purified. 

Tests were carried out at 25°C and at initial pH 6.9. Cultures in the liquid medium were incubated in 50 mL Falcon tubes, continuously shaked at 220 rpm. Each culture contained a fresh Pseudomonas sp. 0X1 colony in 10 mL of medium. The airlift with 10 g of pumice was sterilized at 121°C for 30 min and then housed in a sterile room. One-day culture was transferred to the reactor and, after a batch phase, liquid medium with phenol as the only carbon source was continuously fed. The reactor volume V was fixed at 0.13 L. Aerobic conditions were established sparging technical air. Under these conditions microorganism started to grow immobilized on the solid s support. When immobilized biomass approached steady state, cyclic operation of the airlift was started by alternating aerobic/anaerobic conditions. 

Coal Char Coal char is, generically, the nonagglomerated, non-fusible residue from the thermal treatment of coal however, it is more specifically the solid residue from low- or medium-temperature carbonization processes. Char is used as a fuel or a carbon source. Chars have compositions intermediate between those of coal and coke the volatile matter, sulfur content, and heating values of the chars are lower, and the ash content is higher, than those of the original coal. 

Fig. 23.1 Microbial routes from natural raw materials to and between natural flavour compounds (solid arrows). Natural raw materials are depicted within the ellipse. Raw material fractions are derived from their natural sources by conventional means, such as extraction and hydrolysis (dotted arrows). De novo indicates flavour compounds which arise from microbial cultures by de novo biosynthesis (e.g. on glucose or other carbon sources) and not by biotransformation of an externally added precursor. It should be noted that there are many more flavour compounds accessible by biocatalysis using free enzymes which are not described in this chapter, especially flavour esters by esterification of natural alcohols (e.g. aliphatic or terpene alcohols) with natural acids by free lipases. For the sake of completeness, the C6 aldehydes are also shown although only the formation of the corresponding alcohols involves microbial cells as catalysts. The list of flavour compounds shown is not intended to be all-embracing but focuses on the examples discussed in this chapter... 

Trapping Device Experiments. The system used to collect the organic compounds extracted from the aqueous stream was, in most cases, a series of glass U-tubes held at —76 °C. That temperature represented a practical lowest limit to prevent deposition of solid carbon dioxide. During the course of this program, it became evident that, for many compounds, complete mass balances were not being achieved. The trapping system appeared to be a likely source of such losses because many of the compounds studied had a finite vapor pressure at —76 °C. An effluent C02 stream saturated with these... 

Georgsson, J., Hallberg, A. and Larhed, M., Rapid palladium-catalysed synthesis of esters from aryl halides utilizing Mo(CO)6 as a solid carbon monoxide source, /. Comb. Chem., 2003, 5, 350-352. 

Dickens, A. F., Baldock, J. A., Smernik, R. J., Wakeham, S. G., Arnarson,T. S., Gehnas, Y., and Hedges, J. I. (2006). Solid-state 13C NMR analysis of size and density fractions of marine sediments Insight into organic carbon sources and preservation mechanisms. Geochim. Cosmochim. Acta 70, 666-686. 

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