Combustion of microbial samples

In addition to the recipes of sample preparation given above some special techniques are found in papers on microbial combustion calorimetry. A few of them shall be cited here. 

As the tablets of cell paste take up considerable amounts of moisture when taken out of the desiccator, they should be equilibrated for 15 to 30 min to 

In a paper on microbial cell preparation for combustion, it was shown that the large scatter in literature data on caloric values might be due to inappropriate preparation of biomass [28], With their procedure the authors found a significant difference between bacteria (23.13 0.52 kJ/g) and yeasts (21.21 0.47 kj/g). Moreover, they showed that there was no influence of the dilution rate of continuous cultures on the combustion heat of Kluyveromyces fragilis in agreement with results of Ho and Payne [30], The results of the latter authors were surprisingly good when they assumed in their theoretical calculations that only the C-content of cells is relevant for their caloric value [30]. 

The energy transformation of straw as substrate (lignocellulose) into the fruit bodies of a wood-rotting fungus (the oyster mushroom Pleurotus ostreatus) was estimated by means of bomb calorimetry [69] and compared with the transformation of plant energy into animal protein. With a caloric value of 11.97 kJ/g in Pleurotus fruit bodies and a mean biological energetic efficiency of 23.3 % this 

Further information about the energy content of microorganisms derived from experimental and theoretical data can be found in Chapter Quantitative Calo-rimetty and Biochemical Engineering by von Stockar and coworkers in this Volume. 

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