GENERAL MICROBIOLOGY - T.P. Pirog - 2004

6. MICROBIAL GROWTH

6.4. GROWTH PHYSIOLOGY

6.4.3 Growth of bacteria in a bacterial population

6.4.3.2. Determination of biomass

Biomass is determined using Direct and Indirect Methods. In routine practice, preference is given to indirect methods (using an appropriate calibration curve).

Direct methods. There are several direct Methods for determining biomass:

wet biomass is determined after pelleting Cells by centrifugation. After drying the washed cells, dry biomass can be determined;

determination of total nitrogen (for example, by the Kjeldahl method) or total carbon content (for example, by the Tyurin method);

Determination of protein content (for example, using the biuret method, Lowry Method, or Folin method).

Indirect methods. Several such methods are known:

biomass is determined from the optical density of The Cell suspension with subsequent conversion to dry biomass using a calibration curve;

determination of metabolic rate indicators directly related to growth (oxygen uptake, CO₂ production).