Question

As described in "A Note About Bacterial Reproduction -- and the "Culture Bias,"" the organism Epulopiscium does not divide by binary fission. Rather, each cell increases in size and divides to produce multiple daughter cells that are held within the original cell well. After lysis, those daughters are released to repeat the process. Assuming Epulopiscium could be grown in pure culture in the laboratory in broth and on solid media (it currently cannot), which method would be best for measuring the increase in biomass during growth?

Answer 1

In liquid media or broth difference between dry and wet will give biomass of the Epulopiscium.

Explanation:

Biomass of bacteria can be measured by dry or wet mass. Bacteria numbers can be counted by spread plate method under the microscope.

In solid media the colonies obtained are diluted and number of cells will be seen by plate count method or on automated cell counter. The number would help calculate biomass

The biomass will be calculated by measuring wet and dry mass. Equipments required will be:

hydraulic gravity convection oven and centrifugation set up.

A cellulose acetate filter membrane is used which is 47 mm in diameter and 0.45 micron of pore size.

The cells  grown settles down due to gravity. They are stirred to evenly spread in the broth and is kept in centrifuge.

The cells obtained after centrifugation will be taken and wet weight is obtained.

To obtain dry weight the cells are placed in oven for 6 hours to 24 hours. The resultant cells are weighed and dry weight obtained.

Biomass will be calculated by subtracting the wet mass to dry mass. This way biomass is obtained in epulopisicuium. Here the cells will be of different size so on centrifugation 2 or more phases of cells can be seen due to gravity change.