Question

Microbial growth is measured by what parameter? a. increased cell size b. increased size of cellular components c. increase in total number of cells d. increased cell size and increased size of cellular components e. increased size of cellular components and increase in total number of cells

Answer 1

Answer: e. increased size of cellular components and increase in total number of cells

Growth any microbe is defined as the rate of increase in number of cell by using nutrient medium associated with increase in cellular constituents. For example in case of microorganisms such as coenocytic species in which multinucleated with no chromosomal replication takes place only we can observe increase in cell constituents size before cellular division.

Lag phase is different for different microbial species due to the dissimilar rate of cell divisions, nutrient absorption capacity. This standard curve phase is completely depending on the capability of cell growth, cell repairs, and finally based genetic material (DNA/RNA) replication.

Log Phase- Exponential growth: (more microbial multiplication phase)

In this bacterial population growth we can find the exponential growth as the population rate is increasing with the population size. In this model, birth rate is the crucial factor which implies on the growth rate. But in the virtual medium, due to limited resources availability population rate decrease as the size of the population increases.

Stationary phase is a type of constant logistic growth phase model and this phase of standard curve also if different for different microbes in the medium.

Three factors influence the standard curve dissimilarities for different microbes:

Factor -1: Death rate of the microbes and the release of nutrients from the dead microbes to sustain their growth. Death rate is different for different microbes which based upon the medium availability.

Factor-2: Spatial structure and biofilms of the microbes in their respective colonies at the time of growth in the medium.

Factor-3: Location of the microbes in the medium if it is closer to the nutrients its growth is incredibly faster compared to the growth rate of the microbes located away from the medium thereby we may find low level replication.