Question

what are the similarties and difference between bacterial growth and apical growth of microorganisms?

Answer 1

Bacterial growth

Apical growth (Microbes)

Bacterial growth is the asexual reproduction or cell division of a bacterium into two daughter cells in a process called binary fission. the resulting daughter cells are genetically identical to the original cell.Both daughter cells from the division do not necessarily survive. Bacterial growth always follows a predictable pattern with four phases: Lag phase: very little to no bacterial growth. Log phase: the number of bacterial cells doubles at a constant, exponential rate. Stationary phase: population growth levels off as the rate of cell death equals the rate of cell division. Death Phase: ?the temperatures at which bacteria is killed varies and depends on nature of bacteria. ?Environmental factors influence rate of bacterial growth such as acidity (pH), temperature, water activity, macro and micro nutrients, oxygen levels, and toxins.

The growth of filamentous microorganisms is contributed by tip extension and branching. Fungi have a filamentous branching system of cells, with apical growth, lateral branching and a heterotrophic nutrition. The hypha extends by tip growth and multiplies by branching, creating a fine network called a mycelium. Growth occurs at the hyphal tip by the fusion of characteristic membrane-bound vesicles derived from the Golgi. These vesicles accumulate in the apical hyphal tip. As the hypha grows, the tip cell becomes larger and larger as it accumulates biomass. This gives rise to two phenomena, one septation and the other is branching. Branching occurs some way behind the first septum. Branching occurs by the formation of another apical cell growth point within a subapical cell. Usually the branches are at a very precise angle to the parent hypha, characteristic of the karyotype of the cell. The enzymes from hyphae create zones of substrate erosion around the hyphae but the tips can grow continuously out of these nutrient-exhausted zones. For this reason, fungi are the major decomposers of organic matter (Ex:wood decay fungi) and also are efficient in capturing mineral nutrients in mycorrhizal associations. Apical growth enables fungi to extend into fresh zones of substrate. Apical growth gives penetrating power. Hyphal tips can penetrate plant cell walls and insect cuticle, making fungi important as plant and insect pathogens, and as the major degraders of physically hard materials such as wood.