What are the growth patterns of bacteria?

What are the growth patterns of bacteria?

Bacterial colonies progress through four phases of growth: the lag phase, the log phase, the stationary phase, and the death phase. The generation time, which varies among bacteria, is controlled by many environmental conditions and by the nature of the bacterial species.

What is agar deep slant?

To make agar deeps or agar slants, melted agar is poured into a test tube and then allowed to solidify vertically (agar deep), or at a slant (agar slant). Agar plates are made by pouring melted agar into a petri dish.

What is an agar slant quizlet?

Agar slants are test tubes containing solid media that were left an an angle while the agar solidified. They provide a solid growth surface for bacteria and are also easily stored and transported.

Is there bacterial growth on the slant?

Slanting the surface of the agar gives the bacteria a greater surface area on which to grow in a test tube. Furthermore, slants are created in test tubes that can be capped, which minimizes water loss.

How does bacteria grow on agar plates?

Agar, which is a polysaccharide derived from red seaweed (Rhodophyceae) is preferred because it is an inert, non-nutritive substance. The agar provides a solid growth surface for the bacteria, upon which bacteria reproduce until the distinctive lumps of cells that we call colonies form.

How does agar affect bacterial growth?

A higher nutrient concentration allows bacteria to spread more quickly. If agar concentration is high but the nutrient level is low, then bacteria must rely on nutrients diffusing towards the colony. The resulting pattern of growth follows the diffusion-limited aggregation model and forms a branching pattern.

What is the primary use of slants in microbiology?

Micro Lab Exercise 4

Question Answer
What is the primary use of slants? Long-term storage. Pure cultures.
What is the primary use of deeps? To store anaerobic bacteria. To test oxygen requirements.
What is the primary use of broths? To grow large amounts of bacteria.

What is a culture slant?

n. A culture made on the slanting surface of a solidified medium in a test tube that has been tilted to provide a greater area for growth. slope culture.

What are the different uses of agar slants compared to broths?

Agar plates will be used for isolation and some assays, and for short term maintenance of cultures. Agar slant tubes will be used for long term maintenance of isolates. Broths (liquid media) will be used to grow isolates for some assays or for the assays themselves.

What is agar slant in microbiology?

An agar slant tube (or simply an agar slant) is a screw-capped culture tube partly filled with an agar mix such as nutrient agar, R2A agar, or TSA (figure 1). To make it a slant tube the agar is allowed to cool with the tube laying at an angle, resulting in a large surface area for spreading a culture.

What is slant culture?

[ slănt ] n. A culture made on the slanting surface of a solidified medium in a test tube that has been tilted to provide a greater area for growth. slope culture.

What’s the difference between agar plates and slants?

As a working microbiologist, it is of utmost importance to be able to recognize the different bacterial growth morphologies on agar plates and slants and even in broths. This is important in the identification process. Slants are usually used for cultivating pure cultures, whereas plates are often subcultured to get pure cultures.

How are bacterial growth patterns determined on agar plates?

Recognizing different bacterial growth morphologies on agar plates is a useful and often crucial step in the identification process. Agar slants are typically used for cultivation of pure cultures. Bacteria also frequently display distinct morphological color and texture on agar slants.

How are slants and plates used to grow bacteria?

Slants are usually used for cultivating pure cultures, whereas plates are often subcultured to get pure cultures. Bacteria grow as distinct morphologies, shapes, colors and consistencies on agars. We start out with a single, lone bacterial cell, which is deposited on a solid nutrient medium agar.

Why are agar slants better suited to maintain stock cultures?

Why are agar slants better suited than agar plates to maintain stock cultures? Slants are better suited because they can be capped, preventing the agar and culture from drying out. The cap also prevents airborne contaminates from entering the slant. Slants take up less storage space.