Question

A scientist describes an organism as a chemoheterotrophic, aerotolerant, mesophilic, facultatively halophilic coccus. Describe the cell's metabolic and structural features in plain English.

Short answer

In plain English, an organism described as a chemoheterotrophic, aerotolerant, mesophilic, facultatively halophilic coccus obtains its energy by consuming organic substances. It can tolerate exposure to oxygen and thrives best in moderate temperatures. Furthermore, while it can survive in high salt conditions, it does not require such an environment to live. Structurally, this organism is spherical.

Step-by-step solution

Define Each Term

Chemoheterotrophic refers to organisms that derive their energy by consuming organic substances. Aerotolerant suggests tolerance to oxygen by the organism. Mesophilic refers to organisms that thrive in moderate temperatures. Facultatively halophilic indicates that the organism can survive in high-salt environments, but doesn't necessarily need it. Coccus represents the shape of the cell, which is spherical.

Interpret Metabolic Features

Based on these definitions, a chemoheterotrophic, aerotolerant, mesophilic, facultatively halophilic coccus would exhibit the following metabolic features:1. It would derive its energy by consuming organic substances—this is implied by the term chemoheterotrophic.2. The cell could survive in both oxygen-rich and oxygen-poor environments– a feature indicated by the term aerotolerant.3. The organism would thrive best at moderate temperatures, which is suggested by the term mesophilic.4. It would be able to survive in salty environments, but it could also survive in low-salt environments—the meaning of the term facultatively halophilic.

Interpret Structural Features

The main structural feature implied by these definitions is the cell's shape. The term 'coccus' suggests the cell would be spherical in shape. This shape can impact many features including how the cell moves, how it connects with other cells, and possibly its efficiency in consuming nutrients.

Key concepts

Chemoheterotrophs

Chemoheterotrophs are organisms that need to consume organic compounds to obtain energy and nutrients. Unlike plants that make their own food using sunlight in a process called photosynthesis, chemoheterotrophs rely on organic matter. This category includes many bacteria, fungi, animals, and even some plants. By breaking down carbohydrates, fats, and proteins, these organisms get the energy required for their cellular processes.
Chemoheterotrophs are important for ecosystems because they help break down complex organic materials into simpler substances, enriching the environment with nutrients.
Without them, dead matter would accumulate, disrupting ecological balance.

Aerotolerance

Aerotolerance describes an organism's ability to survive and grow in the presence of oxygen, even if it does not necessarily thrive in it. Aerotolerant bacteria, for example, do not use oxygen for growth, but they are not harmed by it either.
This is different from obligate anaerobes, which cannot survive in the presence of oxygen. Some common aerotolerant lactobacilli in our digestive systems thrive with or without oxygen, contributing to gut health.
Such bacteria possess enzymes that neutralize toxic oxygen byproducts, allowing them to endure in aerobic environments.

Mesophiles

Mesophiles are organisms that grow best at moderate temperatures. They thrive in environments that range from about 20°C to 45°C. This range coincides with temperatures found in many human environments, which is why mesophiles are such a common group of microorganisms.
They include many pathogenic bacteria, which can infect humans and other warm-blooded animals, as human body temperature is around 37°C.
Refrigeration often prevents mesophilic activity by dropping temperatures below their optimal range, acting as an effective food preservation approach.

Halophiles

Halophiles are fascinating organisms that live in high-salt environments, such as salt flats and seas. The term "halophile" means "salt-loving." Facultative halophiles, in particular, can adapt to both normal and high-salinity conditions, unlike obligate halophiles that require high salt concentrations to grow.
This ability to survive in different salt levels is advantageous for their survival and distribution across varying environments.

• Facultative halophiles are notable in industries such as food preservation, where salt is used as a preservative.
• By thriving in salty conditions, they play unique roles in the microbiomes of salty habitats.

Halophiles have specialized cellular machinery to manage osmotic pressure changes caused by salt, ensuring their cells don’t dehydrate.

Coccus Shape

The coccus shape is a spherical form often seen in bacteria. This simple shape can form different arrangements due to the way the cells divide and stick together. For instance, some cocci form chains, known as streptococci, while others form clusters like grapes, called staphylococci.
The shape of bacterial cells can influence how they move and interact with their environment.

• Spherical cells, like cocci, have a higher surface area-to-volume ratio, which can affect their nutrient absorption.
• They also navigate easily in fluid environments due to their shape.

Understanding the coccus form is essential for identifying certain bacteria in laboratory settings, aiding in diagnosing infections and determining appropriate treatments.