Difference Between Actinomycetes and Bacteria

The main difference between actinomycetes and bacteria is that the actinomycetes are a type of bacteria considered as the transitional state of fungi from bacteria whereas the bacteria is a single-celled organism with a simple cellular structure. Moreover, the physical difference between actinomycetes and bacteria is that the actinomycetes is an oval-shaped bacterium while the usual bacteria are rod- or spherical-shaped. 

Actinomycetes and bacteria are two types of prokaryotes. Actinomycete is a facultative anaerobe that favors anaerobic conditions. However, bacteria can be aerobes, facultative aerobes or anaerobes.  

Key Areas Covered 

1. What are Actinomycetes
     – Definition, Features, Importance
2. What are Bacteria
     – Definition, Features, Importance
3. What are the Similarities Between Actinomycetes and Bacteria
     – Outline of Common Features
4. What is the Difference Between Actinomycetes and Bacteria
     – Comparison of Key Differences

Key Terms: Actinomycetes, Aerobes, Anaerobes, Bacteria, Endospores, Facultative, Hyphae, Prokaryotes

What are Actinomycetes 

Actinomycetes are higher bacteria in the transitional state of fungi and bacteria. One of the characteristic features of actinomycetes is the formation of hyphae, resembling the fungi. But, actinomycetes differ from fungi due to the presence of murine in the cell wall. Actinomycetes live in the soil, decaying organic matter, and as normal microbiota in animals. Some species are associated with the plants, involving in the nitrogen fixation.

Figure 1: Actinomycetes Bacteria  

Actinomycetes belong to the order Actinomycetales, which is further classified into four families: Mycobacteriaceae, Actinomycetaceae, Streptomycetaceae, and Actinoplanaceae. The main role of actinomycetes is the decomposition of the organic matter while some of them help in the production of antibiotics.  

What are Bacteria 

Bacteria are a type of unicellular prokaryotes whose cell wall is made up of murine polysaccharides. They lack membrane-bound organelles including a nucleus. Their genetic material consists of circular, double-stranded DNA located in the nucleoid. Bacteria have 70S ribosomes. Some genes are included in the extrachromosomal elements such as plasmids. Some bacteria are motile and consist of flagella.

Figure 2: Bacteria  

Coccus, Bacillus, and Spirillum are the basic shapes of bacteria. The main reproductive method of bacteria is asexual reproduction by binary fission. Sexual reproduction rarely occurs by conjugation.  

Similarities Between Actinomycetes and Bacteria 

• Actinomycetes and bacteria are prokaryotes. 
• They do not have a membrane-bound nucleus and organelles. 
• Both have a cell wall made up of murine.  
• They are microorganisms that form colonies on the solid media. 
• Both form endospores. 
• They occur in the environment and as a part of the normal microbiota. 
• Both can be pathogens. 

Difference Between Actinomycetes and Bacteria 

Definition 

Actinomycetes refer to filamentous bacteria while bacteria refer to a large group of microorganisms with a murine cell wall and no membrane-bound organelles.  

Taxonomy 

Actinomycetes belong to the order Actenomycetales while bacteria are a domain. 

Gram-Positive or -Negative 

Actinomycetes are Gram-positive while bacteria can be either Gram-positive or Gram-negative.  

Abundance 

Actinomycetes are abundant next to bacteria while bacteria are one of the most abundant types of microorganisms. 

Type of Respiration 

Actinomycetes is a facultative anaerobe while bacteria can be aerobes, anaerobes or facultative aerobes. 

Shape 

Actinomycetes are oval-shaped while bacteria are rod- or spherical-shaped. 

Colony Structure 

Actinomycetes form powdery colonies that stick firmly to agar while bacterial colonies are slimy and distinct. Further, Actinomycetes colonies grow slowly while bacterial colonies grow faster. 

Hyphae and Conidia 

Actinomycetes form hyphae and conidia as fungi while bacteria do not form such structures. 

Motility 

Actinomycetes are non-motile while some bacteria are motile. 

Conclusion 

Actinomycetes are a type of bacteria that produce fungal-like hyphae. Bacteria are a large group of microorganisms. Both Actinomycetes and bacteria are prokaryotes. The main difference between actinomycetes and bacteria is the formation of hyphae. 

Reference:

1. “Soil Microorganism – Actinomycetes.” My Agriculture Information Bank, Available Here.
2. Rogers, Kara, and Robert J. Kadner. “Bacteria.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 22 Feb. 2018, Available Here

Image Courtesy:

1. “Actinomycetes bacteria (10332880924)” By Oregon Caves from Cave Junction, USA – Actinomycetes bacteria (CC BY 2.0) via Commons Wikimedia  
2. “Bacteria photomicrograph” By Muntasir du – Own work (Public Domain) via Commons Wikimedia