Understanding common microbial classifications allows us to be more targeted in selecting suitable preservatives and bactericides in the next step!

Introduction to Microbial Classification

 

In water-based products, microbial growth is frequently discussed. Microbial contamination can negatively impact our products, such as pH changes, odor, discoloration, viscosity changes, and performance degradation. Understanding the types of microbial contamination is crucial for product formulators to apply targeted solutions. Below is an introduction to microbial classification:

 

Overview Chart of Microbial Classification

 

 

After reviewing the chart above, we have a general understanding of microbial classification. Next, we will introduce the characteristics of various microorganisms in detail.

 

Bacteria Bacteria

 

   

Escherichia coli

 

· Single-celled, very small cells, various morphologies, prokaryotes

· Requires water, carbon, nitrogen, vitamins, and minerals for survival

· Suitable growth temperature 10-40 ℃ , pH range 4-10

· Reproduces every 20 minutes, rapid growth

 

 

Based on the different staining capabilities of bacterial cells, bacteria are divided into the following two categories:

 

G- (gram negative) Gram-negative bacteria	G+ (gram positive) Gram-positive bacteria
Pseudomonas aeruginosa	Staphylococcus aureus
Escherichia coli	Bacillus subtilis
Proteus vulgaris	Streptococcus faecalis

 

Bacteria can also be classified into aerobic and anaerobic bacteria based on their oxygen requirements.

· Obligate aerobes: Grow rapidly and efficiently utilize various nutrients/oxygen; such as Pseudomonas

· Facultative anaerobes: Release odor (butyric acid) under anaerobic conditions; such as Escherichia coli

· Obligate anaerobes: Release H2S gas, causing darkening/odor; such as sulfate-reducing bacteria

· Microaerophiles: such as lactic acid bacteria

 

Yeasts Yeast

 

 

· Single-celled, typically oval-shaped, eukaryotes

· Very small cells

· Requires water, carbon, nitrogen, vitamins, and minerals for survival

· Suitable growth temperature 4-40 ℃ , prefers acidic environments

· Reproduction is slower than bacteria; budding to form daughter cells takes 80 minutes

 

Moulds Mold

 

 

· Multicellular

· Requires water, food, oxygen, suitable temperature, and pH for growth

· Reproduces through spores     

 

 

Algae

 

 

· Algae are plants

· Obtain energy through photosynthesis

· Single-celled (green algae), multicellular (seaweed)

· Requires water, neutral pH, carbon dioxide, oxygen, light, and trace elements for growth

 

Understanding common microbial classifications allows for a more targeted approach when selecting appropriate preservatives and bactericides!