UNIT 2.2 – FT745 Food Microbiology – Bacterial Groups in Foods

- Lactic Acid Bacteria
- Acetic Acid Bacteria
- Propionic Acid Bacteria
- Butyric Acid Bacteria
- Proteolytic Bacteria
- Lipolytic Bacteria
- Saccharolytic Bacteria
- Thermophilic Bacteria
- Psychrotrophic Bacteria
- Thermoduric Bacteria
- Halotolerant Bacteria
- Aciduric Bacteria
- Osmophilic Bacteria
- Gas-Producing Bacteria
- Slime Producers
- Spore Formers
- Aerobes
- Anaerobes
- Facultative Anaerobes
- Coliforms
- Fecal Coliforms
- Enteric Pathogens

- Produce lactic acid from
carbohydrates
- Lactococcus, Leuconostoc, Pediococcus, Lactobacillus, Streptococcus thermophilus

- Produce acetic acid
- Acetobacter aceti

- Produce propionic acid and used it in dairy fermentation
- Propionibacterium freudenreichii

- Produce butyric acid
- Clostridium butyricum

- Hydrolyze proteins because they produce extracellular proteinases
- Micrococcus, Staphylococcus, Bacillus, Clostridium, Pseudomonas, Alteromonas, Flavobacterium, Alcaligenes, Enterobacteriaceae, Brevibacterium

- Hydrolyze triglycerides because they produce extracellular lipases
- Micrococcus, Staphylococcus, Pseudomonas, Alteromonas, Flavobacterium

- Hydrolyze complex carbohydrates
- Bacillus, Clostridium, Aeromonas, Pseudomonas, Enterobacter

- Grow at >50°C
- Bacillus, Clostridium, Pediococcus, Streptococcus, Lactobacillus

- Grow at refrigerated temperature
- Pseudomonas, Alteromonas, Alcaligenes, Flavobacterium, Serratia, Bacillus, Clostridium, Brochrothrix, Listeria, Yersinia, Aeromonas

- Survive pasteurization temperature treatment
- Micrococcus, Enterococcus, Lactobacillus, Pediococcus, Bacillus, Clostridium

- Survive high salt concentrations
(≥10%)
- Bacillus, Micrococcus, Staphylococcus, Pediococcus, Vibrio, Corynebacterium

- Survive at low pH (<4.0)
- Lactobacillus, Pediococcus, Lactococcus, Enterococcus, Streptococcus

- Grow at the relatively higher osmotic environment
- Staphylococcus, Leuconostoc, Lactobacillus

- Produce gas (CO2, H2, H2S) during metabolism of nutrients
- Leuconostoc Lactobacillus, Propionibacterium, Escherichia, Enterobacter, Clostridium, Desulfotomaculum

- Produce slime because they can synthesize polysaccharides
- Xanthomonas, Leuconostoc, Alcaligenes, Enterobacter, Lactococcus, Lactobacillus

- Ability to produce spores
- Bacillus, Clostridium, Desulfotomaculum

- Require oxygen for growth and
multiplication
- Pseudomonas, Bacillus, Flavobacterium

- Cannot grow in the presence of oxygen
- Clostridium

- Grow in both the presence and absence of oxygen
- Lactobacillus, Pediococcus, Leuconostoc, Bacillus, Listeria, Salmonella, Serratia

- Used as an index of sanitation
- Escherichia, Enterobacter, Citrobacter, Klebsiella

- Used as an index of sanitation
- Escherichia coli

- Cause gastrointestinal infection
- Salmonella, Shigella, Campylobacter, Yersinia, Escherichia, Vibrio, Hepatitis A