The document examines food microbiology, detailing various microorganisms such as bacteria, fungi, protozoa, algae, and viruses that impact food safety, fermentation, and quality. It highlights the importance of microbiological testing to prevent food poisoning and the innovative methodologies in studying probiotics and functional foods. Additionally, the document categorizes microorganisms based on their oxygen requirements and discusses the role of different microorganisms in food production and preservation.

1. Food Microbiology
Microbiology is the study of a variety of living things, such as bacteria,
fungus, and other tiny creatures, that are not visible to the naked eye. However, these
little creatures are the foundation of all life on earth.. all types of living things that are
invisible to the unaided eye.
Important categories have been divided based on certain traits in the study of bacteria
in food. These classifications have no taxonomic relevance.
Food technology, food safety and hygiene, food poisoning, food genomics, and, more
generally, food omics, functional foods, and probiotics, along with newly developed
methodologies that have been used to analyze food, have all been the subject of recent
food microbiology papers that have been published. These papers have been
characterised by multidisciplinary interests that have confirmed the growing body of
evidence that has implicated microorganisms in these various areas. Research and
innovation in the manufacture of functional foods including probiotics demand special
consideration. Numerous studies have examined the potential probiotic bacteria's
ability to survive in the gastrointestinal tract (GIT), the gut's microbial adhesiveness
and colonization, the safety of probiotic strains, and the maintenance of the gut
microbiome's homeostasis by inhibiting pathogen growth or producing antimicrobial
compounds.
Metagenomics can be used to characterize unknown microbiota and provide
information on the presence of disease and spoilage bacteria, notably in fermented
foods (Trenholm, 2018). Numerous investigations on various conventionally
fermented foods and drinks have been published in the "Food Microbiology" section
of journals. The significance of microbial consortia in converting raw animal and
plant resources into palatable fermented meals with high nutritional content and that
are abundant in helpful bioactive chemicals for consumers was thoroughly examined.
Since their invention more than 3,500 years ago, ethnic fermented foods and drinks
have evolved to preserve crops and dairy products as fermented foods, frequently
employing back-slopping to inoculate the current batch by transferring an aliquot
from the previous batch.

2. Bacteria called lactic acid producers consume carbohydrates to create lactic acid. The
major genera include Streptococcus thermophilus, Leuconostoc, Pedi coccus,
Lactobacillus, and Lactococcus.
Acetic acid is produced by acetic acid bacteria like Acetobacter acetic.
Dairy products are fermented using bacteria that produce propionic acid, such as
Propionibacterium freudenreichii.
Butyric acid is produced by several Clostridium species, including Clostridium
butyric.
Extracellular proteinases, which are produced by proteolytic bacteria, hydrolyze
proteins. There are bacteria species in this group from the genera Micrococcus,
Staphylococcus, Bacillus, Clostridium, Pseudomonas, Alter monas, Flavobacterium,
and Alcaligin's, as well as a smaller number from Enterobacteriaceae and
Brevibacterium.
Triglycerides are hydrolyzed by extracellular lipases produced by lipolytic bacteria.
Microbiological tests, such as those for infections and spoilage organisms, are
necessary to assure the safety of food items. IIn this way, food poisoning outbreaks
can be contained by determining the risk of contamination under normal use
conditions. Along the whole supply chain, testing of food items and components is
crucial since product faults might arise at any point during the production process.[10]
Microbiological tests can not only identify spoiling but also determine germ content,

3. recognize yeasts, molds, and Salmonella. Scientists are working on quick, portable
technologies that can recognize distinct Salmonella variations in order to treat
Salmonella.[11]
According to "PCR (Polymerase Chain Reaction)," (2008), the Polymerase Chain
Reaction (PCR) is a rapid and low-cost way to produce several copies of a DNA
fragment at a particular band.
2. Gas concentration in the environment • This pertains to the existence and
level of gas concentration around food. • Different bacteria need oxygen to
flourish, either in large concentrations (aerobic), low concentrations
(microaerobic), or none at all (anaerobic). • Some microbes may thrive in
environments with high oxygen tension or even without it (facultative
anaerobes).
According to their need for oxygen, microorganisms may be divided into
the following categories: 1) In the presence of air containing molecular
oxygen, aerobes grow. Aerobic respiration is used by obligatory aerobes to
grow and reproduce. 2) Microaerophiles • Only grow at 5% molecular
oxygen concentrations or below.
Anaerobes that can develop with or without air are referred to as facultative
anaerobes. Anaerobic respiration will occur if oxygen is not present.
Types of Microbiology
There are many types of food microbiology:
1) Bacteria

4. Microorganisms that are unicellular, capable of autonomous reproduction, and
generally free-living are known as bacteria. In nature, bacteria are found everywhere.
The term "bacteria" refers to a large class of unicellular microorganisms without
nuclei or organelles, some of which can cause disease.
There are two types of Bacteria:
1) Useful Bacteria
The majority of these beneficial bacteria are found on or in your skin, stomach, or
digestive tract. Groups of bacteria residing in and on your body are referred to as
resident flora or your microbiome.
2) Harmful Bacteria
The most common bacteria and viruses in the US that cause diseases, hospitalizations,
or fatalities are listed below..
Campylobacter.
it is Clostridium perfringens.
E. coli.
Listeria.

5. Norovirus.
Salmonella.
2) Fungi
The kingdom of fungi (plural: fungus) includes heterotrophic (unable to produce their
own food) multicellular eukaryotic creatures that play significant roles in the nutrient
cycle in ecosystems. Furthermore, fungi have symbiotic relationships with both plants
and bacteria and may reproduce both sexually and asexually. However, they are also
to blame for a few ailments that affect both plants and animals. The term "mycology"
refers to the study of fungus.
Fungi Characteristics
While some fungus are multicellular, others are single-celled. Yeast is the name for
single-celled fungus. Depending on what stage of their life cycle they are in, certain
fungi switch between single-celled yeast and multicellular forms. Like plant and
animal cells, fungi cells have a nucleus and organelles. Chitin, a hard material also
present in the exoskeletons of insects and other arthropods like crustaceans, is a
component of the cell walls of fungus. They lack cellulose, which is usually present in
the cell walls of plants.
Fungi Reproduction
The majority of fungi have sexual and asexual reproductive methods. Mycelial
fragmentation, in which the mycelium breaks into several sections that each grow
independently, or spore discharge are two methods of asexual reproduction.. Separate
individuals fuse their hyphae together during sexual reproduction. The precise life

6. cycle depends on the species, but multicellular fungi often go through three stages:
haploid (where they have one set of chromosomes), diploid (where they have two
dikaryotic (having two sets of chromosomes but maintaining them apart): two sets of
chromosomes..
All fungus use spores to reproduce. Small cells or groups of cells called spores
separate from their parent fungus and mostly move through the air or water. Until
circumstances are favorable for development, spores can remain latent for a very long
period. Here is
3) Protozoa
Protozoa are heterotrophic, eukaryotic, unicellular creatures. Either they are parasites
or they live freely. There are over 65000 different categories that protozoan species
can be categorised into. Their cell wall is absent. There are several distinct cell
organelles, which in higher animals carry out the diverse functions carried out by
various organs, such as the mouth, anus, digestive system, etc.

7. General Characteristics of Protozoa
1)Habitat Protozoa are organisms that live in water. They are marine or freshwater
creatures. Some are parasitic on plants and animals, while others live freely. Although
they are mostly aerobic, some of them can also be found in the human gut or
rumen.Hot springs, for example, are home to several of the species. Some of them
develop resting cysts in order to live in dry environments..
2)Size and Shape-
Protozoa range in size and form from microbial (1m) to big enough to be seen with
the naked eye. Unicellular foraminifera have 20 cm-diameter shells.
Because they lack a hard cell wall, they are flexible and come in a variety of forms. A
thin plasma membrane surrounds cells. Some of the species have a hard shell on the
outside of their bodies. Pellicle, which can be flexible or stiff and gives organisms a
distinct form and aids in motility, supports the cell in some protozoans, particularly
ciliates.
3)Life Cycle-
Most protozoa have a life cycle that alternates between a latent cyst stage and a
proliferating vegetative stage, such as trophozoites. The cyst stage may live in arid
environments without water or nutrients. It can persist outside the host for an extended
period of time before being transferred. The trophozoite stage is contagious, and it is
at this stage that they feed and multiply.
4)Reproduction-
They mostly reproduce asexually. They procreate by binary, longitudinal, transverse,
and budding fission.. Sexual reproduction is possible in several animals. Conjugation,
syngamy, or the formation of gametocytes are all methods of sexual reproduction.
4) Algae
In addition to ponds, brackish waterways, and even snow, algae may be found in
rivers, lakes, seas, and ponds. Algae are often green, although they can also be found
in other hues. For instance, the presence of algae in snow that produce carotenoid
pigments in addition to chlorophyll gives the snow around them a characteristic red
color..

8. Algae have several general traits with both plants and animals.
Eukaryotic cells are seen in algae. Algae, for instance, may photosynthesize similarly
to plants and possess specific cell organelles and features that are only found in
animals, such as centrioles and flagella.Mannans, cellulose, and Galatians make up
the cell walls of algae. Some of the general properties of algae are listed below.
Photosynthetic creatures are algae.
Algae are unicellular or multicellular creatures.
Because algae lack a well-defined body, structures such as roots, stems, and leaves are
lacking.
Algae grow where there is enough moisture.
Algal reproduction takes both asexual and sexual forms. Spore creation is used in
asexual reproduction.
Algae are self-contained creatures, yet some may create symbiotic relationships with
other species.
Algae Classification
Examples of Algae
Algae that are well-known include:
Ulothrix Fucus

9. Porphyria Spirogyra
5) Virues
The smallest type of parasite is a virus, which can range in size from 0.02 to 0.3
micrometers (m) in most cases but up to 1 m in certain cases.
The contents of a virus
Short nucleic acid sequences, either in the form of ribonucleic acid (RNA) or
deoxyribonucleic acid (DNA), make up viruses. In contrast to most other animals,
whose DNA typically has a double-stranded structure, viruses are unusual in that their
DNA or RNA material can either be single-stranded or double-stranded..
A virion, which is the word used to describe a single virus, has a characteristic
structure that comprises an exterior shell known as the protein capsid or membrane.
The main purpose of this outer shell is to protect the genetic material of the virion
from damage caused by physical agents, chemicals, or enzymatic agents..
Classifying human viruses
A virus's physicochemical qualities, genomic structure, size, morphology, and
molecular processes are frequently used to classify it. Viruses are classed based on
whether they are RNA or DNA viruses, as well as the strangeness of their genetic
material, which can be double-stranded (ds), single-stranded (ss), or partly ds. The
classification of so viruses will also include positive, negative, and negative with
ambience viruses.

10. Adenoviridae, herpesviridae, papillomaviridae, parvoviridae, and poxivirdae are the
five dsDNA human virus families that are currently recognised. Picobirnaviridae,
Picornaviridae, and Reoviridae are the three human dsRNA viruses that have been
discovered.
How do viruses infect?
The virus's outer surface is critical for its ability to recognise and adhere to host cells.
Biological receptors can be recognised and bound by proteins found on viral surfaces,
enabling the virus to attach to the host cell.
Once the virus has attached to the host cell, it is absorbed by the cellular membrane
and enters the cytoplasm. Within the cell, the virus will disassemble its viral coat into
smaller cellular vesicles, releasing its genetic material into the cytoplasm for
reproduction.
Reference
 https://www.sciencedirect.com/journal/food-microbiology
 https://www.britannica.com/science/microbiology/Food-microbiology
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7150063/