Main microorganisms and microbial toxins in agricultural products

Main microorganisms in agricultural products

Although there are many different kinds of microorganisms in nature, under normal circumstances, there are only a few kinds of microorganisms in a certain type of agricultural products, and those microorganisms suitable for growth on such products will become the dominant flora
.

(1) Vegetables

The inside of the plant tissue is basically sterile, except for a few porous vegetables (carrots, onions) and leafy vegetables (cabbage, Brussels sprouts)
.

Microorganisms will exist on the surface of vegetables, because vegetables often come into contact with the environment in various ways during planting, harvesting, storage, transportation, and sales, resulting in the pollution of microorganisms or their toxins

(2) Livestock and poultry products

Microorganisms on livestock and poultry products are mainly bacteria, and their sources are: ① animal skin, hair, gastrointestinal tract, etc.
; ② feeding farm and pasture environment (feed, water, soil, manure); ③ slaughter and processing facility environment (equipment, Air, water, people)
.

Mesophilic microorganisms often grow on meat, such as some bacteria of Micrococcus, Enterococcus, Staphylococcus, Bacillus, Clostridium, Lactobacillus and Enterobacteriaceae

(3) Aquatic products

The muscles of aquatic products are sterile before capture, but there are a certain amount of bacteria, viruses, parasites and protozoa in the scales, gills and intestines
.

The products captured from the marine environment contain Vibrio halophilus, Pseudomonas, Alteromonas, Flavobacterium, Enterococcus, Micrococcus, and coliforms

Microbial toxins

Microbial toxins are toxic secondary metabolites produced during the growth of microorganisms.
The pollution of agricultural products by harmful microorganisms and the resulting biological toxins in the process of production, processing, storage and transportation has become more and more prominent, and the public is paying more and more attention
.

Microbial toxins mainly include mycotoxins and bacterial toxins

Mycotoxins are a kind of highly toxic secondary metabolites that are carcinogenic, teratogenic, and mutagenic, which are produced by molds during the growth and reproduction process
.

So far, more than 350 types of mycotoxins have been detected, and dozens of them are recognized as harmful to humans and animals

Bacterial toxins are divided into bacterial exotoxin and bacterial endotoxin
.

Bacterial exotoxin is a toxic substance synthesized and secreted out of the bacteria during the growth and reproduction of bacteria.

Bacterial endotoxins are lipopolysaccharides on the cell walls of Gram-negative bacteria
.

It is released only when the bacteria die, rupture, autolyse the bacteria or lyse by artificial methods

Microbial toxins have become an important factor affecting the quality and safety of edible agricultural products, and the resulting safety issues have been highly valued by countries around the world and relevant international organizations