A bacterium is a relatively simple, single-celled organism without a cell nucleus. This distinguishes them from fungi. Bacteria are indispensable to our daily existence. Of the approximately 1,600 species, most are saprotrophic organisms that break down the enormous quantities of organic material produced by humans and animals. Bacteria are found in the intestines, among other places, where they help to digest our food.

How can you recognize bacteria?

Identifying bacteria is difficult because they often lack typical external features. Molecular techniques that can distinguish the unique DNA of a bacterium have therefore become an indispensable tool in establishing a correct diagnosis. Some bacteria may have cilia or whip hairs with which they propel themselves. Multiplication also always occurs through division, where a mother cell divides into two daughter cells.

What symptoms do they cause?

Bacteria that cause disease in plants can be disastrous. Entire crops can be lost within days as bacteria multiply very rapidly in the plant. Symptoms can range from necrotic sunken spots, wilting and the formation of cankers, to fruit rot and death.

How do they spread?

Most bacteria responsible for plant disease multiply inside the plant as parasites, on the leaf surface or in remnants of plant material. Some are able to survive in the soil as saprotrophic organisms. Spread is usually through infected plant material or water. However, control is difficult because chemical pesticides are not allowed. Hygienic work and adherence to hygiene measures are the best way to prevent the spread and control the disease.