Predators bacteria

The effects of pollution can be direct, such as toxic emissions providing a fatal dose of toxicant to fish, animal life, and even human beings. The effects also can be indirect. Toxic materials which are nonbiodegradable, such as waste from the manufacture of insecticides and pesticides, if released to the environment, are absorbed by bacteria and enter the food chain. These compounds can remain in the environment for long periods of time, slowly being concentrated at each stage in the food chain until ultimately they prove fatal, generally to predators at the top of the food chain such as fish or birds. 

Hay ME, Pawlik JR, Duffy JE, Fenical W (1989) Seaweed-herbivore-predator interactions host plant specialization reduces predation on small herbivores. Oecologia 81 418—427 Hellio C, De La Broise D, Dufosse L, Le Gal Y, Bourgougnon N (2001) Inhibition of marine bacteria by extracts of macroalgae potential use for environmentally friendly antifouling paints. Mar Environ Res 52 231-247... 

An inventory of known biomacromolecules is provided in Table 22.3. Many of these play essential metabolic roles in enabling growth and reproduction, such as the carbohydrates, lipids, proteins, and polynucleotides. Others are components of cell walls and exoskeletons. Some organisms, such as bacteria, plankton, plants, and lower invertebrates, synthesize biomolecules, called secondary metabolites, that are used to control ecological relationships, including predator/prey, host/symbiont, mating/spawning, and competition for food or space. 

In addition to serving as the major food source to heterotrophic bacteria, DOM plays an important ecological role in enabling marine organisms to control various aspects of their environment including trophic interrelationships. This is accomplished by the secretion or exudation of specific molecules, called secondary metabolites. These are generally LMW compounds that tend to be species specific in their source and targets. Some act as toxins that repel or kill competitors or predators. As noted earlier, some diatoms... 

Tomatoes, a major food source for humans, accumulate a variety of secondary metabolites including glycoalkaloids (1). These metabolites protect against the adverse effects of pathogens and predators, including fungi, bacteria, viruses, and insects. 

It can also fail to adapt and either be weakened in health and vigour, and therefore made vulnerable to being made extinct by other factors, such as disease or predation, or be made extinct by the novel chemicals themselves. The mass extinction of a high percentage of the life forms on the planet by oxygen, when this was first produced by photosynthesizing bacteria, is an example of the latter. 

---