Pathogens

Mikroorganizmi su prisutni svugdje u okolišu, pa čak i u samom čovjeku. Unatoč brojnim korisnim procesima koje izazivaju, mnogi mikroorganizmi su i uzročnici raznih bolesti i epidemija. Takve mikroorganizme nazivamo patogenim mikroorganizmima. Njihova mnogobrojnost u okolišu ukazuje na kompleksnost same klasifikacije mikroorganizama. Mikroorganizmi se mogu podijeliti na bakterije, viruse, gljive, alge i protozoe. Bakterije su dio čovjekove normalne flore te imaju brojne korisne funkcije. Bakterije su bile vrlo bitne i u biološkoj evoluciji. Zajednička karakteristika mikroorganizama je da su vidljivi samo pod mikroskopom. Za uzgoj i rast mikroorganizama potrebni su određeni uvjeti kao što su: optimalna temperatura, pH, vlažnost, odsutnost ili prisutnost zraka. Neki mikroorganizmi se mogu razmnožavati spolno ili nespolno, a neki (primjerice virusi) trebaju stanicu domaćina da bi opstali i bili aktivni. Mikroorganizmi mogu imati prokariotski tip stanice ili eukariotski tip stanice. Prokarioti imaju stanice jednostavnije građe, dok su eukariotske stanice mnogo složenije građe. Mikroorganizmi imaju veliki značaj u "čišćenju" prirode, medicini te procesima u prehrambenoj industriji.Microorganisms are present everywhere in the environment, and even the man himself. Despite numerous useful processes that they cause, many microorganisms are also causing a variety of diseases and epidemics. Those microorganisms are called pathogens. Their multiplicity in the environment indicates the complexity of the classification of microorganisms. Microorganisms can be divided into bacteria, viruses, fungi and protozoa. Bacteria are part of humans normal flora and have numerous useful functions. Bacteria were also very important in biological evolution. The common characteristic of microorganisms is that they are only visible under a microscope. Microorganisms require certain conditions to occure and to multiply: a suitable temperature, absence or presence of air, moisture and host. Some microorganisms are able to reproduce sexually or asexually, and some (such as viruses) need a host cell to survive and to be active. Microorganisms may be prokaryotes and eukaryotes. Prokaryotes are made up of only one cell, while eukaryotes are made of two or more cells. Microorganisms have great significance in the "cleansing" of nature, medicine and processes in the food industry