OGRANICZONA DOSTĘPNOŚĆ
SKŁADNIKÓW ODŻYWCZYCH W ŚRODOWISKU WZROSTU
JAKO INDUKTOR ZMIAN METABOLICZNYCH U BAKTERII HETEROTROFICZNYCH
Kamila Myszka, Katarzyna Czaczyk
Katedra Biotechnologii i Mikrobiologii Żywności, Akademia Rolnicza im. A. Cieszkowskiego
ul. Wojska Polskiego 48, 60-627 Poznań
Wpłynęło w lipcu 2005
1. Wprowadzenie. 2. Oligotrofia. 3. Wzrost drobnoustrojów w warunkach głodowych. 4. Zmiany morfologiczne drobnoustrojów przy ograniczonej dostępności składników odżywczych. 5. Biosynteza i rola zewnątrzkomórkowych biopolimerów w warunkach głodowych. 6. Zmiany na poziomie molekularnym 7. Inne zmiany warunkowane ograniczoną dostępnością składników odżywczych. 8. Podsumowanie
Limited nutrients availability in the growth environment as an inductor of metabolic changes within heterotrophic bacteria
Abstract: This review paper describes the character of complex adaptation mechanisms initiating by microorganisms during starvation. Microorganisms take buildings and energy materials from culture medium to provide themselves growth, motion and reproduction. Limited availability of carbon and nitrogen sources induces directly metabolic changes of bacteria, also pathogenic (include aquatic and soil ones). Conducted researches proved that the lack of energy substrates in the culture medium permanently change cells viability and its physiological state. During starvation cylindrical form of bacteria reduce their original size, shape and also reorganize the surface membrane's structure. As a result of limited supply of building substances microorganisms reduce biosynthesis of vitamins, endogenous amino acids and nucleic acids that is: RNA and DNA, even about 80%. Taking place in this conditions extra-cellular polypeptides degradations supply the compounds for supporting basic cell vital function. In the environment with lower availability of carbon and nitrogen sources the intensification of bacterial adhesion to solid surfaces process is also observed. Microorganisms in "Viable but Nonculturable" stage show high resistance to the influence of typical antymicrobiological agents (antibioties, disinfectants and high temperature) what implicates numerous hygienic and public health problems. The correct understanding the specific of setting adaptation mechanisms by microorganisms under starvation is very
essential.
1. Introduction. 2. Oligotrophy. 3. Microorganisms growth under
starvation. 4. Microorganisms morphological changes under limited nutrient availability conditions 5. Biosynthesis and the role of extra-cellular biopolymers under
starvation. 6. Molecular level changes. 7. Other changes conditioned by limited nutrient
availability. 8. Recapitulation
Słowa kluczowe: heterotrofia, oligotrofia, ograniczona dostępność składników
odżywczych
Key words: heterotrophy, oligotrophy, limited nutrient availability
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