RSS Feed (xml)

Powered By

Skin Design:
Free Blogger Skins

Powered by Blogger

Thursday, March 12, 2009

article : Factors Controlling Growth of Microorganisms

1. NUTRIENT AVAILABILITY: the accessibility of a necessary resource, substance or compound providing nourishment to maintain life, i.e. capable of conversion to energy and structural building blocks

Fastidious: having complex nutritional or cultural requirements that make isolation and culture more difficult


C, O, H, N, S, P, K, Mg, Ca, Fe, Na, Cl


Zn, Mn, Mo, Se, Co, Cu, Ni, W


Water activity (aw): represents the available water

Osmotic pressure (p): expressed in atmospheres; reflects the concentration of solute in an aqueous solution

OXYGEN: pathogenic microorganisms may have metabolic oxygen requirements that are OBLIGATE or FACULTATIVE, ANAEROBIC or AEROBIC, or somewhere in between, MICROAEROPHILIC
pH: "power of hydrogen"; a measurement of the amount of hydrogen ion in solution; the logarithm of the reciprocal of the hydrogen ion concentration in an aqueous solution used to express its acidity or alkalinity (0-14)
Psycrophile(psychrophilic): liking cold temperatures; optimal growth at 15o to 20oC
Mesophile (mesophilic): liking moderate temperatures; optimal growth at 20o to 45oC
Thermophile (thermophilic): liking elevated temperatures; optimal growth at 50o to 70oC

3. COMPETITION: the simultaneous demand by two or more organisms or species for a necessary, common resource or physical space that is in limited or potentially limited supply, resulting in a struggle for survival

Niche: the place of an organism within its community or ecosystem

4. HOST IMMUNE SYSTEM: the cells and tissues involved in recognizing and attacking foreign substances in the body

Designed & Maintained by David M. Rollins
Copyright © 2000, D.M. Rollins and S.W. Joseph
Revised: September 2003

No comments:

Search by Google

Custom Search

Search Engine Optimization - AddMe

Enter your email address:

Delivered by FeedBurner