沈萍版微生物微生物的生长繁殖与控制-3.pdf

第四节 环境对微生物生长的影响 影响微生物生长的因素 • 营养物质 • 水的活性 • 温度 • pH • 氧 1.温度（Temperature ） 1）嗜冷微生物（Psychrophile） Grows well at 0°C and has an optimum growth temperature of 15°C or lower Bacillus psychrophilus （嗜冷芽孢杆菌） 2 ）兼性嗜冷微生物（Psychrotroph） Can grow at 0–7°C; has an optimum between 20 and 30°C and a maximum around 35°C Listeria monocytogenes Pseudomonas fluorescens 3 ）嗜温微生物（Mesophile） Has growth optimum around 20–45°C Escherichia coli 4 ）嗜热微生物（Thermophile ） Can grow at 55°C or higher; optimum often between 55 and 65°C Bacillus stearothermophilus Thermus aquaticus （水生栖热菌 ） 5）超嗜热微生物（Hyperthermophile） Has an optimum between 80 and about 113°C Pyrolobus fumarii(热叶菌） 2.酸碱度（pH） • 1）嗜酸微生物（Acidophile ） Growth optimum between pH 0 and 5.5 • Fungi tend to be more acid-tolerant than bacteria although their interior pH is close to neutrality. • Several bacteria are obligate acidophilic (such as Thiobacillus （硫杆菌）, Sulfolobus （硫化叶菌） 2 ）嗜碱微生物（Alkalophile ） Growth optimum between pH 8.5 and 11.5 A few organisms are alkaliphilic (pH 10-11), usually found in highly basic habitates such as soda lakes and high carbonate soils. 3 ）中性微生物（Neutrophile） Growth optimum between pH 5.5 and 8.0 3.渗透压（osmotic pressure） • 嗜盐微生物：Microorganisms that have a specific requirement for sodium ion are often called halophiles • 嗜渗微生物：Organisms able to live in environment high in sugar are called osmophiles • 极度嗜盐微生物：Organisms capable of living in very salty environments are called extreme halophiles • 嗜干微生物：Organisms able to live in very dry environments are called xe