Kobayashi Daisuke, Sakata Takashi
Department of Basic Sciences, Ishinomaki Senshu University, Miyagi, Japan.
J Nutr Sci Vitaminol (Tokyo). 2006 Feb;52(1):66-9. doi: 10.3177/jnsv.52.66.
We studied the effect of incubation temperature on the production of shortchain fatty acids (SCFA) by pig cecal bacteria in vitro in order to assess short-term influences of body temperature on bacterial metabolism in the large intestine. We employed a 200 mL scale continuous culture system using cecal bacteria from commercially slaughtered pigs as innoculum. The culture was maintained at 30, 37, 40 or 42 degrees C and continuously diluted by continuous feeding of bicarbonate buffer (pH 7.4) added with lactose (10 g/L) and by simultaneous continuous efflux both at 4.17 mL/h. We monitored SCFA concentration of the culture for 12 h, which represents their production rate. Concentrations of SCFA increased during the first several hours and plateaued at around 11 h of incubation. Incubation temperature significantly affected mean concentrations from 1 to 12 h of acetic (40 degrees C>42 degrees C= 37 degrees C>30 degrees C), propionic (40 degrees C>42 degrees C=30 degrees C), n-butyric (42 degrees C>37 degrees C>30 degrees C, 40 degrees C>30 degrees C) and n-valeric (42 degrees C=40 degrees C>37 degrees C>30 degrees C) acids, and total SCFA (40 degrees C>42 degrees C= 37 degrees C> 30 degrees C) (p<0.05). These results indicate that both hyperthermia and hypothermia depress the microbial breakdown of carbohydrates.
我们研究了培养温度对猪盲肠细菌体外产生短链脂肪酸（SCFA）的影响，以评估体温对大肠细菌代谢的短期影响。我们采用了一个200毫升规模的连续培养系统，使用来自商业屠宰猪的盲肠细菌作为接种物。培养物维持在30、37、40或42摄氏度，并通过连续投喂添加乳糖（10克/升）的碳酸氢盐缓冲液（pH 7.4）以及同时以4.17毫升/小时的流速连续流出进行连续稀释。我们监测了培养物12小时的SCFA浓度，这代表了它们的产生速率。SCFA浓度在最初几个小时内增加，并在培养约11小时时达到平稳。培养温度显著影响了1至12小时内乙酸（40摄氏度>42摄氏度=37摄氏度>30摄氏度）、丙酸（40摄氏度>42摄氏度=30摄氏度）、正丁酸（42摄氏度>37摄氏度>30摄氏度，40摄氏度>30摄氏度）和正戊酸（42摄氏度=40摄氏度>37摄氏度>30摄氏度）以及总SCFA（40摄氏度>42摄氏度=37摄氏度>30摄氏度）的平均浓度（p<0.05）。这些结果表明，体温过高和过低都会抑制碳水化合物的微生物分解。
