title: Influence of temperature on short-chain fatty acid production by pig cecal bacteria in vitro.
abstract: 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.
authors.affiliation: Department of Basic Sciences, Ishinomaki Senshu University, Miyagi, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kobayashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Sakata
mesh_terms: D019342:Acetic Acid / Q000032:analysis; D000818:Animals; D001419:Bacteria / Q000378:metabolism*; D020148:Butyric Acid / Q000032:analysis; D002432:Cecum / Q000382:microbiology*; D005232:Fatty Acids, Volatile / Q000096:biosynthesis*; D007700:Kinetics; D008297:Male; D009919:Orchiectomy; D010421:Pentanoic Acids / Q000032:analysis; D011422:Propionates / Q000032:analysis; D013552:Swine; D013696:Temperature
chemical_list: D005232:Fatty Acids, Volatile; D010421:Pentanoic Acids; D011422:Propionates; D020148:Butyric Acid; C038780:n-pentanoic acid; C029658:propionic acid; D019342:Acetic Acid