Physiological Study of an Obligately Anaerobic Ureolytic Bacterium

Evidence for bacterial urea production in marine sediments

“…Urease activity has been demonstrated in more than 200 species of bacteria including, both Gram-positive and Gram-negative [36]. Among these were aerobic, microaerophilic, facultatively anaerobic and anaerobic bacteria [36][37][38]. Urease synthesis is often repressed in the presence of ammonia or nitrogen-rich compounds, including urea; synthesis is derepressed under nitrogenlimiting or nitrogen starvation conditions [36,39,40].…”

Studies on the Bacterial Flora of the Alimentary Tract of Pigs. Ii. Streptococci: Selective Enumeration and Differentiation of the Dominant Group

“…This strain only partially hydrolyzed urea in LAPT containing 0.1% of glucose (Table 9). Since Gibbons & Doetsch (1959) have said that "Most bacteriological culture media are rich in organic nitrogenous materials, and subsequently could inhibit urease formation . .…”

“…I n the second part of the results presented here it was shown that this character, which is easily demonstrated, is stable after successive subculture of a urease positive strain (258/10) without urea, and it would therefore appear that hydrolysis of urea is catalyzed by a constitutive enzyme system. However, it would be necessary t o cultivate this strain in a chemically defined medium in the same manner as Gibbons & Doetsch (1959) in order to substantiate this hypothesis because bacterial action on guanidine compounds with subsequent urea formation in a medium such as LAPTg5 may not be excluded. De Turk (1955) has, in fact, shown that urease production by Pseudomoms aeruginosa is adaptive, even though this enzyme appeared in a medium to which urea had not been added.…”

Some Nutritional Characteristics of Predominant Culturable Ruminal Bacteria

“…Previous studies indicated that some strains of bacteria known to function in the rumen could be grown in defined media. These bacteria include many strains of Streptococcus bovtis (Niven, Washburn, and White, 1948), anaerobic lactobacilli (Wasserman, Seeley, and Loosli, 1953;Huhtanen, 1955;Gibbons and Doetsch, 1959;Phillipson, Dobson, and Blackburn, 1959), Bacteroides succinogenes (Bryant, Robinson, and Chu, 1959), and the genus Ruminococcus Sijpesteijn (1948) (Fletcher, 1956;Allison, Bryant, and Doetsch, 1958;Ayers, 1958;Bryant and Robinson, 1961 a, b); two strains of the genus Butyrivibrio Bryant and Small (1956b) (Gill and King, 1958;Gordon and Moore, 1961); and one strain each of Lachnospira multiparus Bryant and Small (1956a) (Emery, Smith, and Fai To, 1957) and Bacteroides ruminicola subsp. brevis Bryant et al (1958).…”