Publications

in vitro activity of ticarcillin, carbenicillin and ampicillin against some gram-negative bacilli.	alpha-carboxy-3-thienylmethyl penicillin (ticarcillin) is a relatively new semisynthetic penicillin which is more active than carbenillin against pseudomonas aeruginosa. among the strains tested, those isolated from the respiratory tract showed an increased susceptibility to carbenicillin and ticarcillin. as with carbenicillin, synergistic activity against p. aeruginosa could be demonstrated with ticarcillin in combination with gentamicin. like other penicillins, the antibacterial activity was i ...	1975	811636
thin-layer chromatographic technique for rapid detection of bacterial phospholipases.	silica gel thin-layer chromatography was employed to detect lecithinase activity induced from bacterial resting cell preparations induced from bacterial resting cell preparations incubated at 37 c for 4 h in the presence of purified egg yolk lecithin. bacillus subtilis, bacillus cereus, serratia marcescens, and pseudomonas aeruginosa hydrolyzed lecithin with the formation of free fatty acids as the sole lipid-soluble product. in none of the escherichia coli and citrobacter freundii strains teste ...	1975	811682
[relation of acetoin and valine in enterobacteriaceae cultures on media with glucose and glycerin].	the ratio between acetoin and valine produced by the cultures of the family enterobacteriaceae changes upon the addition of glucose and glycerol or their mixture to a defined medium. the experiments were carried out with 12 strains of aerobacter aerogenes and 2 strains of aerobacter cloacae and serratia marcescens. the highest yield of acetoin was found on the medium with glucose (12.5--13.0 g/litre); the maximum accumulation of valine was registered on the medium with glucose and glycerol (1.8- ...	1975	775256
citrate uptake in membrane vesicles of klebsiella aerogenes.	in whole cells of klebsiella aerogenes grown anaerobically on citrate as sole carbon source, citrate uptake is followed by rapid catabolism of the substrate via the inducible citrate fermentation pathway. membrane vesicles prepared from such cells take up citrate but do not catabolize it. vesicles process d-lactate dehydrogenase and the na+-requiring oxalacetate decarboxylase. citrate is taken up in the presence of na+, and other monovalent cations, such as nh4+, rb+, cs+, or k+, do not substitu ...	1975	1112775
citrate lyase from streptococcus diacetilactis. association with its acetylating enzyme.	citrate lyase (ec 4.1.3.6) was purified 38-fold from cell-free extracts of streptococcus diacetilactis. the enzyme was homogeneous in analytical ultracentrifugation and polyacrylamide gel electrophoresis. the final enzyme preparation contained acetate: hs-citrate lyase ligase--an acetylating enzyme which converts inactive hs-citrate lyase into enzymatically active acetyl-s-citrate lyase. this enzyme activity was purified 25-fold over the crude extract and seemed to be associated with citrate lya ...	1975	1115558
regulation of arylsulfatase synthesis by sulfur compounds in klebsiella aerogenes.	in klebsiella aerogenes, arylsulfatase synthesis was repressed by inorganic sulfate, sulfite, sulfide, thiosulfate, and cysteine, but not by methionine under normal growth conditions. we isolated cysteine-requiring mutants (cys minus), and mutants (atss minus, atsr minus) in which the regulation of arylsulfatase synthesis was altered. in the cysteine auxotroph, enzyme synthesis was also repressed by inorganic sulfate or cysteine. kinetic studies on mutants of the cysteine auxotroph showed that i ...	1975	1116990
changes in cutaneous flora after wet occlusion.	aerobic flora from wet-occluded forearms of six volunteers was sampled the day before treatment, on the 3rd day when dressings were removed, and daily, when possible, for 8 days thereafter. erythema was not present. all bacterial colonies appearing on appropriate dilution plates were identified with the aid of a replica-plating technique. flora of each individual increased to over 10-4 colony-forming units/cm2 as a result of wet-occlusion, but counts rapidly fell by about 10-2 units once dressin ...	1975	1122426
on the molecular weights of the three nonidentical subunits of citrate lyase from klebsiella aerogenes.	the molecular weights of the three nonidentical subunits of citrate lyase of klebsiella aerogenes have been determined by three methods: sedimentation equilibrium in 6 m guanidinium chloride, sodium dodecyl sulfate gel electrophoresis, and gel filtration on 6 percent agarose column in 6 m guanidinium chloride. the molecular weights of the subunits, names i, ii, and iii (or acyl carrier protein) in order of elution from the agarose column, were 54,500, 32,000, and 11,000, respectively. the agaros ...	1975	1123340
crystallization and properties of cysteine desulfhydrase from aerobacter aerogenes.		1975	1132487
induction by sodium of the citrate fermentation enzymes in klebsiella aerogenes.		1975	1140396
determination of the efficiency of oxidative phosphorylation in continuous cultures of aerobacter aerogenes.	for anaerobic glucose-limited chemostat cultures of aerobacter aerogenes a values of 14.0 g/mole was found for ymax/atp and a value of 6.8 mmoles atp/g dry weight/hr for the maintenance coefficient. both values are much lower than those previously determined for tryptophan-limited anaerobic chemostat cultures. it is concluded that generally the largest part of the maintenance energy is not used for true maintenance processes. for aerobic glucose-limited chemostat cultures two phases could be dif ...	1975	1156084
dual pathways of glycerol assimilation in klebsiella aerogenes ncib418: their regulation and possible functional significance.	klebsiella aerogenes ncib 418 assimilates glycerol via alternative pathways: one involves a glycerol kinase with a high affinity for glycerol (apparent km = 1-2x10(-6)m), and the second a glycerol dehydrogenase with a much lower affinity for its substrate (apparent km=2-4x10(-2)m). in variously-limited chemostat cultures, one or the other pathway predominated. thus, aerobic carbon-limited organisms contained only the glycerol kinase pathway whereas aerobic sulphate-limited or ammonia-limited o ...	1975	1156097
use of bile-esculin agar for rapid differentiation of enterobacteriaceae.	bile-esculin agar has been used for several years for the presumptive identification of group d streptococci. all members of the enterobacteriaceae family will also grow on this medium, but only certain ones can hydrolyze esculin to 6,7-dihydroxycoumarin, which reacts with iron to produce a characteristic blackening of the medium. one thousand and six cultures from clinical specimens representing 20 genera were isolated and identified. heavy inocula from fresh pure culture isolates on heart infu ...	1975	1176613
formation of methyl mercury by bacteria.	twenty-three hg2+-resistant cultures were isolated from sediment of the savannah river in georgia; of these, 14 were gram-negative short rods belonging to the genera escherichia and enterobacter, six were gram-positive cocci (three staphylococcus sp. and three streptococcus sp.) and three were bacillus sp. all the escherichia, enterobacter, and the bacillus strain were more resistant to hg2+ than the strains of staphylococci and streptococci. adaptation using serial dilutions and concentration g ...	1975	1180551
immobilized diol dehydrase and its use in studies of cobalamin binding and subunit interaction.	coenzyme b12 dependent diol dehydrase from aerobacter aerogenes was immobilized by covalent binding to cnbr-activated sepharose 4b. the sepharose-bound enzyme exhibited a markedly high catalytic activity, viz., 75-95% of the specific activity of the original free enzyme. the apoenzyme acquired much greater stability to heat by immobilization. no significant difference between the immobilized and free enzymes was observed in the following properties: the affinity for coenzyme b12; the sensitivity ...	1975	1182099
isolation and characterization of a bacteriophage polysaccharide.	a high molecular weight heteropolysaccharide, composed of glucose, glucuronic acid, n-acetylglucosamine, and mannose in an approximate molar ratio of 1:2:2:5, respectively, was isolated from phage k-2 and from the soluble fraction of phage-infected aerobacter aerogenes lysates. treatment of pure phage with 8 m urea at 4 degrees quantitatively solubilizes the bound polysaccharide and capsular polysaccharide (yurewicz, e.c., ghalambor, m.a., duckworth, d.h., and heath, e.c. (1971) j. biol. chem. 2 ...	1975	1184587
radiographic method for anatomic study of the teat canal: characteristics related to resistance to new intramammary infection during lactation and the early dry period.	an in vivo radiographic method to determine teat canal anatomy has shown that resistant quarters had teat canals with a smaller diameter than that of susceptible quarters. the length of the teat canal did not appear to be related to resistance to new intramammary infections. these findings relate to new infection caused by aerobacter aerogenes, streptococcus agalactiae, and staphylococcus aureus. quarters guarded by teat canals with larger diameter were less resistent to new infection during bot ...	1975	1192747
[role of monovalent cations in reactions catalyzed by glycerol dehydrase from aerobacter aerogenes].	cobamide-dependent glyceroldehydrase (gdh) is shown to have an absolute requirement in monovalent cations: k+, nh4+, tl+, rb+ and cs+. dependencies of initial dehydratation rates of three substrates: glycerol, ethyleneglycol and 1,2-propandiol on the concentration of k+ are studied. km values for k+, nh4+ and tl+ are calculated to be 7-10-3, 4-10-3 and 1-10-3 m respectively. effect of k+ on km values for glycerol and coenzyme and on maximal reaction rate is investigated. it is shown that the app ...	1975	1203374
stereochemistry of decarboxylation of trans-4-hydroxycinnamic acid by aerobacter.	the stereochemistry of the decarboxylation of trans-p-coumaric acid to 4-hydroxystyrene by aerobacter aerogenes has been examined. the decarboxylation has been found to proceed with retention of the geometry about the trans-substituted double-bond.	1975	1057163
[nitrogen fixation in monospecific and mixed cultures of aerobacter aerogenes and agrobacterium azotophilum using different sources of carbon].		1975	1059219
isolation of subunits of citrate lyase and characterization of their function in the enzyme complex.	citrate lyase [ec 4.1.3.6; citrate oxaloacetate-lyase (pro-3s-ch2-coo--leads to acetate)] from klebsiella aerogenes has been dissociated with urea; the three different subunits, alpha-chain (molecular weight congruent to 54,000), beta-chain (molecular weight congruent to 32,000), and gamma-chain (acyl carrier protein; molecular weight congruent to 10,000), have been isolated in pure and catalytically active state. recombination of the three subunits produced citrate lyase that was indistinguisha ...	1975	1060145
composition of the citrate lyase acyl carrier protein from klebsiella aerogenes.		1975	1091504
stereoselective reduction of cobalt(iii) complexes by bacteria.	a strain of enterobacter cloacae, isolated from soil, reduces racemic abdtriglycinatocobalt(iii), triglycinatocobalt(iii), stereoselectively under anaerobic conditions; washed suspensions oc cells, grown anaerobically in the absence of triglycinatocobalt(iii) initially reduce the l-enantiomer stereospecifically under argon yielding a labile co(ii) chelate. an approximately 5-fold increase in the rate of reduction of the complex occurs using cells disrupted by 2-phenylethanol; decomposition now p ...	1975	1092371
reversible inactivation of the isocitrate dehydrogenase of escherichia coli ml308 during growth on acetate.	during aerobic growth of escherichia coli ml308 on acetate as sole carbon source, the apparent synthesis of isocitrate dehydrogenase was repressed relative to cultures on other carbon sources, such as glucose, which do not employ the glyoxylate bypass as an anaplerotic sequence. when cells were removed from an acetate medium, or when compounds were added which made the operation of the glyoxylate bypass unnecessary, the activity of isocitrate dehydrogenase rapidly increased 3- to 4-fold but fell ...	1975	1094097
genes for ribitol and d-arabitol catabolism in escherichia coli: their loci in c strains and absence in k-12 and b strains.	escherichia coli c strains can grow at the expense of the two natural pentitols ribitol and d-arabitol, sugar alcohols previously thought not to be utilized by e. coli. e. coli strains k-12 and b cannot utilize either compound. the genetic loci responsible for pentitol catabolism in e. coli c, designated rtl and atl, are separate and closely linked. each lies between metg and his and is highly co-transducible with metg and with a p2 prophage attachment site. rtl and atl readily can be transduced ...	1975	1097416
growth rate of enterobacteriaceae at elevated temperatures: limitation by methionine.	the effect of elevated temperatures on growth rate was studied in five strains of enterobacteriaceae. in all the strains tested a shift to the elevated temperature resulted in an immediate decrease in growth rate which was due to limitation in the availability of endogenous methionine. the first biosynthetic enzyme of the methionine pathway-homoserine transsuccinylase-was studied in extracts of aerobacter aerogenes, salmonella typhimurium, and escherichia coli and was shown to be temperature sen ...	1975	1100601
nature and properties of hexitol transport systems in escherichia coli.	in escherichia coli k-12 the naturally occurring hexitols d-mannitol, d-glucitol, and galactitol are taken up and phosphorylated via three distinct transport systems by a mechanism called either group translocation or vectorial phosphorylation. for every system, a membrane-bound enzyme ii-complex of the phosphoenolpyruvate-dependent phosphotransferase system has been found, each requiring phosphoenolpyruvate, enzyme i, and hpr or alternatively p-hpr as the phosphate donor. cells with a constitut ...	1975	1100608
effects of an antibacterial soap on the ecology of aerobic bacterial flora of human skin.	the effects of ad lib use of an antibacterial soap containing 1.0% trichlorocarbanilide and 0.5% trifluoromethyldichlorocarbanilide on the bacterial flora of six skin sites of 132 subjects were measured by comparison with the flora of 93 control subjects who avoided the use of topical antibacterials. each subject was examined once. the test soap produced significant reductions in geometric mean counts of the total aerobic flora on the back, chest, forearm, calf, and foot; counts were also reduce ...	1975	1103729
production of gluconic acid and 2-ketogluconic acid by klebsiella aerogenes ncta 418.	2-ketogluconic acid and, to a lesser extent, gluconic acid were found to be major products of glucose catabolism by phosphate-limited cultures of klebsiella aerogenes nctc 418, and together accounted for up to 46% of the glucose carbon that was metabolized. although the concentrations of both acids increased substantially at low growth rates, their specific rates of synthesis decreased markedly, ad did the proportion of glucose converted into these products. determination of the affinity constan ...	1975	1106345
construction of intergeneric hybrids using bacteriophage p1cm: transfer of the klebsiella aerogenes ribitol dehydrogenase gene to escherichia coli.	study of many of the interesting properties of klebsiella aerogenes is limited by the lack of a well-characterized genetic system for this organism. our investigations of the evolution of the enzyme ribitol dehydrogenase (ec 1.1.1.56) in k. aerogenes would be greatly facilitated by the availability of such a system, and we here report two approaches to developing one. we have isolated mutants sensitive to the coliphage p1, which will efficiently tranduce genetic markers between such sensitive st ...	1976	1107331
transient response of enterobacter aerogenes under a dual nutrient limitation in a chemostat.	utilizing a chemostat with a dual nutrient limitation of nitrogen and phosphate, we examined the transient response of the culture following a pulse of one of the limiting nutrients (ammonia). this method provided quantitative evidence that cells can be grown under dual nutrient limitation. furthermore, the pattern of response was consistent with the hypothesis that phosphate limitation restricts nucleic acid synthesis in the cell and that nitrogen limitation restricts protein synthesis. the net ...	1976	1252609
bioenergetic aspects of aerobic growth of klebsiella aerogenes nctc 418 in carbon-limited and carbon-sufficient chemostat culture.	carbon-limited chemostat cultures of klebsiella aerogenes nctc 418 consumed more oxygen per unit of cell synthesis when growing on mannitol or glycerol than when growing on glucose; and since the "maintenance" requirements were similar, this suggested that the extra reducing equivalents present in these compounds were oxidized wastefully. by comparison with carbon-limited cultures, carbon-sufficient cultures that were ammonia-, sulphate- or phosphate-limited generally consumed considerably more ...	1976	1259519
decreased riboflavin formation in mutants of aerobacter (enterobacter) aerogenes deficient in the butanediol pathway.	riboflavin concentration increased linearly for more than 60 h in wild type cultures, whereas in three mutants deficient in the formation of acetoin and 2,3-butanediol the production ceased at the end of exponential growth.	1976	1260022
dna relatedness among species of enterobacter and serratia.	species of enterobacter and serratia were examined for deoxyribonucleic acid relatedness to klebsielleae, to atypical erwiniae, and to other members of enterobacteriaceae. deoxyribonucleic acid hybridization and then hydroxyapatite chromatography was the technique used to assess relatedness. strains of enterobacter cloacae formed two separate hybridization groups that correlate with the presence or absence of yellow pigment. pigmented e. cloacae were 75-100% related, but they were only 40-50% re ...	1976	1260520
ammonia-sensitive mutant of klebsiella aerogenes.	we have isolated a temperature-sensitive mutant of klebsiella aerogenes unable to grow aerobically at 42 c in standard glucose minimal medium containing 0.03 m ammonium sulfate as a source of nitrogen. this strain, mk810, will grow at this temperature in significantly lower concentrations of ammonia (1 mm) or when ammonia is replaced by a growth rate-limiting source of nitrogen such as histidine or glutamate. a detailed physiological characterization and preliminary biochemical tests support the ...	1976	1262316
blockage by acetylene of nitrous oxide reduction in pseudomonas perfectomarinus.	suspensions of denitrifying cells of pseudomonas perfectomarinus reduced nitrate and nitrate as expected to dinitrogen; but, in the presence of acetylene, nitrous oxide accumulated when nitrate or nitrate was reduced. when supplied at the outset in place of nitrate and nitrate, nitrous oxide was rapidly reduced to dinitrogen by cells incubated in anaerobic vessels in the absence of acetylene. in the presence of 0.01 atmospheres of acetylene, however, nitrous oxide was not reduced. ethylene was n ...	1976	1267447
studies on inosine monophosphate dehydrogenase. an associating-dissociating system.	the techniques of polyacrylamide gel electrophoresis, sedimentation velocity and frontal analysis on sephadex have been used to demonstrate that preparations of imp dehydrogenase (imp: nad+ oxidoreductase, ec 1.2.1.14) from aerobacter aerogenes consist of a mixture of molecular weight isomers. further, it has been shown that dissociation of the higher molecular weight forms is promoted by urea, sodium dodecyl sulphate and dithiothreitol. under conditions comparable to those used for kinetic anal ...	1976	1268228
[formation of bactericidal substances by cosmarium impressulum (author's transl)].	1. an already published test method for detecting bactericidal substances in paper chromatograms was further improved. 2. in cultures of cosmarium impressulum free from bacteria, two bactericidal substances were found in the ether extracts from the algae and two others in the extracts of the culture medium. the are active against some or all bacteria testes (serratia marcescens, pseudomonas fluorescens; aerobacter aerogenes or bacillus pumilus). 3. if the culture medium of cosmarium or another d ...	1976	1275650
the enzyme complex citramalate lyase from clostridium tetanomorphum.	1. the enzyme citramalate from clostridium tetanomorphum is not stable in crude extracts. however, the inactive enzyme can be reactivated by incubation with dithioerythritol followed by acetylation with acetic anhydride. reactivation was also obtained with acetate, atp, mgcl2 and acetate : sh-enzyme ligases (amp) from c. tetanomorphum or klebsiella aerogenes. 2. incubation of the inactive enzyme with iodoacetate resulted in rapid loss of enzymic activity as determined by reactivation with acetic ...	1976	1278156
the importance of prolonged incubation for the synthesis of dimethylnitrosamine by enterobacteria.	tests with 140 strains representing escherichia coli, klebsiella aerogenes, k. ozaenae, proteus mirabilis, p. vulgaris, p. rettgeri and p. morganii in a defined medium supplemented with 0-09m dimethylamine (dma) and 0-1m potassium nitrate showed that at least 89% of the 136 strains able to reduce nitrates produced up to 9mm dimethylnitrosamine (dmn) in 70h at 37 degrees c. four nitratase-negative strains produced dmn from dma in the presence of sodium nitrate. prolonged incubation was the most i ...	1976	778390
microbial metabolism of amino alcohols. ethanolamine catabolism mediated by coenzyme b12-dependent ethanolamine ammonia-lyase in escherichia coli and klebsiella aerogenes.		1976	784902
[characterization by zymograms of r factor-determined beta-lactamases: plasmids of defined and undefined compatibility groups (author's transl)].	an easy biochemical method is described, discriminating the beta-lacta-mases coded by various r factors. electrophoretic mobility and substrate affinity of beta-lactamases were studied simultaneously for 7 different penicillins and cephalosporins. they are i like r factors assigned into different compatibility groups (n, p, com6, com7, com8, x and com 9), five r factors isolated from piglets faeces and one r factor, ru1, originated from enterobacter aerogenes. three electrophoretic types of beta ...	1976	786104
formation of crystalline deposits by several genera of the family enterobacteriaceae.	several species of bacteria from the family enterobacteriaceae formed crystalline materials containing calcium when grown in a defined culture medium. enterobacter aerogenes, proteus vulgaris, citrobacter freundii, and c. intermedius produced calcium pyrophosphate crystals. edwardsiella tarda and escherichia coli formed calcite iii crystals, whereas proteus mirabilis, klebsiella pneumoniae, providencia stuartii, and serratia marcescens produced hydroxyapatite crystals. several of these bacteria ...	1976	786887
isolation of rough mutants of klebsiella aerogenes and their synthesis of polysaccharides.	two mutants which lacked both capsular and lipopolysaccharide o-antigen polysaccharides were isolated from klebsiella aerogenes serotype 2 by phage selection; these were designated rough mutants. the polysaccharide fractions solubilized by partial acid hydrolysis of the lipopolysaccharide from both the wild type and mutants were chromatographed on sephadex g-50. analysis of the fractions obtained confirmed that the rough mutants lacked the galactan portion of the molecule, which is analogous to ...	1976	789814
oxygen transfer rate, respiration and yields in batch and chemostat cultures of klebsiella aerogenes.	the effect was studied of oxygen supply on the changes in total and specific rate of oxygen consumption by the cells, oxygen transfer rate, saturation concentrations of dissolved oxygen and the yields of batch and continuous cultivations. experiments were done on the microorganism klebsiella aerogenes ccm 2318 growing on synthetic glucose medium. continuous cultivations were carried out at dilution rates of 0.96 and 0.178 h-1. the rate of oxygen transfer was determined by the sulphite method and ...	1976	791773
in vitro growth inhibition of mastitis-causing coliform bacteria by bovine apo-lactoferrin and reversal of inhibition by citrate and high concentrations of apo-lactoferin.	bovine apo-lactoferrin (apo-lf) was added to in vitro cultures of eight strains of coliform bacteria associated with bovine mastitis. as little as 0.02 mg of apo-lf per ml resulted in marked inhibition of growth of all coliforms. growth inhibition was lost if saturated lf or iron plus apo-lf was added to the synthetic medium. the inhibition of growth increased as the concentration of apo-lf increased from 0.02 to 0.2 mg/ml for klebsiella pneumoniae (oardc-a1), klebsiella spp. (k1-21), and aeroba ...	1976	791866
cadmium and zinc sensitivity and tolerance in klebsiella (aerobacter) aerogenes.	the resistance of strains of k. aerogenes ncib 418 'trained' to cd2+ or zn2+ in liquid medium is graded to the training concentration. training to cd2+ increased the sensitivity to zn2+ but training to zn2+ reduced the sensitivity to cd2+. the trained organisms, particularly those trained to cd2+, grow slowly in medium containing the metals and the growth rates after 20 and 200 subcultures were not significantly different. the survival of untrained organisms on cd2+-agar decreased progressively ...	1976	792633
the butanol-soluble proteins of klebsiella aerogenes.	membranes of klebsiella aerogenes were extracted with acid butanol at ph 4.2 and the solubilized proteins were fractionated by precipitation at 0 degrees c and -20 degrees c. the -20 degrees c precipitate was examined by polyacrylamide gel electrophoresis in sodium dodecyl sulphate. several enzyme activities associated with polysaccharide biosynthesis have been identified in the crude -20 degrees c precipitate and an attempt was made to separate the enzymes from other protein. the role of certai ...	1976	792634
the lactose system of klebsiella aerogenes v9a. 5. lac-permease defective mutants of two klebsiella lac plasmids and their apparent reversion to wild type.		1976	795725
highly specific bacteriophage-associated polysaccharide hydrolases for klebsiella aerogenes type 8.	two phage-bound polysaccharide hydrolases specific for klebsiella aerogenes type 8 exopolysaccharides were isolated. each enzyme was specific for the polysaccharide produced by the host strain. one enzyme hydrolysed a pyruvylated and acetylated polymer, while the other only acted on the substrate lacking these substituents. both enzymes were endogalactosidases releasing tetrasaccharides from their substrates which were only hydrolysed to a limited extent.	1976	932688
[a flavinogenic mutant of the yeast pichia guilliermondii with impaired iron transport].	a mutant of the yeast pichia guilliermondii was produced by means of uv; the mutant was capable of riboflavin overproduction in the presence of high concentrations of iron in the medium. the content of total and non-hemin iron and cytochrome c, and the activity of catalase, were lower in the cells of the mutant than in the parent cells, while the activity of riboflavin synthetase was higher. the content of iron in the cells increased when the mutant was cultivated on media with citric acid, side ...	1976	933879
the fate of bacteria in frozen red cells.	units of blood were intentionally contaiminated with suspensions of either aerobacter aerogenes, escherichia coli, bacillus subtilis, enterobacter cloacae, pseudomonas aeruginosa, sarcina lutea, seratia marcesens, staphylococcus epidermidis, streptococcus faecalis, paracolabacterum aerogenoides (enterobacter hafriae), mima polymorpha or acinetobacter- calcoaceticus. when inoculation was made prior to glycerolization, the subsequent glycerolization, freezing, thawing, and deglycerolization result ...	1976	936269
growth of enterobacter aerogenes in a chemostat with double nutrient limitations.	the behavior of enterobacter aerogenes during growth in chemostats limited by single and double nutrient restrictions was examined. on the assumption that different essential nutrients act to limit growth in different ways, we selected pairs of nutrients likely to affect different aspects of metabolism. results show that macromolecular cell composition can be controlled by using more than one nutrient restriction. the polysaccharide content of the cells is readily manipulated by the ratio of car ...	1976	942212
extracellular and protease-released pullulanases.	the extracellular form of pullulanase (ec 3.2.1.41) from klebsiella aerogenes has been purified to homogeneity by successive chromatography through diethylaminoethyl-cellulose, sephadex g-200, and 1,6-diaminohexane-sepharose. in addition, the cell-bound form of pullulanase has been released by the action of a serine endopeptidase obtained from pronase and purified to apparent homogeneity. protease-released pullulanase has a slightly larger molecular weight and a specific activity over twice that ...	1976	942714
[studies on the antibacterial activity of the combination sulfamoxole/trimethoprim (cn 3123) (author's transl)].	after giving a survey on the situation of antibiotic resistance in the region of northern bavaria during 1973/74 and comparing the activity of a sulfamethoxazole (smz) trimethoprim (tmp) combination to other commonly used antibiotics and chemotherapeutic agents, the results of tests with the new combination of n1-(4,5-dimethyl-2-oxazolyl)-sulfanilamide) (sulfamoxole) and 2,4-diamino-5-(3,4,5-trimethoxy-benzyl)-pyrimidine (trimethoprim) at a ratio of 5:1 (cn 3123; nevin, supristol) are compared t ...	1976	947327
[study of enterobacter strains belonging to a particular group related to enterobacter aerogenes (author's transl)].	thirty strains of enterobacteriaceae constitute a new group related to e. aerogenes with the following differential biochemical characters: urease+, kcn-, sorbitol-, mucate- and gelatinase-. ten of these strains with antigenic similarities and polyresistance to antibiotics were isolated from urine in the same hospital.	1976	970833
comparison of activity of sisomicin and gentamicin in mouse protection tests with gram-negative bacilli.	the efficacy of sisomicin and gentamicin was compared in mouse protection studies against strains of escherichia coli, klebsiella sp., enterobacter aerogenes, serratia marcescens, proteus mirabilis, and pseudomonas aeruginosa. there was no significant difference in mortality of the mice in any of the protocol groups when five different dosages of sisomicin and gentamicin given by three separate schedules were compared for each bacterial inoculum in each antibiotic protocol. the mean protective d ...	1976	984779
deconjugation of bile acids by human intestinal bacteria.	the purpose of this report is to present the deconjugation of bile acids by numbers of strains of bacteria in the small intestine and feces. the small intestinal juice was aseptically aspirated by a double lumen tube with a rubber cover on the tip devised by us ("fukushima type 1"). bile acids were analyzed with thin layer chromatography. the results: 1) among aerobic bacteria, species of which all of the strains split conjugated bile acids was enterococcus, and most of the strains split were st ...	1976	992250
[isolation and identification of the iron-binding organic compounds synthesized by klebsiella aerogenes].		1976	994872
klebsiella aerogenes in mares.		1976	997193
klebsiella aerogenes in mares.		1976	1014302
the role of energy-spilling reactions in the growth of klebsiella aerogenes nctc 418 in aerobic chemostat culture.	when cell-saturating amounts of glucose and phosphate were added to steady state cultures of klebsiella aerogenes that were, respectively, glucose- and phosphate-limited, the organisms responded immediately with an increased oxygen consumption rate. this suggested that in neither case was glucose transport the rate-limiting process, and also that organisms must possess effective mechanisms for spilling the excess energy initially generated when a growth-limitation is temporarily relieved. steady ...	1976	1015953
urease activity in the rumen of sheep and the isolation of ureolytic bacteria.	urease activity in the sheep rumen varied with the diet of the sheep, but appeared to be largely or entirely present in the small bacterial fraction. screening of over 1000 strains of rumen bacteria isolated on different media showed that urease activity was apparently confined to species of staphylococcus, lactobacillus casei var. casei and klebsiella aerogenes. consideration of the numbers in which these occurred and their activities suggested that the bacteria could not be responsible for the ...	1976	812952
dense growth of aerobic bacteria in a bench-scale fermentor.	escherichia coli b, escherichia coli mre 600, escherichia coli k 12-3300, pseudomonas fluorescens, and aerobacter aerogenes were grown exponentially in a bench-scale fermentor to cell concentrations in the range of 20 to 41 g dry cells/liter at 30 degrees c and 30 to 55 g dry cells/liter at 25 degrees c. the high cell concentrations were achieved in a growth system previously described for growth of escherichia coli w (biotechnol. bioeng., 16, 933 (1974); ibid. 17, 227 (1975)). various enzyme ac ...	1976	813791
the effect of cooling and warming rates on the survival of a variety of bacteria.	cooling and warming rates affect bacterial survival profoundly with all bacteria tested (azotobacter chroococcum, klebsiella aerogenes, salmonella typhimurium, pseudomonas aeruginosa, streptococcus faecalis) behaving similarly. most bacteria were sensitive to salt on freezing and thawing. viabilities of population frozen and thawed in saline were always less (by at least 20%) than comparable ones frozen in water alone. under these conditions, s. faecalis was resistant to the presence of sodium c ...	1976	814981
]acute severe mastitis in cows of the dutch-friesian breed (author's transl)].	one hundred cases of severe acute mastitis are reported. bacteriological examination of the milk was negative in 23% of the cases. e. coli was most frequently found to be the causative organism (23%), followed by st. aureus (19%), c. pyogenes (10%), str. dysgalactiae (9%), str. agalactiae (5%) and a number of other pathogenic agents such as atypical streptococci, str. uberis, haemolytic streptococci, aerobacter aerogenes, kl. pneumoniae, a clostridium and p. multocida. in several cases, a tentat ...	1976	818734
discrimination of rhizobium japonicum, rhizobium lupini, rhizobium trifolii, rhizobium leguminosarum and of bacteroids by uptake of 2-ketoglutaric acid, glutamic acid and phosphate.	rhizobium strains (one each of rh. japonicum, rh. lupini, rh. leguminosarum) take up 2-ketoglutaric acid in general much faster and from lower concentrations in the medium than strains of escherichia coli, bacillus subtilis and chromobacterium violaceum. a strain of enterobacter aerogenes, however, is more similar to some rhizobium strains. the same strains of rhizobium take up also phosphate much faster and from lower concentrations than the other bacteria tested. 4 strains of rh. lupini proved ...	1976	818969
in vitro evaluation of cefoxitin and cefamandole.	cefoxitin and cefamandole were evaluated in vitro against 263 organisms. studies were performed in mueller-hinton and nutrient broth and agar employing inoculum sizes of 10(6) and 10(8) organisms per ml. at obtainable serum levels both antibiotics were bactericidal for nearly all strains of escherichia coli, klebsiella, proteus mirabilis, and staphylococcus aureus but were inactive against pseudomonas aeruginosa and enterococcus. in agar, cefamandole appeared to be active against most strains of ...	1976	820241
absence of bacterial resistance to povidone iodine.	povidone iodine is now being increasingly used in hospitals as an antiseptic. the possible habituation of bacteria to iodine was studied by serial passage of two strains of pseudomonas aeruginosa, two strains of escherichia coli, two strains of klebsiella aerogenes, and one strain of serratia marcescens in subinhibitory concentrations. after 20 passages, no significant change was observed in the minimal inhibitory concentration, minimal bactericidal concentration, and killing times between paren ...	1976	821972
the presence of a variant of type-iiia beta-lactamase in a series of strains isolated in a burns unit.	an outbreak of carbenicillin-resistant pseudomonas aeruginosa infection in a burns unit in 1968-69 occurred in two phases separated by a period when no resistant pseudomonas were detected. nevertheless, strains of klebsiella aerogenes carrying r factors similar to those in the pseudomonas strains were encountered in the intervening period. the similarity of the plasmids occurring in all stages of this outbreak has been confirmed by the fact that each specifies a novel variant of type-iiia beta-l ...	1976	822168
[infective situation in a cow barn contaminated with klebsiella mastitis].	the infection situation in a four-row cow-house for 153 animals with a frequent occurrence of klebsiella mastitis was subject to a detailed analysis. the following results were obtained after two collections of blood and udder-quarter milk samples examined by the test-tube agglutination, gel precipitation, and bacteriological diagnosis methods: 1. streptococcus agalactiae was isolated from milk samples 28 and 31 times, pseudomonas aeruginosa 15 and 19 times, staphylococcus arueus 16 and 19 times ...	1976	828991
nutritional requirement for 4-aminobenzoate caused by mutation of dihydropteroate synthetase.	aerobacter aerogenes mutant 62-1 ac requires high concentrations of 4-aminobenzoate for growth. the mutant accumulates n-glucosyl-4-aminobenzoate and has an intact 4-aminobenzoate synthetase (bacher, gilch, rappold, and lingens, z. naturforsch. 28 c, 614-617 [1973]). on the other hand the ability of the mutant to synthesize dihydropteroate is markedly reduced. the dihydropteroate synthetase level of mutant 62-1 ac is 1% as compared to the parent strain. spontaneous revertants of mutant 62-1 ac s ...	1976	134570
studies on inosine monophosphate dehydrogenase. steady state kinetics.	the reaction catalyzed by imp dehydrogenase (imp: nad+ oxidoreductase ec 1.2.1.14) from aerobacter aerogenes has been investigated kinetically at ph 8.1 as a three reactant system by means of steady-state velocity studies in the absence of products, as well as by inhibition studies using products and substrate analogues. the mechanism appears to be a partially random one in which imp and k+ can bind randomly to the free enzyme while nad does not react unless k+ or both k+ and imp are present on ...	1976	178371
regulation of tyramine oxidase synthesis in klebsiella aerogenes.	tyramine oxidase in klebsiella aerogenes is highly specific for tyramine, dopamine, octopamine, and norepinephrine, and its synthesis is induced specifically by these compounds. the enzyme is present in a membrane-bound form. the km value for tyramine is 9 x 10(-4) m. tyramine oxidase synthesis was subjected to catabolite repression by glucose in the presence of ammonium salts. addition of cyclic adenosine 3',5'-monophosphate (camp) overcame the catabolite repression. a mutant strain, k711, whic ...	1976	179974
natural and altered induction of the l-fucose catabolic enzymes in klebsiella aerogenes.	mutants of klebsiella aerogenes w70 were isolated that had gained the ability to utilize the uncommon pentose d-arabinose as their sole source of carbon and energy. in contrast to the d-arabinose-negative, parent strain, these mutants were found to be either constitutive for certain enzymes of the l-fucose catabolic pathway or inducible for such enzymes when incubated in the presence of d-arabinose. the mutants used l-fucose isomerase to convert d-arabinose to d-ribulose, which is an intermediat ...	1976	179982
structure of the prosthetic group of klebsiella aerogenes citrate (pro-3s)-lyase.	the prosthetic group of citrate (pro-3s)-lyase [citrate oxaloacetate-lyase (pro-3s-ch2coo- leads to acetate); ec 4.1.3.6] from klebsiella aerogenes was obtained by mild alkaline hydrolysis of the enzyme and purified by deae-cellulose chromatography. several chemical and enzymatic degradation products of the compound have been isolated, and analyses of these have shown the structure of the prosthetic group to be 3'(or 2') leads to 1 inch-(5 inches-phosphoribosyl) dephosphocoenzyme a. proof as to ...	1976	180526
chirality of the hydrogen transfer to nad catalyzed by myo-inositol dehydrogenase from klebsiella pneumoniae.	chirality, hydrogen transfer, myo-inositol dehydrogenase. the chirality of the hydrogen transfer to nad catalyzed by myo-inositol dehydrogenase (myo-inositol: nad 2-oxydoreductase, ec 1.1.1.18) from klebsiella pneumoniae (formerly classified taxonomically as aerobacter aerogenes or kleb siella aerogenes) was investigated. [4-3h] nad was enzymatically reduced to [4-3h] nadh with non-labeled myoinositol and myo-inositol dehydrogenase. the stereochemistry of the prochiral center at c4 of the nadh p ...	1976	185832
enzymic activities of cadmium- and zinc-tolerant strains of klebsiella (aerobacter) aerogenes growing in glucose-limited chemostats.	the activities of phosphatases and some enzymes of glucose metabolism were determined in k. aerogenes ncib 418 and in two strains derived from it, resistant to 50 mug cd2+ ml-1 and 16 mug zn2+ ml-1 respectively, during growth at d = 0.38 h-1 in medium containing beta-glycerophosphate as sole phosphorus source and supplemented with cd2+ and zn2+, as appropriate, for the resistant strains. the ph-activity profiles of the phosphatases differed from strain to strain but all showed maximum activity a ...	1976	186694
diminished effect of gentamicin under anaerobic or hypercapnic conditions.	the in-vitro activity of gentamicin, judged by m.i.c. determinations, was much reduced when a normal aerobic atmosphere was replaced either by air +4% co2 or by anaerobic conditions. the phenomenon was greatest for staphylococcus aureus, where a decrease in activity of up to 20-fold was found. for escherichia coli, klebsiella aerogenes, enterobacter spp., and proteus spp. the factor of decrease was between 15-fold and 2-5-fold. changes in medium ph, as a result of bacterial growth, can explain t ...	1976	55718
energetic aspects of anaerobic growth of aerobacter aerogenes in complex medium.	molar growth yields for anaerobic growth of aerobacter aerogenes in complex medium were much higher than for growth in minimal medium. in batch cultures the molar growth yield for glucose varied from 44 to 50 and yatp from 17.1 to 18.8. for glucose-limited chemostat cultures a value of 17.5 g/mole was found for y max atp and a value of 2.3 mmoles atp/g dry weight h for the maintenance coeficient. growth-dependent ph changes were used to control the addition of fresh medium, containing excess of ...	1976	13757
a microcalorimetric study of the growth of klebsiella aerogenes in simple salts/glucose media.	heat output-time records or 'thermograms' produced during the aerobic growth of klebsiella aerogenes in simple salts/glucose media with growth limiting glucose concentrations of 2.0, 1.0 and 0.5 g dm-3 were obtained using a flow-microcalorimeter fitted with an aerobic cell. these traces are interpreted in terms of the recorded oxygen tension, ph, glucose concentration and bacterial population of the culture. heat output is greatest during the phase of exponential growth, indicating that here the ...	1976	17049
transduction of chromosomal genes between enteric bacteria by bacteriophage p1.	we have used p1 transduction to create intergeneric hybrid strains of enteric bacteria by moving the gena and hut genes between klebsiella aerogenes, escherichia coli and salmonella typhimurium. the use of e. coli as the recipient in such transductions permits the construction of episomes and specialized transducing phage containing non-e. coli material. the effect of host restriction modification and deoxyribonucleic acid homology on the frequency of intergeneric transduction of these loci has ...	1976	3494
l-asparaginase of klebsiella aerogenes. activation of its synthesis by glutamine synthetase.	an l-asparaginase has been purified some 250-fold from extracts of klebsiella aerogenes to near homogeneity. the enzyme has a molecular weight of 141,000 as measured by gel filtration and appears to consist of four subunits of molecular weight 37,000. the enzyme has high affinity for l-asparagine, with a km below 10(-5) m, and hydrolyzes glutamine at a 20-fold lower rate, with a km of 10(-3) m. interestingly, the enzyme exhibits marked gamma-glutamyltransferase activity but comparatively little ...	1976	4459
the existence of three types of acetohydroxy acid synthetase in an isoleucine-requiring mutant of aerobacter aerogenes.	the synthesis of the three types of acetolactate synthase (ec 4.1.3.18) which are responsible for the biosynthesis os isoleucine and valine, was observed in aerobacter aerogenes i-12, an isoleucine-requiring mutant, when grown on the four kinds of media. when the cells were grown on isoleucine-rich medium, acetolactate synthase sensitive to feedback inhibition and having an optimum ph at 8.0 was formed. by increasing the amount of potassium phosphate in the medium, the catabolite repression of t ...	1976	5136
regulation of histidase synthesis in intergeneric hybrids of enteric bacteria.	regulation of the expression of the histidase coded by hutk of klebsiella aerogenes in salmonella typhimurium and in escherichia coli and of the expression of the histidase coded by huts of s. typhimurium in e. coli was investigated. the hutk histidase was found to be sensitive to catabolite repression in k. aerogenes and in e. coli, but insensitive to catabolite repression in s. typhimurium; huts histidase has previously been shown to be catabolite sensitive in all three organisms. the expressi ...	1976	6426
glutamate dehydrogenase: genetic mapping and isolation of regulatory mutants of klebsiella aerogenes.	the gene for glutamate dehydrogenase (gdhd) has been mapped in klebsiella aerogenes by p1 transduction. it is linked to pyrf and trp with the order pyrf-trp-gdh. complementation analysis using f' episomes from escherichia coli suggests an analogous location in e. coli. two mutants able to produce glutamate dehydrogenase in the presence of high levels of glutamine synthetase have been isolated. one, tightly linked to gdhd, shows normal repression control by glutamine synthetase but produces four ...	1976	6429
regulation of enzyme formation in klebsiella aerogenes by episomal glutamine synthetase of escherichia coli.	we studied the physiology of cells of klebsiella aerogenes containing the structural gene for glutamine synthetase (glna) of escherichia coli on an episome. the e. coli glutamine synthetase functioned in cells of k. aerogenes in a manner similar to that of the k. aerogenes enzyme: it allowed the level of histidase to increase and that of glutamate dehydrogenase to decrease during nitrogen-limited growth. the phenotype of mutations in the glna site was restored to normal by the introduction of th ...	1976	6431
kinetic properties of serratia marcescens adenosine 5'-diphosphate glucose pyrophosphorylase.	the regulatory properties of partially purified adenosine 5'-diphosphate-(adp) glucose pyrophosphorylase from two serratia marcescens strains (atcc 274 and atcc 15365) have been studied. slight or negligible activation by fructose-p2, pyridoxal-phosphate, or reduced nicotinamide adenine dinucleotide phosphate (nadph) was observed. these compounds were previously shown to be potent activators of the adpglucose pyrophosphorylases from the enterics, salmonella typhimurium, enterobacter aerogenes, e ...	1976	6432
the effect of nitrogen limitation on catabolite repression of amidase, histidase and urocanase in pseudomonas aeruginosa.	in pseudomonas aeruginosa, the synthesis of histidase, urocanase and amidase is severly repressed when succinate is added to a culture growing in pyruvate + ammonium salts medium. when growth is nitrogen-limited, catabolite repression by succinate of histidase and urocanase synthesis does not occur but succinate repression of amidase synthesis persists. amidase synthesis is not regulated in the same way as histidase synthesis by the availability of other nitrogen compounds for growth. growth of ...	1976	6623
spore germination promoter of dictyostelium discoideum excreted by aerobacter aerogenes.	the nutrient medium in which aerobacter aerogenes was grown, contains a spore germination promoter (sgp) for the cellular slime mould dictyostelium discoideum. sgp can cuase synchronous spore germination in a short time, and triggers the germination process in just a few minutes. germination-promoting capacity of sgp decreases as it comes in contact with increasing number of spores. when spores activated by sgp are stored at 4 degrees c, they gradually return to the dormant state. sgp is compara ...	1976	9416
approach to a practical method for screening and identifying microorganism genera from urine (author's transl).	in this study the author reported upon a practical new system for screening and identifying the microbial agents causing urinary tract infections. this system is composed of a combination of 3 screening procedures (ph-value + nitrite-test + catalase-test) and 8 selective culture media for the purpose of genus identification within 24 hours (uripret-g). a total of 130 cultures was investigated. the employed microorganisms were mainly recovered from urine samples. they included the following speci ...	1976	11179
effect of environmental factors on inactivation of b12-dependent glycerol dehydratase from aerobacter aerogenes.	effect of temperature, ph and univalent cation on kinetics of self-activation of b12-dependent glycerol dehydratase (gd) from aerobacter aerogenes with co alpha-alpha-(5,6-dimethylbenzimidazolyl-co beta-adenosylcobamide (adocbl) was investigated. the activation energy of the process of gd inactivation is found to be 3.9 kkal/m, the effect of ph on gd inactivation being insignificant. monovalent cation is not required for the formation of gd-adocbl complex, but it protects the complex from selfin ...	1976	11842
tryptophan operon regulation in interspecific hybrids of enteric bacteria.	we examined tryptophan regulation in merodiploid hybrids in which a plasmid carrying the trp operon of escherichia was introduced into trp mutants of other enteric genera, or in which a plasmid carrying the trpr+ (repressor) gene of e. coli was transfered into fully constitutive trpr mutants of other genera. in these hybrids the trp operon of one species is controlled by the repressor of a different species. similar investigations were possible in transduction hybrids in which either the trp ope ...	1976	770450
derivation and properties of f-prime factors in escherichia coli carrying nitrogen fixation genes from klebsiella pneumoniae.	a his+ nif+ escherichia coli k12, hfr strain (unf43) was constructed by an intergeneric mating between a klebsiella pneumoniae donor strain (hf3) and a his-hfr e. coli strain (sbi824) which transfers his as an early marker. an f-prime nif plasmid, fn39, carrying genes which correspond to the e. coli chromosomal region, metg gnd his shia, but excluding purf and arod, was isolated from unf43. translocation of carbenicillin resistance genes from a p-type r-factor, r68, to fn39 increased the stabili ...	1976	772161
bactericidal activity of bovine neonatal serums for selected coliform bacteria in relation to total protein and immunoglobulin g1 and immunoglobulin m concentrations.	bactericidal activity for a serum-sensitive aerobacter aerogenes strain was associated with antibodies present in immunoglobulin g1 (igg1) and immunoglobulin m (igm), with the greatest activity on a weight basis in igm. activity in immunoglobulin g2 was absent. a total of 118 serums were prepared from blood collected from neonatal calves on farms experiencing unusually high mortality from diarrhea. the serums were allotted to 4 groups on the basis of total serum protein concentrations as follows ...	1976	773223
subunit and chemical composition of citrate lyase from klebsiella pneumoniae.	citrate lyase from klebsiella pneumoniae (previously called klebsiella aerogenes) is shown by amino acid sequencing techniques to contain equimolar amounts of three nonidentical subunits. together with the molecular weight of the enzyme, this finding is interpreted to indicate that there are 6 mol of each of these subunits per mol of native enzyme. a partial amino acid sequence of each of the three subunits is presented. the pure enzyme with a specific activity of 73 units/mg of dry protein has ...	1976	773936
acetylene reduction (nitrogen fixation) by enterobacteriaceae isolated from paper mill process waters.	using selective media containing galactitol, over 130 enterobacteriaceae have been isolated from paper mill process waters collected from different localities. these bacteria were extensively characterized and tested for acetylene-reducing (nitrogen-fixing) activity under anaerobic conditions. high activity was found in representatives of klebsiella pneumoniae, enterobacter aerogenes, enterobacter cloacae, erwinia herbicola, citrobacter freundii, citrobacter intermedius, and escherichia coli. un ...	1976	16345168
transport of cyclitols by a proton symport in klebsiella aerogenes.	the respiration and the atp content of klebsiella aerogenes in the presence of various inhibitors were compared to the transport of scyllo-inositol. the atpase was found to be inhibited by dicyclohexyl carbodiimide. the transport has been tested in anaerobiosis and aerobiosis. from the results obtained it is concluded that either atp or respiration can sustain the transport activity in independent manner. 2. the energy derived from the respiratory chain reactions or the atp hydrolysis results in ...	1977	12979
effect of metabolites on epsilon-n-hydroxylysine formation in cell-free extracts of aerobacter aerogenes 62-1.	the conversion of l-lysine to its corresponding epsilon-n-hydroxy derivative has been achieved for the first time by cell-free extracts of aerobacter aerogenes 62-1. partial fractionation by differential centrifugation (at 12 000 x g) revealed that both supernatant and pellet are essential for maximum enzymatic activity. the omega-n-hydroxylase (ec 1.14.99) was found to function optimally at ph 7-7.5 and exhibited an apparent km of about 75 mum for l-lysine. l(+)-lactate or dl-lactate and pyruva ...	1977	18266
urease of klebsiella aerogenes: control of its synthesis by glutamine synthetase.	urease was purified 24-fold from extracts of klebsiella aerogenes. the enzyme has a molecular weight of 230,000 as determined by gel filtration, is highly substrate specific, and has a km for urea of 0.7 mm. a mutant strain lacking urease was isolated; it failed to grow with urea as the sole source of nitrogen but did grow on media containing other nitrogen sources such as ammonia, histidine, or arginine. urease was present at a high level when the cells were starved for nitrogen; its synthesis ...	1977	18438