scholarly journals Growth and Amino Acid Requirements of Various Strains of Group B Streptococci

1978 ◽  
Vol 7 (1) ◽  
pp. 28-33
Author(s):  
Thomas W. Milligan ◽  
Terence I. Doran ◽  
David C. Straus ◽  
Stephen J. Mattingly

A chemically defined medium (FMC; B. Terleckyj, N. P. Willett, and G. D. Shockman, Infect. Immun. 11 :649-655, 1975) was used to compare the growth and amino acid requirements of 16 strains of group B streptococci, consisting of both laboratory-passaged organisms and fresh clinical isolates from adult and neonatal infections. The 5 standard Lancefield immunizing strains of group B streptococci, 090 (Ia), H36B (Ib), A909 (Ic), 18RS21 (II), and D136C (III), had doubling times in FMC (28 to 36 min) similar to those observed in Todd-Hewitt glucose broth (24 to 30 min). Similar doubling times were obtained with 11 clinical isolates growing in Todd-Hewitt glucose broth and FMC. The optimum buffering capacity of FMC was provided by 0.06 M sodium phosphate, and 1% glucose gave maximum cell yield. The group B streptococci, with minor exceptions, were very homogeneous in their amino acid requirements under both aerobic and anaerobic growth conditions. Phenylalanine, tyrosine, tryptophan, glutamate, arginine, valine, leucine, lysine, methionine, isoleucine, cystine, and histidine were required by all 16 strains under both aerobic and anaerobic growth conditions. In addition, threonine was required by all strains under aerobic growth conditions, whereas only 9 strains required threonine under anaerobic conditions. Serine was required by only 3 type III fresh clinical isolates aerobically, but not anaerobically. A requirement for glycine varied from strain to strain, apparently influenced by the oxidation-reduction potential of the growth medium.

2020 ◽  
Vol 212 ◽  
pp. 103583 ◽  
Author(s):  
Kristin Surmann ◽  
Marius Stopp ◽  
Sebastian Wörner ◽  
Vishnu M. Dhople ◽  
Uwe Völker ◽  
...  

2013 ◽  
Vol 57 (10) ◽  
pp. 4707-4716 ◽  
Author(s):  
Wei Liu ◽  
Shi Lei Dong ◽  
Fei Xu ◽  
Xue Qin Wang ◽  
T. Ryan Withers ◽  
...  

ABSTRACTAntimicrobial peptides (AMPs) can cause lysis of target bacteria by directly inserting themselves into the lipid bilayer. This killing mechanism confounds the identification of the intracellular targets of AMPs. To circumvent this, we used a shuttle vector containing the inducible expression of a human cathelicidin-related AMP, LL-37, to examine its effect onEscherichia coliTOP10 under aerobic and anaerobic growth conditions. Induction of LL-37 caused growth inhibition and alteration in cell morphology to a filamentous phenotype. Further examination of theE. colicell division protein FtsZ revealed that LL-37 did not interact with FtsZ. Moreover, intracellular expression of LL-37 results in the enhanced production of reactive oxygen species (ROS), causing lethal membrane depolarization under aerobic conditions. Additionally, the membrane permeability was increased after intracellular expression of LL37 under both aerobic and anaerobic conditions. Transcriptomic analysis revealed that intracellular LL-37 mainly affected the expression of genes related to energy production and carbohydrate metabolism. More specifically, genes related to oxidative phosphorylation under both aerobic and anaerobic growth conditions were affected. Collectively, our current study demonstrates that intracellular expression of LL-37 inE. colican inhibit growth under aerobic and anaerobic conditions. While we confirmed that the generation of ROS is a bactericidal mechanism for LL-37 under aerobic growth conditions, we also found that the intracellular accumulation of cationic LL-37 influences the redox and ion status of the cells under both growth conditions. These data suggest that there is a new AMP-mediated bacterial killing mechanism that targets energy metabolism.


PROTEOMICS ◽  
2010 ◽  
Vol 10 (18) ◽  
pp. 3235-3247 ◽  
Author(s):  
Claire E. Price ◽  
Andreas Otto ◽  
Fabrizia Fusetti ◽  
Dörte Becher ◽  
Michael Hecker ◽  
...  

1999 ◽  
Vol 181 (19) ◽  
pp. 5922-5929 ◽  
Author(s):  
Georg Homuth ◽  
Alexandra Rompf ◽  
Wolfgang Schumann ◽  
Dieter Jahn

ABSTRACT Previous characterization of Bacillus subtilis hemN, encoding a protein involved in oxygen-independent coproporphyrinogen III decarboxylation, indicated the presence of a secondhemN-like gene (B. Hippler, G. Homuth, T. Hoffmann, C. Hungerer, W. Schumann, and D. Jahn, J. Bacteriol. 179:7181–7185, 1997). The corresponding hemZ gene was found to be split into the two potential open reading frames yhaV andyhaW by a sequencing error of the genome sequencing project. The hemZ gene, encoding a 501-amino-acid protein with a calculated molecular mass of 57,533 Da, complemented aSalmonella typhimurium hemF hemN double mutant under aerobic and anaerobic growth conditions. A B. subtilis hemZmutant accumulated coproporphyrinogen III under anaerobic growth conditions. A hemN hemZ double mutant exhibited normal aerobic and anaerobic growth, indicating the presence of a third alternative oxygen-independent enzymatic system for coproporphyrinogen III oxidation. The hemY gene, encoding oxygen-dependent protoporphyrinogen IX oxidase with coproporphyrinogen III oxidase side activity, did not significantly contribute to this newly identified system. Growth behavior of hemY mutants revealed the presence of an oxygen-independent protoporphyrinogen IX oxidase inB. subtilis. A monocistronic hemZ mRNA, starting 31 bp upstream of the translational start codon, was detected. Reporter gene fusions of hemZ and hemNdemonstrated a fivefold anaerobic induction of both genes under nitrate ammonifying growth conditions. No anaerobic induction was observed for fermentatively growing B. subtilis. The B. subtilis redox regulatory systems encoded by resDE,fnr, and ywiD were indispensable for the observed transcriptional induction. A redox regulation cascade proceeding from an unknown sensor via resDE, throughfnr and ywiD to hemN/hemZ, is suggested for the observed coregulation of heme biosynthesis and the anaerobic respiratory energy metabolism. Finally, only hemZwas found to be fivefold induced by the presence of H2O2, indicating further coregulation of heme biosynthesis with the formation of the tetrapyrrole enzyme catalase.


2012 ◽  
Vol 47 (No. 2 - 3) ◽  
pp. 38-44 ◽  
Author(s):  
K. Holovská ◽  
V. Lenártová ◽  
K. Holovská ◽  
P. Javorský

Superoxide dismutase (SOD) isoenzymes of the rumen bacterium Streptococcus bovis 4/1 were studied. Native PAGE showed a single band of Mn-SOD, unaffected by 10 mM cyanide or 5 mM hydrogen peroxide under both aerobic and anaerobic growth conditions. When the metals were removed from the growth medium by Chelex 100, the addition of manganese increased enzymatic activity, while addition of iron inhibited SOD activity. Changes in Mn-SOD and glutathione peroxidase (GSHPx) activities evoked by paraquat and increased values of TBARS indicated that these enzymes were not able to sufficiently prevent oxidative stress at given paraquat concentrations.


1980 ◽  
Vol 12 (3) ◽  
pp. 421-423 ◽  
Author(s):  
D C Straus ◽  
S J Mattingly ◽  
T W Milligan ◽  
T I Doran ◽  
T J Nealon

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