Evaluation of a chemically defined medium for controlling growth rate in staphylococci

1993 ◽  
Vol 32 (5) ◽  
pp. 779-780
Author(s):  
M. J. ASHBY
Keyword(s):  
Growth Rate ◽  
Defined Medium ◽  
Chemically Defined Medium

Growth and hemolysin production by Haemophilus pleuropneumoniae cultivated in a chemically defined medium

1986 ◽  
Vol 32 (10) ◽  
pp. 801-805 ◽  
Author(s):  
James R. Maudsley ◽  
Solomon Kadis
Keyword(s):  
Growth Rate ◽  
Yeast Extract ◽  
Hemolytic Activity ◽  
Culture Supernatant ◽  
Iron Concentration ◽  
Defined Medium ◽  
Chemically Defined Medium ◽  
Sterile Cell ◽  
Stages Of Growth ◽  
Cell Free Culture Supernatant

A chemically defined medium (CDM) has been developed which supports both growth and hemolysin production by Haemophilus pleuropneumoniae. Although the growth rate in stationary cultures was substantially slower in CDM than in trypticase soy broth plus 0.6% yeast extract (TSBYE) and slightly slower than in heart infusion broth (HIB), extracellular hemolysin activity in CDM was slightly higher than in HIB and 16-fold greater than in TSBYE. Maximum hemolytic activity was produced in CDM in early to mid log phase of growth. Hemolytic activity in sterile, cell-free culture supernatant fluids persisted for over 10 days at 4 °C and 3–5 days at 37 °C, but was completely destroyed at 56 °C after 30 min. Total hemolysin inactivation was also achieved in the presence of trypsin or pronase (10 units/mL), but no decrease in hemolytic activity was noted in the presence of DNase or RNase. Iron had little effect on the hemolytic activity in the early stages of growth. However, in the later stages of growth, iron had a pronounced effect with hemolyic activity decreasing as the iron concentration increased from 1 to 500 μM. None of these iron concentrations had any effect on the hemolytic activity when added directly to prepared cell-free culture supernatant fluids. The extracellur hemolysin produced by H. pleuropneumoniae in CDM appears to be a heat-labile protein the activity of which is influenced by iron at certain phases of growth.

Improved cryopreservation of domestic cat sperm in a chemically defined medium

2012 ◽  
Vol 78 (9) ◽  
pp. 2120-2128 ◽  
Author(s):  
M.M. Vick ◽  
H.L. Bateman ◽  
C.A. Lambo ◽  
W.F. Swanson
Keyword(s):  
Defined Medium ◽  
Domestic Cat ◽  
Chemically Defined Medium

scholarly journals In vitro mouse spermatogenesis with an organ culture method in chemically defined medium

PLoS ONE ◽  
2018 ◽  
Vol 13 (2) ◽  
pp. e0192884 ◽  
Author(s):  
Hiroyuki Sanjo ◽  
Mitsuru Komeya ◽  
Takuya Sato ◽  
Takeru Abe ◽  
Kumiko Katagiri ◽  
...  
Keyword(s):  
Organ Culture ◽  
Culture Method ◽  
Defined Medium ◽  
Chemically Defined Medium

Cultivation and properties of Neisseria sp. grown in chemically defined media

1972 ◽  
Vol 18 (7) ◽  
pp. 1087-1090 ◽  
Author(s):  
C. P. Kenny ◽  
B. B. Diena ◽  
R. Wallace ◽  
L. Greenberg
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Present Report ◽  
Defined Medium ◽  
Chemically Defined Medium ◽  
Chemically Defined Media ◽  
Defined Media ◽  
Specific Antisera

Neisseria Chemically Defined Medium (NCDM) has been used routinely in our laboratory for a variety of purposes. The present report describes the development of NCDM agar, wherein the NCDM base is sterilized by filtration and defined supplements and agar are added. The medium is transparent and both meningococci and gonococci grow within 72 h. When grown on NCDM agar, Types 2 and 3 gonococcal colonies tend to revert to Type 1. The serological grouping of meningococci with specific antisera is not affected by growth on this medium.Parallel investigations on the growth of these species in liquid NCDM demonstrated that the yield of Neisseria gonorrhoeae is enhanced when the medium is sterilized by filtration.

scholarly journals Characterization of the Role of para-Aminobenzoic Acid Biosynthesis in Folate Production by Lactococcus lactis

2007 ◽  
Vol 73 (8) ◽  
pp. 2673-2681 ◽  
Author(s):  
Arno Wegkamp ◽  
Wietske van Oorschot ◽  
Willem M. de Vos ◽  
Eddy J. Smid
Keyword(s):  
Gene Cluster ◽  
Lactococcus Lactis ◽  
Gene Clusters ◽  
Defined Medium ◽  
Biosynthesis Pathway ◽  
Chemically Defined Medium ◽  
Aminobenzoic Acid ◽  
Biosynthesis Gene Cluster ◽  
Gene Coding ◽  
Aba Biosynthesis

ABSTRACT The pab genes for para-aminobenzoic acid (pABA) biosynthesis in Lactococcus lactis were identified and characterized. In L. lactis NZ9000, only two of the three genes needed for pABA production were initially found. No gene coding for 4-amino-4-deoxychorismate lyase (pabC) was initially annotated, but detailed analysis revealed that pabC was fused with the 3′ end of the gene coding for chorismate synthetase component II (pabB). Therefore, we hypothesize that all three enzyme activities needed for pABA production are present in L. lactis, allowing for the production of pABA. Indeed, the overexpression of the pABA gene cluster in L. lactis resulted in elevated pABA pools, demonstrating that the genes are involved in the biosynthesis of pABA. Moreover, a pABA knockout (KO) strain lacking pabA and pabB C was constructed and shown to be unable to produce folate when cultivated in the absence of pABA. This KO strain was unable to grow in chemically defined medium lacking glycine, serine, nucleobases/nucleosides, and pABA. The addition of the purine guanine, adenine, xanthine, or inosine restored growth but not the production of folate. This suggests that, in the presence of purines, folate is not essential for the growth of L. lactis. It also shows that folate is not strictly required for the pyrimidine biosynthesis pathway. L. lactis strain NZ7024, overexpressing both the folate and pABA gene clusters, was found to produce 2.7 mg of folate/liter per optical density unit at 600 nm when the strain was grown on chemically defined medium without pABA. This is in sharp contrast to L. lactis strains overexpressing only one of the two gene clusters. Therefore, we conclude that elevated folate levels can be obtained only by the overexpression of folate combined with the overexpression of the pABA biosynthesis gene cluster, suggesting the need for a balanced carbon flux through the folate and pABA biosynthesis pathway in the wild-type strain.

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