Minimum nutritional requirements for growth of host-independent derivatives of Bdellovibrio bacteriovorus strain 109 Davis

1974 ◽  
Vol 20 (2) ◽  
pp. 263-265 ◽  
Author(s):  
Edward E. Ishiguro
Keyword(s):  
Escherichia Coli ◽  
Growth Factors ◽  
Carbon Source ◽  
Defined Medium ◽  
Nutritional Requirements ◽  
Chemically Defined Medium ◽  
Carbon Source Utilization ◽  
Bdellovibrio Bacteriovorus ◽  
Derivatives Of ◽  
I Cells

A chemically defined medium for host-independent (H-I) derivatives of Bdellovibrio bacteriovorus strain 109 Davis has been developed. Carbon-source utilization studies indicated that H-I cells can assimilate a wider variety of compounds than host-dependent bdellovibrios. The defined medium did not support growth of freshly isolated H-I strains which required unidentified growth factors present in Escherichia coli cell-free extracts and in yeast extract.

scholarly journals Metabolic engineering of Escherichia coli W for isobutanol production on chemically defined medium and cheese whey as alternative raw material

2020 ◽  
Vol 47 (12) ◽  
pp. 1117-1132
Author(s):  
Katharina Novak ◽  
Juliane Baar ◽  
Philipp Freitag ◽  
Stefan Pflügl
Keyword(s):  
Escherichia Coli ◽  
Cheese Whey ◽  
Strain Improvement ◽  
Defined Medium ◽  
Raw Material ◽  
Efficient Production ◽  
Substrate Uptake ◽  
Chemically Defined Medium ◽  
E Coli ◽  
Plasmid Library

AbstractThe aim of this study was to establish isobutanol production on chemically defined medium in Escherichia coli. By individually expressing each gene of the pathway, we constructed a plasmid library for isobutanol production. Strain screening on chemically defined medium showed successful production in the robust E. coli W strain, and expression vector IB 4 was selected as the most promising construct due to its high isobutanol yields and efficient substrate uptake. The investigation of different aeration strategies in combination with strain improvement and the implementation of a pulsed fed-batch were key for the development of an efficient production process. E. coli W ΔldhA ΔadhE Δpta ΔfrdA enabled aerobic isobutanol production at 38% of the theoretical maximum. Use of cheese whey as raw material resulted in longer process stability, which allowed production of 20 g l−1 isobutanol. Demonstrating isobutanol production on both chemically defined medium and a residual waste stream, this study provides valuable information for further development of industrially relevant isobutanol production processes.

Effects of Selected Growth Factors on Porcine Meniscus in Chemically Defined Medium

Orthopedics ◽  
2003 ◽  
Vol 26 (8) ◽  
pp. 799-803 ◽  
Author(s):  
Steven A Lietman ◽  
William Hobbs ◽  
Nozomu Inoue ◽  
A Hari Reddi
Keyword(s):  
Growth Factors ◽  
Defined Medium ◽  
Chemically Defined Medium

Growth and differentiation of Tubularia cells in a chemically defined physiological medium

Development ◽  
1968 ◽  
Vol 20 (1) ◽  
pp. 73-80
Author(s):  
Allison L. Burnett ◽  
Faith E. Ruffing ◽  
June Zongker ◽  
Anna Necco
Keyword(s):  
Defined Medium ◽  
Control Mechanisms ◽  
Mucous Cells ◽  
Chemically Defined Medium ◽  
Experimental Animals ◽  
Molecular Weights ◽  
Large Numbers ◽  
High Degree ◽  
I Cells

Although hydroids have proven valuable experimental animals for studies involving polarity and regeneration, they have not been extensively used by chemical embryologists studying control mechanisms in differentiation. Ideally, hydroids should be valuable tools for such a study. Their morpohology is relatively simple since they are diploblastic; their cells achieve a high degree of specialization (cnidoblasts, nerve cells, gland and mucous cells); cell differentiation (and morphogenesis) from a reserve stock of interstitial or i-cells is rapid; and many species can be cultured in large numbers under controlled environmental conditions. Probably one of the reasons for this lack of attention is that no one has succeeded in cloning cells of a particular type in a chemically defined medium. In vivo systems, mainly because of their impermeability to most exogenous materials with molecular weights over 200, have not proven to be especially reliable.

scholarly journals Carriage of Shiga toxin phage profoundly affects Escherichia coli gene expression and carbon source utilization

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Petya Berger ◽  
Ivan U. Kouzel ◽  
Michael Berger ◽  
Nadja Haarmann ◽  
Ulrich Dobrindt ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Carbon Source ◽  
Shiga Toxin ◽  
Carbon Source Utilization

Utilization of chymotrypsin as a sole carbon and (or) nitrogen source by Escherichia coli

1992 ◽  
Vol 38 (4) ◽  
pp. 290-295 ◽  
Author(s):  
Arthur S. Brecher ◽  
Timothy A. Moehlman ◽  
William D. Hann
Keyword(s):  
Escherichia Coli ◽  
Carbon Source ◽  
Nitrogen Source ◽  
Degradation Products ◽  
Defined Medium ◽  
Host Protein ◽  
Mammalian Host ◽  
Sole Nitrogen Source ◽  
E Coli ◽  
Nitrogen Nutrients

α-Chymotrypsin serves as a sole carbon source, sole nitrogen source, and as sole carbon plus nitrogen source for wild-type Escherichia coli in a totally defined medium. Hence, a mammalian host for E. coli may supply the necessary carbon and nitrogen nutrients for the microorganism. Growth is most rapid when chymotrypsin is a sole nitrogen source,and least rapid with chymotrypsin as a carbon source. The approximate doubling times for E. coli utilizing chymotrypsin as a nitrogen source, carbon plus nitrogen source, and carbon source are 1.6, 4.6, and 11.3 h, respectively. The activity of the residual enzyme in the culture supernates falls off asymptotically over the course of time, as followed by cleavage of glutaryl-L-phenylalanine-p-nitroanilide. Chymotrypsin hydrolyzes succinyl-L-ala-L-ala-L-ala-p-nitroanilide, the elastase substrate, to some extent. Peptidases do not appear to be secreted that hydrolyze such model substrates as benzoyl-DL-arginine-p-nitroanilide, the tryptic and cathepsin B substrate, L-leucine-p-nitroanilide, the leucine aminopeptidase substrate, or L-lysine-p-nitroanilide, the aminopeptidase B substrate. Growth of E. coli is generally directly related to the loss of chymotryptic activity in the medium. Hence, autolysis of chymotrypsin, i.e., self-degradation, is an important factor for the availability of degradation products of the enzyme to the bacterium for growth purposes. Accordingly, the degradation of a host protein by autolysis presents an opportunity for E. coli to survive during periods of host nutritional crisis by utilization of the degradation peptides that are produced during autolysis. Key words: chymotrypsin, Escherichia coli, growth, nutrition, peptide source.

scholarly journals Lovastatin Biosynthesis by Aspergillus terreus in a Chemically Defined Medium

2001 ◽  
Vol 67 (6) ◽  
pp. 2596-2602 ◽  
Author(s):  
Hassan Hajjaj ◽  
Peter Niederberger ◽  
Philippe Duboc
Keyword(s):  
Carbon Source ◽  
Aspergillus Terreus ◽  
Glucose Repression ◽  
Nitrogen Sources ◽  
Glucose Consumption ◽  
Defined Medium ◽  
Specific Productivity ◽  
Chemically Defined Medium ◽  
Carbon And Nitrogen Sources ◽  
Carbon And Nitrogen

ABSTRACT Lovastatin is a secondary metabolite produced by Aspergillus terreus. A chemically defined medium was developed in order to investigate the influence of carbon and nitrogen sources on lovastatin biosynthesis. Among several organic and inorganic defined nitrogen sources metabolized by A. terreus, glutamate and histidine gave the highest lovastatin biosynthesis level. For cultures on glucose and glutamate, lovastatin synthesis initiated when glucose consumption levelled off. When A. terreus was grown on lactose, lovastatin production initiated in the presence of residual lactose. Experimental results showed that carbon source starvation is required in addition to relief of glucose repression, while glutamate did not repress biosynthesis. A threefold-higher specific productivity was found with the defined medium on glucose and glutamate, compared to growth on complex medium with glucose, peptonized milk, and yeast extract.

Nutritional requirements for chloramphenicol biosynthesis in Streptomyces venezuelae

1983 ◽  
Vol 29 (2) ◽  
pp. 247-253 ◽  
Author(s):  
S. Chatterjee ◽  
L. C. Vining ◽  
D. W. S. Westlake
Keyword(s):  
Growth Rate ◽  
Carbon Source ◽  
Mineral Nutrition ◽  
Phase Variation ◽  
Nutritional Requirements ◽  
Carbon Source Utilization ◽  
Streptomyces Venezuelae ◽  
Lactate Medium ◽  
Inoculation Procedure ◽  
Medium Preparation

Cultures grown in a glycerol serine lactate medium were used to establish the inoculation procedure, aeration level, and trace-mineral nutrition optimizing chloramphenicol production in Streptomyces venezuelae. The stimulatory effect of lactate in this medium was concluded not to be an artifact of medium preparation but to reside in its influence on carbon-source utilization. In media with ammonium sulfate as a nonrestricting source of nitrogen, chloramphenicol production varied with the carbon source chosen. Production occurred during the growth phase and was highest on galactose, lactose, cellobiose, and starch. The rate of synthesis was related directed to the growth rate and decreased in the stationary phase. Variation of the nitrogen source with glucose as a nonrestricting source of carbon showed that the highest antibiotic titres were obtained with poorly utilized compounds such as isoleucine or phenylalanine. Proline gave yields comparable with those obtained in the more complex glycerol serine lactate medium in a shorter time. Although rate of growth is not the sole determining parameter, chloramphenicol synthesis is concluded to be a "growth-linked" process.

scholarly journals Development of a Chemically Defined Medium and Discovery of New Mitogenic Growth Factors for Mouse Hepatocytes: Mitogenic Effects of FGF1/2 and PDGF

PLoS ONE ◽  
2014 ◽  
Vol 9 (4) ◽  
pp. e95487 ◽  
Author(s):  
William C. Bowen ◽  
Amantha W. Michalopoulos ◽  
Anne Orr ◽  
Michael Q. Ding ◽  
Donna B. Stolz ◽  
...  
Keyword(s):  
Growth Factors ◽  
Defined Medium ◽  
Chemically Defined Medium ◽  
Mouse Hepatocytes

Na+ responses of two marine bacteria that did not appear to require Na+ for growth

1993 ◽  
Vol 39 (3) ◽  
pp. 297-303 ◽  
Author(s):  
Michelle F. Manuel ◽  
Gesine A. Wisse ◽  
Robert A. MacLeod
Keyword(s):  
Carbon Source ◽  
Liquid Medium ◽  
Marine Bacteria ◽  
Binding Sites ◽  
Initial Rate ◽  
Nadh Oxidase ◽  
Defined Medium ◽  
Chemically Defined Medium ◽  
Limited Extent ◽  
Bacterial Strains

Two Gram-negative heterotrophic marine bacterial strains had been reported not to require Na+ when grown on a chemically defined medium solidifed with purified agar and prepared without added Na+. When these strains were tested in a chemically defined liquid medium they required at least 3 mM Na + for growth. The agar used in the plating medium was found to contribute 3.3 mM Na+. Increasing the concentrations of Na+ in the liquid medium above 3 mM increased the rate and extent of growth of both organisms and decreased the lag periods. Optimal Na+ concentrations for growth varied from 100 to 500 mM depending on the organism and the carbon source in the medium. Na+ was also required for the transport of the carbon source into the cells. For the maximal rate of transport of L-glutamate, one organism required only 10 mM Na +, the other, 50 mM. For acetate and succinate transport the optimal Na+ concentrations varied from 30 to 200 mM depending on the substrate and the organism. When the initial rate of transport of glutamate into one of the organisms was plotted against Na+ concentration the reponse curve was sigmoid and a Hill plot of the data indicated that the transport protein may possess three binding sites for Na+. Evidence was obtained indicating that both organisms possess a Na+-stimulated NADH oxidase. The results indicate that there are marine bacteria that grow to a limited extent at appreciably lower concentrations of Na+ than have been realized previously and for these a much more definitive examination of the requirement for Na+ is necessary.Key words: marine bacteria, Na+ requirement, growth, membrane transport, NADH oxidase.

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