Showing papers on "Growth medium published in 1985"
TL;DR: The medium, KDM-C, contains activated charcoal and has potential value for antigen preparation and physiological studies and was effective for both primary isolations from fish and repeated transfers.
Abstract: Charcoal is an effective replacement for serum in media for the isolation and culture of Renibacterium salmoninarum, the causative agent of bacterial kidney disease in salmonid fish. The medium, KDM-C, contains 10 g of peptone, 0.5 g of yeast extract, 1 g of L-cysteine hydrochloride, 1 g of activated charcoal, and 15 g of agar per liter and is adjusted to pH 6.8 with NaOH before autoclaving. Eight strains of R. salmoninarum grew from dilute inocula as well on KDM-C as on a standard serum-containing medium (KDM-2). The medium was effective for both primary isolations from fish and repeated transfers and has potential value for antigen preparation and physiological studies.
101 citations
TL;DR: A strain of Pseudomonas putida resistant to low concentrations of cadmium adapted to growth in the presence of 3 mM-Cd2+ in a chemically defined medium and adapted so as to control both the extent and rate of Cd 2+ uptake when compared to control cells.
Abstract: Summary: A strain of Pseudomonas putida resistant to low concentrations of cadmium (0.25 mM-Cd2+) adapted to growth in the presence of 3 mM-Cd2+ in a chemically defined medium. This increased resistance was rapidly lost if Cd2+ was omitted from the growth medium. P. putida concentrated 109Cd2+ actively. Mechanisms appeared to exist for expelling cadmium from cells during the lag and exponential phases and for continued growth in the presence of high intracellular Cd2+ concentrations. Cd2+-resistant cells adapted so as to control both the extent and rate of Cd2+ uptake when compared to control cells.
62 citations
TL;DR: It is strongly argued that the CYC1 UAS binding protein(s) that the authors have identified mediate the oxygen and heme control of cytochrome C biosynthesis.
Abstract: On the basis of a gel electrophoresis retardation assay, protein(s) which interact specifically with the upstream activating site (UASc) of the yeast iso-1-cytochrome C (CYC1) gene were identified and separated by heparin ultrogel chromatography. DNase I protection experiments indicate that these factors protect a 23-bp sequence overlapping the UASc site previously defined. The specific binding activity is strongly reduced in extracts prepared from a wild-type strain grown anaerobically. It is absent in a mutant strain blocked in the biosynthesis of heme but it is restored upon the addition of the missing precursor, delta amino levulinic acid (dALA) to the growth medium. In contrast, the binding activity does not differ significantly in extracts form a wild-type strain grown in either glucose or glycerol as carbon source. These data strongly argue that the CYC1 UAS binding protein(s) that we have identified mediate the oxygen and heme control of cytochrome C biosynthesis.
57 citations
TL;DR: The enzyme was found to be membrane associated, and preliminary evidence has been obtained that it is located on the periplasmic side of the cytoplasmic membrane and functionally linked to the respiratory chain, consistent with glucose dehydrogenase serving as a low impedance energy generating system.
Abstract: In order to assess the functional significance of the quinoprotein glucose dehydrogenase recently found to be present in K+ -limited Klebsiella aerogenes, a broad study was made of the influence of specific environmental conditions on the cellular content of this enzyme. Whereas high activities were manifest in cells from glucose containing chemostat cultures that were either potassium- or phosphate-limited, only low activities were apparent in cells from similar cultures that were either glucose-, sulphate- or ammonia-limited. With these latter two cultures, a marked increase in glucose dehydrogenase activity was observed when 2,4-dinitrophenol (1 mM end concentration) was added to the growth medium. These results suggested that the synthesis of glucose dehydrogenase is not regulated by the level of glucose in the growth medium, but possibly by conditions that imposed an energetic stress upon the cells. This conclusion was further supported by a subsequent finding that K+ -limited cells that were growing on glycerol also synthesized substantial amounts of glucose dehydrogenase. The enzyme was found to be membrane associated, and preliminary evidence has been obtained that it is located on the periplasmic side of the cytoplasmic membrane and functionally linked to the respiratory chain. This structural and functional orientation is consistent with glucose dehydrogenase serving as a low impedance energy generating system.
49 citations
TL;DR: The sulfonylurea herbicides chlorsulfuron and SM appear to act in soybean by blocking the synthesis of valine and leucine between pyruvate and 2-ketoisovalerate and in E. coli by inhibiting isoleucine biosynthesis.
49 citations
TL;DR: The aqueous soluble phase of acidified and autolyzed fish viscera was used as the nitrogen source in a growth medium for bacteria and the bacteria tested grew faster and produced higher yields of cell mass on this growth medium than on corresponding media with standard tryptone preparations.
Abstract: The aqueous soluble phase of acidified and autolyzed fish viscera was used as the nitrogen source in a growth medium for bacteria. The bacteria tested grew faster and produced higher yields of cell mass on this growth medium than on corresponding media with standard tryptone preparations as the nitrogen source.
49 citations
TL;DR: A period of culture within collagen is required to permit mammary epithelial cells to become responsive for hormone-induced differentiation, and it is possible that during growth within the collagen the cells synthesize and deposit extracellular matrix components important in modulating gene expression.
47 citations
TL;DR: Growth of the yeast Debaryomyces hansenii in 1% (w/v) glucose medium containing NaCl or KCl resulted in the accumulation of glycerol during the exponential phase of growth and arabinitol during the stationary phase, and the results indicate that the intracellular Glycerol concentration increases concomitantly with the solute concentration of the growth medium, while the accumulation is less pronounced.
Abstract: Growth of the yeast Debaryomyces hansenii in 1% (w/v) glucose medium containing NaCl or KCl resulted in the accumulation of glycerol during the exponential phase of growth and arabinitol during the stationary phase. Similar results were obtained during growth of the yeast in 12.5% (w/v) glucose, 25% glucose, 25% fructose, and 1% glucose plus 25% polyethylene glycol M.W.200 (PEG 200). The results indicate that the intracellular glycerol concentration increases concomitantly with the solute concentration of the growth medium, while the accumulation of arabinitol is less pronounced. Growth of the yeast in media containing meso-erythritol or D-mannitol as carbon sources without or with 1 M NaCl resulted in the pronounced inhibition of arabinitol accumulation because of the intracellular accumulation of the exogenous polyols. Mannitol accumulated primarily during the stationary phase, while erythritol accumulation occurred primarily during the exponential phase. The erythritol concentration attained very high ...
41 citations
TL;DR: The inclusion of very low levels of an elicitor fraction from the cell walls of Phytophthora megasperma in the medium in which lignification of the soybean cells occurs suppressed both the accumulation of extracellular lignin and phloroglucinol staining of the cell Walls without affecting the levels of bound hydroxycinnamic acids.
Abstract: Soybean (Glycine max L.) cells cultured in B5 medium produce extremely low amounts of lignin. However, modification in the growth medium, by lowering the concentration of NO−3 and PO2−4, results in the lignification of these cells without affecting levels of cell wall-esterified 4-coumaric and ferulic acid. The production of an extracellular, macromolecular complex by the cultured soybean cells (Moore TS Jr 1973 Plant Physiol 51: 529-536) allows a rapid, nondestructive solubilization of the lignin which can be estimated by reaction with phloroglucinol in free solution. This system has been used to study the effects of fungal elicitor on the synthesis of lignin in soybean cells. The inclusion of very low levels of an elicitor fraction from the cell walls of Phytophthora megasperma in the medium in which lignification of the soybean cells occurs suppressed both the accumulation of extracellular lignin and phloroglucinol staining of the cell walls without affecting the levels of bound hydroxycinnamic acids. The activity profiles of phenylalanine ammonia-lyase (EC 4.3.1.5) and isoenzymes of 4-coumarate:CoA ligase (EC 6.2.1.12) were compared in lignifying and elicitor-treated cell cultures as was the activity of chalcone synthase, an enzyme of flavonoid biosynthesis. The measured activities of these enzymes in cell cultures treated with elicitor were considerably lower than in untreated cells.
39 citations
TL;DR: In this paper, the usefulness of silicon emulsions as oxygen carriers is demonstrated in the case of l-amino acid oxidase activity of immobilized cells, an increase by a factor of four was found in the presence of silicon-emulsions.
Abstract: The relatively low solubility of oxygen in water presents a problem in particular when immobilized cells are used or enzymes are applied for oxygen dependent reactions. The other main purpose is the requirement of oxygen for the increase of biomass. In this investigation the usefulness of silicon emulsions as oxygen carriers is demonstrated. In case of l-amino acid oxidase activity of immobilized cells, an increase by a factor of four was found in the presence of silicon emulsions. Likewise, growth medium enriched with silicon emulsions showed a significantly increased growth of cells inside alginate beads compared to normal growth medium.
38 citations
TL;DR: It is concluded that current hollow-fiber membrane reactors should be limited to cell cultures having low growth rates, low O2 requirements, and low CO2 production rates.
Abstract: Cells ofSaccharomyces cerevisiae ATCC 4126, immobilized within the macroporous walls of asymmetric hollow-fiber membranes, were alternately perfused with 10% glucose complex medium and with 10% glucose defined medium which was deficient in nitrogen. Using complex growth medium, ethanol productivities during the initial 10 h of culture attained a maximum level of 133 g/l-h based on the total fiber volume (3% ethanol). Productivities during nitrogen deficiency stabilized at 10 g/l-h (0.5 ethanol). In subsequent growth phases, ethanol production rates increased to levels 40–70% of initial growth-phase values, but the ability to regenerate the fermentation activity decreased with culture age. During nitrogen deficiency, the fermentation efficiency declined with a concomitant reduction in the total protein concentration of immobilized cells within the hollow-fiber membranes. The molar ratio of acetaldehyde to ethanol increased seven-fold during nitrogen deficiency, indicating that the overall decline in glycolytic activity was accompanied by preferential reduction in alcohol dehydrogenase activity. The molar ratio of glycerol to ethanol increased two-fold during nitrogen deficiency, and large lipid-like droplets accumulated within the nitrogen-deficient cells. In addition to these findings, we conclude that current hollow-fiber membrane reactors should be limited to cell cultures having low growth rates, low O2 requirements, and low CO2 production rates.
TL;DR: Analysis of the metabolism of radiolabelled mannose and sucrose in the presence and absence of glucose demonstrated that glucose functions as the preferred carbon source, inhibiting the uptake and oxidation of the sugars within 15 min of its addition.
Abstract: The formation of aerial mycelia and spores by Streptomyces alboniger has been observed to be inhibited by glucose supplied in the growth medium as the sole carbon source or supplied in combination with other utilizable carbon sources. Analysis of the metabolism of radiolabelled mannose and sucrose in the presence and absence of glucose demonstrated that glucose functions as the preferred carbon source, inhibiting the uptake and oxidation of the sugars within 15 min of its addition. The inhibition of aerial mycelium formation was shown to result from the excretion of an acidic metabolite, and could be overcome by the addition of a buffering system. The acid metabolite was identified as pyruvic acid by high-performance liquid chromatography and by paper chromatography. Acid was not produced in substantial quantities in dextrin broth or in glucose broth supplemented with 5 mM adenine. Analysis of the pathway of pyruvate overproduction demonstrated that growth on glucose resulted in increased glycolytic activ...
01 Jan 1985
TL;DR: For most large-scale biological production requirements, as well as for routine cell culture and bench-scale pilot development, the traditional enriched culture medium supplemented with fetal bovine serum represents the most convenient culture system.
Abstract: In this brief review, we have illustrated the historical development of the growth media commonly employed for the propagation of cultured mammalian cells. While substantial progress has been achieved, the field may best be described as conservative and pragmatic. To date, the function of many components of the growth medium essential for cellular proliferation and biological production has not been precisely defined at the molecular level. Thus, for most large-scale biological production requirements, as well as for routine cell culture and bench-scale pilot development, the traditional enriched culture medium supplemented with fetal bovine serum represents the most convenient culture system. Many cell types may be more economically grown without reduction in biological yield by substituting alternative mammalian sera. Where reduction of total protein or greater definition of growth medium components outweighs the use of more universally applicable culture media, substitution of serum-free, customized formulations of highly enriched growth medium plus defined growth factors may be of significant utility. Optimization of mammalian cell culture media for large-scale biological production should include the following: An initial time investment to optimize the cell culture medium by enriching intermediary metabolite composition (rather than expecting serum or additional growth factors to perform nutritional functions) may result in higher productivity and reduced cost. When screening potential growth media for biological production applications, proliferative rate should not be the sole criterion for performance. Although rapid, logarithmic growth is advantageous to establish large-scale cultures, the maximal cell density and duration of the viable, productive period must also be weighed. Many cell types generate the highest titers of biological product either at stationary phase or under mildly stressful ("controlled death") conditions suboptimal for cellular replication. Thus, the ultimate determinant of growth medium efficacy is neither the degree of definition of medium composition nor the cellular proliferative rate, but the ability to support synthesis of substantial titers of the desired product at reasonably high purity.
TL;DR: It is concluded that during cultivation of the fungi, the metabolic state of the culture changes, influencing the antigenic composition of the extracts obtained after different periods of cultivation.
Abstract: Four allergologically important fungi, viz. Aspergillus fumigatus, Alternaria alternata, Penicillium notatum, and Cladosporium herbarum, were cultured in a pure synthetic medium and the patterns of growth as characterized by the pH, protein and carbohydrate concentration of the culture fluid, were studied. A. fumigatus and P. notatum showed a similar growth pattern, characterized by a rapid decrease in the pH of the culture medium (pH 7.4 → 4.0), while proteins were slowly released and saccharose poorly consumed. In contrast, A. alternata and C. herbarum demonstrated a different pattern of growth, in which the pH of the culture hardly changed during incubation. Enrichment of the synthetic medium with yeast extract greatly improved the growth of all four fungi, as was confirmed by the enhanced yield of antigenic material and strongly increased consumption of saccharose. The yeast extract especially changed the growth pattern of A. fumigatus and P. notatum, which now is characterized by three phases. Phase I; fall in pH of the growth medium and excretion of proteins. phase II: increase in pH and fall in protein concentration; phase III; stabilization of pH at alkaline values and renewed excretions of proteins. It is concluded that during cultivation of the fungi, the metabolic state of the culture changes, influencing the antigenic composition of the extracts obtained after different periods of cultivation.
TL;DR: Analysis of the lytic behavior and composition of outer membrane proteins of an osmotically fragile mutant strain revealed a similar dependence on the osmolarity of the growth medium.
Abstract: The rate and extent of lysis of Vibrio cholerae cells under nongrowing conditions were dependent on the osmolarity of the growth medium. Gross alterations in cellular morphology were observed when V. cholerae cells were grown in media of high and low osmolarity. The rate of lysis of V. cholerae cells under nongrowing conditions increased after treatment with chloramphenicol. Chloramphenicol-treated V. cholerae 569B cells showed formation of sphaeroplast-like bodies in medium of high osmolarity, but not in low osmolarity. Changes in the osmolarity of the growth medium also regulated the expression of the outer membrane proteins. This regulation was abolished if V. cholerae cells were grown in Pi-depleted medium. Analysis of the lytic behavior and composition of outer membrane proteins of an osmotically fragile mutant strain revealed a similar dependence on the osmolarity of the growth medium.
TL;DR: The presence of trace metals, inorganic phosphate, and a high rate of agitation were necessary for formation of maximal D-amino-acid oxidase activity and the enzyme is not subject to glucose repression.
Abstract: Production of D-amino-acid oxidase by Trigonopsis variabilis has been investigated using a two-stage cultivation technique. After transfer of exponentially growing cells to fresh medium, the enzyme was induced by addition of D-amino acids to the growth medium, among which D-methionine and D-alanine were the most effective. The simultaneous presence of the L form of amino acids or did not affect this induction. The presence of trace metals, inorganic phosphate, and a high rate of agitation were necessary for formation of maximal D-amino-acid oxidase activity. The enzyme is not subject to glucose repression.
TL;DR: In this article, roots of Pisum sativum were exposed for 48 h to 60Hz electric fields of 430 V/m in an aqueous inorganic growth medium, and the growth in length of the exposed roots was 44% of that for control roots.
Abstract: Roots of Pisum sativum were exposed for 48 h to 60-Hz electric fields of 430 V/m in an aqueous inorganic growth medium. The growth in length of the exposed roots was 44% of that for control roots. Root tips were analyzed for mitotic index and cell cycle duration. Mature, differentiated root sections from tissue produced after electrode energization were analyzed for cell lengths and number of files. The major reason for the observation that exposed roots are shorter than control roots is that cell elongation in the former is greatly diminished relative to controls.
TL;DR: The GS inhibitor methionine sulphoximine (MSX) inhibited GS activity but had no effect on exponentially growing cells, and the presence of MSX either lengthened or shortened the period between spore inoculation and initiation of exponential growth, depending on the source of nitrogen.
Abstract: Summary: Glutamine synthetase (GS; EC 6.3.1.2) from Streptomyces cattleya was purified using a single affinity-gel chromatography step, and some of its properties were determined. Levels of GS in S. cattleya cells varied by a factor of 8 depending upon the source of nitrogen in the growth medium. Of 24 nitrogen sources examined only glutamine or NH4Cl utilization resulted in very low GS activity. Addition of NH4Cl to a culture with high GS levels appeared to stop further synthesis and resulted in a progressive decrease in the specific activity of the enzyme. The GS inhibitor methionine sulphoximine (MSX) inhibited GS activity but had no effect on exponentially growing cells. The presence of MSX either lengthened or shortened the period between spore inoculation and initiation of exponential growth, depending on the source of nitrogen. In glutamine minimal medium MSX produced earlier and more efficient spore germination while in glutamate or nitrate minimal medium germination was delayed by its presence.
TL;DR: Staphylococcus aureus survived for longer periods in fish and oil than in water at temperatures up to 95°C and heat resistance varied between strains (NCTC 10652 and 68-7895) and was affected by the age of culture prior to use.
TL;DR: In this article, the authors used Kappa-Carrageenan beads (2-3 mm) to yield an in situ grown immobilized cell population which could be induced to produce the antibiotic and mycotoxin, patulin.
Abstract: Conidia of Penicillium urticae were immobilized in Kappa-Carrageenan beads (2–3 mm) by a previously described procedure to yield an in situ grown immobilized cell population which could be induced to produce the antibiotic and mycotoxin, patulin. When repeatedly transferred into a nitrogen-free production medium every 2 days, the patulin productivity of these cells gradually decreased to 50% within 14 days while the total cell protein remained constant. This decline was due to the gradual loss of the cells' catalytic capacity for converting glucose to 6-methylsalicylic acid (6-MSA), the first metabolite of the patulin pathway, as well as for converting 6-MSA to patulin. When these 14 day-old cells were incubated in a nutrient rich growth medium for 2 days their patulin producing activity increased from 50% to 130%. On the other hand the addition of a protein synthesis inhibitor, cycloheximide, to the N-free production medium drastically reduced the patulin producing activity of the immobilized cells; in particular, their capacity for converting 6-MSA to patulin. The cells' patulin producing activity was maintained at >100% for longer than 15 days when the cells were repeatedly transferred into a yeast extract supplemented production medium or when they were occasionally transferred into 10 or 20% strength growth medium. Repeated transfers to a 10% strength growth medium appeared to stabilize the cells' capacity for converting 6-MSA to patulin.
TL;DR: The results indicated that the mammary cell lines, particulary COMMA-D and MOD are good model systems to examine the uptake, retention, localization, and function of inorganic selenium under conditions where it acts as a growth inhibitory agent.
Abstract: The steady state levels of growth inhibitory doses of inorganic selenium were examined in five different mammary epithelial cell lines: MOD, COMMA-D, COMMA-F, COMMA-T, and YN-4. The retention of selenium was monitored using a radioactive isotope,75Se. Growth inhibition correlated with high levels of selenium in the cell. Generally, the retention of intracellular selenium was not dependent upon cell density, cell number, net growth rate, or tumorigenicity of the mammary cell lines. One cell line, COMMA-D, exhibited an unique response wherein the amount of selenium retained was low and the growth inhibitory effects of selenium were negligible when the cells were exposed to selenium at low density. However, at high cell densities, the COMMA-D cells responded like the other four cell lines. The growth inhibitory effect of selenium was reversible; upon removal of selenium from the medium, cells start synthesizing DNA within 24h. The retention of selenium was influenced by constituents in the growth medium. In particular, cysteine, but not methionine, purines, or pyrimidines altered selenium retention and counteracted the growth inhibitory effects of selenium. These results indicated that the mammary cell lines, particulary COMMA-D and MOD are good model systems to examine the uptake, retention, localization, and function of inorganic selenium under conditions where it acts as a growth inhibitory agent.
TL;DR: Accessibility to substrates with whole cells, adhesion of enzymes to spheroplasts, and solubilization of enzymes by treatment of whole cells with Triton X-100 under mild conditions suggest that phosphodiesterases and glycerol-3-phosphate phosphohydrolase are loosely associated with the outer side of the yeast plasma membrane.
TL;DR: Recycled organisms were capable of hydroxylating biphenyl more rapidly than cells in the primary fermentation culture and there was no lag period between introduction of biphenYL and the onset of hydoxylation.
Abstract: We carried out experiments designed to increase the rate of production of 4,4′-dihydroxybiphenyl (biphenol) from biphenyl by Aspergillus parasiticus. We show that 0.5 mg/ml biphenyl, the substrate for the reaction, significantly inhibits growth of the organism and that at 0.04 mg/ml, 2-hydroxybiphenyl or 4-hydroxybiphenyl (an intermediate of the reaction) strongly inhibit oxygen uptake, probably by inhibition of mitochondrial electron transport. Both factors may contribute to the low hydroxylation rates observed previously [J. H. Golbeck and J. C. Cox, Biotechnol. Bioeng., 26, 434 (1984)]. We therefore adapted the organism to the presence of 0.08 mg/ml 2- and 4-hydroxybiphenyl in the growth medium and found that cultures of adapted strains hydroxylated biphenyl at rates ca. three-fold faster than control cultures. Once the fungal mycelia were grown, they could be recycled at least twice into fresh fermentation broth. Recycled organisms were capable of hydroxylating biphenyl more rapidly than cells in the primary fermentation culture and there was no lag period between introduction of biphenyl and the onset of hydroxylation. Cell recycle thus results in a considerable saving in carbon costs and fermentation time.
TL;DR: The thermophilic fungus, Thermomyces lanuginosus, grows satisfactorily in a synthetic medium containing glucose as carbon source if the pH of the medium is controlled.
Abstract: In contrast to a published report [Wali et al. Arch Microbiol 118:49–53 (1978)], an organic acid is not essential for the growth of thermophilic fungi. The thermophilic fungus, Thermomyces lanuginosus, grows satisfactorily in a synthetic medium containing glucose as carbon source if the pH of the medium is controlled. The control of pH is essential for the concentration of carbon dioxide in the growth medium and the activity of anaplerotic enzyme, pyruvate carboxylase.
TL;DR: A cholesterol-deficient growth medium for human skin fibroblasts was prepared by adding to Eagle's Minimum Essential Medium a bovine serum treated with ultracentrifugation to remove bulk lipoproteins and cholesterol.
TL;DR: Cell suspension cultures of parsley exhibited an altered pattern of protein synthesis after transfer from complete growth medium to water or medium containing no macronutrients, and the synthesis of a few characteristic proteins (starvation-related proteins, STPs) increased strongly.
Abstract: Cell suspension cultures of parsley (Petroselinum crispum) exhibited an altered pattern of protein synthesis after transfer from complete growth medium to water or medium containing no macronutrients. Similar changes occurred when cultures were grown in the original medium until the nutrients were depleted. The effect was reversible upon transfer to fresh medium and was not observed during regular subculturing of the cells. While total protein synthesis decreased sharply after nutrient depletion, the synthesis of a few characteristic proteins (starvation-related proteins, STPs) increased strongly. The protein labeled at highest rates with [(35)S]methionine in vivo (STP 62) had an apparent molecular weight of about 62000 and a pI of about 6.3. Although its increased rate of synthesis was therefore easily detected by labeling in vivo, translation of mRNA in vitro did not give comparable results. Thus, regulatory control may be exerted mainly at the level of translation. Synthesis of STP ceased rapidly when heat shock (37° C) was applied under conditions of nutrient depletion, whereas heat-shock proteins were strongly induced.
TL;DR: Analyses of the cell-free culture fluid of diazotrophic Azotobacter vinelandii revealed the presence of a typical polypeptide pattern with a predominant 60 K polypeptic, significant amounts of ammonia at low oxygen concentrations as well as glutamic acid in both monomeric and polymeric form.
Abstract: Up to 5% of the totally fixed nitrogen and up to 11% of the totally formed protein were detected in cell-free culture fluids of diazotrophic Azotobacter vinelandii growing in continuous culture. The actual amounts of nitrogen and protein changed with ambient oxygen concentrations in the growth medium. While with whole cells the ratio of nitrogen per protein remained constant it varied with the extracellular moiety with changes of the oxygen concentration. Analyses of the cell-free culture fluid revealed the presence of a typical polypeptide pattern with a predominant 60 K polypeptide, significant amounts of ammonia at low oxygen concentrations as well as glutamic acid in both monomeric and polymeric form. Steady state levels of these extracellular components varied independently of each other with changes of the ambient oxygen concentration.
TL;DR: The physiological state of Pn1 cells seems to change significantly after only a few passages in liquid medium, and these changes can be prevented or partially reversed by manipulating the medium in which the cells and protoplasts are cultured.
Abstract: Protoplasts isolated from Datura cells requiring pantothenate for growth (Pn1 cell line) failed to divide in a medium containing 0.5 M mannitol if the cells from which they were derived had been subcultured in liquid medium more than four times. Division could be reinduced either by increasing the concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) in the growth medium from 1 to 2.5–5 mg/L, by adding low concentrations (0.01 – 1 mg/L) of benzyladenine to a growth medium containing 1 mg/L of 2,4-D, or by diluting the 0.5 M mannitol in the medium to 0.2 M immediately after isolation of the protoplasts. Thus, the physiological state of Pn1 cells seems to change significantly after only a few passages in liquid medium. These changes can be prevented or partially reversed by manipulating the medium in which the cells and protoplasts are cultured. Similar physiological changes did not occur in the case of cultured wild-type (Ph4), adenine-requiring (Ad1), or isoleucine–valine-requiring (I–VI) cells of Datura.
TL;DR: The ratio of unsaturated/saturated phospholipid fatty acids decreased on ethanol supplementation but increased in the presence of glycerol, and Steady state accumulation of labelled amino acids was affected under these conditions.
Abstract: Supplementation of glucose-containing medium with ethanol and replacement of glucose by glycerol in the Sabouraud’s growth medium ofMicrosporum gypseum altered the levels of total phospholipids as well as their apolar and polar head groups. The levels of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) increased under these growth conditions; also, the ratio of unsaturated/saturated phospholipid fatty acids decreased on ethanol supplementation but increased in the presence of glycerol. Steady state accumulation of labelled amino acids (glycine, lysine and aspartic acid) was affected under these conditions.
Patent•
09 Aug 1985
TL;DR: In this article, the authors proposed a method for the production of lactic bacteria in the cheese and wine making industries. But this method was performed in two stages, the first stage is conducted in the absence of ultrafiltration while the pH of the growth medium is maintained within the range of 6-7 by the addition of a neutralizing agent.
Abstract: This invention relates to the production of the microorganisms. The operation is conducted in two stages. The first stage is conducted in the absence of ultrafiltration while the pH of the growth medium is maintained within the range of 6-7 by the addition of a neutralizing agent. Nutrient substratum and dilution water are added during the first stage to maintain the growth rate at a constant level, and the volume of growth medium is permitted to increase. When the amount of growth inhibiting agent produced in the fermentation reaches a predetermined maximum level, the second stage is initiated and the growth rate is maintained in a range of 0.10 to 0.50/hr, which is less than the growth rate in the first stage. By increasing the amount of dilution water the concentration of the growth inhibiting agent is maintained so as to achieve the desired moderate growth rate. The growth inhibiting agent is also continuously removed from the growth medium during the second stage and the volume of the growth medium is maintained substantially constant. The invention may be applied to the production of lactic bacteria, in particular for example in the cheese and wine making industries.