Nitrification: an old process, a new concern

1971 ◽  
Vol 24 ◽  
Author(s):  
W. H. Verstraete
Keyword(s):  
Culture Medium ◽  
Nitrogen Sources ◽  
Living Cells ◽  
Factors Affecting ◽  
Inhibiting Effect ◽  
Proteose Peptone ◽  
Asparaginase Activity

Some  factors affecting the L-asparaginase activity of E.  aroideae were investigated. Increasing  concentrations of glucose in the culture medium had an inhibiting effect on  the production of L-asparaginase by this microorganism. Buffering of the  culture medium in order to stabilize the pH during growth resulted in a decrease  of the L-asparaginase activity. From the different nitrogen sources examined,  tryptone, proteose peptone nr 2 and nr 3 stimulated the L-asparaginase  production. Toluene treatment of the cells practically destroyed the  L-asparaginase. Acetone dried cells showed an L-asparaginase activity  comparable with the activity of living cells.

Optimization and Purifi cation of L-Asparaginase Produced by Streptomyces tendae TK-VL_333

2010 ◽  
Vol 65 (7-8) ◽  
pp. 528-531 ◽  
Author(s):  
Alapati Kavitha ◽  
Muvva Vijayalakshmi
Keyword(s):  
Culture Medium ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Nitrogen Sources ◽  
Laterite Soil ◽  
Factors Affecting ◽  
Carbon And Nitrogen ◽  
Initial Ph ◽  
Streptomyces Tendae

Cultural factors affecting the production of L-asparaginase by Streptomyces tendae isolated from laterite soil samples of Guntur region were investigated on glycerolasparagine- salts (modified ISP-5) broth. Optimal yields of L-asparaginase were recorded in the culture medium with the initial pH 7.0 incubated at 30 °C for 72 h. The strain utilized sucrose (2%) and yeast (2%) extract as carbon and nitrogen sources for L-asparaginase production. The productivity of L-asparaginase was slightly enhanced when the strain was treated with cell-disrupting agents like EDTA. The crude enzyme was purifi ed to homogeneity by ammonium sulfate precipitation, Sephadex G-100 and CM-Sephadex G-50 gel filtration. By employing sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the molecular weight of the enzyme was recorded as 97.4 kDa. This is the first report on production and purification of L-asparaginase from S. tendae.

THE PROTEOLYTIC ENZYMES OF MICROORGANISMS: II. FACTORS AFFECTING THE PRODUCTION OF PROTEASES IN SUBMERGED CULTURE

1950 ◽  
Vol 28c (6) ◽  
pp. 586-599 ◽  
Author(s):  
W. M. Dion
Keyword(s):  
Culture Medium ◽  
Proteolytic Enzymes ◽  
Inorganic Nitrogen ◽  
Maximum Yield ◽  
Nitrogen Sources ◽  
Protease Production ◽  
Carbohydrate Source ◽  
Factors Affecting ◽  
Main Factors ◽  
High Yields

The main factors that influence the production of proteolytic enzymes by a few selected cultures have been studied. The time taken to reach the maximum yield of proteases is dependent upon the growth rate of each organism, and varies from two to five days. The fungi tested require the presence of an easily available carbohydrate source in addition to a protein substrate in order to produce high yields of proteolytic enzymes. The Streptomyces cultures will produce proteases in the absence of a carbohydrate source, but yields are generally low. The fungi studied will not produce significant amounts of proteases when grown on predominately inorganic nitrogen sources in contrast with the Streptomyces cultures, one of which produced almost as high yields of proteolytic enzymes when grown with sodium nitrate as when grown with Klim. Of a number of protein sources Klim and malt sprouts provided the best media for protease production. The temperature of incubation and pH of the culture medium are also important factors affecting the yield of proteolytic enzymes.

scholarly journals Optimum conditions for Prodigiosin production by Serratia marcescens S11

2011 ◽  
Vol 5 (3) ◽  
pp. 34-40
Author(s):  
Abdulkareem Jasim ◽  
Hameed M. Jasim ◽  
Isra'a M. Dhahi
Keyword(s):  
Serratia Marcescens ◽  
Culture Medium ◽  
Casein Hydrolysate ◽  
Brain Heart Infusion ◽  
Nitrogen Sources ◽  
Optimum Conditions ◽  
Carbon And Nitrogen Sources ◽  
Carbon And Nitrogen ◽  
Phosphate Source ◽  
Initial Medium

Different nutritional and cultural factors were studied to determine the optimum conditions for prodigiosin production by Serratia marcescens S11 in a batch culture of brain-heart infusion broth medium. These factors include carbon source and its concentration, nitrogen source and its concentration, phosphate source, temperature and pH. Results showed that the optimum conditions for prodigiosin production were achieved when the production medium was supplemented with olive oil and casein hydrolysate as a carbon and nitrogen sources respectively in a concentration of 1.5% for broth, KH2PO4 as a phosphate source at initial medium pH8, and incubation at 28°C for 24 hours. Under these optimal conditions, prodigiosin activity produced by Serratia marcescens S11 in culture medium was increased from 200 U/cell before optimization to 3000 U/cell.

scholarly journals Glass beads load macromolecules into living cells

1987 ◽  
Vol 88 (5) ◽  
pp. 669-678
Author(s):  
P.L. McNeil ◽  
E. Warder
Keyword(s):  
Culture Medium ◽  
Small Volume ◽  
Cultured Cells ◽  
Cell Monolayer ◽  
Cell Loss ◽  
Living Cells ◽  
Glass Beads ◽  
Cell Type ◽  
Large Numbers ◽  
Micron Diameter

We describe and characterize an exceptionally rapid and simple new technique for loading large numbers of cultured cells with large macromolecules. The culture medium of the cell monolayer is replaced by a small volume of the macromolecule to be loaded. Glass beads (75–500 micron diameter) are then sprinkled onto the cells, the cells are washed free of beads and exogenous macromolecules, and ‘bead-loading’ is completed. The conditions for bead-loading can readily be modified to accommodate cell type and loading objectives: for example, the amount of loading per cell increases if bead size is increased or if beads are agitated after sprinkling onto the monolayer, but at the expense of increased cell loss. As many as 97% of a population of bovine aortic endothelial (BAE) cells were loaded with a 10,000 Mr dextran; and 79% with a 150,000 Mr dextran using bead-loading. Various cell lines have been loaded using glass beads. Moreover, bead-loading has the advantage of producing loaded cells that remain adherent and well-spread, thus minimizing recovery time and permitting immediate microscopic examination.

scholarly journals Influence of cultivation conditions on IAA - producing activity of endophytic bacterial strains isolated from morning-glory (IPOMOEA PES-CAPRAE (L.) R.Br.)

2021 ◽  
Vol 36 ◽  
pp. 05003
Author(s):  
Nguyen Van Zhang ◽  
Nguyen Thi Thu ◽  
Vu Thi Linh ◽  
V.V. Pylnev ◽  
M.I. Popchenko
Keyword(s):  
Carbon Source ◽  
Culture Medium ◽  
Nitrogen Sources ◽  
Morning Glory ◽  
Bacterial Strains ◽  
Cultivation Conditions ◽  
Bacillus Mycoides ◽  
Carbon And Nitrogen Sources ◽  
Carbon And Nitrogen ◽  
Study Results

This work presents the experimental study results of the influence of the culture medium on the ability to IAA synthesis of three endophytic strains TH10R, TH11T, and TH13T from roots of Ipomoea pes-caprae. Three investigated strains give the highest IAA concentration after 96 h of cultivation. A significant increase in IAA biosynthesis was obtained by cultivating the TH10R strain in a medium containing lactose or starch as a carbon source and NH4Cl or KNO3 as a nitrogen source. The TH11T strain produces the maximum amount of IAA, using glucose or xylose and KNO3 or NH4NO3 as carbon and nitrogen sources, respectively. Sucrose is a suitable carbon source for the TH13T strain; on a sucrose-containing medium, the TH13T strain produces the highest IAA amount. The most active strain is TH10R, identified as Bacillus mycoides and named Bacillus mycoides TH10R.

Biological factors affecting enflagellation of Naegleria fowleri

1982 ◽  
Vol 152 (2) ◽  
pp. 803-808
Author(s):  
T W Woodworth ◽  
D T John ◽  
S G Bradley
Keyword(s):  
Population Density ◽  
Stationary Phase ◽  
Culture Medium ◽  
Actinomycin D ◽  
Suitable Model ◽  
Naegleria Fowleri ◽  
Biological Factors ◽  
Factors Affecting ◽  
Nægleria Fowleri ◽  
Amoeboid Cells

Naegleria fowleri is a pathogenic amoeboflagellate that can be evoked to transform from amoebae to flagellates by subculture to nonnutrient buffer. More than half of the amoebae of strains KUL, nN68, and Lovell became enflagellated 300 min after subculture to amoeba-saline, whereas no amoebae of strains NF66, NF69, and HB4 did. N. fowleri nN68 enflagellated best when grown at 32 or 37 degrees C and subcultured to amoeba-saline at 37 or 42 degrees C. Amoebae from the stationary phase of growth enflagellated more readily than did actively growing amoebae. Incubation in expended culture medium from stationary-phase cultures enhanced the capability of growing amoebae to enflagellate after subculture to amoebasaline. Enflagellation was more extensive when the population density in amoebasaline did not exceed 2 x 10(5) amoebae per ml. Cycloheximide at 1 microgram/ml and actinomycin D at 25 micrograms/ml inhibited growth of N. fowleri nN68. Cycloheximide at 0.5 microgram/ml and actinomycin D at 25 micrograms/ml completely prevented enflagellation when added at time zero. Cycloheximide at 0.5 microgram/ml, added 120 to 300 min after initiation of enflagellation, prevented further differentiation and caused existing flagellates to revert to amoeboid cells. Similarly, actinomycin D at 25 micrograms/ml, added 90 to 300 min after initiation of enflagellation, retarded differentiation and caused flagellates to revert. Radiolabeled precursors were incorporated into macromolecules during differentiation in nonnutrient buffer. Enflagellation of N. fowleri is a suitable model for studying regulation of a eucaryotic protist.

Experiments in Nanomechanical Properties of Live Osteoblast Cells and Cell–Biomaterial Interface

2011 ◽  
Vol 2 (4) ◽  
Author(s):  
Rohit Khanna ◽  
Kalpana S. Katti ◽  
Dinesh R. Katti
Keyword(s):  
Cell Culture ◽  
Culture Medium ◽  
Cell Structure ◽  
Living Cells ◽  
Actin Stress Fiber ◽  
Cell Culture Medium ◽  
Nanomechanical Properties ◽  
Cell Substrate ◽  
Significant Difference

Characterizing the mechanical characteristics of living cells and cell–biomaterial composite is an important area of research in bone tissue engineering. In this work, an in situ displacement-controlled nanoindentation technique (using Hysitron Triboscope) is developed to perform nanomechanical characterization of living cells (human osteoblasts) and cell–substrate constructs under physiological conditions (cell culture medium; 37 °C). In situ elastic moduli (E) of adsorbed proteins on tissue culture polystyrene (TCPS) under cell culture media were found to be ∼4 GPa as revealed by modulus mapping experiments. The TCPS substrates soaked in cell culture medium showed significant difference in surface nanomechanical properties (up to depths of ∼12 nm) as compared to properties obtained from deeper indentations. Atomic force microscopy (AFM) revealed the cytoskeleton structures such as actin stress fiber networks on flat cells which are believed to impart the structural integrity to cell structure. Load-deformation response of cell was found to be purely elastic in nature, i.e., cell recovers its shape on unloading as indicated by linear loading and unloading curves obtained at 1000 nm indentation depth. The elastic response of cells is obtained during initial cell adhesion (ECell, 1 h, 1000 nm = 4.4–12.4 MPa), cell division (ECell, 2 days, 1000 nm = 1.3–3.0 MPa), and cell spreading (ECell, 2 days, 1000 nm = 6.9–11.6 MPa). Composite nanomechanical responses of cell–TCPS constructs were obtained by indentation at depths of 2000 nm and 3000 nm on cell-seeded TCPS. Elastic properties of cell–substrate composites were mostly dominated by stiff TCPS (EBulk = 5 GPa) lying underneath the cell.

scholarly journals Hydrophobic glycosides of N-acetylglucosamine can act as primers for polylactosamine synthesis and can affect glycolipid synthesis in vivo

1995 ◽  
Vol 307 (3) ◽  
pp. 791-797 ◽  
Author(s):  
D C A Neville ◽  
R A Field ◽  
M A J Ferguson
Keyword(s):  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Culture Medium ◽  
Linear Array ◽  
Chinese Hamster ◽  
Living Cells ◽  
Anomeric Configuration ◽  
Glycolipid Synthesis ◽  
Synthetic Capacity

Several hydrophobic glycosides of N-acetylglucosamine (GlcNAc) served as primers for polylactosamine synthesis when added to Chinese hamster ovary (CHO) cells. The modified glycosides, containing one to six lactosamine repeats in linear array, were sialylated and secreted into the culture medium. The relative efficiencies of the glycosides to serve as primers were dependent on the nature of the aglycone and on the anomeric configuration of the GlcNAc residue. The same compounds were tested for their effects on glycolipid synthesis in CHO cells. All of the beta-glycosides significantly inhibited the synthesis of the lactoseries glycolipid GM3 whereas the alpha-glycoside was inactive. The compound GlcNAc alpha 1-O-benzyl- was the most efficient primer of polylactosamine synthesis and had no effect on glycolipid synthesis. This compound may have potential for the assay of the polylactosamine synthetic capacity of living cells.

scholarly journals Evaluation of the process conditions for the production of microbial carotenoids by the recently isolated Rhodotorula mucilaginosa URM 7409

2019 ◽  
Vol 22 ◽  
Author(s):  
Whallans Raphael Couto Machado ◽  
Lucas Gomes da Silva ◽  
Ellen Silva Lago Vanzela ◽  
Vanildo Luiz Del Bianchi
Keyword(s):  
Experimental Design ◽  
Yeast Extract ◽  
Culture Medium ◽  
Nitrogen Sources ◽  
Process Conditions ◽  
Malt Extract ◽  
Rhodotorula Mucilaginosa ◽  
Process Characteristics ◽  
Initial Ph ◽  
Microbial Carotenoids

Abstract This study aimed to improve the physical and nutritional process conditions for the production of carotenoids by the newly isolated Rhodotorula mucilaginosa, a red basidiomycete yeast. The carotenoid bioproduction was improved using an experimental design technique, changing the process characteristics of agitation (130 rpm to 230 rpm) and temperature (25 °C to 35 °C) using seven experiments, followed by a 25-1 fractional design to determine the relevant factors that constitute the culture medium (glucose, malt extract, yeast extract, peptone and initial pH). A complete second order experimental design was then carried out to optimize the composition of the culture medium, the variables being yeast extract (0.5 to 3.5 g/L), peptone (1 to 5 g/L) and the initial pH (5.5 to 7.5), with 17 experiments. The maximum carotenoid production was 4164.45 μg/L (252.99 μg/g), obtained in 144 h in YM (yeast malt) medium with 30 g/L glucose, 10 g/L malt extract, 2 g/L yeast extract, 3 g/L peptone, an initial pH 6, 130 rpm and 25 °C, demonstrating the potential of this yeast as a source of bio-pigments. In this work, the nitrogen sources were the factors that most influenced the intracellular accumulation of carotenoids. The yeast R. mucilaginosa presented high production at a bench level and may be promising for commercial production.

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