Production of exocellular polysaccharides by Alternaria solani

1968 ◽  
Vol 14 (10) ◽  
pp. 1063-1068 ◽  
Author(s):  
James L. Goatley
Keyword(s):  
Carbon Source ◽  
Nitrogen Content ◽  
Alternaria Solani ◽  
Dry Weight ◽  
Shake Culture ◽  
Chromatographic Techniques ◽  
Polysaccharide Production ◽  
Exocellular Polysaccharide ◽  
Exocellular Polysaccharides ◽  
Fraction I

Alternaria solani produced two homogeneous exocellular polysaccharide fractions when grown in shake culture with fructose as the carbon source and the NH4NO3 concentration of the medium 1.7 g/l. Chromatographic techniques indicated that fraction I contained glucose, galactose, and glucosamine in a 2.4:1:1 ratio whereas fraction II contained glucose, galactose, and mannose in a 6.4:1:1.2 ratio. Fraction I was found at levels seven times greater than II. Total polysaccharide produced was 1.8% of the dry weight of the mycelium and 1.2% of the available carbohydrate.Growth and polysaccharide production were greatest with fructose as the carbon source. Decreasing levels of growth occurred with mannitol, glucose, and sucrose, respectively. Exocellular polysaccharides were not detected with mannitol as carbon source. At 10 days, growth on fructose is maximum at NH4NO3 concentrations of 1.5 to 2.5 g/l, but exocellular polysaccharide production is maximum at 0.8 g/l. When produced on a medium of 2.0 g/l NH4NO3 the nitrogen content of I is double that when the medium is 0.8 g/l NH4NO3. In addition the ratio of I to II is about four times greater.

The Interactions of Carbon and Nitrogen in Liquid Silicon

2014 ◽  
Vol 33 (4) ◽  
pp. 363-368 ◽  
Author(s):  
Halvor Dalaker ◽  
Merete Tangstad
Keyword(s):  
Silicon Nitride ◽  
Carbon Source ◽  
Nitrogen Content ◽  
High Purity ◽  
Liquid Silicon ◽  
Interaction Parameters ◽  
Carbon And Nitrogen ◽  
Temperature Range ◽  
High Purity Silicon

AbstractThe interactions between carbon and nitrogen in liquid silicon have been studied experimentally. High purity silicon was melted in silicon nitride crucibles under an Ar atmosphere with a graphite slab inserted in the crucible prior to melting as a carbon source. The system was thus simultaneously equilibrated with Si3N4 and SiC. Samples were extracted in the temperature range 1695–1798 K and analyzed using Leco.It was observed that the simultaneous saturation of nitrogen and carbon caused a significant increase in the solubilities of both elements. The interaction parameters were derived as The solubility of carbon in liquid silicon as a function of temperature and nitrogen content was found to follow: And the solubility of nitrogen in liquid silicon found to follow:

scholarly journals Isolation and Characterization of a Mutant of the Marine Bacterium Alcanivorax borkumensis SK2 Defective in Lipid Biosynthesis

2010 ◽  
Vol 76 (9) ◽  
pp. 2884-2894 ◽  
Author(s):  
Efraín Manilla-Pérez ◽  
Alvin Brian Lange ◽  
Stephan Hetzler ◽  
Marc Wältermann ◽  
Rainer Kalscheuer ◽  
...  
Keyword(s):  
Carbon Source ◽  
Sole Carbon Source ◽  
Marine Bacterium ◽  
Neutral Lipids ◽  
Nile Red ◽  
Dry Weight ◽  
Wax Ester ◽  
Gene Encoding ◽  
Isolation And Characterization ◽  
Key Enzyme

ABSTRACT In many microorganisms, the key enzyme responsible for catalyzing the last step in triacylglycerol (TAG) and wax ester (WE) biosynthesis is an unspecific acyltransferase which is also referred to as wax ester synthase/acyl coenzyme A (acyl-CoA):diacylglycerol acyltransferase (WS/DGAT; AtfA). The importance and function of two AtfA homologues (AtfA1 and AtfA2) in the biosynthesis of TAGs and WEs in the hydrocarbon-degrading marine bacterium Alcanivorax borkumensis SK2 have been described recently. However, after the disruption of both the AtfA1 and AtfA2 genes, reduced but substantial accumulation of TAGs was still observed, indicating the existence of an alternative TAG biosynthesis pathway. In this study, transposon-induced mutagenesis was applied to an atfA1 atfA2 double mutant to screen for A. borkumensis mutants totally defective in biosynthesis of neutral lipids in order to identify additional enzymes involved in the biosynthesis of these lipids. At the same time, we have searched for a totally TAG-negative mutant in order to study the function of TAGs in A. borkumensis. Thirteen fluorescence-negative mutants were identified on Nile red ONR7a agar plates and analyzed for their abilities to synthesize lipids. Among these, mutant 2 M131 was no longer able to synthesize and accumulate TAGs if pyruvate was used as the sole carbon source. The transposon insertion was localized in a gene encoding a putative cytochrome c family protein (ABO_1185). Growth and TAG accumulation experiments showed that the disruption of this gene resulted in the absence of TAGs in 2 M131 but that growth was not affected. In cells of A. borkumensis SK2 grown on pyruvate as the sole carbon source, TAGs represented about 11% of the dry weight of the cells, while in the mutant 2 M131, TAGs were not detected by thin-layer and gas chromatography analyses. Starvation and lipid mobilization experiments revealed that the lipids play an important role in the survival of the cells. The function of neutral lipids in A. borkumensis SK2 is discussed.

scholarly journals Rhizobacteria inoculation in maize associated with nitrogen and zinc fertilization at sowing

2021 ◽  
Vol 25 (2) ◽  
pp. 96-100
Author(s):  
Andréia de L. Moreno ◽  
Jorge F. Kusdra ◽  
Angelita A. C. Picazevicz
Keyword(s):  
Bacillus Subtilis ◽  
Nitrogen Content ◽  
Plant Height ◽  
Nitrogen Fertilization ◽  
Azospirillum Brasilense ◽  
Dry Weight ◽  
Stem Diameter ◽  
Wide Range ◽  
Maize Plants ◽  
Total Dry Weight

ABSTRACT Rhizobacteria have a wide range of plant growth-promoting mechanisms of action, making them an alternative and/or complementary biological input for chemical fertilizers. In this respect, the present study aimed to assess growth and nitrogen accumulation in maize plants as a function of Azospirillum brasilense, Bacillus subtilis, zinc and nitrogen application at sowing. The experiment with the ‘AL Bandeirante’ maize variety was conducted in a greenhouse, using a completely randomized design. The treatments were arranged in a 2 x 2 x 2 x 2 factorial scheme, with six repetitions, considering the presence and absence of Azospirillum brasilense (5 g kg-1), Bacillus subtilis (5 mL kg-1) and zinc (20 g kg-1) in the seeds and addition or not of nitrogen (30 kg ha-1) to the soil. The variables assessed were plant height, stem diameter, leaf, stem, shoot, root and total dry weight, and shoot nitrogen content. Nitrogen fertilization in the absence of zinc increased shoot and total dry weight as well as shoot nitrogen content. Zinc applied to the seeds improved the total and stem dry weight of maize plants in the absence of Bacillus subtilis. Inoculation with Azospirillum brasilense and Bacillus subtilis increased the stem diameter and shoot nitrogen content of maize plants when nitrogen fertilization was not performed at sowing. There was no isolated or interaction effect between factors for plant height and root dry weight.

Statistical Analysis of Growth and Amylase Production by Aspergillus flavus grown on Different Carbon Sources

2013 ◽  
Vol 2 (1) ◽  
Author(s):  
M O Oyewale
Keyword(s):  
Carbon Source ◽  
Aspergillus Flavus ◽  
Amylase Activity ◽  
Carbon Sources ◽  
Dry Weight ◽  
Soluble Starch ◽  
Optimum Growth ◽  
Amylase Production ◽  
Level Of Significance ◽  
Cassava Peel

The mycelial dry weight and dinitrosalicylic acid (D.N.S.A.) method was used to determine growth and amylase production by Aspergillus flavus grown on different carbon sources. Growth of the fungus was determined at 24 h intervals over a period of six days by the dry mycelial weight methods, while the amylase activity in the culture filtrates of A. flavus was determined by the D.N.S.A method. A total of 45 samples were prepared to determine growth and amylase activity of Aspergillus flavus grown on different carbon sources. The concentration of the various carbon sources ranges between 0.4 to 2% W/V. Duncan’s multiple range test was used to determine the level of significance of the different carbon sources for effective growth and amylase production by Aspergillus flavus. Aspergillus flavus demonstrated the capability to produce significant growth and amylase activities in the medium containing soluble starch, sorghum and cassava peel as sole carbon source. The amount of mycelial dry weight produced from soluble starch, sorghum and cassava peel is significantly higher than those produced from other carbon sources. The data revealed that there is a correlation between growth and amylase production by Aspergillus flavus. The available data from this study showed that soluble starch is the best carbon source for optimum growth and amylase production by A flavus while sorghum and cassava peel are close substitute for optimum growth and amylase production by Aspergillus flavus. Keywords: Growth, amylase activity and Aspergillus flavus

Effect of Simazine and Diuron on the Nitrogen Content and Dry Weight of Wheat and Sorghum 1

1974 ◽  
Vol 66 (5) ◽  
pp. 701-702 ◽  
Author(s):  
G. A. Rottman ◽  
J. A. Tweedy ◽  
George Kapusta
Keyword(s):  
Nitrogen Content ◽  
Dry Weight

DIFFERENCES IN NITROGEN CONTENT IN EXTRACTS OF CHILLED AND NON-CHILLED TISSUES

1958 ◽  
Vol 36 (1) ◽  
pp. 45-49
Author(s):  
S. Fedoroff ◽  
R. Altschul
Keyword(s):  
Nitrogen Content ◽  
Human Placenta ◽  
Phosphorus Content ◽  
Growth Promotion ◽  
Dry Weight ◽  
Chick Embryos ◽  
Tissue Cultures ◽  
Significant Difference ◽  
Nitrogen Phosphorus

In an attempt to elucidate the increase of growth promotion of tissue cultures by extracts obtained from tissues chilled before extraction, determinations of nitrogen content were made on (a) fresh, and chilled chick embryos, (b) extracts prepared from fresh and chilled chick embryos, (c) fresh and chilled human placenta, (d) extracts prepared from fresh and chilled human placenta.There was no difference in dry weight, nitrogen content, phosphorus content, and nitrogen: phosphorus ratio between chilled and fresh chick embryos and chilled and fresh human placenta. There was, however, a significant difference in the nitrogen content of the extracts prepared from fresh and from chilled tissues, It is suggested that chilling of tissues for 7 days at + 4 °C. prior to extraction may render the cells more easily destructible during extraction, and thus supply a better yield of nutritive substances.

scholarly journals Nodule efficiency of three soybean genotypes inoculated by different methods

2011 ◽  
Vol 48 (No. 8) ◽  
pp. 356-360
Author(s):  
V. Milić ◽  
N. Mrkovački ◽  
M. Popović ◽  
Đ. Malenčić
Keyword(s):  
Nitrogen Content ◽  
Bradyrhizobium Japonicum ◽  
Dry Matter ◽  
Nitrogen Assimilation ◽  
Soybean Seed ◽  
Dry Weight ◽  
Affected Plant ◽  
Whole Plant ◽  
Soybean Genotypes ◽  
Nr Activity

The objective of the study was to investigate how the inoculation of soybean seed (variety Afrodita, and lines NS-L-2016 and NS-L-300168) with strains of Bradyrhizobium japonicum (1, 1a, 2b), Azotobacter chroococcum (3, 13, 14), and GA3 (gibberellic acid) affected plant dry weight, nitrogen content of nodules and whole plant, the enzymes of nitrogen assimilation (NR, GS) and soluble protein content. The highest dry matter mass and nitrogen content were found in the variety Afrodita, followed by line NS-L-300168. The GS and NR activity was increased significantly by all three inoculation treatments relative to the control. In all three genotypes, the highest values for the enzymatic activity were achieved with treatment mixture of B. japonicum and A. chroococcum strains. Each measurement was performed with three replications. The results were processed using variance analysis and the values were tested with the LSD at 5%.

Effect of weed management on weeds, and on the nodulation, nitrogenase activity, growth and yield of pea (Pisum sativum)

2006 ◽  
Vol 54 (4) ◽  
pp. 469-485 ◽  
Author(s):  
G. Singh ◽  
D. Wright
Keyword(s):  
Pisum Sativum ◽  
Nitrogen Content ◽  
Weed Management ◽  
Plant Biomass ◽  
Nitrogenase Activity ◽  
Strong Relationship ◽  
Dry Weight ◽  
Growth And Yield ◽  
N Content ◽  
Shoot Dry Weight

Effects of one pre-emergence herbicide (terbutryn/terbuthylazine) and one post-emergence herbicide (bentazone) along with unweeded and hand-weeded controls on weeds and on the nodulation, nitrogenase activity, nitrogen content, growth and yield of pea (Pisum sativum) were studied. Terbutryn/terbuthylazine was applied pre-emergence @ 1.40, 2.80 and 5.60 kg/hawhereas bentazone was sprayed 6 weeks after sowing @ 1.44, 2.88 and 5.76 kg/h. Terbutryn/terbuthylazine controlled all the weeds very effectively, whereas bentazone did not control some weeds such as Polygonum aviculare, Poa annua and Elymus repens. The herbicides decreased the number of nodules, the dry weight of nodules, the nitrogenase activity, the shoot dry weight, the nitrogen content in the straw and seeds, and the seed yield of peas, the effects generally being higher at higher rates of application. The adverse effects of herbicides on these parameters might be due to their effects on plant growth, as both the herbicides are known to adversely affect photosynthesis. Nitrogenase activity did not correlate well with plant-N content or shoot dry weight. However, there was a strong relationship between plant biomass and plant-N content, which suggests that researchers can rely on these parameters for studying the effects of treatments on nitrogen fixation, rather than measuring nitrogenase activity.

scholarly journals Effect of Lactose on Soluble-glucan Production and on the Ultrastructure of Sclerotium rolfsii Sacc. Grown in Submerged Culture

Microbiology ◽  
2000 ◽  
Vol 81 (1) ◽  
pp. 145-149 ◽  
Author(s):  
Y. Okon ◽  
I. Chet ◽  
Naomi Kislev ◽  
Y. Henis
Keyword(s):  
Carbon Source ◽  
Submerged Culture ◽  
Sole Carbon Source ◽  
Synthetic Medium ◽  
Sclerotium Rolfsii ◽  
Dry Weight ◽  
Solid Media

SUMMARY A significant increase in mycelial dry weight and a decrease in production of extracellular glucan were observed when lactose was added to a submerged culture of Sclerotium rolfsii grown in a liquid glucose-synthetic medium. When added as a sole carbon source, lactose at 2·5% (w/v) induced the formation of dark, spherical, compact bodies. The ultrastructure of these bodies is compared with that of sclerotia formed on solid media.

Influence of fertilizer treatment on apple fruit composition and physiology. II. Influence on respiration rate and contents of nitrogen, phosphorus, and titratable acidity

1969 ◽  
Vol 20 (6) ◽  
pp. 1073 ◽  
Author(s):  
DS Letham
Keyword(s):  
Nitrogen Content ◽  
Respiration Rate ◽  
Phosphorus Content ◽  
Titratable Acidity ◽  
Dry Weight ◽  
Apple Fruit ◽  
Fertilizer Treatment ◽  
Soluble Nitrogen ◽  
Tissue Contents ◽  
Nitrogen Phosphorus

The respiration rates and tissue contents of nitrogen, phosphorus, and titratable acidity were determined for apple fruit from trees receiving differential fertilizer treatments U, N, P, NP, and NPK (U, no fertilizer; N, 2 lb ammonium sulphate; P, 4 1b superphosphate; and K, 1 Ib potassium sulphate, per tree per year). The results obtained (expressed on a dry weight basis) are summarized as follows: Respiration rate: N > NP = NPK = U > P. Total nitrogen content: NPK > NP = N > U = P. Ethanol-insoluble nitrogen content: NPK = NP = N > U = P. Ethanol-soluble nitrogen content: NPK > NP = N > U = P. Phosphorus content : P > NP = NPK > U > N. Titratable acidity content: NPK > N > NP = U > P. The incidence of internal breakdown in stored fruit from these treatments has positively correlated with respiration rate per cell and negatively correlated with phosphorus content. Phosphorus content was negatively correlated with cell volume and respiration rate. Mechanisms by which phosphorus content might regulate the incidence of internal breakdown are discussed.

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