Relationship between aeration, carbon source, and respiration yield and the ethylene production and differentiation of static cultures of Penicillium cyclopium and P. velutinum

1989 ◽  
Vol 35 (6) ◽  
pp. 619-622 ◽  
Author(s):  
Jaroslav Pažout ◽  
Sylvie Pažoutová
Keyword(s):  
Carbon Source ◽  
Liquid Medium ◽  
Ethylene Production ◽  
Narrow Range ◽  
Aerial Mycelium ◽  
Dry Weight ◽  
Phosphate Content ◽  
Anaerobic Conditions ◽  
Aerial Hyphae ◽  
Penicillium Cyclopium

Fully aerated surface cultures of Penicillium cyclopium and P. velutinum grown on liquid medium with 2-oxoglutarate or glutamate (34 mM) produced ethylene in association with the formation of aerial hyphae at about the 5th day (ethylene peak EP 1), its concentration then declined, and rose again during conidiation at about the 7th day (peak EP 2). In P. cyclopium glucose (22.2 mM) shortened differentiation, EP 1 and EP 2 merged, and culture pH dropped to 1.8. Methionine (34 mM) prevented the formation of aerial mycelium in P. cyclopium and penicilli initiation in P. velutinum; ethylene production was low. Under conditions of delayed aeration, P. cyclopium grown on glucose produced no ethylene and weak formation of immature conidia was observed. On other substrates both conidiation and ethylene production occurred after reaeration, but phase EP 1 was lacking. Penicillium velutinum grown on 2-oxoglutarate and glutamate with delayed aeration developed immature conidia within 36 h and traces of ethylene were produced. In the cultures with methionine and glucose, conidiation and ethylene production occurred after reaeration, but phase EP 1 was missing. In both strains, no ethylene was formed under anaerobic conditions. Intensively producing cultures were characterized by a narrow range of respiration yields (6.8–7.5 g dry weight per mole of consumed O2). A prerequisite for high ethylene production was a drop in the phosphate content of the medium to less than 0.45 mM.Key words: Penicillium cyclopium, Penicillium velutinum, ethylene, conidiation.

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.

Evolution of ethylene by Saccharomyces cerevisiae as influenced by the carbon source for growth and the presence of air

1978 ◽  
Vol 24 (6) ◽  
pp. 637-642 ◽  
Author(s):  
K. C. Thomas ◽  
Mary Spencer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Ethylene Production ◽  
Atp Synthesis ◽  
Yeast Cells ◽  
Yeast Culture ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Absolute Requirement ◽  
Wild Type Yeast

Effects of the carbon source and oxygen on ethylene production by the yeast Saccharomyces cerevisiae have been studied. The amounts of ethylene evolved by the yeast culture were less than those detected in the blank (an equal volume of uninoculated medium), suggesting a net absorption of ethylene by the yeast cells. Addition of glucose to the lactate-grown yeast culture induced ethylene production. This glucose-induced stimulation of ethylene production was inhibited to a great extent by cycloheximide. Results suggested that the yeast cells in the presence of glucose synthesized an ethylene precursor and passed it into the medium. The conversion of this precursor to ethylene might be stimulated by oxygen. The fact that ethylene was produced by the yeast growing anaerobically and also by respiration-deficient mutants isolated from the wild-type yeast suggested that mitochondrial ATP synthesis was not an absolute requirement for ethylene biogenesis.

scholarly journals Chitosan Elicitation for Enhancing of Vincristine and Vinblastine Accumulation in Cell Culture of Catharanthus roseus (L.) G. Don

2018 ◽  
Vol 10 (12) ◽  
pp. 287
Author(s):  
Pawnpirun Pliankong ◽  
Padungsak Suksa-Ard ◽  
Surawit Wannakrairoj
Keyword(s):  
Molecular Weight ◽  
Cell Culture ◽  
Stationary Phase ◽  
Liquid Medium ◽  
Cell Cultures ◽  
Catharanthus Roseus ◽  
Dry Weight ◽  
Shrimp Shell ◽  
Anti Cancer ◽  
Herbal Plant

Catharanthus roseus (L.) G. Don is an important herbal plant. There are two important alkaloids, vinblastine and vincristine, use in anti-cancer drugs. In this study production of the two alkaloids was enhanced in C. roseus cell cultures, in a Murashige and Skoog (MS) liquid medium supplemented with 1.5 mg/L 2,4-D, 0.5 mg/L kinetin and 30 g/L sucrose, by adding 0, 50, 100, 250 or 500 mg/L medium molecular weight chitosan or chitosan derived from shrimp shell. After 14 days of culture, the cell suspension at stationary phase in the 100 mg/L medium molecular weight chitosan could produce the highest amounts of vinblastine and vincristine at 4.15 and 5.48 µg/mg cell dry weight, respectively. At the same time, the controls (0 mg/L chitosan) produced the two alkaloids at only 2.43 and 2.49 µg/mg cell dry weight, respectively. For chitosan from shrimp shell, it was found that 100 mg/L chitosan could lead to the highest quantity of 4.09 µg vinblastine/mg cell dry weight. The highest amount of 5.47 µg vincristine/mg cell dry weight was obtained when 250 mg/L chitosan was added.

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

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.

Production of polyhydroxyalkanoates by glycogen accumulating organisms treating a paper mill wastewater

2008 ◽  
Vol 58 (2) ◽  
pp. 323-330 ◽  
Author(s):  
Simon Bengtsson ◽  
Alan Werker ◽  
Thomas Welander
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Dry Weight ◽  
Paper Mill ◽  
Batch Experiments ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Pha Production ◽  
Paper Mill Wastewater ◽  
Enrichment Strategy

A process for production of polyhydroxyalkanoates (PHA) by activated sludge treating a paper mill wastewater was investigated. The applied strategy was to select for glycogen accumulating organisms (GAOs) by alternating anaerobic/aerobic conditions. Acidogenic fermentation was used as pretreatment to convert various organic compounds to volatile fatty acids which are preferable substrates for PHA production. Enrichment resulted in a culture dominated by GAOs related to Defluviicoccus vanus (56%) and Candidatus Competibacter phosphatis (22%). Optimization of PHA accumulation by the enriched GAO culture was performed through batch experiments. Accumulation of PHA under anaerobic conditions was limited by the intracellular glycogen stored. Under aerobic conditions significant glycogen production (to 25% of sludge dry weight) was observed alongside PHA accumulation (to 22% of sludge dry weight). By applying a subsequent anaerobic period after an initial aerobic, the produced glycogen could be utilized for further PHA accumulation and by this strategy PHA content was increased to 42% of sludge dry weight. The PHA yield over the entire process was 0.10 kg per kg of influent COD treated which is similar to what has been achieved with a process applying feast/famine enrichment strategy with the same wastewater.

Investigations of nitrogenase activity in rheotrophic peat

1976 ◽  
Vol 22 (10) ◽  
pp. 1561-1566 ◽  
Author(s):  
George John Waughman
Keyword(s):  
Ethylene Production ◽  
Acetylene Reduction ◽  
Nitrogenase Activity ◽  
Anaerobic Bacteria ◽  
Organic Soils ◽  
Nitrogen Fixing ◽  
Anaerobic Conditions ◽  
Time Courses ◽  
Aerobic And Anaerobic ◽  
Stimulation Of

Acetylene reduction by the peat microflora was unaffected by light, but was sensitive to temperature, with an optimum of about 30 °C. The nitrogenase was inactivated by exposure to temperatures above about 35 °C. Activity occurred in completely anaerobic conditions; the rate of ethylene production was of the order of 0.5 nmol C2H4 ml−1h−1. Experiments with time courses indicated that exposure to oxygen caused an initial inhibition of activity followed by a period in which ethylene production was stimulated to rates much higher than in the anaerobic tests; both the inhibition and stimulation appeared to be related to the level of oxygenation. It is suggested that these results could be explained by the existence of nitrogen-fixing associations of aerobic and anaerobic bacteria in the peat. The stimulation of activity caused by exposure to air indicates that care must be taken when interpreting results of the assay obtained from waterlogged organic soils.

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.

Ethylene is synthesized by vegetative mycelium in surface cultures of Penicillium cyclopium Westling

1989 ◽  
Vol 35 (3) ◽  
pp. 384-387 ◽  
Author(s):  
Jaroslav Pažout ◽  
Sylvie Pažoutová
Keyword(s):  
Aerial Mycelium ◽  
Phosphate Concentration ◽  
Ethylene Synthesis ◽  
Ammonium Ions ◽  
Surface Culture ◽  
Aeration System ◽  
Penicillium Cyclopium ◽  
Hyphal Density ◽  
Agar Layer ◽  
Two Phases

Surface cultures of Penicillium cyclopium, grown in a closed aeration system on a semisolid minimal medium with 2-keto-glutarate, glutamate or glucose as carbon source, produced ethylene in two phases. The first was associated with aerial hyphae formation; the second, with conidiation. The maximum rate of ethylene synthesis coincided with intensive oxygen consumption whereas the cessation and reutilization of ethylene occurred together with a low respiration rate. After the removal of the aerial mycelium, vegetative hyphae continued ethylene production up to 50% of the value reached in intact cultures. Neither detached aerial mycelium with penicilli nor pure conidia produced ethylene. The content of ethylene in the medium of a producing culture was four-fold higher than would correspond to its concentration in the atmosphere above the culture. In the upper agar layer (1.25 mm), a high pH (8.8) and 30 mM [Formula: see text]was found, presumably because of mycelium autolysis. The pH in the layer 3 mm below the surface was 2.4. In lower layers (up to 2 mm beneath the last vegetative hyphae), ammonium ions were completely depleted. The phosphate content was inversely proportional to the hyphal density. We suggest that the low phosphate concentration (0.06 mM) in the upper layers permitted ethylene formation.Key words: conidiation, vegetative hyphae, ethylene, ion gradients, surface culture.

Regulation of ethylene production and ripening by saskatoon (Amelanchier alnifolia Nutt.) fruit

1998 ◽  
Vol 76 (10) ◽  
pp. 1743-1754
Author(s):  
Suzy Y Rogiers ◽  
GN Mohan Kumar ◽  
N Richard Knowles
Keyword(s):  
Ethylene Production ◽  
Acc Oxidase ◽  
Fold Increase ◽  
Dry Weight ◽  
Oxidase Inhibitor ◽  
Aminooxyacetic Acid ◽  
Acid Oxidase ◽  
Amelanchier Alnifolia ◽  
Endogenous Ethylene ◽  
Maturity Class

Changes in respiration and ethylene production were characterized during maturation and ripening of saskatoon (Amelanchier alnifolia Nutt.) fruit. On a per fruit basis, respiration and ethylene production increased 78 and 400%, respectively, as fruit ripened on the plant and trends were consistent with those for climacteric fruits. When estimated on a fresh and dry weight basis, increased rates of ethylene production were still apparent during ripening; however, respiration rate declined. Trends in respiration rates and endogenous ethylene levels of harvested fruit of nine maturity classes, from immature green (class one) to fully ripe and purple (class nine), were consistent with those of fruit growing on the plant. Tissue prints showed that ACC (1-aminocyclopropane-1-carboxylic acid) oxidase was distributed throughout the pericarp of fruit at all nine maturity stages and that the enzyme was most concentrated in the immature stages on a per fruit basis. On a protein basis, ACC oxidase increased progressively with development of cv. Smoky fruit but remained relatively constant over the nine maturity classes of cv. Northline fruit. In contrast, ACC oxidase levels were relatively low in cv. Pembina fruit over the first four maturity classes, increased substantially as fruits developed from class four to five, then remained constant as fruit ripened to maturity class nine. Treating immature harvested Pembina fruit (maturity classes one to three) with ACC effected a 28- to 108-fold increase in ethylene production, compared with an average of only 7-fold for ACC-treated fruit of maturity classes four through nine. Preharvest treatment of class-three fruit with ACC induced ripening to maturity class eight within 5 days, while untreated fruit required 15 days to reach class eight. Vacuum infiltrating class four fruit with alpha-aminooxyacetic acid (AOA) or aminoethoxyvinyl glycine (AVG) inhibited ethylene production and color development substantially. The inhibiting effect of AOA on ripening was eliminated when fruit were infiltrated with equimolar concentrations of AOA and ACC. Cobalt, an ACC oxidase inhibitor, also inhibited ethylene production and ripening. Collectively, our results indicate that ethylene synthesis by preclimacteric fruit is limited by the availability of ACC, ethylene is responsible for initiating ripening, and thus, saskatoon fruit are climacteric.Key words: Amelanchier alnifolia, saskatoon, fruit ripening, ethylene.

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