Growth and Terpenoid Production of an Axenic Culture from the Liverwort Ricciocarpos natans

1990 ◽  
Vol 45 (1-2) ◽  
pp. 13-18 ◽  
Author(s):  
Gerald Wurzel ◽  
Hans Becker

Abstract Ricciocarpos natans grows best on Gamborg B5 medium supplemented with 2% sucrose. Six other mineral media were less effective on the growth. During a culture period, pH of the media changed depending on the ammonium and nitrate content of the respective media. In media of a molar ratio of ammonium to nitrate of 1:1 or 1:1.9, pH first dropped from 6.0 to about 3.5 and then rose again. In media where nitrate is the only nitrogen source or where there is a ratio of ammonium to nitrate of 1:12.5, pH rose during the first two weeks and after this dropped. Differences in the light intensity (2000 an d 6000 lx) and light regime (14 h light/ 10 h dark) had no effects on the growth. The cultures produced a variety of terpenoids. The same pattern of compounds was seen in field-collected material as well as in cultivated material. The content of the terpenoids decreased on nitrogen and phosphorous-deficient media.

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Rianne C. Prins ◽  
Sonja Billerbeck

Abstract Background Fungi are premier hosts for the high-yield secretion of proteins for biomedical and industrial applications. The stability and activity of these secreted proteins is often dependent on the culture pH. As yeast acidifies the commonly used synthetic complete drop-out (SD) media that contains ammonium sulfate, the pH of the media needs to be buffered in order to maintain a desired extracellular pH during biomass production. At the same time, many buffering agents affect growth at the concentrations needed to support a stable pH. Although the standard for biotechnological research and development is shaken batch cultures or microtiter plate cultures that cannot be easily automatically pH-adjusted during growth, there is no comparative study that evaluates the buffering capacity and growth effects of different media types across pH-values in order to develop a pH-stable batch culture system. Results We systematically test the buffering capacity and growth effects of a citrate-phosphate buffer (CPB) from acidic to neutral pH across different media types. These media types differ in their nitrogen source (ammonium sulfate, urea or both). We find that the widely used synthetic drop-out media that uses ammonium sulfate as nitrogen source can only be effectively buffered at buffer concentrations that also affect growth. At lower concentrations, yeast biomass production still acidifies the media. When replacing the ammonium sulfate with urea, the media alkalizes. We then develop a medium combining ammonium sulfate and urea which can be buffered at low CPB concentrations that do not affect growth. In addition, we show that a buffer based on Tris/HCl is not effective in maintaining any of our media types at neutral pH even at relatively high concentrations. Conclusion Here we show that the buffering of yeast batch cultures is not straight-forward and addition of a buffering agent to set a desired starting pH does not guarantee pH-maintenance during growth. In response, we present a buffered media system based on an ammonium sulfate/urea medium that enables relatively stable pH-maintenance across a wide pH-range without affecting growth. This buffering system is useful for protein-secretion-screenings, antifungal activity assays, as well as for other pH-dependent basic biology or biotechnology projects.


2020 ◽  
Vol 20 (8) ◽  
pp. 5019-5033 ◽  
Author(s):  
Yuning Xie ◽  
Gehui Wang ◽  
Xinpei Wang ◽  
Jianmin Chen ◽  
Yubao Chen ◽  
...  

Abstract. The Chinese government has exerted strict emission controls to mitigate air pollution since 2013, which has resulted in significant decreases in the concentrations of air pollutants such as SO2. Strict pollution control actions also reduced the average PM2.5 concentration to the low level of 39.7 µg m−3 in urban Beijing during the winter of 2017. To investigate the impact of such changes on the physiochemical properties of atmospheric aerosols in China, we conducted a comprehensive observation focusing on PM2.5 in Beijing during the winter of 2017. Compared with the historical record (2014–2017), SO2 decreased to the low level of 3.2 ppbv in the winter of 2017, but the NO2 level was still high (21.4 ppbv in the winter of 2017). Accordingly, the contribution of nitrate (23.0 µg m−3) to PM2.5 far exceeded that of sulfate (13.1 µg m−3) during the pollution episodes, resulting in a significant increase in the nitrate-to-sulfate molar ratio. The thermodynamic model (ISORROPIA II) calculation results showed that during the PM2.5 pollution episodes particle pH increased from 4.4 (moderate acidic) to 5.4 (more neutralized) when the molar ratio of nitrate to sulfate increased from 1 to 5, indicating that aerosols were more neutralized as the nitrate content elevated. Controlled variable tests showed that the pH elevation should be attributed to nitrate fraction increase other than crustal ion and ammonia concentration increases. Based on the results of sensitivity tests, future prediction for the particle acidity change was discussed. We found that nitrate-rich particles in Beijing at low and moderate humid conditions (RH: 20 %–50 %) can absorb twice the amount of water that sulfate-rich particles can, and the nitrate and ammonia with higher levels have synergetic effects, rapidly elevating particle pH to merely neutral (above 5.6). As moderate haze events might occur more frequently under abundant ammonia and nitrate-dominated PM2.5 conditions, the major chemical processes during haze events and the control target should be re-evaluated to obtain the most effective control strategy.


Author(s):  
A. F. H. Marker

The production of extracellular carbohydrate has been studied in Isochrysis galbana and Prymnesium parvum in axenic culture. Increased extracellular production of carbohydrate occurred at reduced and increased salinity, low light intensity and under conditions of nitrogen starvation in Isochrysis, and in some cases appeared to be associated with the sedimentation of the cells from stagnant culture. Extracellular carbohydrate production was found to be greatest during the early and later stages in growth and dropped to a minimum during the mid-growth phase. Experiments indicated that the cells were not being damaged during harvesting of the cultures. A close similarity was found between the monosaccharide components of the intra- and extracellular carbohydrate after acid hydrolysis; both contained glucose, galactose, arabinose, xylose and ribose. It is suggested that the production of most of the extracellular carbohydrate is due to the passive release of organic matter from dead or dying cells.


Mycorrhiza ◽  
2001 ◽  
Vol 11 (1) ◽  
pp. 53-56 ◽  
Author(s):  
Ian C. Anderson ◽  
Susan M. Chambers ◽  
J. W. G. Cairney

Foods ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 677 ◽  
Author(s):  
Onofrio Davide Palmitessa ◽  
Massimiliano Renna ◽  
Pasquale Crupi ◽  
Angelo Lovece ◽  
Filomena Corbo ◽  
...  

Microgreens are gaining more and more interest, but little information is available on the effects of the chemical composition of the nutrient solution on the microgreen yield. In this study, three Brassica genotypes (B. oleracea var. italica, B. oleracea var. botrytis, and Brassica rapa L. subsp. sylvestris L. Janch. var. esculenta Hort) were fertigated with three modified strength Hoagland nutrient solutions (1/2, 1/4, and 1/8 strength) or with three modified half-strength Hoagland nutrient solutions with three different NH4:NO3 molar ratios (5:95, 15:85, and 25:75). Microgreen yields and content of inorganic ions, dietary fiber, proteins, α-tocopherol, and β-carotene were evaluated. Micro cauliflower showed the highest yield, as well as a higher content of mineral elements and α-tocopherol (10.4 mg 100 g−1 fresh weight (FW)) than other genotypes. The use of nutrient solution at half strength gave both a high yield (0.23 g cm−2) and a desirable seedling height. By changing the NH4:NO3 molar ratio in the nutrient solution, no differences were found on yield and growing parameters, although the highest β-carotene content (6.3 mg 100 g−1 FW) was found by using a NH4:NO3 molar ratio of 25:75. The lowest nitrate content (on average 6.8 g 100 g−1 dry weight) was found in micro broccoli and micro broccoli raab by using a nutrient solution with NH4:NO3 molar ratios of 25:75 and 5:95, respectively. Micro cauliflower fertigated with a NH4:NO3 molar ratio of 25:75 showed the highest dry matter (9.8 g 100 g−1 FW) and protein content (4.2 g 100 g−1 FW).


2011 ◽  
Vol 318 ◽  
pp. 1-10
Author(s):  
Dipti Vaya ◽  
Abhilasha Jain ◽  
Savitri Lodha ◽  
V. K. Sharma ◽  
Suresh C. Ameta

In the present investigation the photocatalytic activity of zinc sulphide has been enhanced using KCl in different molar ratios. The progress of the reaction was monitored spectrophotometrically. The effect of various parameters like pH, concentration of dye, amount of semiconductor, light intensity etc. upon the rate of photocatalytic bleaching of eosin Y has been observed. The molar ratio of KCl: ZnS = 0.25 was found to be a most efficient mixture for bleaching of eosin Y. A tentative mechanism for the photocatalytic bleaching of the dye has also been proposed.


2011 ◽  
Vol 189-193 ◽  
pp. 2448-2455
Author(s):  
Bao Zhong Du ◽  
Wei Luo ◽  
Ru Min Wang

Layered double hydroxides (LDHs), consist of cationic brucite-like layers and exchangeable interlayer anions. In this thesis LDHs consist of brucite-like layers of zinc hydroxide, with the exchanging propertity of interlayer anions in hydrotalcites, used Mg/Zn/Al-LDH as precursor to prepare the theophylline intercalation assembly hydrotalcites to obtain supramolecular complex for the first time by co-precipitation under a nitrogen atmosphere, determined the reaction conditions and influential factors of the synthesis of theophylline-pillared hydrotalcites, and tested its sustained-release performance in different media. The product has been characterized by powder X-ray diffraction (XRD), FT-IR spectroscopy, uv-vis spectrophotometer and thermogravimetry-Differential thermal analysis (TG-DTA) . Results demonstrated that : Through co-precipitation intercalation methods, with molar ratio of Mg/Zn/Al/ theophylline being 3:1:1:2, co-precipitation medium pH9, crystallization temperature 80 °C and crystallization time 12h can obtain the clear chemical composition and good crystallization of inorganic - organic hybrid-type drugs hydrotalcites. In addition, according to Pharmacopoeia measured the release rate of theophylline-LDH in the different media including distilled water,0.9%saline,simulated intestinal fluid (pH7.4 phosphate buffer) by UV spectrophotometry, Theophylline pillared hydrotalcite has a certain release in the media above all. And calculated the release of intercalation theophylline, lay the foundation for the further clinical application.


1974 ◽  
Vol 52 (3) ◽  
pp. 451-460 ◽  
Author(s):  
Gaëtan Harvais

Field studies were made of eight terrestrial orchid species of the Thunder Bay region during their active growing period. In four of them roots were examined for infection, then isolation and identification of endophytes attempted.Seeds were collected from all species and, along with those of two alien ones, were grown on various media in axenic culture. Their germination and development were studied and described.Seeds were also tested in dixenic cultures with locally isolated endophytes and four fungi known to be good symbionts with other orchids. The nature of infection was finally assessed and discussed.In the field the roots of mature plants of the orchid species differed in their degree of infection and reaction to their endophytes. Only two species of Rhizoctonia were isolated. These are described.In axenic culture, germination of some species was affected by the organic (and inorganic) components of the media, in others it was not. For growth they all responded differently to such components, but most were intolerant of casamino acids, yeast extract, and potato extract. Generally there seemed to be a direct correlation between percentage of germination and amounts of subsequent growth, but a less defined one with the number of cells per seed.In dixenic cultures the orchids responded differently also to the fungi. Their reaction to infection had no relation to their ability to germinate on poor media or to germinate and grow on richer ones. Only one good symbiotic association was established. It was between Goodyera oblongifolia from British Columbia and Rs10, a rice pathogen from Malaysia.The results and their implications are briefly discussed.


1983 ◽  
Vol 40 (11) ◽  
pp. 1853-1860 ◽  
Author(s):  
B. G. Brownlee ◽  
T. P. Murphy

Nitrogen fixation by Aphanizomenon flos-aquae in a prairie lake in southwestern Manitoba was dependent on the light intensity and in situ oxygen concentrations. The mean molar ratio of acetylene reduction to nitrogen reduction was 5.8:1. High external ammonium concentrations did not appear to inhibit nitrogen fixation over the short term. Nitrogen fixation was not directly initiated by the bloom collapse. We propose that the coupled sequence of ammonia volatilization and nitrogen fixation was triggered by the bloom collapse and that the bloom collapse was caused by coprecipitation of orthophosphate with carbonates. 32PO4 turnover was most rapid during periods when the lake was opalescent, presumably due to carbonate precipitaton.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1085E-1086
Author(s):  
Donald J. Merhaut ◽  
Julie P. Newman

Lilies are produced throughout the year in coastal areas of California. Cultural practices involve daily applications of water and fertilizer, using both controlled release fertilizers (CRF) and liquid fertilizers (LF). However, many production facilities are in proximity to coastal wetlands and are therefore at greater risk of causing nitrogen pollution via runoff and leaching. Due to federal and state regulations, nurseries must present a plan of best management practices (BMPs) to mitigate nutrient runoff and leaching and begin implementing these practices in the next 2 years. In the following studies, we determined the potential for nitrate leaching from four different types of substrates (coir, coir: peat, peat, and native soil). There were four replications of each treatment, with a replication consisting of one crate planted with 25 bulbs. Two cultivars were used in two separate experiments, `Star Fighter' and `Casa Blanca'. Nitrate leaching was determined by placing an ion-exchange resin bag under each crate at the beginning of the study. After plant harvest (14–16 weeks), resin bags were collected and analyzed for nitrate content. Plant tissues were dried and ground and analyzed for nitrogen content. Based on the results of these studies, it appears that the use of coir, peat, and soil may not influence plant growth significantly. Substrate type may mitigate the amount of nitrate leaching through the media. However, the cultivar type may also influence the degree of nitrate mitigation, since leaching results varied between the two cultivars.


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