scholarly journals The beauty and the yeast: can the microalgae Dunaliella form a borderline lichen with Hortaea werneckii?

Symbiosis ◽  
2020 ◽  
Vol 82 (1-2) ◽  
pp. 123-131 ◽  
Author(s):  
Lucia Muggia ◽  
Polona Zalar ◽  
Armando Azua-Bustos ◽  
Carlos González-Silva ◽  
Martin Grube ◽  
...  
Keyword(s):  
Growth Media ◽  
Bright Field ◽  
Hortaea Werneckii ◽  
Symbiotic Interactions ◽  
Halotolerant Fungus ◽  
Living Together ◽  
Axenic Strains ◽  
Lichen Symbioses ◽  
Set Up ◽  
Borderline Lichens

AbstractLichenized fungi usually develop complex, stratified morphologies through an intricately balanced living together with their algal partners, but several species are known to form only more or less loose associations with algae. These borderline lichens are still little explored although they could inform us about early stages of lichen evolution. We studied the association of the extremely halotolerant fungus Hortaea werneckii with the alga Dunaliella atacamensis, discovered in a cave in the Atacama Desert (Chile), and with D. salina, common inhabitant of saltern brines. D. atacamensis forms small colonies, in which cells of H. werneckii can be frequently observed, while such interaction has not been observed with D. salina. As symbiotic interactions between Dunaliella and Hortaea have not been reported, we performed a series of co-cultivation experiments to inspect whether these species could interact and develop more distinct lichen-like symbiotic structures. We set up co-cultures between axenic strains of Hortaea werneckii (isolated both from Mediterranean salterns and from the Atacama cave) and isolates of D. atacamensis (from the Atacama cave) and D. salina (isolated from Mediterranean salterns). Although we used different growth media and cultivation approaches, bright field and SEM microscopy analyses did not indicate any mutual effects in these experiments. We discuss the implications for fungal algal interactions along the transition from algal exploiters to lichen symbioses.

scholarly journals Global Molecular Diversity of the Halotolerant Fungus Hortaea werneckii

Life ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 31 ◽  
Author(s):  
Alessia Marchetta ◽  
Bert Gerrits van den Ende ◽  
Abdullah Al-Hatmi ◽  
Ferry Hagen ◽  
Polona Zalar ◽  
...  
Keyword(s):  
Molecular Diversity ◽  
Sea Water ◽  
Elongation Factor ◽  
Clonal Expansion ◽  
Translation Elongation Factor ◽  
Translation Elongation ◽  
Hortaea Werneckii ◽  
Halotolerant Fungus ◽  
Elongation Factor 1 ◽  
Partial Translation

A global set of clinical and environmental strains of the halotolerant black yeast-like fungus Hortaea werneckii are analyzed by multilocus sequencing and AFLP, and physiological parameters are determined. Partial translation elongation factor 1-α proves to be suitable for typing because of the presence/absence of introns and also the presence of several SNPs. Local clonal expansion could be established by a combination of molecular methods, while the population from the Mediterranean Sea water also responds differently to combined temperature and salt stress. The species comprises molecular populations, which in part also differ physiologically allowing further diversification, but clinical strains did not deviate significantly from their environmental counterparts.

scholarly journals Penggunaan Pupuk Organik Cair Sebagai Media Produksi Inokulan Azotobacter Chroococcum

Agrologia ◽  
2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Reginawanti Hindersah ◽  
H Yulina ◽  
Ane Nurbaity
Keyword(s):  
Organic Fertilizer ◽  
Scaling Up ◽  
Azotobacter Chroococcum ◽  
Growth Media ◽  
Total N ◽  
Support Cell ◽  
Commercial Scale ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Set Up

Azotobacter chroococcum based biofertilizers have been widely used in the production of environmentally agriculture. For commercial scale, cheap growth media for Azotobcter inoculant  will affect the quality and price of liquid biofertilizer. Growth medium should support cell proliferation as well as its  nitrogen fixation and phytohormone production.  The objective of this study was to determine whether  liquid organic fertilizer (LOF) containing low N can be used as a medium for scaling up  A. chroococcum inoculant without lowering the survival of bacteria and its activity in N2 fixation and phytohormones production. LOF generally contains a complete nutrient although in a small quantities. Experiment was set up in completely randomized design which tested two types of commercial LOF. The results showed that both of  LOF were only able to support cell growth up to 72 hours and at 96 hours cell viability began to decline compared to the control medium,  free-N Ashby. At 72 hour total N and cytokinin  concentration in LOF was lower than those in Ashby media. This study revealed  that LOF  could be used as A. chroococcum growth media, but without optimization of its composition, cell density and cytokinin content would be lower than those of inoculant  in Ashby Media.

scholarly journals Frontières Et Dynamiques Socio-Spatiales En Afrique : Une Analyse À Partir Des Frontières Sud- Camerounaises

2018 ◽  
Vol 14 (5) ◽  
pp. 285
Author(s):  
Abdoulay Mfewou ◽  
Hervé Tchekote ◽  
Josephine Lemouogue
Keyword(s):  
Free Movement ◽  
Equatorial Guinea ◽  
Economic Prosperity ◽  
Economic Dynamics ◽  
Cross Border ◽  
Border Communities ◽  
Living Together ◽  
Set Up ◽  
Elected Representatives ◽  
National Systems

This article focuses on the openness and socio-economic dynamics associated with the meeting of different communities from many inland territories of Africa: on the borders of South Cameroon, northern Equatorial Guinea and North of Gabon, attracted by the oil windfall. The study illustrates the effectiveness of "living together" in this vast sub-region. It shows how development is based on the organization of trade that is not simply based on the differences between national systems, but on the establishment of South- South relations. While the challenges based on planning on these cross-border spaces is indispensable, local elected representatives are trying to set-up networking arrangements for cross-border communities. Border management makes it possible to ensure security, counter-threats to people and economic prosperity. The construction of a motorable high-way and the implementation of treaties on the opening of borders signed between the States since the 16th of March 1994 deemed at facilitating the free movement of economic actors, while many still consider the arrival of foreigners in these Eldorado as an invasion.

scholarly journals Characterization of a Halotolerant Fungus from a Marine Sponge

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Yitayal S. Anteneh ◽  
Melissa H. Brown ◽  
Christopher M. M. Franco
Keyword(s):  
Sequence Similarity ◽  
Marine Sponges ◽  
Rrna Gene ◽  
28S Rrna ◽  
Symbiotic Interaction ◽  
28S Rrna Gene ◽  
Symbiotic Interactions ◽  
Isolation And Characterization ◽  
Halotolerant Fungus

Introduction. Marine sponges have established symbiotic interactions with a large number of microorganisms including fungi. Most of the studies so far have focussed on the characterization of sponge-associated bacteria and archaea with only a few reports on sponge-associated fungi. During the isolation and characterization of bacteria from marine sponges of South Australia, we observed multiple types of fungi. One isolate in particular was selected for further investigation due to its unusually large size and being chromogenic. Here, we report on the investigations on the physical, morphological, chemical, and genotypic properties of this yeast-like fungus. Methods and Materials. Sponge samples were collected from South Australian marine environments, and microbes were isolated using different isolation media under various incubation conditions. Microbial isolates were identified on the basis of morphology, staining characteristics, and their 16S rRNA or ITS/28S rRNA gene sequences. Results. Twelve types of yeast and fungal isolates were detected together with other bacteria and one of these fungi measured up to 35 μm in diameter with a unique chromogen compared to other fungi. Depending on the medium type, this unique fungal isolate appeared as yeast-like fungi with different morphological forms. The isolate can ferment and assimilate nearly all of the tested carbohydrates. Furthermore, it tolerated a high concentration of salt (up to 25%) and a range of pH and temperature. ITS and 28S rRNA gene sequencing revealed a sequence similarity of 93% and 98%, respectively, with the closest genera of Eupenidiella, Hortaea, and Stenella. Conclusions. On the basis of its peculiar morphology, size, and genetic data, this yeast-like fungus possibly constitutes a new genus and the name Magnuscella marinae, gen nov., sp. nov., is proposed. This study is the first of its kind for the complete characterization of a yeast-like fungus from marine sponges. This novel isolate developed a symbiotic interaction with living hosts, which was not observed with other reported closest genera (they exist in a saprophytic relationship). The observed unique size and morphology may favour this new isolate to establish symbiotic interactions with living hosts.

Dislocation contrast in high-angle hollow-cone dark-field TEM

1993 ◽  
Vol 51 ◽  
pp. 694-695
Author(s):  
Z. L. WANG
Keyword(s):  
Strong Dependence ◽  
Dark Field ◽  
Diffraction Reflection ◽  
High Angle ◽  
Hollow Cone ◽  
Bright Field ◽  
Transmission Electron ◽  
Set Up ◽  
The One ◽  
Dramatic Variation

Dislocations were imaged using the high-angle hollow-cone dark-field transmission electron microscopy (HADF-TEM) technique. Experiments were performed using a Philips CM30 TEM at 300 kV Dislocations and grain boundaries show bright contrast in HADF-TEM images and there are no contrast reversals with thickness or defocus. The dislocation contrast shows no dramatic variation when the average semi-conical angle θ was increased from 40 to 110 mrad, but does show strong dependence on the diffracting conditions that are set up for the corresponding on-axis bright-field (BF) TEM image (Fig. 1). Under the "one-beam" (random orientation without strong diffraction) reflection condition (Figs, 1a and 1a'), the visibility of the dislocations is poor in either the BF-TEM or the HADF-TEM image. Under the two-beam diffracting condition (Figs, 1b and 1b') both BF-TEM and HADF-TEM images show optimized contrast. The features appearing in the HADF-TEM images have a good one-to-one correspondence with the features shown in the corresponding BF-TEM images; the dislocation contrast disappears in the HADF-TEM images if the condition g·b = 0 is satisfied in the BF-TEM images, where b is the Burgers vector (Fig 2).

scholarly journals TINJAUAN KUALITAS PUPUK ORGANIK DAN PENGAWASANNYA BAGI KEAMANAN DAN KETAHANAN PANGAN DI INDONESIA

Jurnal Solum ◽  
2010 ◽  
Vol 7 (2) ◽  
pp. 67
Author(s):  
Agustian Agustian
Keyword(s):  
Organic Fertilizer ◽  
Quality Criteria ◽  
Organic Content ◽  
Organic Fertilizers ◽  
Growth Media ◽  
Valuable Product ◽  
Set Up ◽  
The Moment

The use of organic fertilizers in agricultural production can not only increase soil fertility but also at the same time improve soil quality. Organic fertilizer is a unique product because it can improve physical properties, chemical, and biological soil as plant growth media. These characteristics bring the organic fertilizers into a valuable product that can be used in a variety of use. Today in Indonesia, there are so many outstanding varieties of organic fertilizer products either refined or imported products. Monitoring of the quality and feasibility of organic fertilizer materials is needed, so they will not harm the farmers as consumers. Each country develops criteria standard of organic fertilizer valuing each country's interest. United States, Canada, Australia and Europe use different compost quality criteria tailored to the needs and environmental rules that apply. So far in Indonesia rules used in determining quality is Permentan No. 02/Pert/HK.060/2/2006 which was then updated with Permentan No.28/PERMENTAN/OT.140/2/2009 on Organic Fertilizers and Soil Ameliorant. Basically, the appraisal made on the maturity and quality of organic fertilizers is based on observation of physical, chemical, and biological parameters. Review of the criteria used in the Regulation of the Minister of Agriculture was necessary in considering the criteria used which are very harmful to consumers, such as if it is satated that C-organic content is approximately 12%, which is low, it means that there might exist some follow-up materials such as glass, plastic in the fertilizer about 2%. If the rules are maintained, it will be very detrimental to Indonesia because of invasion from over seas. Import organic fertilizers would be siege to Indonesian farmers. Permentan No.28/PERMENTAN/SR.130/5/2009 has also set up institutions in charge of monitoring the quality of organic fertilizers. However, the quality control must be carried out. It is not only at the level of the end product, but it must also begin from the moment of the production process by establishing a supervisory agency competent. Since organic fertilizers can be produced by large industries, small and medium-scale farmers, the level of supervision is needed with different approaches. Keywords: organic fertilizer, quality, processes and controls

Al Compositional Profile In Algaas/Gaas Quantum Wells

1999 ◽  
Vol 5 (S2) ◽  
pp. 168-169
Author(s):  
D. Q. Cai ◽  
J. Zou ◽  
D. J. H. Cockayne.
Keyword(s):  
Fine Structure ◽  
Sample Preparation ◽  
Quantum Well ◽  
Quantum Wells ◽  
Ccd Camera ◽  
Bright Field ◽  
Compositional Profile ◽  
Set Up ◽  
Cleavage Method

The TEM thickness fringe method [1] was developed as a potential routine technique to determine compositional profiles in quantum well systems. This technique has the advantages that a) TEM sample preparation is simple and the experiment is easy to set up and b) thickness fringe profiles show fine structure which is sensitive to chemistry [2]. In this paper, we demonstrate the ability of the method to measure the chemical abruptness at the interface between two layers of different composition.90° wedge AlGaAs/GaAs TEM samples were prepared by the cleavage method, where the samples were cleaved along two orthogonal {110} planes. The samples were mounted on Cu grids and were investigated in a Philips EM430 TEM. Samples were orientated to the [100] direction precisely and bright-field images were acquired digitally using a CCD camera. Fig 1 shows an enlarged image of thickness fringes.Since the edges of samples are 90° wedges, the thickness at any point can be accurately determined and the fringe profile can be compared with fringe profiles calculated for a range of Al compositions.

scholarly journals (71) Comparison of Phytophthora Disease Incidence in Composted Pine Bark Mixes to Chemical and Biological Controls

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1019B-1019
Author(s):  
Jennifer Green ◽  
Derald A. Harp ◽  
Kevin L. Ong
Keyword(s):  
Statistical Analysis ◽  
Disease Incidence ◽  
Pine Bark ◽  
Growth Media ◽  
Chi Square ◽  
Complete Control ◽  
Set Up ◽  
The Impact ◽  
Control Equivalent ◽  
Chemical Fungicides

Phytophthora diseases are economically important, requiring the use of chemical fungicides and, more recently, biological controls. Recent research suggests that composted bark products may lessen the impact of the disease, even in the absence of these chemicals. An experiment was conducted to compare chemical and biological fungicides to untreated pine bark compost. Impatiens wallerana plugs were transplanted from 288 trays into 1801 trays. All plants were planted into Berger BM-7, 35% composted bark mix (Berger Horticulture, Quebec, Canada). Media was prepared by premixing one of the five following fungicide treatments: 1) Control, 2) Banrot at 0.6 g/L, 3) Root Shield at 1.6 g/L, 4) Actino-Fe at 5.1 g/Ll, or 5) SoilGard at 1.6 g/L. Plants received no fertilizer. Three strains of Phytophthora were grown in 25 °C on clarified V8 media. Pathogenic inoculum was made by macerating the growth media and fungi in 100 ml H2O. Mixture was pulse-blended for 1 min, and an additional 200 mL dH2O was added. Inoculation was 5 ml per plant. Flats were kept on a misting bench, and misted twice daily for 15 min. The experiment was set up using a RBD repeated six times with three plants per rep. Plants were rated weekly for 5 weeks using a damage scale of 0 to 5, with 0 indicating no sign of disease and 5 being dead. Statistical analysis was conducted using a Chi-Square. Disease incidence between the biological, chemical, and composted bark treatments did not differ, with all treatments providing complete control. At least in this study, the use of composted pine bark media provided Phytophthora control equivalent to current chemical and biological fungicides.

scholarly journals The Halophilic Fungus Hortaea werneckii and the Halotolerant Fungus Aureobasidium pullulans Maintain Low Intracellular Cation Concentrations in Hypersaline Environments

2005 ◽  
Vol 71 (11) ◽  
pp. 6600-6605 ◽  
Author(s):  
Tina Kogej ◽  
José Ramos ◽  
Ana Plemenitaš ◽  
Nina Gunde-Cimerman
Keyword(s):  
Aureobasidium Pullulans ◽  
Hypersaline Environments ◽  
Ionic Homeostasis ◽  
Hyperosmotic Shock ◽  
Hortaea Werneckii ◽  
Halotolerant Fungus ◽  
Better Regulation ◽  
Wide Range ◽  
Homeostasis Regulation ◽  
Efficient Mechanisms

ABSTRACT Hortaea werneckii and Aureobasidium pullulans, black yeast-like fungi isolated from hypersaline waters of salterns as their natural ecological niche, have been previously defined as halophilic and halotolerant microorganisms, respectively. In the present study we assessed their growth and determined the intracellular cation concentrations of salt-adapted and non-salt-adapted cells of both species at a wide range of salinities (0 to 25% NaCl and 0 to 20% NaCl, respectively). Although 5% NaCl improved the growth of H. werneckii, even the minimal addition of NaCl to the growth medium slowed down the growth rate of A. pullulans, confirming their halophilic and halotolerant nature. Salt-adapted cells of H. werneckii and A. pullulans kept very low amounts of internal Na+ even when grown at high NaCl concentrations and can be thus considered Na+ excluders, suggesting the existence of efficient mechanisms for the regulation of ion fluxes. Based on our results, we can conclude that these organisms do not use K+ or Na+ for osmoregulation. Comparison of cation fluctuations after a hyperosmotic shock, to which nonadapted cells of both species were exposed, demonstrated better ionic homeostasis regulation of H. werneckii compared to A. pullulans. We observed small fluctuations of cation concentrations after a hyperosmotic shock in nonadapted A. pullulans similar to those in salt-adapted H.werneckii, which additionally confirmed better regulation of ionic homeostasis in the latter. These features can be expected from organisms adapted to survival within a wide range of salinities and to occasional exposure to extremely high NaCl concentrations, both characteristic for their natural environment.

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