scholarly journals Sorption of Zinc by exopolysaccharides produced by liquid media of phytopatogenic fungi

2021 ◽  
Vol 26 (1) ◽  
pp. 2312-2317
Author(s):  
JUAN DIEGO VALENZUELA-COBOS ◽  
ANA GRIJALVA-ENDARA

Phytopathogenic fungi such as: Colletotrichum gloeosporioides and Rhizopus stolonifer were cultivated in three different liquid culture media: LCC (glucose 40 g L-1 , yeast extract 3 g L-1 ), LC2 (glucose 40 g L-1 , yeast extract 3 g L-1 and tryptone peptone 2 g L-1 ) and LC3 (glucose 40 g L-1 , yeast extract 3 g L-1 and tryptone peptone 10 g L-1 ) under pH of 5.5 for the production of mycelial biomass and exopolysaccharides (EPS). The liquid culture medium (LC3) used in cultivation of Colletotrichum gloeosporioides showed the highest production of biomass (15.40 g L-1 ) and exopolysaccharides (3.40 g L-1 ). Exopolysaccharides (EPS) obtained from the liquid culture medium (LC3) of Colletotrichum gloeosporioides presented the highest absorption content of Zinc (56 mg g-1 ). The results presented that the exopolysaccharides (EPS) produced by Colletotrichum gloeosporioides showed the greatest biosorbent capacity of Zinc (Zn) using the culture medium with the highest amount of tryptone peptone.

Author(s):  
Juan Diego Valenzuela Cobos ◽  
René Oscar Rodríguez-Grimón ◽  
Ana Grijalva-Endara ◽  
Raúl Marcillo-Vallejo ◽  
Onay Adonys Mercader-Camejo

Colletotrichum gloeosporioides (GC003) and Rhizopus stolonifer (RS001) were cultivated in two different liquid culture media: LC1 (glucose 40 g L-1, yeast extract 3 g L-1 and tryptone peptone 2 g L-1) and LC2 (glucose 40 g L-1, yeast extract 3 g L-1 and tryptone peptone 10 g L-1) for the production of mycelial biomass and exopolysaccharides (EPS). By using the liquid culture (LC2) under pH of 4.5 presented the highest biomass content (15.73 g L-1) in the propagation of Rhizopus stolonifer. The highest production of exopolysaccharides (1.74 g L-1) was obtained by the liquid culture (LC2) under pH of 4.5 in the cultivation of Colletotrichum gloeosporioides. The results presented that the production of biomass and exopolysaccharides (EPS) is directly related with the pHs values and the strain used in the cultivation.


2015 ◽  
Vol 17 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Ariadne Vegas García ◽  
Yanet Sandrea ◽  
Ohitza Gonzalez ◽  
Andy Diaz ◽  
José Gerardo Albarran ◽  
...  

<strong>Título en ingles: Micropropagation of papaya plants in temporary immersion recipients from axilary shoots</strong><p><strong>Título corto: Micropropagación de lechosa en recipientes de inmersión temporal.</strong></p><strong>Resumen: </strong>Se estandarizaron las condiciones de iniciación, multiplicación, enraizamiento y aclimatización de plantas hermafroditas de lechosa cv Maradol provenientes de brotes axilares, producidos en recipientes de inmersión temporal RITA<sup>®</sup>. En cada envase, contentivo de 200 ml de medio de cultivo líquido de Fitch, se colocaron cuatro brotes de 2 a 3 cm de longitud. Los biorreactores se conectaron a tres líneas de inmersión de 5, 2 y 1 min cada 4h y se colocaron 6 envases en promedio por línea, en condiciones de fotoperíodo de 16 h. Transcurridos 30 a 45 días, se cuantificaron los brotes y se clasificaron de acuerdo al tamaño: &lt; 2 cm (pequeños), entre 2 a 3 cm (medianos),  ˃ 3 cm con y sin raíz (grandes). Los dos primeros tipos de brotes se continuaron multiplicando en los mismos medios; y los más elongados se aclimatizaron utilizando el Sistema Autotrófico Hidropónico (SAH). Se determinó la sanidad y la fidelidad de las plantas producidas mediante pruebas de ELISA y RAPD, respectivamente. Durante un periodo de 6 meses se reciclaron un total de 47 recipientes, los cuales produjeron 1.091 brotes: 377  pequeños; 482 medianos; 175 grandes sin raíz y 57 con raíz. Usando el SAH se obtuvo 89,5% de plantas aclimatizadas cuando se usaron brotes enraizados, y 41,6% a partir de brotes sin  raíces. Con la combinación de las técnicas RITA y SAH se logró un sistema continuo y eficiente de producción de plantas sanas y fieles al tipo, en comparación con los métodos convencionales de micropropagación y aclimatización.<p><strong>Palabras clave</strong>: <em>Carica papaya</em>, RITA<sup>®</sup>, sistema autotrófico, estabilidad genética.</p><p><strong>Abstract: </strong>We standardized initiation, multiplication, rooting and acclimatization conditions of papaya cv Maradol hermaphrodite plants from axillary buds produced in temporary immersion reactor RITA<sup>®</sup>. Recipients contained 200 ml of Fitch liquid culture medium, and four shoots of 2 to 3 cm. in length were placed in each. The bioreactors were connected to three different immersion lines of 5, 2, and 1 min each 4h,  with 6 containers per line on average, in 16 h photoperiod. After 30 to 45 days, the shoots produced were quantified and classified according to size: &lt;2 cm (small), from 2 to 3 cm (medium), &gt;3 cm with or without roots (large). The first two types of shoots were multiplied in the same culture media, and more elongated shoots were acclimatized using Autotrophic Hydroponic System (AHS). The sanity and fidelity of the produced plants were determined using ELISA and RAPD, respectively. For a period of six months 47 vessels were recycled and 1,091 shoots were produced: 377 small; 482 medium; 175 large without roots and 57 rooted shoots. Using AHS, 89.5% acclimatized plants were obtained when rooted shoots were used, and 41.6% from rootless shoots. With the combination of RITA and AHS techniques we achieved a continuous and efficient production of healthy and true to type papaya plants, in comparison to conventional micropropagation and acclimatization procedures.</p><p><strong>Key words</strong>: <em>Carica</em><em> papaya</em>, RITA<sup>®</sup>, autotrophic system, genetic stability.</p><p><strong>Recibido:</strong> mayo 16 de 2014<strong>   Aprobado: </strong>abril 21 de 2015</p>


2021 ◽  
Vol 91 (11) ◽  
pp. 1793
Author(s):  
П.А. Алешин ◽  
А.Н. Алешин ◽  
Е.Ю. Розова ◽  
Е.Н. Дресвянина ◽  
Н.Н. Сапрыкина ◽  
...  

Composite fibers based on chitosan, coated with a conducting polymer, polypyrrole (PPyr), have been obtained. Their morphology was studied by scanning electron microscopy. The electrical conductivity of the fibers in a dry state and in a liquid culture medium simulating tissue fluid has been estimated. The values of resistivity, ro, and conductivity, sigma , of the investigated fibers are determined depending on the number of PPyr layers, the degree of drawing (orientation) of the fibers in dry and in liquid media. It was found that with an increase in the amount of drawing from 0 to 100%, ro of fibers decreases both in a dry state and in a liquid culture medium. In this case, the maximum drop ro of fibers upon immersion in a liquid culture medium was observed for undrawn fibers with two layers of PPyr. It was shown that after an initial drop in ro of oriented chitosan fibers with 1 and 2 layers of PPyr ro changes weakly in a liquid culture medium for 2 hours. The investigated oriented polymer fibers of chitosan coated with 1 and 2 layers of PPyr are promising for use in the field of tissue engineering and regenerative medicine.


2011 ◽  
Vol 84 (1) ◽  
pp. 52-60 ◽  
Author(s):  
Nikki Kenters ◽  
Gemma Henderson ◽  
Jeyamalar Jeyanathan ◽  
Sandra Kittelmann ◽  
Peter H. Janssen

1938 ◽  
Vol 21 (5) ◽  
pp. 601-620 ◽  
Author(s):  
M. Kunitz

1. A powerful kinase which changes trypsinogen to trypsin was found to be present in the synthetic liquid culture medium of a mold of the genus Penicillium. 2. The concentration of kinase in the medium is increased gradually during the growth of the mold organism and continues to increase for some time even after the mold has ceased growing. 3. Mold kinase transforms trypsinogen to trypsin only in an acid medium. It differs thus from enterokinase and trypsin which activate trypsinogen best in a slightly alkaline medium. 4. The action of the mold kinase in the process of transformation of trypsinogen is that of a typical enzyme. The process follows the course of a catalytic unimolecular reaction, the rate of formation of a definite amount of trypsin being proportional to the concentration of kinase added. The ultimate amount of trypsin formed, however, is independent of the concentration of kinase used. 5. The formation of trypsin from trypsinogen by mold kinase is not accompanied by any measurable loss of protein. 6. The temperature coefficient of formation of trypsin from trypsinogen by mold kinase varies from Q5–15 = 1.70 to Q25–30 = 1.25 with a corresponding variation in the value of µ from 8100 to 4250. 7. Trypsin formed from trypsinogen by means of mold kinase is identical in crystalline form with the crystalline trypsin obtained by spontaneous autocatalytic activation of trypsinogen at pH 8.0. The two products have within the experimental error the same solubility and specific activity. A solution saturated with the crystals of either one of the trypsin preparations does not show any increase in protein concentration or activity when crystals of the other trypsin preparation are added. 8. The Penicillium mold kinase has a slight activating effect on chymo-trypsinogen the rate being only 1–2 per cent of that of trypsinogen. The activation, as in the case of trypsinogen, takes place only in an acid medium. 9. Mold kinase is rapidly destroyed when brought to pH 6.5 or higher, and also when heated to 70°C. In the temperature range of 50–60°C. the inactivation of kinase follows a unimolecular course with a temperature coefficient of Q10 = 12.1 and µ = 53,500. The molecular weight of mold kinase, as determined by diffusion, is 40,000.


1989 ◽  
Vol 52 (2) ◽  
pp. 105-108 ◽  
Author(s):  
SUSAN S. SUMNER ◽  
STEVE L. TAYLOR

A detection method for histamine-producing, dairy-related bacteria was developed that involves a two-step sequential enzyme system. First, isolated bacteria are incubated in MRS broth or trypticase soy broth fortified with histidine. The histamine formed during this incubation period is reacted with diamine oxidase, which catalyzes the oxidation of histamine to form imidazole acetaldehyde, ammonia, and hydrogen peroxide. The hydrogen peroxide is then detected by the formation of crystal violet from the leuco base in the presence of horseradish peroxidase. Liquid culture medium containing bacteria that produce greater than 1200 nmole histamine per ml will develop a positive purple color. Cultures containing bacteria that produce little or no histamine will not develop a purple color. Other amines often found in cheese, such as tyramine, cadaverine, or putrescine, will not interfere with the color formation.


1971 ◽  
Vol 34 (3) ◽  
pp. 119-123 ◽  
Author(s):  
C. N. Shih ◽  
E. H. Marth

A rapid and efficient method has been developed to recover aflatoxin from cheese and other foods. The procedure involves: (a) blending the sample with a mixture of chloroform, methanol, and water (solvents are used in such proportions that a miscible (monophasic) system is formed, (b) adding more chloroform and water so the mixture becomes biphasic, (c) filtering to remove the food residue, (d) separating the lower chloroform layer which contains virtually all of the aflatoxin, and (e) purification, if necessary, of the material in step (d) after it has been concentrated. Purification is achieved by sequential addition of methanol, water, and hexane; recovery of tho methanol-water fraction; and extraction of aflatoxins from it with chloroform. Purification can be eliminated if the substrate contains little or no lipid or pigment which, if present, interfere with thin-layer chromaographic analysis. Extraction can be done in approximately 35 min and purification in approximately 20 min. When aflatoxins were added to various substrates, the method recovered 92–98% B1 and 96–100% G1 from rice; 95–96% B1 and 90–95% G1 from peanut butter; 93–94% B1 and 92–98% G1 from Cheddar cheese; 100% B1 and G1 from corn meal; 91–100% B1, 91–100% B2, 90–96% G1, and 92–100% G2 from brick cheese; and 97–100% B1, 95–100% B2, 92–100% G1, and 98–100% G2 from a liquid culture medium.


2020 ◽  
Vol 39 (11) ◽  
pp. 1415-1424
Author(s):  
Yuhya Wakasa ◽  
Atsushi Kasai ◽  
Muneo Yamazaki ◽  
Yutaka Tabei ◽  
Mutsuo Tsuyama ◽  
...  

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