scholarly journals Benefits of understanding the enzymatic activities in saline Lake Letea in the Danube Delta

2021 ◽  
Vol 26 (2) ◽  
pp. 2448-2454
Author(s):  
ANCA IOANA LUCACI ◽  
◽  
SIMONA NEAGU ◽  
ROXANA COJOC ◽  
ROBERT RUGINESCU ◽  
...  

The purpose of this paper was to isolate halophiles from Letea saline lake and to performed a screening for industrially relevant extracellular enzymes. The investigations were conducted from October 2016 until May 2018. After a random selection of colonies that grew on the medium culture, 82 isolates were investigated. Based on their salt requirements and tolerance, it was remarked the presence of isolates belonging to halotolerant and moderate halophilic bacteria. Morphological and biochemical tests were used to characterize them. The ability of the tested isolates to produce extracellular enzymes was evaluated on the culture medium with salinity varying between 0-4M and supplemented with a specific substrate. The highest hydrolytic activities were recorded for casein at 0M NaCl, 1M NaCl, 2M NaCl, and Tween 80 and inulin at 0M NaCl, 1M NaCl, 2M NaCl, and 3M NaCl.

2013 ◽  
Vol 1 (2) ◽  
Author(s):  
Denovis Sambode ◽  
Henneke Pangkey ◽  
Sartje Lantu

The aim of this study was to find out the effect of different organic fertilizers on the population growth of Chydorus sp. This research was conducted at Laboratorium of Nutrition and Food Technology, Faculty of Fishery and Marine Sciences, Sam Ratulangi University, from December, 2012 to January, 2013. The experiment was run in the Completely Randomized Design with 3 treatments and 3 replication. Chydorus sp. was cultured in 9 glass jars with a volume of 1 L each. Three treatments applied in this research included A: medium culture composed of 500ml of water and 50 grams of soil; B: medium culture composed of 500ml of water, 50 grams of soil and 10g of cow dung; C: medium culture composed of 500ml of water, 50 grams of soil and 10g of horse dung. The density of Cydorus sp. in each media was 10 individuals /500 ml water. Observation on the population growth, development of live preys, and water quality parameters was conducted for 20 days period. Data were statistically analized with Analysis of variance. The results showed the highest density of Chydorus sp. was reached by Chydorus cultured in medium with horse manure (2169 individual/500 ml), followed by medium culture with cow manure (1715 individual/500 ml), and the lowest in medium culture with soil which was 1065,33 individual/500 ml. However, Analysis of variances showed that Chydorus population growth were not significantly affected by different culture medium. Keywords: manure, liquid fertilizer, growth, Chydorus sp.


Author(s):  
Reda Bellaouchi ◽  
Houssam Abouloifa ◽  
Yahya Rokni ◽  
Amina Hasnaoui ◽  
Nabil Ghabbour ◽  
...  

Abstract Background This work aims to study the optimal conditions of the fermentation culture medium used for the production of extracellular enzymes (amylase, cellulase, lipase, and protease) from previously isolated Aspergillus niger strains in date by-products. Results The five most powerful isolates selected based on the zone of degradation formed on Petri plates by the substrate were subjected to the quantitative evaluation of their enzymatic production. All five strains showed almost similar API-ZYM profiles, with minor variations observed at the level of some specific enzyme expression. The production of cellulase and amylase was depending on pH and incubation temperatures. ASP2 strain demonstrated the high production rate of amylase (at pH 5 and 30 °C) and cellulase (at pH 6 and 30 °C) for 96 h of incubation. Conclusion The A. niger showed the ability to produce several extracellular enzymes and can be used in the valorization of different agroindustrial residues.


2012 ◽  
Vol 554-556 ◽  
pp. 1400-1405
Author(s):  
Yan Duan ◽  
Wen Rui Guo ◽  
Lin Su ◽  
Yue Ying Guo ◽  
Ye Jin

A total of 69 gram-positive, catalase-negative strains isolated from Inner Mongolia traditional meat sausages were characterized in respect to their technological properties, including acid production, salt and nitrite tolerance, gas, slime and H2S production, hydrolysis of arginine and biogenic amine production. All of the isolated strains decrease the pH below 5.0 after 24h of cultivation. All isolates are able to grow with 6.5% NaCl or with 150mg L-1NaNO2and 51 isolates are able to grow with 10% NaCl. All isolates don’t produce gas and slime. 54 isolates don’t produce H2S. 23 isolated strains don’t produce NH3 from arginine, and 40 isolates don’t produce biogenic amine. Consolidation of these results, 8 strains show the best technological properties to be used as starter culture for sausage production. The bacterial selected are then subjected to biochemical tests using the API 50 CH and they are identified as 6 Lactobacillus planarum and 2 Lactobacillus curvatus.


2021 ◽  
Author(s):  
Jan-Chi Yang ◽  
Ping-Chun Wu ◽  
Chia-Chun Wei ◽  
Qilan Zhong ◽  
Sheng-Zhu Ho ◽  
...  

Abstract Epitaxial growth is of significant importance over the past decades, given it has been the key process of modern technology for delivering high-quality thin films. For conventional heteroepitaxy, the selection of proper single crystal substrates not only facilitates the integration of different materials but also fulfills interface and strain engineering upon a wide spectrum of functionalities. Nevertheless, the lattice structures, regularity and crystalline orientation are determined once a specific substrate is chosen. In this work, we reveal the growth of twisted oxide lateral homostructures with multiple conjunction degree of freedom. The twisted lateral homostructures with atomically sharp interfaces can be composed of epitaxial “blocks” with different crystalline orientations, ferroic orders and phases. We further demonstrate that this approach is universal for fabricating various complex systems. Our results establish an efficient pathway towards twisted lateral homostructures, allowing epitaxial films to be arbitrarily tailored at designated positions with unbounded in-plane conjunction tunability.


Toxins ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 519 ◽  
Author(s):  
Kimiko Yabe ◽  
Haruna Ozaki ◽  
Takuya Maruyama ◽  
Keisuke Hayashi ◽  
Yuki Matto ◽  
...  

The dichlorvos-ammonia (DV-AM) method is a simple but sensitive visual method for detecting aflatoxigenic fungi. Here we sought to develop a selective medium that is appropriate for the growth of aflatoxigenic fungi among soil mycoflora. We examined the effects of different concentrations of carbon sources (sucrose and glucose) and detergents (deoxycholate (DOC), Triton X-100, and Tween 80) on microorganisms in soils, using agar medium supplemented with chloramphenicol. The results demonstrated that 5–10% sucrose concentrations and 0.1–0.15% DOC concentrations were appropriate for the selective detection of aflatoxigenic fungi in soil. We also identified the optimal constituents of the medium on which the normal rapid growth of Rhizopus sp. was completely inhibited. By using the new medium along with the DV-AM method, we succeeded in the isolation of aflatoxigenic fungi from non-agricultural fields in Fukui city, Japan. The fungi were identified as Aspergillus nomius based on their calmodulin gene sequences. These results indicate that the new medium will be useful in practice for the detection of aflatoxigenic fungi in soil samples including those from non-agricultural environments.


2017 ◽  
Vol 52 (12) ◽  
pp. 1140-1148 ◽  
Author(s):  
Patrícia Elias Haddad ◽  
Luis Garrigós Leite ◽  
Cleusa Maria Mantovanello Lucon ◽  
Ricardo Harakava

Abstract: The objective of this work was to evaluate, in vitro and in vivo, the potential of Trichoderma spp. strains to control Sclerotinia sclerotiorum in soybeans (Glycine max) and to perform the molecular identification of the best perfoming strains. The effect of 120 strains of Trichoderma spp. on the viability of S. sclerotiorum sclerotia was evaluated in vitro through immersion in suspension of conidia from the antagonists and plating in culture medium. The best performing strains were evaluated in vivo, in a greenhouse, for control of the pathogen inoculated on 'Pintado' soybean seeds and plants. Of the 120 strains tested in vitro, 22 strains of Trichoderma spp. caused 100% inhibition of sclerotia germination. In the greenhouse, five strains inhibited the negative effect of the pathogen on seed germination and two strains increased in up to 67% plant dry matter. The best performing strains were identified as T. koningiopsis (3 strains), T. asperelloides (3), T. atroviride (2), and T. virens (1). Trichoderma strains are able to protect soybean plants from the harmful effect of S. sclerotiorum and, at the same time, they can promote the growth of the aerial part in greenhouse conditions.


2021 ◽  
Vol 43 ◽  
pp. e51656
Author(s):  
Nara Priscila Barbosa Bravim ◽  
Anatércia Ferreira Alves ◽  
José Fábio França Orlanda ◽  
Patricia Barbosa Rodrigues Silva

The objective of the present study was to isolate fungi from agricultural soils and evaluate fungal growth in culture medium contaminated with atrazine, glyphosate and pendimethalin. Filamentous fungi were isolated from agricultural soils and cultured in a modified culture medium containing 0, 10, 20, 50, and 100 μg mL-1 atrazine, glyphosate and pendimethalin for 14 days at 28°C. The fungi that presented optimal and satisfactory growth were plated in Sabouraud culture medium with 4% dextrose and containing the herbicides at concentrations of 0, 10, 20, 50, and 100 μg mL-1 for seven days at 28°C. The mean mycelial growth values were submitted to analysis of variance and the Tukey test (p < 0.05%) for comparison and relative growth determination, and maximum inhibition rates were calculated. The isolated fungi Aspergillus fumigatus, Fusarium verticillioides and Penicillium citrinum were shown to be resistant to atrazine, glyphosate and pendimethalin. F. verticillioides showed higher mean mycelial growth in the culture media contaminated with atrazine and glyphosate than the other two fungi. In the culture medium contaminated with pendimethalin, F. verticillioides, and A. fumigatus presented the highest mean mycelial growth values.


ScientiaTec ◽  
2020 ◽  
Vol 7 (03) ◽  
Author(s):  
Giandra Volpato ◽  
Victória Furtado Migliavacca ◽  
Bruna Coelho de Andrade ◽  
Júlio Xandro Heck ◽  
Marco Antônio Záchia Ayub

The industrial application of lipolytic enzymes has been studied mainly due to the ability of these enzymes in catalyze reactions of synthesis and their stability in various organic solvents. One possibility is the use of lipase the organic synthesis, taking advantage as the generation of waste and difficult recovery of sub bioproducts. In this work, we carried out a selection of eighty-four isolates of Bacillus amazonian for lipase production, of which 30 strains showed lipolytic activity. The study of the culture conditions was performed through a Plackett-Burman experimental design using the strain that presented the highest lipolytic activity in a culture medium using glycerol as substrate.  The studied conditions were: concentration of soybean oil, olive oil, triton X-100, gum arabic, glycerol, and (NH4)2SO4, pH, temperature and concentration of inoculums. The best result obtained were 27 U/L in 48 h of cultivation by Bacillus circulans BL53. This work shows that the search and selection of microorganism with lipolytic activities can facilitate the discovery of new lipases, with potential use as by-product surplus.


Author(s):  
I.L. Astapchuk ◽  
◽  
N.A. Marchenko ◽  
G.V. Yakuba ◽  
A.I. Nasonov ◽  
...  

The influence of various culture media on the growth, morphological and cultural characteristics of the fungus F. sporotrichioides was studied. Ten culture media were used in our research. A comparative study of the growth rate of the F. sporotrichioides mycelium made it possible to identify two media that are the most suitable for the cultivation and identification of this species, namely carrot and tomato agar. We took into account such criteria as ensuring the maximum degree of sporulation, rapid growth and development of mycelium (the 7th day), colony diameter (71–78 mm), as well as the ease of preparation. Nirenberg culture medium can be used to obtain a large number of conidia of the fungus. Because of the high variability of cultural characteristics of F. sporotrichioides, we recommend using different composition of media.


1974 ◽  
Vol 20 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Cecily Mills ◽  
J. N. Campbell

Micrococcus sodonensis has been shown to produce several extracellular enzymes: an alkaline phosphatase, at least two forms of phosphodiesterase, a 5′-nucleotidase, and an alkaline proteinase. The quantitative release of these enzymes into the culture medium during logarithmic growth under all the various culture conditions tested indicates that these enzymes are truly extracellular in nature. Inorganic phosphate repressed the production of the alkaline phosphatase in synthetic as well as in complex media, whereas, the repression of the production of active diesterase and 5′-nucleotidase by inorganic phosphate was partly reversed by the addition of supplemental organic nutrients to the culture medium. Proteinase production was independent of the culture conditions used. A mutant strain of M. sodonensis with an altered production of diesterase was obtained; the other extracellular enzymes were unaffected. These results suggest that the extracellular enzymes of M. sodonensis are not produced in a pleiotropic fashion since the level of one of the enzymes can be changed without affecting a corresponding change in the levels of the other enzymes. An extracellular high molecular weight carbohydrate fraction was shown to be produced by M. sodonensis in synthetic medium. The fraction was also shown to contain glycoprotein.


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