scholarly journals Effect of the deficiency of nitrate and silicate on the growth and composition of the benthic diatom Navicula incerta

2020 ◽  
Vol 48 (2) ◽  
pp. 280-286
Author(s):  
José Jesús Encinas-Arzate ◽  
Enrique Marquez-Ríos ◽  
José Antonio López-Elías ◽  
Wilfrido Torres-Areola ◽  
José Ángel Huerta-Ocampo ◽  
...  
Keyword(s):  
Growth Kinetics ◽  
Biochemical Composition ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Benthic Diatom ◽  
Lipid Concentration ◽  
Silicate Concentration ◽  
Chlorophyll Protein ◽  
Potential Use ◽  
Navicula Incerta

Navicula incerta is a benthic diatom with potential use in nutrition and health for humans and aquaculture. Therefore, it is important to know its optimal growth conditions and biochemical composition. In this study, the effects of nitrate and silicate concentration on the growth kinetics and biochemical composition of N. incerta under laboratory conditions were measured. F/2 media was used as the control, and different concentrations of nitrogen (N/4, N/8 and N/16) and silicates (Si/4, Si/8 and Si/16) were evaluated. We measured cell concentration, chlorophyll-a and conducted proximal chemical analyses. It was found that different concentrations of nutrients affected the diatom’s growth kinetics and affected the concentrations of ash, chlorophyll, protein, lipids and carbohydrates. The highest concentration of lipids was obtained in the limiting treatment of nitrogen N/8 (27.09%), while the lowest value was found with silicate Si/8 media (16.97%). Carbohydrates increased compared to the control, with the N/16 treatment presenting the maximal concentration (23.31%). Treatments with reduced nitrate (N/8 and N/16) demonstrated the lowest concentrations of protein (18.75 and 12.44%, respectively), while in reduced silicate treatments, no statistical differences (P ≥ 0.05) were observed. Therefore, media limited nitrogen and silicates affected the growth kinetics and proximal chemical composition of N. incerta. The growth of this species using the N/8 medium is a suitable method for increasing lipid concentration in N. incerta.

scholarly journals Naturally Occurring Ecdysteroids in Triticum aestivum L. and Evaluation of Fenarimol as a Potential Inhibitor of Their Biosynthesis in Plants

2021 ◽  
Vol 22 (6) ◽  
pp. 2855
Author(s):  
Anna Janeczko ◽  
Jana Oklestkova ◽  
Danuše Tarkowská ◽  
Barbara Drygaś
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Triticum Aestivum L ◽  
Growth Conditions ◽  
Animal Kingdom ◽  
Experimental Conditions ◽  
P450 Monooxygenase ◽  
Naturally Occurring ◽  
Regulatory Effects ◽  
Potential Use

Ecdysteroids (ECs) are steroid hormones originally found in the animal kingdom where they function as insect molting hormones. Interestingly, a relatively high number of these substances can also be formed in plant cells. Moreover, ECs have certain regulatory effects on plant physiology, but their role in plants still requires further study. One of the main aims of the present study was to verify a hypothesis that fenarimol, an inhibitor of the biosynthesis of ECs in the animal kingdom, also affects the content of endogenous ECs in plants using winter wheat Triticum aestivum L. as a model plant. The levels of endogenous ECs in winter wheat, including the estimation of their changes during a course of different temperature treatments, have been determined using a sensitive analytical method based on UHPLC-MS/MS. Under our experimental conditions, four substances of EC character were detected in the tissue of interest in amounts ranging from less than 1 to over 200 pg·g−1 FW: 20-hydroxyecdysone, polypodine B, turkesterone, and isovitexirone. Among them, turkesterone was observed to be the most abundant EC and accumulated mainly in the crowns and leaves of wheat. Importantly, the level of ECs was observed to be dependent on the age of the plants, as well as on growth conditions (especially temperature). Fenarimol, an inhibitor of a cytochrome P450 monooxygenase, was shown to significantly decrease the level of naturally occurring ECs in experimental plants, which may indicate its potential use in studies related to the biosynthesis and physiological function of these substances in plants.

scholarly journals Isolation of a gene required for programmed initiation of development by Aspergillus nidulans.

1992 ◽  
Vol 12 (9) ◽  
pp. 3827-3833 ◽  
Author(s):  
T H Adams ◽  
W A Hide ◽  
L N Yager ◽  
B N Lee
Keyword(s):  
Life Cycle ◽  
Aspergillus Nidulans ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Nutrient Deprivation ◽  
Deletion Mutants ◽  
Wild Type ◽  
Microbial Development ◽  
Type Strains ◽  
Posttranscriptional Level

In contrast to many other cases in microbial development, Aspergillus nidulans conidiophore production initiates primarily as a programmed part of the life cycle rather than as a response to nutrient deprivation. Mutations in the acoD locus result in "fluffy" colonies that appear to grow faster than the wild type and proliferate as undifferentiated masses of vegetative cells. We show that unlike wild-type strains, acoD deletion mutants are unable to make conidiophores under optimal growth conditions but can be induced to conidiate when growth is nutritionally limited. The requirement for acoD in conidiophore development occurs prior to activation of brlA, a primary regulator of development. The acoD transcript is present both in vegetative hyphae prior to developmental induction and in developing cultures. However, the effects of acoD mutations are detectable only after developmental induction. We propose that acoD activity is primarily controlled at the posttranscriptional level and that it is required to direct developmentally specific changes that bring about growth inhibition and activation of brlA expression to result in conidiophore development.

scholarly journals Metabolomic Study of Heterotrophically Grown Chlorella sp. Isolated from Wastewater in Northern Sweden

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2410
Author(s):  
Jean Claude Nzayisenga ◽  
Anita Sellstedt
Keyword(s):  
Sustainable Development ◽  
Butyric Acid ◽  
Lipid Production ◽  
Growth Conditions ◽  
Northern Sweden ◽  
Metabolic Intermediate ◽  
Chlorella Sp ◽  
Lipid Contents ◽  
New Compounds ◽  
Potential Use

There are numerous strains of Chlorella with a corresponding variety of metabolic pathways. A strain we previously isolated from wastewater in northern Sweden can grow heterotrophically as well as autotrophically in light and has higher lipid contents under heterotrophic growth conditions. The aims of the present study were to characterize metabolic changes associated with the higher lipid contents in order to enhance our understanding of lipid production in microalgae and potentially identify new compounds with utility in sustainable development. Inter alia, the amino acids glutamine and lysine were 7-fold more abundant under heterotrophic conditions, the key metabolic intermediate alpha-ketoglutarate was more abundant under heterotrophic conditions with glucose, and maltose was more abundant under heterotrophic conditions with glycerol than under autotrophic conditions. The metabolite 3-hydroxy-butyric acid, the direct precursor of the biodegradable plastic PHB (poly-3-hydroxy-butyric acid), was also more abundant under heterotrophic conditions. Our metabolomic analysis has provided new insights into the alga’s lipid production pathways and identified metabolites with potential use in sustainable development, such as the production of renewable, biodegradable plastics, cosmetics, and nutraceuticals, with reduced pollution and improvements in both ecological and human health.

scholarly journals Characterization of the Antibiotic Compound No. 70 Produced byStreptomycessp. IMV-70

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Lyudmila P. Trenozhnikova ◽  
Almagul K. Khasenova ◽  
Assya S. Balgimbaeva ◽  
Galina B. Fedorova ◽  
Genrikh S. Katrukha ◽  
...  
Keyword(s):  
Optimal Growth ◽  
Growth Conditions ◽  
Culture Broth ◽  
Producer Strain ◽  
New Class ◽  
New Antibiotics ◽  
Actinomycete Strain ◽  
Main Component

We describe the actinomycete strain IMV-70 isolated from the soils of Kazakhstan, which produces potent antibiotics with high levels of antibacterial activity. After the research of its morphological, chemotaxonomic, and cultural characteristics, the strain with potential to be developed further as a novel class of antibiotics with chemotherapeutics potential was identified asStreptomycessp. IMV-70. In the process of fermentation, the strainStreptomycesspp. IMV-70 produces the antibiotic no. 70, which was isolated from the culture broth by extraction with organic solvents. Antibiotic compound no. 70 was purified and separated into individual components by HPLC, TLC, and column chromatography methods. The main component of the compound is the antibiotic 70-A, which was found to be identical to the peptolide etamycin A. Two other antibiotics 70-B and 70-C have never been described and therefore are new antibiotics. The physical-chemical and biological characteristics of these preparations were described and further researched. Determination of the optimal growth conditions to cultivate actinomycete-producer strain IMV-70 and development of methods to isolate, purify, and accumulate preparations of the new antibiotic no. 70 enable us to research further the potential of this new class of antibiotics.

scholarly journals Growth and biochemical composition of Chlorella vulgaris in different growth media

2013 ◽  
Vol 85 (4) ◽  
pp. 1427-1438 ◽  
Author(s):  
MATHIAS A. CHIA ◽  
ANA T. LOMBARDI ◽  
MARIA DA GRACA G. MELAO
Keyword(s):  
Biomass Production ◽  
Chlorella Vulgaris ◽  
Biochemical Composition ◽  
Physiological Response ◽  
Low Cost ◽  
Cost Effective ◽  
Growth Conditions ◽  
Growth Media ◽  
Continuous Cultures ◽  
The Cost

The need for clean and low-cost algae production demands for investigations on algal physiological response under different growth conditions. In this research, we investigated the growth, biomass production and biochemical composition of Chlorella vulgaris using semi-continuous cultures employing three growth media (LC Oligo, Chu 10 and WC media). The highest cell density was obtained in LC Oligo, while the lowest in Chu medium. Chlorophyll a, carbohydrate and protein concentrations and yield were highest in Chu and LC Oligo media. Lipid class analysis showed that hydrocarbons (HC), sterol esthers (SE), free fatty acids (FFA), aliphatic alcohols (ALC), acetone mobile polar lipids (AMPL) and phospholipids (PL) concentrations and yields were highest in the Chu medium. Triglyceride (TAG) and sterol (ST) concentrations were highest in the LC Oligo medium. The results suggested that for cost effective cultivation, LC Oligo medium is the best choice among those studied, as it saved the cost of buying vitamins and EDTA associated with the other growth media, while at the same time resulted in the best growth performance and biomass production.

Toxic properties of Aeromonas proteolytica

1974 ◽  
Vol 20 (10) ◽  
pp. 1403-1409 ◽  
Author(s):  
B. G. Foster ◽  
Mary O. Hanna
Keyword(s):  
Thermal Stability ◽  
Culture Filtrate ◽  
Hemolytic Activity ◽  
Optimal Growth ◽  
Growth Conditions ◽  
The Other ◽  
Activity Peak ◽  
Endopeptidase Activity ◽  
Time Periods ◽  
Thermal Stability Of

Aeromonas proteolytica was grown for various time periods in nutrient broth, tryptic soy broth, a semisynthetic medium, and 1 and 5% peptone under different conditions involving temperature and in continuous shake and stationary flasks. The cell-free culture filtrates were tested for hemolytic, endopeptidase, and dermonecrotic activity and optimal growth conditions for their production were determined. The dermonecrotic activity and endopeptidase activity was found to be parallel in all tests, while hemolysin was independent of the other two. Studies on the thermal stability of the culture filtrate revealed that hemolysin and dermonecrotic and endopeptidase activity were destroyed at 70 °C for 30 min. Fractionation of the filtrate by Sephadex G-200 resolved three peaks at 280 nm. Peak I was inactive; peak II contained endopeptidase and dermonecrotic and hemolytic activity; peak III contained pigment and hemolysin. Evidence is presented that the endopeptidase and dermonecrotic substance found in the cell-free filtrates of A. proteolytica grown medium appear at the same time and thus may be the same entity.

Optimization of Growth Conditions of Citrus Anthracnose Agent Colletotrichum gloeosporioides Isolates in Tunisia

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Ben Hadj-Daoud H ◽  
◽  
Ben Salem I ◽  
Boughalleb-M’Hamdi N ◽  
◽  
...  
Keyword(s):  
Morphological Traits ◽  
Laboratory Experiments ◽  
Plant Pathogens ◽  
Colletotrichum Gloeosporioides ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Fruit Drop ◽  
Nutritional Conditions ◽  
Solid Media ◽  
Wide Range

Background: Colletotrichum gloeosporioides is important plant pathogens on a wide range of plant hosts such as citrus causing pre- or post-harvest infections as anthracnose, post-bloom fruit drop, tearstain and stem-end rot on fruit, or wither-tip of twigs. Method: The optimization of growth conditions of this pathogen was performed (solid media, temperature, pH and water potential under laboratory experiments). Results: Our results revealed that the maximum radial growth of C. gloeosporioides was recorded on SDA medium. All isolates were able to grow on PDA at temperatures of 15 and 30°C (over 0.7cm/day). Optimal growth radial was recorded at pH 5, 6, 7 and 8. Similar responses were obtained with both salt types, but, in general, C. gloeosporioides was more tolerant to KCl than NaCl. Conclusion: Studies of cultural, morphological traits of the pathogen are prominent to understand the response of the pathogen in different environmental and nutritional conditions.

scholarly journals Litoribacter ruber gen. nov., sp. nov., an alkaliphilic, halotolerant bacterium isolated from a soda lake sediment

2010 ◽  
Vol 60 (12) ◽  
pp. 2996-3001 ◽  
Author(s):  
Shi-Ping Tian ◽  
Yong-Xia Wang ◽  
Bin Hu ◽  
Xiao-Xia Zhang ◽  
Wei Xiao ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Soda Lake ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Rrna Gene ◽  
Strictly Aerobic ◽  
Sequence Comparisons ◽  
Respiratory Quinone ◽  
Major Respiratory Quinone ◽  
Respective Type

A novel alkaliphilic, halotolerant, rod-shaped bacterium, designated strain YIM CH208T, was isolated from a soda lake in Yunnan, south-west China. The taxonomy of strain YIM CH208T was investigated by a polyphasic approach. Strain YIM CH208T was Gram-negative, strictly aerobic and non-motile and formed red colonies. Optimal growth conditions were 28 °C, pH 8.5 and 0.5–2.5 % NaCl. Phylogenetic analysis based on 16S rRNA gene sequence comparisons showed that the isolate formed a distinct line within a clade containing the genus Echinicola in the phylum Bacteroidetes and was related to the species Echinicola pacifica and Rhodonellum psychrophilum, with sequence similarity of 91.7 and 91.6 % to the respective type strains. The DNA G+C content was 45.1 mol%. The major respiratory quinone was menaquinone-7 (MK-7). The predominant cellular fatty acids were iso-C17 : 1 ω9c (19.9 %), C15 : 0 3-OH (12.1 %), iso-C17 : 0 3-OH (11.3 %), summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1 ω7c; 10.7 %) and C17 : 1 ω6c (8.7 %). On the basis of the phenotypic, chemotaxonomic and phylogenetic data, strain YIM CH208T represents a novel species of a new genus, for which the name Litoribacter ruber gen. nov., sp. nov. is proposed. The type strain of Litoribacter ruber is YIM CH208T (=ACCC 05414T =KCTC 22899T).

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