Proteomic and cellular views of Arthrospira sp. PCC 8005 adaptation to nitrogen depletion

Cyanobacteria are photosynthetic prokaryotes that play a crucial role in the Earth’s nitrogen and carbon cycles. Nitrogen availability is one of the most important factors in cyanobacterial growth. Interestingly, filamentous non-diazotrophic cyanobacteria, such as Arthrospira sp. PCC 8005, have developed survival strategies that enable them to adapt to nitrogen deprivation. Metabolic studies recently demonstrated a substantial synthesis and accumulation of glycogen derived from amino acids during nitrogen starvation. Nevertheless, the regulatory mechanism of this adaptation is poorly understood. To the best of our knowledge, this study is the first proteomic and cellular analysis of Arthrospira sp. PCC 8005 under nitrogen depletion. Label-free differential proteomic analysis indicated the global carbon and nitrogen reprogramming of the cells during nitrogen depletion as characterized by an upregulation of glycogen synthesis and the use of endogenous nitrogen sources. The degradation of proteins and cyanophycin provided endogenous nitrogen when exogenous nitrogen was limited. Moreover, formamides, cyanates and urea were also potential endogenous nitrogen sources. The transporters of some amino acids and alternative nitrogen sources such as ammonium permease 1 were induced under nitrogen depletion. Intriguingly, although Arthrospira is a non-diazotrophic cyanobacterium, we observed the upregulation of HetR and HglK proteins, which are involved in heterocyst differentiation. Moreover, after a long period without nitrate, only a few highly fluorescent cells in each trichome were observed, and they might be involved in the long-term survival mechanism of this non-diazotrophic cyanobacterium under nitrogen deprivation.

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Probing Direct Interactions between CodY and the oppD Promoter of Lactococcus lactis

Journal of Bacteriology ◽

10.1128/jb.187.2.512-521.2005 ◽

2005 ◽

Vol 187 (2) ◽

pp. 512-521 ◽

Cited By ~ 60

Author(s):

Chris D. den Hengst ◽

Peter Curley ◽

Rasmus Larsen ◽

Girbe Buist ◽

Arjen Nauta ◽

...

Keyword(s):

Amino Acids ◽

Lactococcus Lactis ◽

Nitrogen Availability ◽

Nitrogen Sources ◽

Dnase I ◽

Site Directed Mutagenesis ◽

Upstream Region ◽

Binding Studies ◽

Genes Encoding

ABSTRACT CodY of Lactococcus lactis MG1363 is a transcriptional regulator that represses the expression of several genes encoding proteins of the proteolytic system. These genes include pepN, pepC, opp-pepO1, and probably prtPM, pepX, and pepDA2, since the expression of the latter three genes relative to nitrogen availability is similar to that of the former. By means of in vitro DNA binding assays and DNase I footprinting techniques, we demonstrate that L. lactis CodY interacts directly with a region upstream of the promoter of its major target known so far, the opp system. Our results indicate that multiple molecules of CodY interact with this promoter and that the amount of bound CodY molecules is affected by the presence of branched-chain amino acids and not by GTP. Addition of these amino acids strongly affects the extent of the region protected by CodY in DNase I footprints. Random and site-directed mutagenesis of the upstream region of oppD yielded variants that were derepressed in a medium with an excess of nitrogen sources. Binding studies revealed the importance of specific bases in the promoter region required for recognition by CodY.

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Nitrogen Availability Affects the Metabolic Profile in Cyanobacteria

Metabolites ◽

10.3390/metabo11120867 ◽

2021 ◽

Vol 11 (12) ◽

pp. 867

Author(s):

Kosuke Inabe ◽

Ayaka Miichi ◽

Mami Matsuda ◽

Takanobu Yoshida ◽

Yuichi Kato ◽

...

Keyword(s):

Amino Acids ◽

Nitrogen Assimilation ◽

Nitrogen Availability ◽

Nitrogen Sources ◽

Tca Cycle ◽

Metabolome Analysis ◽

Rate Analysis ◽

Genetic Responses ◽

Synechocystis Sp ◽

Pcc 6803

Nitrogen is essential for the biosynthesis of various molecules in cells, such as amino acids and nucleotides, as well as several types of lipids and sugars. Cyanobacteria can assimilate several forms of nitrogen, including nitrate, ammonium, and urea, and the physiological and genetic responses to these nitrogen sources have been studied previously. However, the metabolic changes in cyanobacteria caused by different nitrogen sources have not yet been characterized. This study aimed to elucidate the influence of nitrate and ammonium on the metabolic profiles of the cyanobacterium Synechocystis sp. strain PCC 6803. When supplemented with NaNO3 or NH4Cl as the nitrogen source, Synechocystis sp. PCC 6803 grew faster in NH4Cl medium than in NaNO3 medium. Metabolome analysis indicated that some metabolites in the CBB cycle, glycolysis, and TCA cycle, and amino acids were more abundant when grown in NH4Cl medium than NaNO3 medium. 15N turnover rate analysis revealed that the nitrogen assimilation rate in NH4Cl medium was higher than in NaNO3 medium. These results indicate that the mechanism of nitrogen assimilation in the GS-GOGAT cycle differs between NaNO3 and NH4Cl. We conclude that the amounts and biosynthetic rate of cyanobacterial metabolites varies depending on the type of nitrogen.

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Utilization of amino acids as sole nitrogen sources by thermophilic fungi

Zeitschrift für allgemeine Mikrobiologie ◽

10.1002/jobm.3630150107 ◽

1975 ◽

Vol 15 (1) ◽

pp. 39-43 ◽

Cited By ~ 3

Author(s):

B. A. Oso

Keyword(s):

Amino Acids ◽

Nitrogen Sources ◽

Thermophilic Fungi

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Mycosporine-Like Amino Acids from Red Macroalgae: UV-Photoprotectors with Potential Cosmeceutical Applications

Applied Sciences ◽

10.3390/app11115112 ◽

2021 ◽

Vol 11 (11) ◽

pp. 5112

Author(s):

Julia Vega ◽

Geniane Schneider ◽

Bruna R. Moreira ◽

Carolina Herrera ◽

José Bonomi-Barufi ◽

...

Keyword(s):

Mass Spectrometry ◽

Amino Acids ◽

High Performance ◽

Nitrogen Availability ◽

Antioxidant Properties ◽

Published Data ◽

Diverse Group ◽

Red Macroalgae ◽

Thermo Stability ◽

The Impact

Macroalgae belong to a diverse group of organisms that could be exploited for biomolecule application. Among the biocompounds found in this group, mycosporine-like amino acids (MAAs) are highlighted mainly due to their photoprotection, antioxidant properties, and high photo and thermo-stability, which are attractive characteristics for the development of cosmeceutical products. Therefore, here we revise published data about MAAs, including their biosynthesis, biomass production, extraction, characterization, identification, purification, and bioactivities. MAAs can be found in many algae species, but the highest concentrations are found in red macroalgae, mainly in the order Bangiales, as Porphyra spp. In addition to the species, the content of MAAs can vary depending on environmental factors, of which solar radiation and nitrogen availability are the most influential. MAAs can confer photoprotection due to their capacity to absorb ultraviolet radiation or reduce the impact of free radicals on cells, among other properties. To extract these compounds, different approaches can be used. The efficiency of these methods can be evaluated with characterization and identification using high performance liquid chromatography (HPLC), associated with other apparatus such as mass spectrometry (MS) and nuclear magnetic resonance (NMR). Therefore, the data presented in this review allow a broad comprehension of MAAs and show perspectives for their inclusion in cosmeceutical products.

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Growth characteristics and hydrogen production by Rhodobacter sphaeroides using various amino acids as nitrogen sources and their combinations with carbon sources

International Journal of Hydrogen Energy ◽

10.1016/j.ijhydene.2010.08.121 ◽

2010 ◽

Vol 35 (22) ◽

pp. 12201-12207 ◽

Cited By ~ 33

Author(s):

Lilit Gabrielyan ◽

Heghine Torgomyan ◽

Armen Trchounian

Keyword(s):

Amino Acids ◽

Hydrogen Production ◽

Rhodobacter Sphaeroides ◽

Carbon Sources ◽

Nitrogen Sources ◽

Growth Characteristics

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The effect of the nitrogen source type on the growth and consumption of crude glycerol by Streptomyces hygroscopicus CH-7

Advanced technologies ◽

10.5937/savteh2101041i ◽

2021 ◽

Vol 10 (1) ◽

pp. 41-45

Author(s):

Slavica Ilić ◽

Jovan Ćirić ◽

Gordana Gojgić-Cvijović

Keyword(s):

Amino Acids ◽

Sunflower Oil ◽

Crude Glycerol ◽

Biomass Concentration ◽

Nitrogen Sources ◽

Biodiesel Production ◽

Streptomyces Hygroscopicus ◽

Basic Medium ◽

Source Type ◽

Glycerol Consumption

In this paper we studied the effect of different amino acids (arginine, tryptophan, tyrosine, and phenylalanine) as nitrogen sources on the growth of actinomycete Streptomyces hygroscopicus CH-7 and the consumption of crude glycerol, obtained as a by-product in the biodiesel production from sunflower oil. The highest biomass concentration (9.5 g/L) was achieved using the basic medium and the medium with tryptophan (9.2 g/L), while the crude glycerol consumption was the highest in the basic medium (5.9 mg/mL) and the medium with phenylalanine (3.3 mg/mL).

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AMPK and vacuole-associated Atg14p orchestrate μ-lipophagy for energy production and long-term survival under glucose starvation

eLife ◽

10.7554/elife.21690 ◽

2017 ◽

Vol 6 ◽

Cited By ~ 64

Author(s):

Arnold Y Seo ◽

Pick-Wei Lau ◽

Daniel Feliciano ◽

Prabuddha Sengupta ◽

Mark A Le Gros ◽

...

Keyword(s):

Energy Source ◽

Energy Production ◽

Alternative Energy ◽

Yeast Cells ◽

Survival Strategies ◽

Glucose Starvation ◽

Term Survival ◽

Long Term Survival ◽

Glucose Depletion

Dietary restriction increases the longevity of many organisms, but the cell signaling and organellar mechanisms underlying this capability are unclear. We demonstrate that to permit long-term survival in response to sudden glucose depletion, yeast cells activate lipid-droplet (LD) consumption through micro-lipophagy (µ-lipophagy), in which fat is metabolized as an alternative energy source. AMP-activated protein kinase (AMPK) activation triggered this pathway, which required Atg14p. More gradual glucose starvation, amino acid deprivation or rapamycin did not trigger µ-lipophagy and failed to provide the needed substitute energy source for long-term survival. During acute glucose restriction, activated AMPK was stabilized from degradation and interacted with Atg14p. This prompted Atg14p redistribution from ER exit sites onto liquid-ordered vacuole membrane domains, initiating µ-lipophagy. Our findings that activated AMPK and Atg14p are required to orchestrate µ-lipophagy for energy production in starved cells is relevant for studies on aging and evolutionary survival strategies of different organisms.

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Effect of metformin therapy on cardiac function and survival in a volume-overload model of heart failure in rats

Clinical Science ◽

10.1042/cs20100527 ◽

2011 ◽

Vol 121 (1) ◽

pp. 29-41 ◽

Cited By ~ 39

Author(s):

Jan Benes ◽

Ludmila Kazdova ◽

Zdenek Drahota ◽

Josef Houstek ◽

Dasa Medrikova ◽

...

Keyword(s):

Heart Failure ◽

Cardiac Function ◽

Glycogen Synthesis ◽

Volume Overload ◽

Left Ventricular ◽

Atp Depletion ◽

Term Survival ◽

Palmitate Oxidation ◽

Substrate Metabolism ◽

Mitochondrial Functions

Advanced HF (heart failure) is associated with altered substrate metabolism. Whether modification of substrate use improves the course of HF remains unknown. The antihyperglycaemic drug MET (metformin) affects substrate metabolism, and its use might be associated with improved outcome in diabetic HF. The aim of the present study was to examine whether MET would improve cardiac function and survival also in non-diabetic HF. Volume-overload HF was induced in male Wistar rats by creating ACF (aortocaval fistula). Animals were randomized to placebo/MET (300 mg·kg−1 of body weight·day−1, 0.5% in food) groups and underwent assessment of metabolism, cardiovascular and mitochondrial functions (n=6–12/group) in advanced HF stage (week 21). A separate cohort served for survival analysis (n=10–90/group). The ACF group had marked cardiac hypertrophy, increased LVEDP (left ventricular end-diastolic pressure) and lung weight confirming decompensated HF, increased circulating NEFAs (non-esterified ‘free’ fatty acids), intra-abdominal fat depletion, lower glycogen synthesis in the skeletal muscle (diaphragm), lower myocardial triacylglycerol (triglyceride) content and attenuated myocardial 14C-glucose and 14C-palmitate oxidation, but preserved mitochondrial respiratory function, glucose tolerance and insulin sensitivity. MET therapy normalized serum NEFAs, decreased myocardial glucose oxidation, increased myocardial palmitate oxidation, but it had no effect on myocardial gene expression, AMPK (AMP-activated protein kinase) signalling, ATP level, mitochondrial respiration, cardiac morphology, function and long-term survival, despite reaching therapeutic serum levels (2.2±0.7 μg/ml). In conclusion, MET-induced enhancement of myocardial fatty acid oxidation had a neutral effect on cardiac function and survival. Recently reported cardioprotective effects of MET may not be universal to all forms of HF and may require AMPK activation or ATP depletion. No increase in mortality on MET supports its safe use in diabetic HF.

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