THE PROBLEMS ON ESTIMATION OF THE RATE OF SUSTAINABILITY

Launching of the sustainable development means solving quantitative problems of controlling of the state of global circulations, functioning of climate machine etc. The main processes determining sustainability of the state of the natural environment area) carbon cycle and the work of the climate machine which in fact are closely connected,b) water cycle, (over)use and pollution of global and regional water resources,c) also the change of the flow of organic substance and biogenic elements into one-way flow “land-»town” instead of the natural circulation “soil-»plant-»animal (human)— »soil”

SUSTAINABLE DEVELOPMENT - PROBLEMS OF MEASUREMENT AND POSSIBILITIES OF REALISATION . (CASE STUDY OF NORTH - EASTERN ESTONIA)

In the middle of the century the exponentially growing mankind lived according to the popular slogan of the Mitchurin - do not ask, take from the Nature everything you need. However, environmental problems we currently encounter indicate that the carrying capacity of the Earth might be soon exhausted. Our environmental consciousness has developed from the "silent spring" through the "Limits of the Growth" to the present concept of the sustainable development. If in 70-ies the main problem seemed ; to be the limitation of the resources, then now reasonable management of the Earth, the development of harpiomous existence of the manking in the Nature is in the focus. It means that much attention is paid to defining in quantitative terms what kind of management, resource Use, style 'o f life is sustainable. Long lists of quantitative parameters, Indicators of sustainability have been proposed (1, 2). Generally speaking the use of indicators should make complicated systems understandable and predictable, to show to the society, where we are, where we are going and how to intergrate different subsystems of noosphere into a sustainable wholeness. The development of adequate set of indicators is feasible only if the noosphere is described using well-founded and syncretic system of models. One of the main goals in the nearest future would probably be formulation and analysis of the hierarchical set of models of the sustainably developing Earth, models where the "climate engine" of the planet and global economy are considered as one integrated system

Decrease of energy spilling in Escherichia coli continuous cultures with rising specific growth rate and carbon wasting

<p>Abstract</p> <p>Background</p> <p>Growth substrates, aerobic/anaerobic conditions, specific growth rate (μ) etc. strongly influence <it>Escherichia coli </it>cell physiology in terms of cell size, biomass composition, gene and protein expression. To understand the regulation behind these different phenotype properties, it is useful to know carbon flux patterns in the metabolic network which are generally calculated by metabolic flux analysis (MFA). However, rarely is biomass composition determined and carbon balance carefully measured in the same experiments which could possibly lead to distorted MFA results and questionable conclusions. Therefore, we carried out both detailed carbon balance and biomass composition analysis in the same experiments for more accurate quantitative analysis of metabolism and MFA.</p> <p>Results</p> <p>We applied advanced continuous cultivation methods (A-stat and D-stat) to continuously monitor <it>E. coli </it>K-12 MG1655 flux and energy metabolism dynamic responses to change of μ and glucose-acetate co-utilisation. Surprisingly, a 36% reduction of ATP spilling was detected with increasing μ and carbon wasting to non-CO₂by-products under constant biomass yield. The apparent discrepancy between constant biomass yield and decline of ATP spilling could be explained by the rise of carbon wasting from 3 to 11% in the carbon balance which was revealed by the discovered novel excretion profile of <it>E. coli </it>pyrimidine pathway intermediates carbamoyl-phosphate, dihydroorotate and orotate. We found that carbon wasting patterns are dependent not only on μ, but also on glucose-acetate co-utilisation capability. Accumulation of these compounds was coupled to the two-phase acetate accumulation profile. Acetate overflow was observed in parallel with the reduction of TCA cycle and glycolysis fluxes, and induction of pentose phosphate pathway.</p> <p>Conclusions</p> <p>It can be concluded that acetate metabolism is one of the major regulating factors of central carbon metabolism. More importantly, our model calculations with actual biomass composition and detailed carbon balance analysis in steady state conditions with -omics data comparison demonstrate the importance of a comprehensive systems biology approach for more advanced understanding of metabolism and carbon re-routing mechanisms potentially leading to more successful metabolic engineering.</p

Change in the carbon footprint of Iranians’ food consumption from 1961 to 2019: A decomposition analysis of drivers

Received: December 1st, 2022 ; Accepted: April 1st, 2023 ; Published: April 18th, 2023 ; Correspondence: [email protected] study investigates the role of three drivers: population, energy intake per capita, and dietary change on the carbon footprint of food consumption in Iran from 1961 to 2019. Iran was chosen for this analysis because the country has experienced a noteworthy population increase in the past century, and the imposed international sanctions have changed the economic welfare of the nation. Logarithmic Mean Division Index, along with data of FAOSTAT Food balance sheets and carbon footprint per item, were utilized to decompose the impacts of the drivers. The results demonstrated that the carbon footprint of food consumption in Iran increased by 1.6 during this period. We also found that population increase, and energy intake per capita were the main drivers of the carbon footprint of food consumption in Iran while diet change contributed negatively

Systems biology approach reveals that overflow metabolism of acetate in Escherichia coli is triggered by carbon catabolite repression of acetyl-CoA synthetase

<p>Abstract</p> <p>Background</p> <p>The biotechnology industry has extensively exploited <it>Escherichia coli </it>for producing recombinant proteins, biofuels etc. However, high growth rate aerobic <it>E. coli </it>cultivations are accompanied by acetate excretion <it>i.e</it>. overflow metabolism which is harmful as it inhibits growth, diverts valuable carbon from biomass formation and is detrimental for target product synthesis. Although overflow metabolism has been studied for decades, its regulation mechanisms still remain unclear.</p> <p>Results</p> <p>In the current work, growth rate dependent acetate overflow metabolism of <it>E. coli </it>was continuously monitored using advanced continuous cultivation methods (A-stat and D-stat). The first step in acetate overflow switch (at μ = 0.27 ± 0.02 h^-1) is the repression of acetyl-CoA synthethase (Acs) activity triggered by carbon catabolite repression resulting in decreased assimilation of acetate produced by phosphotransacetylase (Pta), and disruption of the PTA-ACS node. This was indicated by acetate synthesis pathways PTA-ACKA and POXB component expression down-regulation before the overflow switch at μ = 0.27 ± 0.02 h^-1with concurrent 5-fold stronger repression of acetate-consuming Acs. This in turn suggests insufficient Acs activity for consuming all the acetate produced by Pta, leading to disruption of the acetate cycling process in PTA-ACS node where constant acetyl phosphate or acetate regeneration is essential for <it>E. coli </it>chemotaxis, proteolysis, pathogenesis etc. regulation. In addition, two-substrate A-stat and D-stat experiments showed that acetate consumption capability of <it>E. coli </it>decreased drastically, just as Acs expression, before the start of overflow metabolism. The second step in overflow switch is the sharp decline in cAMP production at μ = 0.45 h^-1leading to total Acs inhibition and fast accumulation of acetate.</p> <p>Conclusion</p> <p>This study is an example of how a systems biology approach allowed to propose a new regulation mechanism for overflow metabolism in <it>E. coli </it>shown by proteomic, transcriptomic and metabolomic levels coupled to two-phase acetate accumulation: acetate overflow metabolism in <it>E. coli </it>is triggered by Acs down-regulation resulting in decreased assimilation of acetic acid produced by Pta, and disruption of the PTA-ACS node.</p

Multi-omics approach to study the growth efficiency and amino acid metabolism in Lactococcus lactis at various specific growth rates

<p>Abstract</p> <p>Background</p> <p><it>Lactococcus lactis </it>is recognised as a safe (GRAS) microorganism and has hence gained interest in numerous biotechnological approaches. As it is fastidious for several amino acids, optimization of processes which involve this organism requires a thorough understanding of its metabolic regulations during multisubstrate growth.</p> <p>Results</p> <p>Using glucose limited continuous cultivations, specific growth rate dependent metabolism of <it>L. lactis </it>including utilization of amino acids was studied based on extracellular metabolome, global transcriptome and proteome analysis. A new growth medium was designed with reduced amino acid concentrations to increase precision of measurements of consumption of amino acids. Consumption patterns were calculated for all 20 amino acids and measured carbon balance showed good fit of the data at all growth rates studied. It was observed that metabolism of <it>L. lactis </it>became more efficient with rising specific growth rate in the range 0.10 - 0.60 h^-1, indicated by 30% increase in biomass yield based on glucose consumption, 50% increase in efficiency of nitrogen use for biomass synthesis, and 40% reduction in energy spilling. The latter was realized by decrease in the overall product formation and higher efficiency of incorporation of amino acids into biomass. <it>L. lactis </it>global transcriptome and proteome profiles showed good correlation supporting the general idea of transcription level control of bacterial metabolism, but the data indicated that substrate transport systems together with lower part of glycolysis in <it>L. lactis </it>were presumably under allosteric control.</p> <p>Conclusions</p> <p>The current study demonstrates advantages of the usage of strictly controlled continuous cultivation methods combined with multi-omics approach for quantitative understanding of amino acid and energy metabolism of <it>L. lactis </it>which is a valuable new knowledge for development of balanced growth media, gene manipulations for desired product formation etc. Moreover, collected dataset is an excellent input for developing metabolic models.</p

Application of the UHPLC-DIA-HRMS Method for Determination of Cheese Peptides

Until now, cheese peptidomics approaches have been criticised for their lower throughput. Namely, analytical gradients that are most commonly used for mass spectrometric detection are usually over 60 or even 120 min. We developed a cheese peptide mapping method using nano ultra-high-performance chromatography data-independent acquisition high-resolution mass spectrometry (nanoUHPLC-DIA-HRMS) with a chromatographic gradient of 40 min. The 40 min gradient did not show any sign of compromise in milk protein coverage compared to 60 and 120 min methods, providing the next step towards achieving higher-throughput analysis. Top 150 most abundant peptides passing selection criteria across all samples were cross-referenced with work from other publications and a good correlation between the results was found. To achieve even faster sample turnaround enhanced DIA methods should be considered for future peptidomics applications.Peer reviewe

Design of sustainable ionic liquids based on l-phenylalanine and l-alanine dipeptides: Synthesis, toxicity and biodegradation studies

A series of dipeptide ionic liquids (ILs) with l-phenylalanine and l-alanine fragments in structure were synthesized and their possible degradation pathways were analyzed. Based on this analysis, potential transformation products (PTPs) were proposed and synthesized. All of these compounds (25 in total) went through microbial toxicity screening and aerobic biodegradation testing. Obtained results demonstrated that by investigating ILs and PTPs with a dipeptide fragment (in tandem with single amino acid analogues), the design of ILs with high biodegradation values in closed bottle test can be accomplished. One finding was that within the scope of the compounds studied, l-phenylalanine containing compounds were more biodegradable than l-alanine derivatives. In addition to the choice of amino acid residue, its position in the dipeptide IL structure also had a significant effect on biodegradability. PyCH2CO-Phe-Ala-OEt IL, where l-phenylalanine was in close proximity to the positively charged pyridinium sub-unit, gave higher biodegradation percentages compared to PyCH2CO-Ala-Phe-OEt IL, where alanine was closer to pyridinium than the phenylalanine residue. Analysis of PTPs data showed that the presence of an alanine residue resulted in undesirable (less green) PTPs more often compared to PTPs containing phenylalanine, especially when alanine was in close proximity to the pyridinium headgroup. Based on both toxicity and biodegradation testing results preferable and less preferable subunits can be chosen for the design of new sustainable chemicals based on amino acids. Results from this study demonstrate a potential of designing new sustainable chemicals using amino acid moieties as part of their structure

1st International Electronic Conference on Food Science and Functional Foods

This research aimed to conduct a comparison of 8 different forms of brewery spent grain (BSG) on their polyphenolic content and antioxidant capacity as part of their potential as a functional food ingredient. The BSGs were dried until they reached a stable weight, grounded to pass through a 385 µm sieve and were vacuum packed in non-transparent packaging for further analysis. The results showed that BSG contained a high dietary fiber content which was dominated by a insoluble dietary fiber level of about 38.0–43.9% and a soluble dietary fiber content of about 3.9–9.6%. There were three groups of polyphenolic identified: flavan-3-ols, phenolic acids and flavonols at quantities of 362.1–1165.7 mg/kg, 65.8–122.5 mg/kg and 3.6–13.8 mg/kg, respectively. Antioxidant capacity was examined using an in vitro assessment: the 2,2′-Azinobis-(3-Ethylbenzthiazolin-6-Sulfonic Acid) (ABTS) capacity ranged from 0.086 to 0.241 mmol Trolox/100 g while the ferric reducing antioxidant potential (FRAP) capacity ranged from 0.106 to 0.306 µmol TE/100 g. In conclusion, BSG as a brewery waste can potentially be used as a functional food ingredient due to its properties. It is suggested that further studies are needed to explore BSG’s impact on the development of functional food products.Keywords: brewery spent grain; valorization; agricultural by-products; functional food; dietary fiber; polyphenolic compounds; antioxidant</p

Effect of enzyme‐assisted hydrolysis on brewer's spent grain protein solubilization – peptide composition and sensory properties

This study aimed to valorize brewer's spent grain (BSG) from a side-stream into protein ingredients suitable for human consumption. The impact of protease treatments was studied for solubilizing BSG proteins. Treatment with Protamex or simultaneous co-incubation of Protamex and Flavourzyme solubilized up to 60% of the total protein in BSG, whereas co-incubation with Flavourzyme increased the availability of hydrophobic amino acids (Val, Phe, Ala, Leu, Ile) in extracts. The scale-up of protease treatments demonstrated comparable solubilized protein fractions in 0.1 L and 10 L reaction volumes. Thorough sequence-based peptide analysis by liquid chromatography-ion mobility-mass spectrometry resulted in the identification of 479 and 451 water-soluble peptides in the hydrolysates obtained with Protamex or co-incubation of Protamex and Flavourzyme, respectively. Main cutting sites on BSG proteins were identified between Leu-Gln, Tyr-Phe, Pro-X (Protamex), complementing with a variety of cutting sites mainly next to Gln, Pro, Ile, and Phe when combined with Flavourzyme. Uniform protease activity throughout the entire B-hordein sequence and the formation of peptides with varying sequence lengths did not increase the bitterness of the hydrolysates compared to the BSG sample with water extraction. These results support the characterization of enzymatic treatments in plant-based materials and the production of hydrolysates with desired composition. </p