scholarly journals Systematic Analysis of Metabolic Pathway Distributions of Bacterial Energy Reserves

2019 ◽  
Vol 9 (8) ◽  
pp. 2489-2496 ◽  
Author(s):  
Liang Wang ◽  
Jianye Yang ◽  
Yue Huang ◽  
Qinghua Liu ◽  
Yaping Xu ◽  
...  
2019 ◽  
Author(s):  
Liang Wang ◽  
Jianye Yang ◽  
Yue Huang ◽  
Qinghua Liu ◽  
Yaping Xu ◽  
...  

AbstractMetabolism of energy reserves are essential for bacterial functions such as pathogenicity, metabolic adaptation, and environmental persistence, etc. Previous bioinformatics studies have linked gain or loss of energy reserves such as glycogen and polyphosphate (polyP) with host-pathogen interactions and bacterial virulence based on a comparatively small number of bacterial genomes or proteomes. Thus, understanding the distribution patterns of energy reserves metabolism across bacterial species provides a shortcut route to look into bacterial lifestyle and physiology theoretically. So far, five major energy reserves have been identified in bacteria due to their effective capacity to support bacterial persistence under nutrient deprivation conditions, which include wax ester (WE), triacylglycerol (TAG), polyhydroxyalkanoates (PHA), polyphosphate, and glycogen. Although unknown pathways directly involved in energy reserves keep being discovered with the continuous endeavour of molecular microbiologists and it is currently rather clear about the enzymes related with the metabolism of energy reserves, there is a lack of systematic study of the pathway or key enzyme distributions of the five energy reserves in bacteria from an evolutionary point of view. With the fast development of sequencing technology, abundant bacterial proteomes are available in public database now. In this study, we sourced 8214 manually reviewed bacterial reference proteomes from UniProt database and used statistical models to search homologous sequences of key enzymes related with energy reserves. The distribution patterns of the pathways for energy reserves metabolism are visualized in taxonomy-based phylogenetic trees. According to the study, it was revealed that specific pathways and enzymes are associated with certain types of bacterial groups, which provides evolutionary insights into the understanding of their origins and functions. In addition, the study also confirmed that loss of energy reserves is correlated with bacterial genome reduction. Through this analysis, a much clearer picture about energy reserves metabolism in bacteria is present, which could serve a guide for further theoretical and experimental analyses of energy reserves metabolism in bacteria.


Author(s):  
F.J. Sjostrand

In the 1940's and 1950's electron microscopy conferences were attended with everybody interested in learning about the latest technical developments for one very obvious reason. There was the electron microscope with its outstanding performance but nobody could make very much use of it because we were lacking proper techniques to prepare biological specimens. The development of the thin sectioning technique with its perfectioning in 1952 changed the situation and systematic analysis of the structure of cells could now be pursued. Since then electron microscopists have in general become satisfied with the level of resolution at which cellular structures can be analyzed when applying this technique. There has been little interest in trying to push the limit of resolution closer to that determined by the resolving power of the electron microscope.


2015 ◽  
Vol 2 (3) ◽  
pp. 61-77
Author(s):  
O. Demydenko ◽  
V. Velychko

The contemporary condition of soil cover in Ukraine is characterized. The attention is focused onto widespread degradation processes in soils. The causes that determine the development of these negative processes are considered. The contemporary informational support for the condition of soil cover in Ukraine is estimated. In general, the current available information is of narrow-departmental nature, obtained by different methods and non-correlated monitoring programs. As a rule, it is stored in under-structured databases, incompatible with other information systems; mainly recorded on paper media unusable with modern technologies, whereby such information resources are diffi cult to be compiled together. These disadvantages are strong constraints against consistent usage of materials for evaluation, forecast and management of changes in the soil cover. The Soil Observation program should thereby be combined with Agrochemical Passportization and ecology-ameliora- tive monitoring; in other words, the application of innovative soil-agrochemical methodology is considered. Each individual type of surveys shall complement the others, and taken altogether, they shall constitute a con- sistent Information System, capable of solving the problems of assessing the condition, forecasting, manage- ment, usage and protection of soil resources. The monitoring procedures should be conducted on the basis of a new soil concept in line with unifi ed programs and methods, so as to meet European approaches to the maxi- mum extent. Such a technical composition enables getting information on present-day processes in soils, and is the only combination that actually helps us to “ecologize” our knowledge of soils, which is the leading trend in the scope of global soil-science. Thus obtained results will serve as a State-owned tool which would subse- quently facilitate the use and protection of soil resources all over the country, to be involved in a united global soil-information scope. The attention is focused onto social signifi cance of the information on soils and their fertility in terms of land resources optimization, as well as the formation of sustainable land use in Ukraine. Aim. To demonstrate the long-term effect of different ways of tillage of typical low-humus chernozem on the change in humus content and composition and the direction of transformation processes of organic fertili- zers. To study the changes in the structure of energy reserves in group and fractional composition of humus in typical low-humus light-loamy chernozem of the Forest-Steppe of Ukraine. Methods. Field, laboratory, microbiological, computational, mathematical and statistical. Results. It was determined that in conditions of long-term subsurface tillage the most effi cient humus accumulation occurs in the 0–20 cm layer of chernozem with simultaneous increase in its content in the lower part of the processed layer without any accumulation differentiation. Surface tillage leads to expressed differentiation in humus accumulation in the 0–20 cm layer of soil (0.005 % per year). When 6 t/ha of humus are replaced by 7 t/ha of by-products the intensity of humus accumulation is decreasing regardless of the way of tillage, but humus accumulation was found to be the most effi cient for subsurface tillage. The application of subsurface tillage leads to the increase in the ratio of C HA : C FA , which is conditioned by the increase in the humifi cation of plant remains of by-products in the 0−20 cm layer of soil by 110–112 % – for subsurface tillage, and by 105 % – for surface tillage. Conclusions. It was established that systematic subsurface tillage of typical chernozem of the Left-Bank Forest-Steppe of Ukraine leads to the structuring both of the total reserves of energy С org , and its quality content, aimed at the increase in the intensity of the processes of humifi cation and accumulation of organic carbon, and the decrease in miner- alization. The ratio of energy reserves С org of humic acids to fulvic acids in the 0−30 cm layer of chernozem is 1.85−1.87 regardless of the way of tillage, which testifi es to the repeatability of humus accumulation, but the total reserves of energy С org was higher for subsurface tillage (+ 31 Teracalorie/ha) compared to deep plough- ing. As for the surface tillage, the energy enrichment was at the level of deep ploughing.


2015 ◽  
Vol 2 (2) ◽  
pp. 39-44
Author(s):  
V. Lopushniak

Aim. To establish the effect of different fertilization systems in short fi eld crop rotation on the change in the state of humus in the dark gray podzolic soils in Western Forest-Steppe of Ukraine. Methods. Field studies were carried out in a stationary experiment of the Department of Soil Science and Agricultural Chemistry of the L’viv National Agrarian University; determination of humus content – according to DSTU 4289:2004, and that of its labile forms – in accordance with DSTU 4732:2007, fraction-group composition – by Ponomare- va-Plotnikova’s method, according to the measurement procedure 31-497058-008-2002. Results. The use of organo-mineral fertilizer system in short fi eld crop rotation with the saturation of organic fertilizers of 15 t/ha of crop rotation contributes to the humus content increase by 0.7 % after the third rotation in 0–40 cm layer of dark gray podzolic soil, the increase in the share of stable forms of humic compounds up to 57–59 % and the increase in the ratio of R HA :R FA to 1.3–1.4. The study demonstrated very high dependence of amount of gross energy reserves in the humus on the R HA :R FA ratio. Conclusions. The combined application of organic fertili- zers in the form of manure, non-market of the crop (straw) and siderate, along with mineral fertilizers is re- commended in short fi eld crop rotations of Western Forest-Steppe of Ukraine toensure expanded reproduction of fertility of dark gray podzolic soil, improvement of its humus status, increase in gross energy reserves and the share of the stable forms and humic acids in the humus.


2020 ◽  
Vol 2020 ◽  
pp. 1483-1484
Author(s):  
Masoumeh Hosseinpour ◽  
◽  
Ralf Terlutter ◽  
Holger Roschk

Author(s):  
Mauricio Drelichman ◽  
Hans-Joachim Voth

This chapter addresses the sustainability of debt. A systematic analysis based on the International Monetary Fund's (IMF) methodology to evaluate fiscal sustainability shows that Castile was able to service its debts in the long run. While liquidity was scarce during periods of intense warfare, years of relative peace brought large surpluses. The data collected from Castile's annual fiscal accounts produced new yearly series of revenue, military expenditure, short-term debt issues, and short-term debt service. The resulting database spans a full 31-year period—enough to employ modern quantitative techniques. This analysis provides strong evidence that Castile's fiscal position in the second half of the sixteenth century was on a solid footing. The chapter then assesses whether the events that led to major downturns in Castile's financial fortunes could have been anticipated.


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