Bacterial Osmolyte System and Its Physiological Roles

Dandapath, Iman; Chatterjee, Megha; Sarkar, Dhoopchhaya; Gupta, Akanksha; Rabbani, Gulam; Minakshi, Rinki

doi:10.1007/978-981-10-3707-8_10

Cited by 3 publications

(3 citation statements)

References 143 publications

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“…They were also identified as crucial obstacles to the establishment of microbial communities in BR Jones et al, 2012;Santini et al, 2015). Indeed, salinity has been reported to reduce microbial biomass (Dandapath et al, 2017) and enzyme activities (Frankenberger and Bingham, 1982;Rietz and Haynes, 2003), and to alter the functional structure and diversity of microbial communities (Guo et al, 2019) in soils. In further studies, it would be very interesting to leach/desorb Na cations from the bauxite residue to the range present in soils, add such residue to a soil, and thus to examine microbial activity of such mixture.…”

Section: Discussionmentioning

confidence: 99%

Effects of increasing concentrations of unamended and gypsum modified bauxite residues on soil microbial community functions and structure – A mesocosm study

Fourrier

Luglia²,

Hennebert³

et al. 2020

Ecotoxicology and Environmental Safety

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Bauxite residues (BR), commonly named red muds, are the saline-sodic waste produced during the extraction of alumina from bauxite. In this study, four kinds of BR were mixed at increasing concentrations with two soils in a mesososm experiment. Unamended BR from Provence (PRO) and Guinea (GUI) bauxite were selected, and Modified Bauxite Residues from PRO and GUI (MBR-PRO and MBR-GUI) were obtained by gypsum application and repeated leaching, in order to reduce their pH, electrical conductivity (EC) and exchangeable sodium percentage (ESP). Several indicators of microbial community functions and structure (growth of culturable bacteria; enzymatic activities; C-sourced substrates degradation (Biolog®); bacteria and fungi PCR-RFLP fingerprints) were measured after 35 days of incubation. Results showed that PRO residue had stronger negative effects than GUI on all the tested indicators. Residues modified by gypsum addition (MBR-PRO, MBR-GUI) were equally or sometimes less harmful compared to unamended residues. Microbial activities (bacterial growth and enzyme activities) were more inhibited than the diversity of microbial functions (Biolog®), and the structure of bacterial and fungal communities was not affected by increasing concentrations of bauxite residues. EC and ESP were the main factors explaining the inhibition of microbial activities, although the origin of bauxite residue is of great importance too.

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Section: Discussionmentioning

confidence: 99%

Effects of increasing concentrations of unamended and gypsum modified bauxite residues on soil microbial community functions and structure – A mesocosm study

Fourrier

Luglia²,

Hennebert³

et al. 2020

Ecotoxicology and Environmental Safety

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“…In order to maintain homeostasis, bacteria use two main strategies, i.e., accumulation of osmoprotectants and production of exopolysaccharides (EPSs) (Weiner et al, 1995; Dandapath et al, 2017). Osmoprotectants are compounds that accumulate into the cell to protect it from different stresses such as drought, dehydration, or the presence of oxygen radicals.…”

Section: Tumor Development Causes Stress In Bacterial and Plant Cellsmentioning

confidence: 99%

Ecological Conditions and Molecular Determinants Involved in Agrobacterium Lifestyle in Tumors

et al. 2019

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The study of pathogenic agents in their natural niches allows for a better understanding of disease persistence and dissemination. Bacteria belonging to the Agrobacterium genus are soil-borne and can colonize the rhizosphere. These bacteria are also well known as phytopathogens as they can cause tumors (crown gall disease) by transferring a DNA region (T-DNA) into a wide range of plants. Most reviews on Agrobacterium are focused on virulence determinants, T-DNA integration, bacterial and plant factors influencing the efficiency of genetic transformation. Recent research papers have focused on the plant tumor environment on the one hand, and genetic traits potentially involved in bacterium-plant interactions on the other hand. The present review gathers current knowledge about the special conditions encountered in the tumor environment along with the Agrobacterium genetic determinants putatively involved in bacterial persistence inside a tumor. By integrating recent metabolomic and transcriptomic studies, we describe how tumors develop and how Agrobacterium can maintain itself in this nutrient-rich but stressful and competitive environment.

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“…These low molecular weight protective compounds called osmolytes include polyols, sugars, amino acid derivatives etc. [1]. They are assumed to increase protein stability and prevent protein aggregation.…”

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confidence: 99%

Molecular modeling of osmolytes’ effect on bacterial luciferase

2022

The Thirteenth International Multiconference

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Motivation and Aim: Intracellular accumulation of organic solutes is one of the strategies used by living organisms to manage the variety of extreme conditions that they encounter in nature. This is also the case for luminous bacteria that inhabit the ocean and can adapt to the variety of temperatures, salinity, concentration of nutrients and toxins. The cells accumulate small molecules to counter the osmotic stress. These low molecular weight protective compounds called osmolytes include polyols, sugars, amino acid derivatives etc. [1]. They are assumed to increase protein stability and prevent protein aggregation. Nevertheless, small organic compounds can cause structural and dynamic changes of proteins and so influence its function, i.e. catalytic activity. For Photobacterium leiognathi luciferase it was revealed that integral intensity of the reaction changes in the presence of different cosolvents as follows: sucrose > sorbitol > glucose > glycerol > ethylene glycol that correlates with the relation of hydrodynamic radii of the cosolvent molecules: 5.2 > 3.9 > 3.6 > 3.1 > 2.6 (Å) [2]. Moreover, sucrose increases catalytic constant of excited state intermediate formation up to 5-fold unlike other cosolvents. Atomic-level molecular dynamics (MD) is useful tool to examine effects of osmolytes on P. leiognathi structure. Thus, the aim of this study was to reveal the structural and dynamic effects caused by osmolytes on the bacterial luciferase using molecular modelling approach. Methods and Algorithms: Three-dimension structure of luciferase from P. leiognathi was obtained by homology modelling using Swiss-model server. Crystal structure of luciferase from Vibrio harveyi (PDB ID: 3FGC) was used as a template. MD simulation of structure of P. leiognathi luciferase in water and in water-cosolvent mixtures (40 w/w %) was performed with GROMACS 2020.4 software. Sucrose, sorbitol, glucose, glycerol and ethylene glycol molecules were used as cosolvents. MD of each modeled system was calculated for 100 ns with three independent runs. Results: To estimate the penetration of cosolvents into active site gorge of P. leiognathi luciferase a radial distribution function (RDF) was calculated between centre of mass of αGLU43 and cosolvent molecules. αGLU43 was chosen as reference point because it locates in the deep of luciferase active site. RDF demonstrates that ethylene glycol and glycerol molecules penetrate deeper the active site of luciferase than other cosolvents that may explain the decrease of integral intensity in the presence of these two osmolytes. Minimum distance of RDF for ethylene glycol is 1,5 Å and for glycerol -1,6 Å, which is close to the value of water (1,45 Å). Sorbitol molecules can be found at 1,7 Å, but this case is extremely rare and the RDF remains close to zero up to the distance of 8 Å relative to the reference point. For glucose and sucrose the RDF function starts to rise from the distance of 4,3 and 5,5 Å respectively, and reaches significant values at >10 Å, i.e. closer to the entrance of the ac...

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Bacterial Osmolyte System and Its Physiological Roles

Cited by 3 publications

References 143 publications

Effects of increasing concentrations of unamended and gypsum modified bauxite residues on soil microbial community functions and structure – A mesocosm study

Effects of increasing concentrations of unamended and gypsum modified bauxite residues on soil microbial community functions and structure – A mesocosm study

Ecological Conditions and Molecular Determinants Involved in Agrobacterium Lifestyle in Tumors

Molecular modeling of osmolytes’ effect on bacterial luciferase

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