Disruption of Autolysis in Bacillus subtilis using TiO2 Nanoparticles

McGivney, Eric; Han, Linchen; Avellan, Astrid; VanBriesen, Jeanne M.; Gregory, Kelvin B.

doi:10.1038/srep44308

Cited by 21 publications

(17 citation statements)

References 56 publications

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“…Since (p)ppGpp is synthesized from GTP/GDP and since the high level of (p)ppGpp inhibits salvaging and de novo synthesis of these nucleotides [120,121,125,126], the synthesis of further (p)ppGpp will cease. The same applies to c-di-AMP since metabolically inactive cells have a reduced proton motive force (PMF) (i.e., reduced ATP level) [24,127]. The cessation of further formation of the two messengers could protect the cell from “early” death, with the hope that the conditions may improve.…”

Section: Resultsmentioning

confidence: 99%

Towards Exploring Toxin-Antitoxin Systems in Geobacillus: A Screen for Type II Toxin-Antitoxin System Families in a Thermophilic Genus

Alkhalili

Wallenius

Canbäck

2019

IJMS

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The toxin-antitoxin (TA) systems have been attracting attention due to their role in regulating stress responses in prokaryotes and their biotechnological potential. Much recognition has been given to type II TA system of mesophiles, while thermophiles have received merely limited attention. Here, we are presenting the putative type II TA families encoded on the genomes of four Geobacillus strains. We employed the TA finder tool to mine for TA-coding genes and manually curated the results using protein domain analysis tools. We also used the NCBI BLAST, Operon Mapper, ProOpDB, and sequence alignment tools to reveal the geobacilli TA features. We identified 28 putative TA pairs, distributed over eight TA families. Among the identified TAs, 15 represent putative novel toxins and antitoxins, belonging to the MazEF, MNT-HEPN, ParDE, RelBE, and XRE-COG2856 TA families. We also identified a potentially new TA composite, AbrB-ParE. Furthermore, we are suggesting the Geobacillus acetyltransferase TA (GacTA) family, which potentially represents one of the unique TA families with a reverse gene order. Moreover, we are proposing a hypothesis on the xre-cog2856 gene expression regulation, which seems to involve the c-di-AMP. This study aims for highlighting the significance of studying TAs in Geobacillus and facilitating future experimental research.

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Section: Resultsmentioning

confidence: 99%

Towards Exploring Toxin-Antitoxin Systems in Geobacillus: A Screen for Type II Toxin-Antitoxin System Families in a Thermophilic Genus

Alkhalili

Wallenius

Canbäck

2019

IJMS

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“…TiO 2 has attracted considerable attention in recent years because of its high oxidative power, abundance, and chemical stability. It is now widely used in environmental cleaning and energy conversion (Cui et al, 2010;Li, 2011;McGivney et al, 2017), but is less used in commercial plant production. We used Ag in our experiment as a stressor to stimulate the production of anthocyanin.…”

Section: Discussionmentioning

confidence: 99%

Leaf Color and Growth Change of Sedum rubrotinctum Caused by Two Commercial Chemical Products

Ma¹,

Li²,

Gu³

et al. 2019

horts

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Sedum rubrotinctum is widely grown as an ornamental because of its attractive leaf shape and color. Increasing the morphological diversity and color will greatly add to its ornamental value. Environmental conditions such as light and temperature can change the leaf color of succulent plants, but the mechanism is uncertain. To examine this mechanism, we tested the effects of two commercial chemical products Sowing Goodliness (Sg) and Aromatic Garden (Ag) on the morphology, pigment content, and growth performance of Sedum rubrotinctum seedlings. The Sg treatment did not change foliage color, but can accelerate plant growth and increase lateral bud number. The Ag treatment had marked changes on the relative proportions of pigments and leaf color, and plant growth was severely reduced with mortality observed in some plants. After Ag stress was discontinued, the surviving plants began to regrow and had good ornamental value but had the fewest number of lateral buds and leaves, and the smallest leaf length and thickness, canopy diameter, and plant height. Foliage color changes are caused directly by shifts in the relative proportions of pigments, particularly chlorophyll b and anthocyanin. In Ag-treated plants, chlorophyll b declined much faster than chlorophyll a, indicating that the transformation of chlorophyll b into chlorophyll a is an important step in the chlorophyll degradation pathway. Ag provides a way to learn more about the mechanism of chlorophyll degradation and should be investigated further. Ag enhanced anthocyanin production rapidly and improved the ornamental value of Sedum rubrotinctum. Different concentrations of Ag and Sg were not studied in this trial and might be tested to determine the ideal balance between leaf color and plant growth.

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“…7). Other additives may also prove useful in stabilizing displaying proteins, such as TiO 2 nanoparticles that have recently been show to limit autolysis as well (McGivney, Han et al 2017). Further rational modification of the protease deficient strains may also improve display and stability, as genetically eliminating the production of lytC and/or lytD (or σ D that controls their expression) reduces cellular lysis (Blackman, Smith et al 1998) and improves protein display (Kobayashi, Toida et al 2000).…”

Section: Discussionmentioning

confidence: 99%

Stabilizing displayed proteins on vegetative Bacillus subtilis cells

Huang

Gosschalk

Kim

et al. 2018

Appl Microbiol Biotechnol

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Microbes engineered to display heterologous proteins could be useful biotechnological tools for protein engineering, lignocellulose degradation, biocatalysis, bioremediation and biosensing. Bacillus subtilis is a promising host to display proteins, as this model Gram-positive bacterium is genetically tractable and already used industrially to produce enzymes. To gain insight into the factors that affect displayed protein stability and copy-number, we systematically compared the ability of different protease-deficient B. subtilis strains (WB800, BRB07, BRB08 and BRB14) to display a Cel8A-LysM reporter protein in which the Clostridium thermocellum Cel8A endoglucanase is fused to LysM cell wall binding modules. Whole-cell cellulase measurements and fractionation experiments demonstrate that genetically eliminating extracytoplasmic bacterial proteases improves Cel8A-LysM displays levels. However, upon entering stationary phase, for all protease-deficient strains, the amount of displayed reporter dramatically decreases, presumably as a result of cellular autolysis. This problem can be partially overcome by adding chemical protease inhibitors, which significantly increase protein display levels. We conclude that strain BRB08 is well-suited for stably displaying our reporter protein, as genetic removal of its extracellular and cell wall-associated proteases leads to the highest levels of surface accumulated Cel8A-LysM without causing secretion stress or impairing growth. A two-step procedure is presented that enables the construction of enzyme coated vegetative B. subtilis cells that retain stable cell-associated enzyme activity for nearly 3 days. The results of this work could aid the development of whole cell display systems that have useful biotechnological applications.

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Disruption of Autolysis in Bacillus subtilis using TiO2 Nanoparticles

Cited by 21 publications

References 56 publications

Towards Exploring Toxin-Antitoxin Systems in Geobacillus: A Screen for Type II Toxin-Antitoxin System Families in a Thermophilic Genus

Towards Exploring Toxin-Antitoxin Systems in Geobacillus: A Screen for Type II Toxin-Antitoxin System Families in a Thermophilic Genus

Leaf Color and Growth Change of Sedum rubrotinctum Caused by Two Commercial Chemical Products

Stabilizing displayed proteins on vegetative Bacillus subtilis cells

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