Changes of cell growth and magnetosome biomineralization in Magnetospirillum magneticum AMB-1 after ultraviolet-B irradiation

Wang, Yinzhao; Lin, Wei; Li, Jinhua; Pan, Yongxin

doi:10.3389/fmicb.2013.00397

Cited by 14 publications

(17 citation statements)

References 87 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cp values were generated automatically using the Abs Quant/2nd Derivative Max program of the LightCycler 480 software. Relative expression levels of different genes were calculated by the 2 ‐ΔΔCp method (Wang et al, ). Data shown are means of three replicates.…”

Section: Resultsmentioning

confidence: 99%

“…In submerged culture of MSR‐1, relative dissolved oxygen concentration (dO 2 ) < 1% was required for magnetosome formation (Zhang et al ., ). Our study demonstrated coordination, co‐dependence and balance of oxygen and iron metabolism gene activity in MSR‐1 during magnetosome synthesis, and suggested that oxygen level affects expression of iron metabolism genes because of coupling between the two metabolic pathways (Wang et al ., ). Questions remaining to be answered include: (i) How many genes are involved in the process of magnetosome synthesis in MTB?…”

Section: Introductionmentioning

confidence: 97%

“…Denitrification genes also affect magnetosome formation, and particularly nap genes (encoding periplasmic nitrate reductases) involved in redox reactions (Li et al ., ; Raschdorf et al ., ). Environmental factors that affect magnetosome formation include initial Fe availability, temperature and ultraviolet‐B radiation (Faivre et al ., ; Baumgartner et al ., ; Wang et al ., ; Moisescu et al ., ).…”

Section: Introductionmentioning

confidence: 97%

See 2 more Smart Citations

Transcriptome analysis reveals physiological characteristics required for magnetosome formation in Magnetospirillum gryphiswaldense MSR‐1

Wang

Zhang

et al. 2016

Environ Microbiol Rep

View full text Add to dashboard Cite

Magnetosome synthesis ability of Magnetospirillum gryphiswaldense MSR-1 in an autofermentor can be precisely controlled through strict control of dissolved oxygen concentration. In this study, using transcriptome data we discovered gene transcriptional differences and compared physiological characteristics of MSR-1 cells cultured under aerobic (high-oxygen) and micro-aerobic (low-oxygen) conditions. The results showed that 77 genes were up-regulated and 95 genes were down-regulated significantly under micro-aerobic situation. These genes were involved primarily in the categories of cell metabolism, transport, regulation and unknown-function proteins. The nutrient transport and physiological metabolism were slowed down under micro-aerobic condition, whereas dissimilatory denitrification pathways were activated and it may supplemental energy was made available for magnetosome synthesis. The result suggested that the genes of magnetosome membrane proteins (Mam and Mms) are not directly regulated by oxygen level, or are constitutively expressed. A proposed regulatory network of differentially expressed genes reflects the complexity of physiological metabolism in MSR-1, and suggests that some yet-unknown functional proteins play important roles such as ferric iron uptake and transport during magnetosome synthesis. The transcriptome data provides a holistic view of the responses of MSR-1 cells to differing oxygen levels. This approach will give new insights into general principles of magnetosome formation.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 97%

See 1 more Smart Citation

Transcriptome analysis reveals physiological characteristics required for magnetosome formation in Magnetospirillum gryphiswaldense MSR‐1

Wang

Zhang

et al. 2016

Environ Microbiol Rep

View full text Add to dashboard Cite

show abstract

“…Similarly, Wang et al . () found that AMB‐1 cells produce more magnetite crystals with large grain sizes and long chains after UV‐B irradiation. Our results are consistent with these findings.…”

Section: Discussionmentioning

confidence: 98%

Light irradiation helps magnetotactic bacteria eliminate intracellular reactive oxygen species

Wang

Chen

et al. 2017

Environmental Microbiology

View full text Add to dashboard Cite

Magnetotactic bacteria (MTB) demonstrate photoresponse. However, little is known about the biological significance of this behaviour. Magnetosomes exhibit peroxidase-like activity and can scavenge reactive oxygen species (ROS). Magnetosomes extracted from the Magnetospirillum magneticum strain AMB-1 show enhanced peroxidase-like activity under illumination. The present study investigated the effects of light irradiation on nonmagnetic (without magnetosomes) and magnetic (with magnetosomes) AMB-1 cells. Results showed that light irradiation did not affect the growth of nonmagnetic and magnetic cells but significantly increased magnetosome synthesis and reduced intracellular ROS level in magnetic cells. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to analyse the expression level of magnetosome formation-associated genes (mamA, mms6, mms13 and mmsF) and stress-related genes (recA, oxyR, SOD, amb0664 and amb2684). Results showed that light irradiation upregulated the expression of mms6, mms13 and mmsF. Furthermore, light irradiation upregulated the expression of stress-related genes in nonmagnetic cells but downregulated them in magnetic cells. Additionally, magnetic cells exhibited stronger phototactic behaviour than nonmagnetic ones. These results suggested that light irradiation could heighten the ability of MTB to eliminate intracellular ROS and help them adapt to lighted environments. This phenomenon may be related to the enhanced peroxidase-like activity of magnetosomes under light irradiation.

show abstract

“…They also discuss the potential of magnetosomes as biomarkers for ancient life and the role of MTB in iron cycling. The study by Wang et al (2013) focuses on the influence of ultraviolet-B radiation on Magnetospirillum magneticum strain AMB-1. The authors note that ultraviolet-B radiation could affect both cell growth and magnetite synthesis, and suggest that magnetosomes may have evolutionary benefits for the survival of MTB under extreme environments.…”

mentioning

confidence: 99%

Intracellular biomineralization in bacteria

2014

Frontiers Research Topics

View full text Add to dashboard Cite

Microorganisms have populated the Earth for billions of years and their activities are important forces shaping our planetary environments through biogeochemical cycles. In particular, microbial biomineralization that selectively take up environmental elements and deposit minerals either intracellularly or extracellularly is of great interest, because these processes play vital roles in the global cycles of numerous elements, such as Fe, Mn, Ca, As, O, S, and P, etc. Biominerals, the products of biomineralization, not only serve as important biosignatures for the search of traces of past life and the reconstruction of ancient environments but also have many important commercial applications.Recent advances in sequencing technologies, molecular analyses and approaches for assaying protein functions pave the way for rapid progress in microbial biomineralization research. The objective of this research topic is to highlight the latest advances in our understanding of intracellular biomineralization in bacteria, with a focus on the magnetotactic bacteria (MTB), a group of phylogenetically diverse microbes synthesizing magnetic minerals of magnetite (Fe 3 O 4 ) and/or greigite (Fe 3 S 4 ) magnetosomes in cells. Magnetosomes are generally less than 150 nm in length, covered by lipid bilayer membrane and organized into one or multiple chain structures that act like a compass needle to facilitate the navigation of MTB using the Earth's magnetic field. The uniform nano sizes, superior magnetic properties and perfect chain arrangement suggest a strict genetic control of magnetosome synthesis in MTB cells, which provides an attractive model system for investigating the mechanisms of bacterial intracellular biomineralization. This research topic provides a selection of interesting and challenging topics of research on the diversity, ecology, evolution, genomics, and biochemistry of MTB. The applications of magnetosomes in biotechnology and paleoenvironmental reconstruction are also covered here.This research topic begins with a review on the relationship between all known magnetosome crystal habits and the phylogenetic affiliations of MTB (Pósfai et al., 2013), which serves as guide to better understand the evolutionary history of magnetosome formation and magnetotaxis in MTB. Following this review, Morillo et al. (2014) report the first cultivation and genomic characterization of a south-seeking Alphaproteobacteria magnetotactic coccus Magnetofaba australis strain IT-1 from the Southern Hemisphere. The findings of their study provide important clues to the evolution of magnetotactic Alphaproteobacteria. Oestreicher et al. (2013) examine the morphological and phylogenetic diversity of MTB in a freshwater lake containing microbialites. Their results raise the interesting question of whether MTB magnetosomes could be preserved in microbialites and serve as robust biomarkers. Kong et al. (2014) investigate the swimming behavior of a rod-shaped magnetotactic Nitrospirae, with hundreds bullet-shaped magnetite magnetosomes per ce...

show abstract

Changes of cell growth and magnetosome biomineralization in Magnetospirillum magneticum AMB-1 after ultraviolet-B irradiation

Cited by 14 publications

References 87 publications

Transcriptome analysis reveals physiological characteristics required for magnetosome formation in Magnetospirillum gryphiswaldense MSR‐1

Transcriptome analysis reveals physiological characteristics required for magnetosome formation in Magnetospirillum gryphiswaldense MSR‐1

Light irradiation helps magnetotactic bacteria eliminate intracellular reactive oxygen species

Intracellular biomineralization in bacteria

Contact Info

Product

Resources

About