Isolation and characterization of wetland VSW-3, a novel lytic cold-active bacteriophage of<i>Pseudomonas fluorescens</i>

Qin, Kunhao; Ji, Xiuling; Zhang, Chunjing; Ding, Yafang; Kuang, Anxiu; Zhang, Shengting; Zhāng, Qí; Lü, Lin; Wei, Yunlin

doi:10.1139/cjm-2016-0368

Cited by 17 publications

(12 citation statements)

References 58 publications

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“…Similar to oceanic, brackish or freshwater ecosystems, bacteriophage represent the largest group of viruses in wetlands [ 20 , 23 ]. Caudovirales is the most common order among dsDNA viruses found in wetlands [ 24 , 25 ], and studies conducted in high-altitude wetlands in China isolated and characterized several bacteriophages within the Caudovirales order and the families Myoviridae [ 26 ], Siphoviridae [ 27 ] and Podoviridae [ 28 ].…”

Section: Introductionmentioning

confidence: 99%

Virus and Potential Host Microbes from Viral-Enriched Metagenomic Characterization in the High-Altitude Wetland, Salar de Huasco, Chile

et al. 2020

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Salar de Huasco is a wetland in the Andes mountains, located 3800 m above sea level at the Chilean Altiplano. Here we present a study aimed at characterizing the viral fraction and the microbial communities through metagenomic analysis. Two ponds (H0 and H3) were examined in November 2015. Water samples were processed using tangential flow filtration to obtain metagenomes from which the DNA fraction of the sample was amplified and sequenced (HiSeq system, Illumina). The ponds were characterized by freshwater and the viral-like particles to picoplankton ratio was 12.1 and 2.3 for H0 and H3, respectively. A great number of unassigned viral sequences were found in H0 (55.8%) and H3 (32.8%), followed by the family Fuselloviridae 20.8% (H0) and other less relatively abundant groups such as Microviridae (H0, 11.7% and H3, 3.3%) and Inoviridae (H3, 2.7%). The dominant viral sequences in both metagenomes belong to the order Caudovirales, with Siphoviridae being the most important family, especially in H3 (32.7%). The most important bacteria phyla were Proteobacteria, Bacteroidetes and Firmicutes in both sites, followed by Cyanobacteria (H0). Genes encoding lysogenic and lytic enzymes (i.e., recombinases and integrases) were found in H0 and H3, indicating a potential for active viral replication at the time of sampling; this was supported by the presence of viral metabolic auxiliary genes at both sites (e.g., cysteine hydrolase). In total, our study indicates a great novelty of viral groups, differences in taxonomic diversity and replication pathways between sites, which contribute to a better understanding of how viruses balance the cycling of energy and matter in this extreme environment.

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Section: Introductionmentioning

confidence: 99%

Virus and Potential Host Microbes from Viral-Enriched Metagenomic Characterization in the High-Altitude Wetland, Salar de Huasco, Chile

et al. 2020

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“…We found that in the last 10 years since Jackson and Jackson (2008), <30 studies had been published and the research focus on freshwater virology has increased twofold ranging from quantitative and qualitative aspects of the viral ecology to virus-prokaryote interactions, metagenomics, and method development (Supplementary Figures S1A,B, Supplementary Table S1). Most of the studies performed in riparian wetlands (Rooks et al, 2010; Fancello et al, 2013; Kyle and Grant, 2013; Basemer, 2015; Alexyuk et al, 2016; Saxton et al, 2016) and freshwater marshes (Leroy et al, 2008; Thomas et al, 2011; Kyle and Grant, 2013; Zheng et al, 2013; Motlagh et al, 2017; Qin et al, 2017; Dalcin Martins et al, 2018). Few studies were also performed in wetland microcosms (Pradeep Ram and Sime-Ngando, 2008, 2010; Esteban et al, 2015), and few others were in the form of reviews (Middelboe et al, 2008; Wilhelm and Matteson, 2008; Danovaro et al, 2008a; Neori Amir, 2017).…”

Section: Introductionmentioning

confidence: 99%

Implication of Viral Infections for Greenhouse Gas Dynamics in Freshwater Wetlands: Challenges and Perspectives

et al. 2019

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Viruses are non-living, acellular entities, and the most abundant biological agents on earth. They are widely acknowledged as having the capacity to influence global biogeochemical cycles by infecting the bacterial and archaeal populations that regulate carbon and nutrient turnover. Evidence suggests that the majority of viruses in wetlands are bacteriophages, but despite their importance, studies on how viruses control the prokaryotic community and the concomitant impacts on ecosystem function (such as carbon cycling and greenhouse gas flux) in wetlands are rare. Here we investigate virus-prokaryote interactions in freshwater wetland ecosystems in the context of their potential influence on biogeochemical cycling. Specifically, we (1) synthesize existing literature to establish current understanding of virus-prokaryote interactions, focusing on the implications for wetland greenhouse gas dynamics and (2) identify future research priorities. Viral dynamics in freshwater wetlands have received much less attention compared to those in marine ecosystems. However, based on our literature review, within the last 10 years, viral ecology studies on freshwater wetlands have increased twofold. Despite this increase in literature, the potential implication of viral infections on greenhouse gas emission dynamics is still a knowledge gap. We hypothesize that the rate of greenhouse gas emissions and the pool of sequestered carbon could be strongly linked to the type and rate of viral infection. Viral replication mechanism choice will consequently influence the microbial efficiency of organic matter assimilation and thus the ultimate fate of carbon as a greenhouse gas or stored in soils.

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“…After introducing the phage to suppress the growth of Pseudomonas in raw milk, it is necessary that the phage is inactivated by the pasteurization process used for market milk and other dairy products. For phage VSW-3, approximately 30 and 15% of initial activities remained after heat treatments at 60°C for 1 h and 70°C for 20 min, respectively (29). In contrast, the activity of phage HU1 decreased to a nondetectable level after heating at 63°C for 30 min (Fig.…”

Section: Discussionmentioning

confidence: 89%

“…Bacteriophages capable of lysing Pseudomonas strains at low temperatures (0 to 7°C) also have also been isolated, partially characterized, and named psychrophilic, psychrotrophic, or cold-active phages (26)(27)(28)(29)(30)(31)(32)(33). Phage VSW-3 can lyse P. fluorescens and was isolated from wetlands, revealing that optimal activity at pH 7.0 decreased when the phage was exposed to temperatures exceeding 60°C, and it could propagate and generate plaques between 4 and 28°C (29). Phage VSW-3 was identified as a member of the family Podoviridae based on TEM results and complete genome sequence analysis (40,556 bp) (33).…”

Section: Discussionmentioning

confidence: 99%

A Lytic Bacteriophage for Controlling Pseudomonas lactis in Raw Cow's Milk

Tanaka

Yamada

Takeuchi

et al. 2018

Appl Environ Microbiol

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The control of bacterial growth during milk processing is crucial for the quality maintenance of commercial milk and milk products. During a period of cold storage prior to heat treatments, some psychrotrophic bacteria grow and produce extracellular heat-resistant lipases and proteases that cause product defects. The use of lytic bacteriophages (phages) that infect and kill bacteria could be a useful tool for suppressing bacterial growth during this cold storage phase. In this study, we isolated a strain and a phage from raw cow's milk. Quantitative characterization of the phage was used to elucidate whether this phage was active under low temperatures and neutral pH and whether it was inactivated during pasteurization. Phage titer determination was possible under conditions ranging from pH 4 to 9 and from 3°C to 25°C; the phage was inactivated under pasteurization conditions at 63°C for 30 min. Furthermore, we showed that this phage reduced viable bacterial cell counts in both skim and whole milk. The results of this study represent the potential uses of phages for controlling psychrotrophic bacterial growth in raw cow's milk during cold storage. Suppression of bacterial growth in raw milk under cold storage is crucial for the quality control of commercially supplied milk. The use of lytic phages as low-cost microbicides is an attractive prospect. Due to strict host specificities, phages must be isolated from the raw milk where the host bacteria are growing. We first isolated the bacterial strain and then the phage infecting that strain. Partial phage genomic analysis showed that this is a newly isolated phage, different from any previously reported. This study reports a lytic phage for, and we have presented evidence here that this phage reduced viable bacterial cell counts not only in rich medium but also in skim and whole milk. As a result, we have concluded that the phage reported in this study would be useful in milk processing.

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Isolation and characterization of wetland VSW-3, a novel lytic cold-active bacteriophage ofPseudomonas fluorescens

Cited by 17 publications

References 58 publications

Virus and Potential Host Microbes from Viral-Enriched Metagenomic Characterization in the High-Altitude Wetland, Salar de Huasco, Chile

Virus and Potential Host Microbes from Viral-Enriched Metagenomic Characterization in the High-Altitude Wetland, Salar de Huasco, Chile

Implication of Viral Infections for Greenhouse Gas Dynamics in Freshwater Wetlands: Challenges and Perspectives

A Lytic Bacteriophage for Controlling Pseudomonas lactis in Raw Cow's Milk

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