1
|
Rahalkar MC, Khatri K, Mohite J, Pandit PS, Bahulikar RA. A novel Type I methanotroph Methylolobus aquaticus gen. nov. sp. nov. isolated from a tropical wetland. Antonie van Leeuwenhoek 2020; 113:959-971. [PMID: 32270325 DOI: 10.1007/s10482-020-01410-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 03/30/2020] [Indexed: 11/28/2022]
Abstract
A novel gammaproteobacterial methanotroph; strain FWC3 was isolated from a tropical freshwater wetland sample collected near a beach in Western India. Strain FWC3 forms flesh pink/peach colored colonies, is non-motile, and the cells are present as diplococci, triads, tetracocci and aggregates. Strain FWC3 grows only on methane and methanol. As the 16S rRNA gene of strain FWC3 showed low similarities with other Type I methanotrophs (less than 94.3%), it was further investigated for its novelty and characterisation by a polyphasic approach. ANI indices and DDH values deduced from the draft genome of strain FWC3 (SEYW00000000.1) with the other nearest type strains (Methylocaldum marinum S8T and Methylococcus capsulatus BathT) were ~ 70% and ~ 15%, respectively. The low level similarities indicated that strain FWC3 can belong to a new genus and species. Additionally, strain FWC3 showed a unique fatty acid profile with the dominance of C16:1 ω7 and ω6c, C16:0 and C16:1 ω9c. During the characterisation of strain FWC3, a morphologically similar methanotroph, strain C50C1 was described (Ghashghavi et al. in mSphere 4:e00631-18, 2019) and named as 'Methylotetracoccus oryzae'. We found that strain FWC3 and strain C50C1 belonged to the same genus but could belong to different species based on the ANI indices and dDDH values (~ 94% and ~ 55%, respectively). However, strain C50C1 has not been deposited in two culture collections and not been validly described. Also, the 16S rRNA gene of strain C50C1 is neither available on the database nor can it be retrieved from the genome assembly. Based on the polyphasic characterisation and comparison to the other type strains of Methylococcaceae, we propose strain FWC3 (= JCM 33786T, = KCTC 72733T, = MCC 4198T) to be the type strain of a novel genus and species, for which the name Methylolobus aquaticus is proposed. Strain C50C1 (Ghashghavi et al. 2019) could represent another species ('Methylolobus oryzae').
Collapse
Affiliation(s)
- Monali C Rahalkar
- C2, Bioenergy Group, MACS Agharkar Research Institute, G. G. Agarkar Road, Pune, Maharashtra, 411004, India. .,Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India.
| | - Kumal Khatri
- C2, Bioenergy Group, MACS Agharkar Research Institute, G. G. Agarkar Road, Pune, Maharashtra, 411004, India.,Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India
| | - Jyoti Mohite
- C2, Bioenergy Group, MACS Agharkar Research Institute, G. G. Agarkar Road, Pune, Maharashtra, 411004, India.,Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India
| | - Pranitha S Pandit
- C2, Bioenergy Group, MACS Agharkar Research Institute, G. G. Agarkar Road, Pune, Maharashtra, 411004, India.,Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India
| | - Rahul A Bahulikar
- BAIF Development Research Foundation, Central Research Station, Urulikanchan, Pune, 412202, India
| |
Collapse
|
2
|
Khatri K, Mohite JA, Pandit PS, Bahulikar R, Rahalkar MC. Description of 'Ca. Methylobacter oryzae' KRF1, a novel species from the environmentally important Methylobacter clade 2. Antonie van Leeuwenhoek 2019; 113:729-735. [PMID: 31813064 DOI: 10.1007/s10482-019-01369-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 11/28/2019] [Indexed: 12/18/2022]
Abstract
Members of the genus Methylobacter (Mtb) have been identified to be the most dominant methanotrophs in aquatic as well as terrestrial habitats. Methylobacter shows four species with validly published names and these are grouped in two clades based on phylogenetic and genomic comparisons. Mtb luteus and Mtb marinus (synonym: Mtb whittenburyi) belong to clade 1 Methylobacter. Clade 2 Methylobacter comprises of two species: Mtb tundripaludum and Mtb psychrophilus (type strain, no longer available). We isolated a yellow pigmented, rod-shaped methanotroph, strain (KRF1), from a tropical rice field in India, which might represent a putative novel species within Methylobacter clade 2. The cells are long, thick and motile rods. The strain grows under variable oxygen concentration (5-80% air) and also in nitrogen free media (5-50% air). The morphological, chemotaxonomic and genomic features of KRF1 were investigated in details. The digital DNA-DNA hybridization values and average nucleotide identity (ANI) comparisons with the members of its closest species, Mtb tundripaludum, were in the range of 20-26% and ~ 73-81%, respectively. The fatty acid methyl esters profile of KRF1 was different from the profile of Mtb tundripaludum SV96T. The major cell wall fatty acids of strain KRF1 are 16:1 ω7c/16:1 ω6c summed feature (55.4%) and 16:1 ω5c (28.6%). The draft genome of KRF1 is of 5.04 Mbp in size with a GC content of 49.3% and the whole genome shotgun sequencing project has the accession number RYFG00000000 (version: RYFG02000000). Due to the difficulties in the maintenance and cryopreservation of this culture, it could not be deposited in two international culture collections. We thereby propose KRF1 to be member of a Candidatus species, 'Candidatus Methylobacter oryzae' KRF1. The culture is maintained live in our laboratory and also in our institutional WDCM approved culture collection (MACS Collection of Microorganisms) as MCMB-1471.
Collapse
Affiliation(s)
- Kumal Khatri
- C2, Bioenergy Group, MACS Agharkar Research Institute, G.G. Agarkar Road, Pune, Maharashtra, 411004, India.,Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India
| | - Jyoti A Mohite
- C2, Bioenergy Group, MACS Agharkar Research Institute, G.G. Agarkar Road, Pune, Maharashtra, 411004, India.,Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India
| | - Pranitha S Pandit
- C2, Bioenergy Group, MACS Agharkar Research Institute, G.G. Agarkar Road, Pune, Maharashtra, 411004, India.,Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India
| | - Rahul Bahulikar
- BAIF Development Research Foundation, Central Research Station, Urulikanchan, Pune, 412202, India
| | - Monali C Rahalkar
- C2, Bioenergy Group, MACS Agharkar Research Institute, G.G. Agarkar Road, Pune, Maharashtra, 411004, India. .,Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India.
| |
Collapse
|
3
|
Imchen M, Kumavath R, Vaz ABM, Góes-Neto A, Barh D, Ghosh P, Kozyrovska N, Podolich O, Azevedo V. 16S rRNA Gene Amplicon Based Metagenomic Signatures of Rhizobiome Community in Rice Field During Various Growth Stages. Front Microbiol 2019; 10:2103. [PMID: 31616390 PMCID: PMC6764247 DOI: 10.3389/fmicb.2019.02103] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 08/26/2019] [Indexed: 11/21/2022] Open
Abstract
Rice is a major staple food across the globe. Its growth and productivity is highly dependent on the rhizobiome where crosstalk takes place between plant and the microbial community. Such interactions lead to selective enrichment of plant beneficial microbes which ultimately defines the crop health and productivity. In this study, rhizobiome modulation is documented throughout the development of rice plant. Based on 16S rRNA gene affiliation at genus level, abundance, and diversity of plant growth promoting bacteria increased during the growth stages. The observed α diversity and rhizobiome complexity increased significantly (p < 0.05) during plantation. PCoA indicates that different geographical locations shared similar rhizobiome diversity but exerted differential enrichment (p < 0.001). Diversity of enriched genera represented a sigmoid curve and subsequently declined after harvest. A major proportion of dominant enriched genera (p < 0.05, abundance > 0.1%), based on 16S rRNA gene, were plant growth promoting bacteria that produces siderophore, indole-3-acetic acid, aminocyclopropane-1-carboxylic acid, and antimicrobials. Hydrogenotrophic methanogens dominated throughout cultivation. Type I methanotrophs (n = 12) had higher diversity than type II methanotrophs (n = 6). However, the later had significantly higher abundance (p = 0.003). Strong enrichment pattern was also observed in type I methanotrophs being enriched during water logged stages. Ammonia oxidizing Archaea were several folds more abundant than ammonia oxidizing bacteria. K-strategists Nitrosospira and Nitrospira dominated ammonia and nitrite oxidizing bacteria, respectively. The study clarifies the modulation of rhizobiome according to the rice developmental stages, thereby opening up the possibilities of bio-fertilizer treatment based on each cultivation stages.
Collapse
Affiliation(s)
- Madangchanok Imchen
- Department of Genomic Sciences, School of Biological Sciences, Central University of Kerala, Kasaragod, India
| | - Ranjith Kumavath
- Department of Genomic Sciences, School of Biological Sciences, Central University of Kerala, Kasaragod, India
| | - Aline B M Vaz
- Molecular and Computational Biology of Fungi Laboratory, Department of Microbiology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Aristóteles Góes-Neto
- Molecular and Computational Biology of Fungi Laboratory, Department of Microbiology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Debmalya Barh
- Molecular and Computational Biology of Fungi Laboratory, Department of Microbiology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil.,Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology (IIOAB), Purba Medinipur, India
| | - Preetam Ghosh
- Department of Computer Sciences, Virginia Commonwealth University, Richmond, VA, United States
| | - Natalia Kozyrovska
- Institute of Molecular Biology and Genetics, National Academy of Sciences, Kyiv, Ukraine
| | - Olga Podolich
- Institute of Molecular Biology and Genetics, National Academy of Sciences, Kyiv, Ukraine
| | - Vasco Azevedo
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| |
Collapse
|
4
|
Rahalkar MC, Khatri K, Pandit PS, Dhakephalkar PK. A putative novel Methylobacter member (KRF1) from the globally important Methylobacter clade 2: cultivation and salient draft genome features. Antonie van Leeuwenhoek 2019; 112:1399-1408. [PMID: 30968234 DOI: 10.1007/s10482-019-01262-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 04/02/2019] [Indexed: 11/28/2022]
Abstract
Methane oxidation by methanotrophs is a very important environmental process in the mitigation of methane. Methylobacter (Mtb.) clade 2 members have been reported as dominant methane oxidisers in soils and sediments worldwide. We enriched and purified a methanotroph from a tropical rice field soil sample from India. The highly enriched culture showed the presence of motile, long and thick rods (3-5 µm × 0.9-1.2 µm) and minor presence of short, thin rods. The culture was purified on agarose medium and formed yellow colonies which showed the presence of only thick and long rods, henceforth termed as strain KRF1. Based on 16S rRNA gene sequence analysis, strain KRF1 shows close phylogenetic affiliation to Methylobacter tundripaludum SV96T (98.6% similarity). Due to the taxonomic novelty, and being the first member of Mtb. related to Mtb. tundripaludum from the tropics, the draft genome was sequenced. From the blastx analysis of the contigs, it was clear that the culture still had contamination of another organism, a Methylophilus species. The data binned in two clear bins: Mtb. related contigs and Methylophilus-related contigs. The binned draft genome of KRF1 shows features including the typical pathways for methane metabolism, denitrification and the presence of molybdenum iron and vanadium-iron nitrogenase genes. KRF1 is phylogenetically distinct from the five strains of Mtb. tundripaludum including SV96T, Lake Washington strains and OWC strains, showing ~ 26% DDH and ~ 81% ANIb values and a unique position in a phylogenomic tree. Subsequently, KRF1 has been completely purified from its methylotrophic partner and a pure culture has been established and maintained in a WDCM approved culture collection, the MACS Collection of Microorganisms (as MCM 1471). KRF1 is thus the first cultured member of a putative novel species of Methylobacter clade 2 isolated from the tropics.
Collapse
Affiliation(s)
- Monali C Rahalkar
- C2, Bioenergy Group, MACS Agharkar Research Institute, G.G. Agarkar Road, Pune, Maharashtra, 411004, India. .,Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India.
| | - Kumal Khatri
- C2, Bioenergy Group, MACS Agharkar Research Institute, G.G. Agarkar Road, Pune, Maharashtra, 411004, India.,Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India
| | - Pranitha S Pandit
- C2, Bioenergy Group, MACS Agharkar Research Institute, G.G. Agarkar Road, Pune, Maharashtra, 411004, India.,Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India
| | - Prashant K Dhakephalkar
- C2, Bioenergy Group, MACS Agharkar Research Institute, G.G. Agarkar Road, Pune, Maharashtra, 411004, India.,Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India
| |
Collapse
|
5
|
Genome-based insights into a putative novel Methylomonas species (strain Kb3), isolated from an Indian rice field. GENE REPORTS 2018. [DOI: 10.1016/j.genrep.2018.08.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
6
|
Yu WJ, Lee JW, Nguyen NL, Rhee SK, Park SJ. The characteristics and comparative analysis of methanotrophs reveal genomic insights into Methylomicrobium sp. enriched from marine sediments. Syst Appl Microbiol 2018; 41:415-426. [DOI: 10.1016/j.syapm.2018.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 05/04/2018] [Accepted: 05/04/2018] [Indexed: 10/16/2022]
|
7
|
Description of ‘Candidatus Methylocucumis oryzae’, a novel Type I methanotroph with large cells and pale pink colour, isolated from an Indian rice field. Antonie van Leeuwenhoek 2018; 111:2473-2484. [DOI: 10.1007/s10482-018-1136-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 07/26/2018] [Indexed: 11/25/2022]
|