1
|
Mohite JA, Manvi SS, Pardhi K, Khatri K, Bahulikar RA, Rahalkar MC. Thermotolerant methanotrophs belonging to the Methylocaldum genus dominate the methanotroph communities in biogas slurry and cattle dung: A culture-based study from India. ENVIRONMENTAL RESEARCH 2023; 228:115870. [PMID: 37060990 DOI: 10.1016/j.envres.2023.115870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/27/2023] [Accepted: 04/08/2023] [Indexed: 05/16/2023]
Abstract
Biogas reactors run on various types of waste, with cattle dung and agricultural wastes being the primary sources in India. As biogas contains 50-60% methane, there is a possibility that the reactors harbour methanotrophs or methane-oxidizing bacteria. We set up serial endpoint dilution enrichments for the cultivation of methanotrophs using slurry from a small biogas reactor and cattle dung samples and obtained cultures of Methylocaldum gracile, a thermotolerant methanotroph. The study was expanded by sampling reactors of another small reactor of 20 L capacity and two 1000 L reactors. Dung samples were obtained from two Indian cattle breeds (Tharparkar and Gir). Pulverized rice straw used for feeding the biogas was also used for experiments. All the enrichment bottles were incubated at 39 °C, the reactors' in-situ temperature, and the rumen gut temperature. Our study isolated four pure cultures most related to Methylocaldum gracile VKM-14LT, two strains from cattle dung samples, and two from reactors. The study also resulted in the cultivation of four additional cultures of Methylocaldum gracile and Methylocaldum tepidum, which were non-axenic and identified by pmoA gene sequencing. Pure cultures Methylocaldum gracile RS-9 and CDP-2 were studied for optimum temperature and oxygen. Both the strains were thermotolerant and grew in the temperature range of 25-45 °C with the optimum between 37 and 45 °C. The cultures could grow with minimal oxygen (0.5%-1%) in the headspace, with growth up to 10% oxygen. To summarize, we report the cultivation and isolation of methanotrophs from biogas slurries and cattle dung samples. Methylocaldum was the dominant methanotroph cultured, probably due to its thermotolerant nature and the ability to grow under variable oxygen conditions. The present study also expands the existing knowledge about habitats known for the genus Methylocaldum. An analysis of the isolated cultures would help us design strategies for methane mitigation from ruminants.
Collapse
Affiliation(s)
- Jyoti A Mohite
- C2 Block, Room 83,84, MACS Agharkar Research Institute, G.G. Agarkar Road, Pune, 411004, Maharashtra, India; Savitribai Phule Pune University, Ganeshkhind Road, Pune, 411007, Maharashtra, India
| | - Shubha S Manvi
- C2 Block, Room 83,84, MACS Agharkar Research Institute, G.G. Agarkar Road, Pune, 411004, Maharashtra, India; Savitribai Phule Pune University, Ganeshkhind Road, Pune, 411007, Maharashtra, India
| | - Kajal Pardhi
- C2 Block, Room 83,84, MACS Agharkar Research Institute, G.G. Agarkar Road, Pune, 411004, Maharashtra, India; Savitribai Phule Pune University, Ganeshkhind Road, Pune, 411007, Maharashtra, India
| | - Kumal Khatri
- C2 Block, Room 83,84, MACS Agharkar Research Institute, G.G. Agarkar Road, Pune, 411004, Maharashtra, India; Savitribai Phule Pune University, Ganeshkhind Road, Pune, 411007, Maharashtra, India
| | - Rahul A Bahulikar
- BAIF Development Research Foundation, Central Research Station, Urulikanchan, Pune, 412202, India
| | - Monali C Rahalkar
- C2 Block, Room 83,84, MACS Agharkar Research Institute, G.G. Agarkar Road, Pune, 411004, Maharashtra, India; Savitribai Phule Pune University, Ganeshkhind Road, Pune, 411007, Maharashtra, India.
| |
Collapse
|
2
|
Kaise H, Sawadogo JB, Alam MS, Ueno C, Dianou D, Shinjo R, Asakawa S. Methylocystis iwaonis sp. nov., a type II methane-oxidizing bacterium from surface soil of a rice paddy field in Japan, and emended description of the genus Methylocystis ( ex Whittenbury et al. 1970) Bowman et al. 1993. Int J Syst Evol Microbiol 2023; 73. [PMID: 37279153 DOI: 10.1099/ijsem.0.005925] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023] Open
Abstract
A novel methane-oxidizing bacterial strain SS37A-ReT was isolated from surface soil of a rice paddy field in Japan. Cells were Gram-stain-negative, motile rods with single polar flagellum and type II intracytoplasmic membrane arrangement. The strain grew on methane or methanol as the sole carbon and energy source. It grew at 15–37 °C (optimum 25–30 °C), pH 6.0–9.0 (optimum 7.0–8.0) and with 0–0.1 % (w/w) NaCl (no growth at 0.5 % or above). Cells formed cysts, but not exospores. The results of sequence analysis of the 16S rRNA gene indicated that SS37A-ReT represented a member of the family
Methylocystaceae
, with the highest similarity (98.9 %) to Methylocystis parva corrig. OBBPT. Phylogenetic analysis of pmoA and mxaF genes and core genes in the genome indicated that the strain was closely related to the members of the genus
Methylocystis
, while the analysis of the mmoX gene indicated the close relationships with the genus
Methylosinus
. The values of genome relatedness between SS37A-ReT and species of the genera
Methylocystis
and
Methylosinus
were 78.6–82.5% and 21.7–24.9 % estimated by the average nucleotide identity and digital DNA–DNA hybridisation, respectively, showing the highest values with
Methylocystis echinoides
LMG 27198T. The DNA G+C content was 63.2 mol% (genome). The major quinone and fatty acids were Q-8 and, C18 : 1 (C18 : 1ω8t and C18 : 1ω8c) and C18 : 2, respectively. On the basis of the phenotypic and phylogenetic features, the strain represents a novel species of the genus
Methylocystis
, for which the name Methylocystis iwaonis sp. nov. is proposed. The type strain is SS37A-ReT (=JCM 34278T =NBRC 114996T=KCTC 82710T).
Collapse
Affiliation(s)
- Hirotaka Kaise
- Graduate School of Bioagricultural Sciences, Nagoya University, Furocho, Chikusa, Nagoya 464-8601, Japan
| | - Joseph Benewindé Sawadogo
- Graduate School of Bioagricultural Sciences, Nagoya University, Furocho, Chikusa, Nagoya 464-8601, Japan
- Université Nazi BONI, Bobo-Dioulasso, 01 BP 1091 Bobo-Dioulasso 01, Burkina Faso
| | - Mohammad Saiful Alam
- Graduate School of Bioagricultural Sciences, Nagoya University, Furocho, Chikusa, Nagoya 464-8601, Japan
- Bangabandhu Sheikh Mujibur Rahman Agricultural University, Salna, Gazipur 1706, Bangladesh
| | - Chihoko Ueno
- Graduate School of Bioagricultural Sciences, Nagoya University, Furocho, Chikusa, Nagoya 464-8601, Japan
| | - Dayéri Dianou
- Graduate School of Bioagricultural Sciences, Nagoya University, Furocho, Chikusa, Nagoya 464-8601, Japan
- Centre National de la Recherche Scientifique et Technologique, Ouagadougou, 03 BP 7047 Ouagadougou 03, Burkina Faso
| | - Rina Shinjo
- Graduate School of Bioagricultural Sciences, Nagoya University, Furocho, Chikusa, Nagoya 464-8601, Japan
| | - Susumu Asakawa
- Graduate School of Bioagricultural Sciences, Nagoya University, Furocho, Chikusa, Nagoya 464-8601, Japan
| |
Collapse
|
3
|
Roldán DM, Menes RJ. Characterisation of 'Candidatus Methylobacter titanis' sp. nov., a putative novel species of Methylobacter clade 2 and their distribution in sediments of freshwater lakes in maritime Antarctica. Antonie Van Leeuwenhoek 2023:10.1007/s10482-023-01840-1. [PMID: 37227602 DOI: 10.1007/s10482-023-01840-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 05/07/2023] [Indexed: 05/26/2023]
Abstract
Global warming has a strong impact on the polar regions, in particular, the Antarctic Peninsula and nearby islands. Methane (CH4) is a major factor in climate change and mitigation of CH4 emissions can be accomplished through microbial oxidation by methanotrophic bacteria. Understanding this biological process is crucial given the shortage of research carried out in this geographical area. The aim of this study was to characterise psychrophilic enrichment cultures of aerobic methanotrophs obtained from lake sediments of the Fildes Peninsula (King George Island, South Shetland Islands) and revealing the distribution of the genus Methylobacter in different lake sediments of the peninsula. Four stable methanotrophic enrichment cultures were obtained and analysed by metagenome-assembled genomes (MAGs). The phylogeny of methanotroph MAGs recovered from these enrichment cultures based on the 16S rRNA gene showed that K-2018 MAG008 and D1-2020 MAG004Ts clustered within the Methylobacter clade 2, with high similarity to Methylobacter tundripaludum SV96T (97.88 and 98.56% respectively). However, the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values with M. tundripaludum were < 95% (84.8 and 85.0%, respectively) and < 70% (30.2 and 30.3%, respectively), suggesting that they represent a putative novel species for which the name 'Ca. Methylobacter titanis' is proposed. This is the first species of clade 2 of the genus Methylobacter obtained from Antarctica. The bacterial diversity assessed by 16S rRNA gene sequencing of 21 samples of different lakes (water column and sediments) revealed 54 ASVs associated with methanotrophs and the genus Methylobacter as the most abundant. These results suggest that aerobic methanotrophs belonging to the Methylobacter clade 2 would be the main responsible for CH4 oxidation in these sediments.
Collapse
Affiliation(s)
- Diego M Roldán
- Laboratorio de Ecología Microbiana Medioambiental, Microbiología, Facultad de Química, Universidad de la República, Montevideo, Uruguay
- Laboratorio de Microbiología, Unidad Asociada del Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Rodolfo Javier Menes
- Laboratorio de Ecología Microbiana Medioambiental, Microbiología, Facultad de Química, Universidad de la República, Montevideo, Uruguay.
- Laboratorio de Microbiología, Unidad Asociada del Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.
| |
Collapse
|
4
|
Kulkarni PP, Chavan SB, Deshpande MS, Sagotra D, Kumbhar PS, Ghosalkar AR. Enrichment of Methylocystis dominant mixed culture from rice field for PHB production. J Biotechnol 2022; 343:62-70. [PMID: 34838616 DOI: 10.1016/j.jbiotec.2021.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/16/2021] [Accepted: 11/20/2021] [Indexed: 11/16/2022]
Abstract
Presence of methanotrophs in diverse environmental habitats helps to reduce emissions of greenhouse gas like methane. Isolation and culture of undiscovered wealth of methanotrophic organisms can help in exploitation of these organisms in value added products. The present study focuses on the enrichment of methanotroph dominated mixed microbial community by use of three stage strategy of revival, proliferation, and segregation. During the enrichment process amplicon sequencing of 16 s rRNA V3-V4 region showed relative abundance of mixed culture comprising single methanotrophic species of Methylocystis genus (88.92%) along with only three other species. Methylocystis dominant mixed culture (MMI-11) was observed to produce polyhydroxyalkanoates (PHA). During studies to identify favourable culture conditions, nitrate was found to be preferred nitrogen source for growth and PHA production. Cell growth ability to produce PHA was also evaluated at 14 L fermentor by supplying gas using continuous bubbling and through pressurization in the headspace. The mixed methanotrophic culture was found to accumulate maximum of 22.20% polyhydroxybutyrate (PHB) under nitrate limited condition. The molecular weight of PHB was found to be 2.221 × 105 g mol-1 with polydispersity of 1.82.
Collapse
Affiliation(s)
- Pranav P Kulkarni
- Department of Technology, Savitribai Phule Pune University, Pune, India; Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India
| | - Sambhaji B Chavan
- Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India
| | - Mandar S Deshpande
- Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India
| | - Dhanishta Sagotra
- Department of Technology, Savitribai Phule Pune University, Pune, India
| | - Pramod S Kumbhar
- Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India
| | - Anand R Ghosalkar
- Department of Technology, Savitribai Phule Pune University, Pune, India; Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India.
| |
Collapse
|
5
|
Rahalkar MC, Khatri K, Pandit P, Bahulikar RA, Mohite JA. Cultivation of Important Methanotrophs From Indian Rice Fields. Front Microbiol 2021; 12:669244. [PMID: 34539593 PMCID: PMC8447245 DOI: 10.3389/fmicb.2021.669244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 08/09/2021] [Indexed: 11/15/2022] Open
Abstract
Methanotrophs are aerobic to micro-aerophilic bacteria, which oxidize and utilize methane, the second most important greenhouse gas. The community structure of the methanotrophs in rice fields worldwide has been studied mainly using culture-independent methods. Very few studies have focused on culturing methanotrophs from rice fields. We developed a unique method for the cultivation of methanotrophs from rice field samples. Here, we used a modified dilute nitrate mineral salts (dNMS) medium, with two cycles of dilution till extinction series cultivation with prolonged incubation time, and used agarose in the solid medium. The cultivation approach resulted in the isolation of methanotrophs from seven genera from the three major groups: Type Ia (Methylomonas, Methylomicrobium, and Methylocucumis), Type Ib (Methylocaldum and Methylomagnum), and Type II (Methylocystis and Methylosinus). Growth was obtained till 10–6–10–8 dilutions in the first dilution series, indicating the culturing of dominant methanotrophs. Our study was supported by 16S rRNA gene-based next-generation sequencing (NGS) of three of the rice samples. Our analyses and comparison with the global scenario suggested that the cultured members represented the major detected taxa. Strain RS1, representing a putative novel species of Methylomicrobium, was cultured; and the draft genome sequence was obtained. Genome analysis indicated that RS1 represented a new putative Methylomicrobium species. Methylomicrobium has been detected globally in rice fields as a dominant genus, although no Methylomicrobium strains have been isolated from rice fields worldwide. Ours is one of the first extensive studies on cultured methanotrophs from Indian rice fields focusing on the tropical region, and a unique method was developed. A total of 29 strains were obtained, which could be used as models for studying methane mitigation from rice fields and for environmental and biotechnological applications.
Collapse
Affiliation(s)
- Monali C Rahalkar
- C2, Bioenergy Group, MACS Agharkar Research Institute, Pune, India.,Department of Microbiology, Savitribai Phule Pune University, Pune, India
| | - Kumal Khatri
- C2, Bioenergy Group, MACS Agharkar Research Institute, Pune, India.,Department of Microbiology, Savitribai Phule Pune University, Pune, India
| | - Pranitha Pandit
- C2, Bioenergy Group, MACS Agharkar Research Institute, Pune, India.,Department of Microbiology, Savitribai Phule Pune University, Pune, India
| | - Rahul A Bahulikar
- Central Research Station, BAIF Development Research Foundation, Pune, India
| | - Jyoti A Mohite
- C2, Bioenergy Group, MACS Agharkar Research Institute, Pune, India.,Department of Microbiology, Savitribai Phule Pune University, Pune, India
| |
Collapse
|
6
|
Isolation, Description and Genome Analysis of a Putative Novel Methylobacter Species (‘Ca. Methylobacter coli’) Isolated from the Faeces of a Blackbuck (Indian Antelope). MICROBIOLOGY RESEARCH 2021. [DOI: 10.3390/microbiolres12020035] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Enteric fermentation of methane by ruminant animals represents a major source of anthropogenic methane. Significantly less information is available on the existence of methanotrophs in the gut of ruminants. Therefore, detailed strain descriptions of methanotrophs isolated from ruminant faeces or gut are rare. We present a first report on the enrichment and isolation of a methanotroph, strain BlB1, from the faeces of an Indian antelope (blackbuck). The 16S rRNA gene sequence of strain BlB1 showed the highest identity (98.40% identity) to Methylobacter marinus A45T and Methylobacter luteus NCIMB 11914T. Strain BlB1 showed coccoidal cells (1.5–2 µm in diameter), which formed chains or aggregates of 3–4 cells of light yellow-coloured colonies on agarose when incubated with methane in the gas phase. The draft genome of BlB1 (JADMKV01) is 4.87 Mbp in size, with a G + C content of 51.3%. The draft genome showed 27.4% digital DNA-DNA hybridization (DDH) and 83.07% average nucleotide identity (ANIb) values with that of its closest phylogenetic neighbour, Methylobacter marinus A45T. Due to the lower values of DDH and ANIb with the nearest species, and <98.7% 16S rRNA gene sequence identity, we propose that strain BlB1 belongs to a novel species of Methylobacter. However, as the culture has to be maintained live and resisted cryopreservation, deposition in culture collections was not possible and hence we propose a Candidatus species name, ‘Ca. Methylobacter coli’ BlB1. ‘Ca. Methylobacter coli’ BlB1 would be the first described methanotroph from ruminants worldwide, with a sequenced draft genome. This strain could be used as a model for studies concerning methane mitigation from ruminants.
Collapse
|
7
|
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
|
8
|
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
|
9
|
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
|
10
|
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
|
11
|
Renaming of ‘Candidatus Methylocucumis oryzae’ as Methylocucumis oryzae gen. nov., sp. nov., a novel Type I methanotroph isolated from India. Antonie van Leeuwenhoek 2018; 112:955-959. [DOI: 10.1007/s10482-018-01218-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 12/11/2018] [Indexed: 11/26/2022]
|
12
|
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]
|
13
|
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]
|
14
|
Rahalkar MC, Patil S, Dhakephalkar PK, Bahulikar RA. Cultivated methanotrophs associated with rhizospheres of traditional rice landraces from Western India belong to Methylocaldum and Methylocystis. 3 Biotech 2018; 8:281. [PMID: 29881659 DOI: 10.1007/s13205-018-1306-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 05/25/2018] [Indexed: 10/14/2022] Open
Abstract
Aerobic methanotrophs associated with Indian rice plants have rarely been cultivated. In the present study, we cultured aerobic methanotrophic bacteria from the rhizosphere regions of rice plants. Rhizospheric soils from seven rice landraces traditionally grown and maintained by tribal people in Jawhar region belonging to part of the Western Ghats in India, were used. Seven methanotrophic cultures were isolated from the last positive dilution (10- 4). Methanotrophs were identified by analyzing the partial methane monooxygenase gene, pmoA gene and three of these belonged to the genus Methylocaldum (gammaproteobacterial, Type I methanotrophs) and four belonged to the genus Methylocystis (alphaproteobacterial, Type II methanotrophs). We present here the first report on the cultivation of methanotrophs from Indian traditional rice landraces originating from a biodiversity hotspot.
Collapse
|
15
|
Rahalkar MC, Bahulikar RA. Hemerythrins are widespread and conserved for methanotrophic guilds. GENE REPORTS 2018. [DOI: 10.1016/j.genrep.2018.04.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
16
|
Frindte K, Maarastawi SA, Lipski A, Hamacher J, Knief C. Characterization of the first rice paddy cluster I isolate, Methyloterricola oryzae gen. nov., sp. nov. and amended description of Methylomagnum ishizawai. Int J Syst Evol Microbiol 2017; 67:4507-4514. [PMID: 28984554 DOI: 10.1099/ijsem.0.002319] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Three gammaproteobacterial methanotrophic strains (73aT, 175 and 114) were isolated from stems of rice plants. All strains are Gram-negative, motile and grow on methane or methanol as sole carbon sources. They oxidize methane using the particulate methane monooxygenase. Strains 114 and 175 possess additionally a soluble methane monooxygenase. All strains contain significant amounts of the cellular fatty acids C16 : 0, C16 : 1ω6c and C16 : 1ω7c, typical for type Ib methanotrophs. Characteristic for strains 114 and 175 are high amounts of C14 : 0 and C16 : 1ω6c , while strain 73aT contains high quantities of C16 : 1ω5c. 16S rRNA gene sequence analyses showed that strains 114 and 175 are most closely related to Methylomagnum ishizawai (≥99.6 % sequence identity). Strain 73aT is representing a new genus within the family Methylococcaceae, most closely related to Methylococcus capsulatus (94.3 % sequence identity). Phylogenetic analysis of the PmoA sequence indicates that strain 73aT represents rice paddy cluster I (RPCI), which has almost exclusively been detected in rice ecosystems. The G+C content of strain 73aT is 61.0 mol%, while strains 114 and 175 have a G+C content of 63.3 mol%. Strain 73aT (=LMG 29185T, =VKM B-2986T) represents the type strain of a novel species and genus, for which the name Methyloterricola oryzae gen. nov., sp. nov. is proposed and a description is provided. Strains 175 (=LMG 28717, VKM B-2989) and 114 are members of the species Methylomagnum ishizawai. This genus was so far only represented by one isolate, so an amended description of the species is given.
Collapse
Affiliation(s)
- Katharina Frindte
- Molecular Biology of the Rhizosphere, Institute of Crop Science and Resource Conservation, University of Bonn, Nussallee 13, 53115 Bonn, Germany
| | - Sarah A Maarastawi
- Molecular Biology of the Rhizosphere, Institute of Crop Science and Resource Conservation, University of Bonn, Nussallee 13, 53115 Bonn, Germany
| | - André Lipski
- Food Microbiology and Hygiene, Institute of Nutritional and Food Sciences, University of Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany
| | - Joachim Hamacher
- Plant Diseases and Crop Protection, Institute of Crop Science and Resource Conservation, University of Bonn, Nussallee 9, 53115 Bonn, Germany
| | - Claudia Knief
- Molecular Biology of the Rhizosphere, Institute of Crop Science and Resource Conservation, University of Bonn, Nussallee 13, 53115 Bonn, Germany
| |
Collapse
|
17
|
Pandit PS, Ranade DR, Dhakephalkar PK, Rahalkar MC. A pmoA-based study reveals dominance of yet uncultured Type I methanotrophs in rhizospheres of an organically fertilized rice field in India. 3 Biotech 2016; 6:135. [PMID: 28330207 PMCID: PMC4910840 DOI: 10.1007/s13205-016-0453-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 06/03/2016] [Indexed: 11/28/2022] Open
Abstract
Rice fields are one of the important sources of anthropogenic methane. Methanotrophs can oxidize up to 30 % of the produced methane and thus have a pivotal environmental role in methane mitigation. India occupies the largest region under rice cultivation; however, most of the studies done on methanotrophic communities have focused on the Northern region. We studied methanotrophic community of a flooded, organically fertilized rice field using pmoA clone library approach. Organic rice fields impose a more serious threat as they produce more methane. pmoA gene is the main functional gene which is primarily used for taxonomical analysis of methanotrophs. Our results showed that the pmoA clone libraries from two growth stages of rice were dominated by pmoA sequences which were very distant from cultivated Type Ia methanotrophic genera (80–82 % nucleotide similarity) indicative of the presence of a putatively novel genus. We designated this group of clones as ‘rice field clones’ as this also includes many pmoA sequences originating from other rice fields. Thus, our current knowledge of methanotroph diversity from Indian rice fields has been expanded revealing that a substantial portion of methanotrophic diversity is unexplored.
Collapse
Affiliation(s)
- Pranitha S Pandit
- MACS Agharkar Research Institute, G.G. Agarkar Road, Pune, Maharashtra, 411004, India
| | - Dilip R Ranade
- MACS Agharkar Research Institute, G.G. Agarkar Road, Pune, Maharashtra, 411004, India
- Microbial Culture Collection, NCCS, Sai-Trinity Building, Pashan, Pune, Maharashtra, 411021, India
| | | | - Monali C Rahalkar
- MACS Agharkar Research Institute, G.G. Agarkar Road, Pune, Maharashtra, 411004, India.
| |
Collapse
|