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Benaud N, Zhang E, van Dorst J, Brown MV, Kalaitzis JA, Neilan BA, Ferrari BC. Harnessing long-read amplicon sequencing to uncover NRPS and Type I PKS gene sequence diversity in polar desert soils. FEMS Microbiol Ecol 2020; 95:5372416. [PMID: 30848780 DOI: 10.1093/femsec/fiz031] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 03/07/2019] [Indexed: 02/02/2023] Open
Abstract
The severity of environmental conditions at Earth's frigid zones present attractive opportunities for microbial biomining due to their heightened potential as reservoirs for novel secondary metabolites. Arid soil microbiomes within the Antarctic and Arctic circles are remarkably rich in Actinobacteria and Proteobacteria, bacterial phyla known to be prolific producers of natural products. Yet the diversity of secondary metabolite genes within these cold, extreme environments remain largely unknown. Here, we employed amplicon sequencing using PacBio RS II, a third generation long-read platform, to survey over 200 soils spanning twelve east Antarctic and high Arctic sites for natural product-encoding genes, specifically targeting non-ribosomal peptides (NRPS) and Type I polyketides (PKS). NRPS-encoding genes were more widespread across the Antarctic, whereas PKS genes were only recoverable from a handful of sites. Many recovered sequences were deemed novel due to their low amino acid sequence similarity to known protein sequences, particularly throughout the east Antarctic sites. Phylogenetic analysis revealed that a high proportion were most similar to antifungal and biosurfactant-type clusters. Multivariate analysis showed that soil fertility factors of carbon, nitrogen and moisture displayed significant negative relationships with natural product gene richness. Our combined results suggest that secondary metabolite production is likely to play an important physiological component of survival for microorganisms inhabiting arid, nutrient-starved soils.
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Affiliation(s)
- Nicole Benaud
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, 2052, Australia
| | - Eden Zhang
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, 2052, Australia
| | - Josie van Dorst
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, 2052, Australia
| | - Mark V Brown
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - John A Kalaitzis
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, 2052, Australia
| | - Brett A Neilan
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Belinda C Ferrari
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, 2052, Australia
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Pudasaini S, Wilson J, Ji M, van Dorst J, Snape I, Palmer AS, Burns BP, Ferrari BC. Microbial Diversity of Browning Peninsula, Eastern Antarctica Revealed Using Molecular and Cultivation Methods. Front Microbiol 2017; 8:591. [PMID: 28439263 PMCID: PMC5383709 DOI: 10.3389/fmicb.2017.00591] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 03/22/2017] [Indexed: 01/07/2023] Open
Abstract
Browning Peninsula is an ice-free polar desert situated in the Windmill Islands, Eastern Antarctica. The entire site is described as a barren landscape, comprised of frost boils with soils dominated by microbial life. In this study, we explored the microbial diversity and edaphic drivers of community structure across this site using traditional cultivation methods, a novel approach the soil substrate membrane system (SSMS), and culture-independent 454-tag pyrosequencing. The measured soil environmental and microphysical factors of chlorine, phosphate, aspect and elevation were found to be significant drivers of the bacterial community, while none of the soil parameters analyzed were significantly correlated to the fungal community. Overall, Browning Peninsula soil harbored a distinctive microbial community in comparison to other Antarctic soils comprised of a unique bacterial diversity and extremely limited fungal diversity. Tag pyrosequencing data revealed the bacterial community to be dominated by Actinobacteria (36%), followed by Chloroflexi (18%), Cyanobacteria (14%), and Proteobacteria (10%). For fungi, Ascomycota (97%) dominated the soil microbiome, followed by Basidiomycota. As expected the diversity recovered from culture-based techniques was lower than that detected using tag sequencing. However, in the SSMS enrichments, that mimic the natural conditions for cultivating oligophilic “k-selected” bacteria, a larger proportion of rare bacterial taxa (15%), such as Blastococcus, Devosia, Herbaspirillum, Propionibacterium and Methylocella and fungal (11%) taxa, such as Nigrospora, Exophiala, Hortaea, and Penidiella were recovered at the genus level. At phylum level, a comparison of OTU's showed that the SSMS shared 21% of Acidobacteria, 11% of Actinobacteria and 10% of Proteobacteria OTU's with soil. For fungi, the shared OTUs was 4% (Basidiomycota) and <0.5% (Ascomycota). This was the first known attempt to culture microfungi using the SSMS which resulted in an increase in diversity from 14 to 57 microfungi OTUs compared to standard cultivation. Furthermore, the SSMS offers the opportunity to retrieve a greater diversity of bacterial and fungal taxa for future exploitation.
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Affiliation(s)
- Sarita Pudasaini
- School of Biotechnology and Biomolecular Sciences, University of New South WalesKensington, NSW, Australia
| | - John Wilson
- School of Biotechnology and Biomolecular Sciences, University of New South WalesKensington, NSW, Australia
| | - Mukan Ji
- School of Biotechnology and Biomolecular Sciences, University of New South WalesKensington, NSW, Australia
| | - Josie van Dorst
- School of Biotechnology and Biomolecular Sciences, University of New South WalesKensington, NSW, Australia
| | - Ian Snape
- Australian Antarctic Division, Department of Sustainability, Environment, Water, Population and CommunitiesKingston, TAS, Australia
| | - Anne S Palmer
- Australian Antarctic Division, Department of Sustainability, Environment, Water, Population and CommunitiesKingston, TAS, Australia
| | - Brendan P Burns
- School of Biotechnology and Biomolecular Sciences, University of New South WalesKensington, NSW, Australia
| | - Belinda C Ferrari
- School of Biotechnology and Biomolecular Sciences, University of New South WalesKensington, NSW, Australia
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Özçelik Ü, Çevik H, Bircan HY, Yarbuğ Karakayalı F, Işıklar İ, Haberal M. Evaluation of Transplanted Kidneys and Comparison with Healthy Volunteers and Kidney Donors with Diffusion-Weighted Magnetic Resonance Imaging: Initial Experience. EXP CLIN TRANSPLANT 2017. [PMID: 28332960 DOI: 10.6002/ect.2016.0341] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVES The aim of this study was to evaluate the feasibility of diffusion-weighted magnetic resonance, by comparing imaging in renal allograft recipients for functional assessment of kidney transplants versus imaging of these features in healthy volunteers and kidney donors with native kidneys. MATERIALS AND METHODS Seventy renal transplant recipients (group A) with stable graft function at postoperative month 1, 40 healthy volunteers (group B), and 40 kidney donors (group C) underwent diffusion-weighted magnetic resonance imaging. An echo-planar diffusion-weighted imaging sequence was performed in coronal orientation by using 6 b values (0, 200, 400, 600, 800, 1000 s/mm²). The apparent diffusion coefficients were determined for the upper and lower poles of the kidney cortex and medulla. Relations between apparent diffusion coefficients and allograft function, determined by the estimated glomerular filtration rate (comparing rates > 60 mL/min/1.73 m² [group A1] versus < 60 mL/min/1.73 m² [group A2]), were investigated in renal transplant recipients, and apparent diffusion coefficients in groups A, B, and C were compared. RESULTS Apparent diffusion coefficients were statistically higher in group A1 than in group A2 (P < .05) and statistically higher in group A than in groups B and C (P < .001). There were no significant differences between groups B and C (P > .05). CONCLUSIONS We observed that apparent diffusion coefficients of transplanted kidneys at postoperative month 1 were higher than values in native kidneys of healthy volunteers and kidney donors. In addition, apparent diffusion coefficients of transplanted kidneys with estimated glomerular filtration rates > 60 mL/min/1.73 m² were higher than transplanted kidneys with rates < 60 mL/min/1.73 m².
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Affiliation(s)
- Ümit Özçelik
- Department of General Surgery, Baskent University School of Medicine, Ankara, Turkey
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Ferrari BC, Bissett A, Snape I, van Dorst J, Palmer AS, Ji M, Siciliano SD, Stark JS, Winsley T, Brown MV. Geological connectivity drives microbial community structure and connectivity in polar, terrestrial ecosystems. Environ Microbiol 2015; 18:1834-49. [DOI: 10.1111/1462-2920.13034] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 08/20/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Belinda C. Ferrari
- School of Biotechnology and Biomolecular Sciences; UNSW Australia; Randwick NSW 2052 Australia
| | - Andrew Bissett
- CSIRO Agriculture Flagship; PO Box 1600 Canberra ACT 2601 Australia
| | - Ian Snape
- Australian Antarctic Division, Department of Sustainability; Environment, Water, Population and Communities; 203 Channel Highway Kingston Tasmania 7050 Australia
| | - Josie van Dorst
- School of Biotechnology and Biomolecular Sciences; UNSW Australia; Randwick NSW 2052 Australia
| | - Anne S. Palmer
- Australian Antarctic Division, Department of Sustainability; Environment, Water, Population and Communities; 203 Channel Highway Kingston Tasmania 7050 Australia
| | - Mukan Ji
- School of Biotechnology and Biomolecular Sciences; UNSW Australia; Randwick NSW 2052 Australia
| | - Steven D. Siciliano
- Department of Soil Science; University of Saskatchewan; Saskatoon Saskatchewan S7N 5A8 Canada
| | - Jonathon S. Stark
- Australian Antarctic Division, Department of Sustainability; Environment, Water, Population and Communities; 203 Channel Highway Kingston Tasmania 7050 Australia
| | - Tristrom Winsley
- School of Biotechnology and Biomolecular Sciences; UNSW Australia; Randwick NSW 2052 Australia
- Australian Antarctic Division, Department of Sustainability; Environment, Water, Population and Communities; 203 Channel Highway Kingston Tasmania 7050 Australia
- Department of Soil Science; University of Saskatchewan; Saskatoon Saskatchewan S7N 5A8 Canada
| | - Mark V. Brown
- School of Biotechnology and Biomolecular Sciences; UNSW Australia; Randwick NSW 2052 Australia
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Venkatachalam S, Gowdaman V, Prabagaran SR. Culturable and culture-independent bacterial diversity and the prevalence of cold-adapted enzymes from the Himalayan mountain ranges of India and Nepal. MICROBIAL ECOLOGY 2015; 69:472-91. [PMID: 25204748 DOI: 10.1007/s00248-014-0476-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 07/28/2014] [Indexed: 05/18/2023]
Abstract
Bacterial diversity of soil samples collected from different geographical regions of Himalayan mountains was studied through culturable (13 samples) and culture-independent approaches (5 samples based on abundance of diversity indices in each ecological niche). Shannon-Wiener diversity index and total bacterial count ranged from 1.50 ± 0.1 to 2.57 ± 0.15 and 7.8 ± 1.6 × 10(5) to 30.9 ± 1.7 × 10(5) cfu ml(-1) of soil, respectively. Based on morphology and pigmentation, 406 isolates were selected by culturing in different cultivable media at various strengths and concentrations. All the strains were subjected to amplified ribosomal DNA restriction analysis and the representative isolates from each cluster were chosen for 16S rRNA gene sequence-based identification. Soil habitat in Himalayan foot hills was dominated by the genera Arthrobacter, Exiguobacterium, Bacillus, Cedecea, Erwinia, and Pseudomonas. Five 16S rRNA gene libraries from the selected five samples yielded 268 clones and were grouped into 53 phylotypes covering 25 genera including the genus of Ferribacterium, Rothia, and Wautersiella, which were reported for the first time in Himalayan tracks. Principal coordinates analysis indicates that all the clone libraries were clearly separated and found to be significantly different from each other. Further, extracellular investigation of cold-active enzymes showed activity of cellulase (23.71%), pectinase (20.24%), amylase (17.32%), phytase (13.87%), protease (12.72%), and lipase (23.71%) among the isolates. Four isolates namely Exiguobacterium mexicanum (BSa14), Exiguobacterium sibiricum (BZa11), Micrococcus antarcticus (BSb10), and Bacillus simplex (BZb3) showed multiple enzyme activity for five different types of enzymes. In addition, various genera like Exiguobacterium, Erwinia, Mycetecola, Cedecea, Pantoea, and Trichococcus have also shown novel hydrolytic enzyme activity in the Himalayan foothills.
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Affiliation(s)
- Siddarthan Venkatachalam
- Molecular Microbiology Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, 641046, Tamil Nadu, India
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