scholarly journals Novel and Conventional Isolation Techniques to Obtain Planctomycetes from Marine Environments

2021 ◽  
Vol 9 (10) ◽  
pp. 2078
Author(s):  
Inês Vitorino ◽  
José Diogo Neves Santos ◽  
Ofélia Godinho ◽  
Francisca Vicente ◽  
Vítor Vasconcelos ◽  
...  

Bacteria from the distinctive Planctomycetes phylum are well spread around the globe; they are capable of colonizing many habitats, including marine, freshwater, terrestrial, and even extreme habitats such as hydrothermal vents and hot springs. They can also be found living in association with other organisms, such as macroalgae, plants, and invertebrates. While ubiquitous, only a small fraction of the known diversity includes axenic cultures. In this study, we aimed to apply conventional techniques to isolate, in diverse culture media, planctomycetes from two beaches of the Portuguese north-coast by using sediments, red, green, and brown macroalgae, the shell of the mussel Mytilus edulis, an anemone belonging to the species Actinia equina, and seawater as sources. With this approach, thirty-seven isolates closely related to seven species from the families Planctomycetaceae and Pirellulaceae (class Planctomycetia) were brought into pure culture. Moreover, we applied an iChip inspired in-situ culturing technique to successfully retrieve planctomycetes from marine sediments, which resulted in the isolation of three additional strains, two affiliated to the species Novipirellula caenicola and one to a putative novel Rubinisphaera. This work enlarges the number of isolated planctomycetal strains and shows the adequacy of a novel methodology for planctomycetes isolation.

2008 ◽  
Vol 20 (3) ◽  
pp. 280-290 ◽  
Author(s):  
Katherine M. Mullaugh ◽  
George W. Luther ◽  
Shufen Ma ◽  
Tommy S. Moore ◽  
Mustafa Yücel ◽  
...  

2021 ◽  
Vol 9 (3) ◽  
pp. 652
Author(s):  
Shigeru Kawai ◽  
Joval N. Martinez ◽  
Mads Lichtenberg ◽  
Erik Trampe ◽  
Michael Kühl ◽  
...  

Chloroflexus aggregans is a metabolically versatile, thermophilic, anoxygenic phototrophic member of the phylum Chloroflexota (formerly Chloroflexi), which can grow photoheterotrophically, photoautotrophically, chemoheterotrophically, and chemoautotrophically. In hot spring-associated microbial mats, C. aggregans co-exists with oxygenic cyanobacteria under dynamic micro-environmental conditions. To elucidate the predominant growth modes of C. aggregans, relative transcription levels of energy metabolism- and CO2 fixation-related genes were studied in Nakabusa Hot Springs microbial mats over a diel cycle and correlated with microscale in situ measurements of O2 and light. Metatranscriptomic analyses indicated two periods with different modes of energy metabolism of C. aggregans: (1) phototrophy around midday and (2) chemotrophy in the early morning hours. During midday, C. aggregans mainly employed photoheterotrophy when the microbial mats were hyperoxic (400–800 µmol L−1 O2). In the early morning hours, relative transcription peaks of genes encoding uptake hydrogenase, key enzymes for carbon fixation, respiratory complexes as well as enzymes for TCA cycle and acetate uptake suggest an aerobic chemomixotrophic lifestyle. This is the first in situ study of the versatile energy metabolism of C. aggregans based on gene transcription patterns. The results provide novel insights into the metabolic flexibility of these filamentous anoxygenic phototrophs that thrive under dynamic environmental conditions.


1991 ◽  
Vol 159 (1) ◽  
pp. 473-487 ◽  
Author(s):  
ELIZABETH DAHLHOFF ◽  
GEORGE N. SOMERO

Effects of temperature and hydrostatic pressure were measured on cytosolic malate dehydrogenases (cMDHs) from muscle tissue of a variety of shallow- and deep-living benthic marine invertebrates, including seven species endemic to the deep-sea hydrothermal vents. The apparent Michaelis-Menten constant (Km) of coenzyme (nicotinamide adenine dinucleotide, NADH), used to index temperature and pressure effects, was conserved within a narrow range (approximately 15–25 μmoll−1) at physiological temperatures and pressures for all species. However, at elevated pressures, the Km of NADH rose sharply for cMDHs of shallow species (depths of occurrence >Approximately 500 m), but not for the cMDHs of deep-sea species. Cytosolic MDHs of invertebrates from the deep-sea hydrothermal vents generally were not perturbed by elevated temperatures (15–25°C) at in situ pressures, but cMDHs of cold-adapted deep-sea species were. At a single measurement temperature, the Km of NADH for cMDHs from invertebrates from habitats with well-characterized temperatures was inversely related to maximal sustained body temperature. This correlation was used to predict the maximal sustained body temperatures of vent invertebrates for which maximal habitat and body temperatures are difficult to estimate. Species occurring on the ‘smoker chimneys’, which emit waters with temperatures up to 380°C, are predicted to have sustained body temperatures that are approximately 20–25°C higher than vent species living in cooler vent microhabitats. We conclude that, just as adaptation of enzymes to elevated pressures is important in establishing species’ depth distribution patterns, adaptation of pressure-adapted enzymes to temperature is critical in enabling certain vent species to exploit warm-water microhabitats in the vent environment.


Life ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 52 ◽  
Author(s):  
Alex Longo ◽  
Bruce Damer

Two widely-cited alternative hypotheses propose geological localities and biochemical mechanisms for life’s origins. The first states that chemical energy available in submarine hydrothermal vents supported the formation of organic compounds and initiated primitive metabolic pathways which became incorporated in the earliest cells; the second proposes that protocells self-assembled from exogenous and geothermally-delivered monomers in freshwater hot springs. These alternative hypotheses are relevant to the fossil record of early life on Earth, and can be factored into the search for life elsewhere in the Solar System. This review summarizes the evidence supporting and challenging these hypotheses, and considers their implications for the search for life on various habitable worlds. It will discuss the relative probability that life could have emerged in environments on early Mars, on the icy moons of Jupiter and Saturn, and also the degree to which prebiotic chemistry could have advanced on Titan. These environments will be compared to ancient and modern terrestrial analogs to assess their habitability and biopreservation potential. Origins of life approaches can guide the biosignature detection strategies of the next generation of planetary science missions, which could in turn advance one or both of the leading alternative abiogenesis hypotheses.


2021 ◽  
Vol 12 ◽  
Author(s):  
Aparna Banerjee ◽  
Shrabana Sarkar ◽  
Tanvi Govil ◽  
Patricio González-Faune ◽  
Gustavo Cabrera-Barjas ◽  
...  

Various microorganisms thrive under extreme environments, like hot springs, hydrothermal vents, deep marine ecosystems, hyperacid lakes, acid mine drainage, high UV exposure, and more. To survive against the deleterious effect of these extreme circumstances, they form a network of biofilm where exopolysaccharides (EPSs) comprise a substantial part. The EPSs are often polyanionic due to different functional groups in their structural backbone, including uronic acids, sulfated units, and phosphate groups. Altogether, these chemical groups provide EPSs with a negative charge allowing them to (a) act as ligands toward dissolved cations as well as trace, and toxic metals; (b) be tolerant to the presence of salts, surfactants, and alpha-hydroxyl acids; and (c) interface the solubilization of hydrocarbons. Owing to their unique structural and functional characteristics, EPSs are anticipated to be utilized industrially to remediation of metals, crude oil, and hydrocarbons from contaminated wastewaters, mines, and oil spills. The biotechnological advantages of extremophilic EPSs are more diverse than traditional biopolymers. The present review aims at discussing the mechanisms and strategies for using EPSs from extremophiles in industries and environment bioremediation. Additionally, the potential of EPSs as fascinating biomaterials to mediate biogenic nanoparticles synthesis and treat multicomponent water contaminants is discussed.


Author(s):  
Zatty Zawani Zaidi ◽  
Fahrul Huyop

Halogenated compound such as 2,2-dichloropropionic acid is known for its toxicity and polluted many areas especially with agricultural activities. This study focused on the isolation and characterization of the bacterium that can utilise 2,2-dichloropropionic acid from palm oil plantation in Lenga, Johor and in silico analysis of putative dehalogenase obtained from NCBI database of the same genus and species. The bacterium was isolated using an enrichment culture media supplemented with 20 mM 2,2-dicholoropropionic acid as a carbon source.  The cells were grown at 30˚C with cells doubling time of 2.00±0.005 hours with the maximum growth at A680nm of 1.047 overnight. The partial biochemical tests and morphological examination concluded that the bacterium belongs to the genus Staphylococcus sp.. This is the first reported studies of  Staphylococcus sp. with the ability to grow on 2,2-dichloropropionic acid. The genomic DNA from NCBI database of the same species was analysed assuming the same genus and has identical genomic sequence.  The full genome of Staphylococcus sp. was screened for dehalogenase gene and  haloacid dehalogenase gene was detected in the mobile genetic element of the species revealed that the dehalogenase sequence has little identities to the previously reported dehalogenases.The main outcome of the studies suggesting an in situ bioremediation can be regarded as a natural process to detoxify the contaminated sites provided that the microorganisms contained a specialised gene sequence within its genome that served the nature for many long years. Whether microorganisms will be successful in destroying man-made contaminants entirely rely on what types of organisms play a role in in situ bioremediation and which contaminants are most susceptible to bioremediation. 


2018 ◽  
Author(s):  
Karen G. Lloyd ◽  
Joshua Ladau ◽  
Andrew D. Steen ◽  
Junqi Yin ◽  
Lonnie Crosby

AbstractTo unequivocally determine a microbe’s physiology, including its metabolism, environmental roles, and growth characteristics, it must be grown in a laboratory culture. Unfortunately, many phylogenetically-novel groups have never been cultured, so their physiologies have only been inferred from genomics and environmental characteristics. Although the diversity, or number of different taxonomic groups, of uncultured clades has been well-studied, their global abundances, or number of cells in any given environment, have not been assessed. We quantified the degree of similarity of 16S rRNA gene sequences from diverse environments in publicly-available metagenome and metatranscriptome databases, which we show are largely free of the culture-bias present in primer-amplified 16S rRNA gene surveys, to their nearest cultured relatives. Whether normalized to scaffold read depths or not, the highest abundance of metagenomic 16S rRNA gene sequences belong to phylogenetically novel uncultured groups in seawater, freshwater, terrestrial subsurface, soil, hypersaline environments, marine sediment, hot springs, hydrothermal vents, non-human hosts, snow and bioreactors (22-87% uncultured genera to classes and 0-64% uncultured phyla). The exceptions were human and human-associated environments which were dominated by cultured genera (45-97%). We estimate that uncultured genera and phyla could comprise 7.3 × 1029(81%) and 2.2 × 1029(25%) microbial cells, respectively. Uncultured phyla were over-represented in meta transcript omes relative to metagenomes (46-84% of sequences in a given environment), suggesting that they are viable, and possibly more active than cultured clades. Therefore, uncultured microbes, often from deeply phylogenetically divergent groups, dominate non-human environments on Earth, and their undiscovered physiologies may matter for Earth systems.


2016 ◽  
Vol 51 (10) ◽  
pp. 4839-4844 ◽  
Author(s):  
Mudrika Khandelwal ◽  
Alan H. Windle ◽  
Nadine Hessler
Keyword(s):  

2002 ◽  
Vol 40 (5) ◽  
pp. 447-454 ◽  
Author(s):  
M. Mendoza ◽  
A. M. Díaz ◽  
M. B. Hung ◽  
E. A. Zambrano ◽  
E. Díaz ◽  
...  

2018 ◽  
Vol 4 (02) ◽  
pp. 81-87
Author(s):  
A. K. Asthana ◽  
S. D. Tewari ◽  
Vishwa Jyotsna Singh ◽  
Isha Pathak ◽  
Vinay Sahu

During the present study an effort has been made to propagate (in-vitro) the endangered and endemic Himalayan liverwort Stephensoniella brevipedunculata Kashyap using different culture media under controlled Laboratory conditions. Axenic cultures of the taxon have been established using tubers as explants. Seven combinations of media with Full Strength Knop’s macronutrients; Half-strength Knop’s macronutrients; Half-strength Knop’s macronutrients + Vitamins; Halfstrength Knop’s macronutrients + 0.2 mg L-1 IBA + 0.1 mg L-1 BAP; Half-strength Knop’s macronutrients + 0.1 mg L-1 Kinetin + 0.1 mg L-1 2,4D; Half-strength Knop’s macronutrients + 0.1 mg L-1 IBA + 0.2 mg L-1 BAP and Hoagland no. 2 basal salt mixture were used for culture. The best growth was observed in the Hoagland no. 2 basal salt mixture medium, in which dichotomously branched young thalli were successfully formed. Subsequently healthy population of culture grown plants has been raised on soil in pots for the first time.


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