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PloS One 2022Auxospore production is a sexual reproductive strategy by diatoms to re-attain normal size after the size-reducing effect of clonal reproduction. Aside from the minimum...
Auxospore production is a sexual reproductive strategy by diatoms to re-attain normal size after the size-reducing effect of clonal reproduction. Aside from the minimum size threshold used as a sex clock by diatoms, the environmental or chemical triggers that can induce sex in diatoms are still not well understood. Here we investigated the influence of six marine bacteria from five families on the production of sexual cells and auxospores of the ubiquitous marine polar centric diatom, Odontella sp. Microbiome association and co-occurrence with the diatom in culture and in nature were investigated using 16S rRNA amplicon sequencing. Indole acetic acid (IAA) secretion, a phytohormone that regulates plants' growth and sexual development, was explored as a potential inducer of sexual reproduction in Odontella and compared between bacterial associates. We found that Odontella co-cultured with Flavobacteriaceae (Polaribacter and Cellulophaga) have significantly more sexual cells and auxospores than bacteria-free Odontella and Odontella co-cultured with other bacteria from Vibrionaceae (Vibrio), Pseudoalteromonadaceae (Pseudoalteromonas), Rhodobacteraceae (Sulfitobacter), or Planococcaceae (Planococcus) family. Differences in IAA secretion were observed between bacterial isolates, but this did not correspond consistently with the diatom's clonal growth or production of sexual cells and auxospores. Microbiome composition survey of Odontella cultures showed that the diatom harbors homologous sequences of the four bacterial isolates at varying proportions, with Sulfitobacter and Polaribacter at high abundances. Microbiome surveys at Santa Cruz Wharf, Monterey Bay, from 2014-2015 showed that Odontella abundance is positively correlated with Flavobacteriaceae and Rhodobacteraceae abundances. Our study demonstrates that specific members of the diatom microbiome can enhance the host's sexual reproduction, with the interkingdom interaction driven by partner compatibility and long-term association. Sex-enhancing bacteria may even be needed by the diatom host to carry out the optimal inducement of sex under normal conditions, allowing for size restitution and maintaining genetic diversity in culture and in nature.
Topics: Humans; Animals; Diatoms; RNA, Ribosomal, 16S; Plant Growth Regulators; Microbiota; Arthropods; Reproduction; Rhodobacteraceae
PubMed: 36260629
DOI: 10.1371/journal.pone.0276305 -
Frontiers in Microbiology 2021Protease-producing bacteria play vital roles in degrading organic matter of aquaculture system, while the knowledge of diversity and bacterial community structure of...
Protease-producing bacteria play vital roles in degrading organic matter of aquaculture system, while the knowledge of diversity and bacterial community structure of protease-producing bacteria is limited in this system, especially in the tropical region. Herein, 1,179 cultivable protease-producing bacterial strains that belonged to Actinobacteria, Firmicutes, and Proteobacteria were isolated from tropical aquaculture systems, of which the most abundant genus was , followed by . The diversity and relative abundance of protease-producing bacteria in sediment were generally higher than those in water. Twenty-one genera from sediment and 16 genera from water were identified, of which dominated by in both and dominated by in water were the dominant genera. The unique genera in sediment or water accounted for tiny percentage may play important roles in the stability of community structure. Eighty isolates were clustered into four clusters (ET-1-ET-4) at 58% of similarity by ERIC-PCR (enterobacterial repetitive intergenic consensus-polymerase chain reaction), which was identified as a novel branch of . Additionally, strains belonged to ET-3 and ET-4 were detected in most aquaculture ponds without outbreak of epidemics, indicating that these protease-producing bacteria may be used as potential beneficial bacteria for wastewater purification. Environmental variables played important roles in shaping protease-producing bacterial diversity and community structure in aquaculture systems. In sediment, dissolved oxygen (DO), chemical oxygen demand (COD), and salinity as the main factors positively affected the distributions of dominant genus () and unique genera ( and ), whereas temperature negatively affected that of (except ). In water, as unique genus and were negatively affected by NO -N and NO -N, respectively, whereas pH as the main factor positively affected the distribution of . These findings will lay a foundation for the development of protease-producing bacterial agents for wastewater purification and the construction of an environment-friendly tropical aquaculture model.
PubMed: 33613508
DOI: 10.3389/fmicb.2021.638129 -
Biology Mar 2022The Taklimakan Desert located in China is the second-largest shifting sand desert in the world and is known for its harsh conditions. Types of γ-rays or UV...
The Taklimakan Desert located in China is the second-largest shifting sand desert in the world and is known for its harsh conditions. Types of γ-rays or UV radiation-resistant bacterial strains have been isolated from this desert. However, there is no information regarding the proportions of the radiation-resistant strains in the total culturable microbes. We isolated 352 bacterial strains from nine sites across the Taklimakan Desert from north to south. They belong to Actinobacteria, Firmicutes, Proteobacteria, and Bacteroidetes. The phylum Actinobacteria was the most predominant in abundance and Firmicutes had the highest species richness. Bacteroidetes had the lowest abundance and was found in four sites only, while the other three phyla were found in every site but with different distribution profiles. After irradiating with 1000 J/m and 6000 J/m UV-C, the strains with survival rates higher than 10% occupied 72.3% and 36.9% of all culturable bacteria, respectively. The members from Proteobacteria had the highest proportions, with survival rates higher than 10%. After radiation with 10 kGy γ-rays, sp. TKL1057 and sp. TKL1152 showed higher radiation-resistant capabilities than R1. Besides obtaining several radiation-resistant extremophiles, this study measured the proportions of the radiation-resistant strains in the total culturable microbes for the first time. This study may help to better understand the origin of radioresistance, especially by quantitatively comparing proportions of radiation-resistant extremophiles from different environments in the future.
PubMed: 35453702
DOI: 10.3390/biology11040501 -
PeerJ 2024Plastic waste is a global environmental issue that impacts the well-being of humans, animals, plants, and microorganisms. Microplastic contamination has been previously...
BACKGROUND
Plastic waste is a global environmental issue that impacts the well-being of humans, animals, plants, and microorganisms. Microplastic contamination has been previously reported at Kung Wiman Beach, located in Chanthaburi province along with the Eastern Gulf of Thailand. Our research aimed to study the microbial population of the sand and plastisphere and isolate microorganisms with potential plastic degradation activity.
METHODS
Plastic and sand samples were collected from Kung Wiman Beach for microbial isolation on agar plates. The plastic samples were identified by Fourier-transform infrared spectroscopy. Plastic degradation properties were evaluated by observing the halo zone on mineral salts medium (MSM) supplemented with emulsified plastics, including polystyrene (PS), polylactic acid (PLA), polyvinyl chloride (PVC), and bis (2-hydroxyethyl) terephthalate (BHET). Bacteria and fungi were identified by analyzing nucleotide sequence analysis of the 16S rRNA and internal transcribed spacer (ITS) regions, respectively. 16S and ITS microbiomes analysis was conducted on the total DNA extracted from each sample to assess the microbial communities.
RESULTS
Of 16 plastic samples, five were identified as polypropylene (PP), four as polystyrene (PS), four as polyethylene terephthalate (PET), two as high-density polyethylene (HDPE), and one sample remained unidentified. Only 27 bacterial and 38 fungal isolates were found to have the ability to degrade PLA or BHET on MSM agar. However, none showed degradation capabilities for PS or PVC on MSM agar. Notably, sp. PP5 showed the highest hydrolysis capacity of 1.64 ± 0.12. The 16S rRNA analysis revealed 13 bacterial genera, with seven showing plastic degradation abilities: , , , , , , and . This study reports, for the first time of the BHET-degrading properties of the genera and . Additionally, The ITS analysis identified nine fungal genera, five of which demonstrated plastic degradation abilities: , , , , and . Microbial community composition analysis and linear discriminant analysis effect size revealed certain dominant microbial groups in the plastic and sand samples that were absent under culture-dependent conditions. Furthermore, 16S and ITS amplicon microbiome analysis revealed microbial groups were significantly different in the plastic and sand samples collected.
CONCLUSIONS
We reported on the microbial communities found on the plastisphere at Kung Wiman Beach and isolated and identified microbes with the capacity to degrade PLA and BHET.
Topics: Actinomycetales; Agar; Bacteria; Microbiota; Plastics; Polyesters; Polystyrenes; RNA, Ribosomal, 16S; Sand
PubMed: 38590706
DOI: 10.7717/peerj.17165 -
Microorganisms Dec 2021Marine bacterial biomineralisation by CaCO precipitation provides natural limestone structures, like beachrocks and stromatolites. Calcareous deposits can also be...
Marine bacterial biomineralisation by CaCO precipitation provides natural limestone structures, like beachrocks and stromatolites. Calcareous deposits can also be abiotically formed in seawater at the surface of steel grids under cathodic polarisation. In this work, we showed that this mineral-rich alkaline environment harbours bacteria belonging to different genera able to induce CaCO precipitation. We previously isolated 14 biocalcifying marine bacteria from electrochemically formed calcareous deposits and their immediate environment. By microscopy and µ-Raman spectroscopy, these bacterial strains were shown to produce calcite-type CaCO. Identification by 16S rDNA sequencing provided between 98.5 and 100% identity with genera and . All 14 strains produced carbonic anhydrase, and six were urease positive. Both proteins are major enzymes involved in the biocalcification process. However, this does not preclude that one or more other metabolisms could also be involved in the process. In the presence of urea, CD6 exhibited the most efficient precipitation of CaCO. However, the urease pathway has the disadvantage of producing ammonia, a toxic molecule. We showed herein that different marine bacteria could induce CaCO precipitation without urea. These bacteria could then be used for eco-friendly applications, e.g., the formation of bio-cements to strengthen dikes and delay coastal erosion.
PubMed: 35056526
DOI: 10.3390/microorganisms10010076 -
PeerJ 2020Numerous bacteria entered the viable but non-culturable state due to the stresses of dry and salt in soils. YeaZ of Gram-negative bacteria is a resuscitation promoting...
Numerous bacteria entered the viable but non-culturable state due to the stresses of dry and salt in soils. YeaZ of Gram-negative bacteria is a resuscitation promoting factor (Rpf) homologous protein could resuscitate bacteria of natural environment in VBNC state. To investigate the promoting effect of YeaZ on the isolation of viable but non-culturable (VBNC) bacteria from soil samples in extreme environments, the recombinant YeaZ of was prepared and added to the soil samples from volcanic soil and saline soil in Northwest China. The study has shown that YeaZ can promote the recovery and growth of soil microorganisms, and the number of cultivable bacteria in volcanic and saline soil has increased from 0.17 × 10 and 2.03 × 10 cfu⋅ml to 1.00 × 10 and 5.55 × 10 cfu⋅ml, respectively. The 16S rDNA gene sequencing and phylogenetic analysis showed that YeaZ played an essential role in the increase of composition and diversity of bacteria. A total of 13 bacterial strains were isolated from the volcanic soil samples, which belong to phyla Actinobacteria, Firmicutes and Gamma-proteobacteria. Four species, including , , and were found in the control group, while , , , , and were isolated from the treatment groups (addition of YeaZ). Twenty-one strains were isolated from the saline soil samples, including eight species from the control group and thirteen species from the treatment groups, among which nine species were only found, including , , , , , , , and . The results suggest that addition of YeaZ to soil samples can promote the recovery of VBNC. This method has the implications for the discovery of VBNC bacteria that have potential environmental functions.
PubMed: 33391864
DOI: 10.7717/peerj.10342 -
Scientific Reports Mar 2021Dwarf bunt of wheat, which is caused by Tilletia controversa J.G. Kühn, is a soil-borne disease which may lead up to an 80% loss of yield together with degradation of...
Dwarf bunt of wheat, which is caused by Tilletia controversa J.G. Kühn, is a soil-borne disease which may lead up to an 80% loss of yield together with degradation of the quality of the wheat flour by production of a fishy smell. In this study, high-throughput sequencing technology was employed to characterize the microbial composition of wheat tissues (roots, spikes, first stem under the ear, and stem base) and rhizosphere soil of wheat varieties that are resistant and susceptible to T. controversa. We observed that the soil fungal community abundance and diversity were higher in resistant varieties than in susceptible varieties in both inoculated and uninoculated wheat, and the abundances of Sordariomycetes and Mortierellomycetes increased in the resistant varieties infected with T. controversa, while the abundances of Dothideomycetes and Bacteroidia increased in the susceptible varieties. Regarding the bacteria present in wheat tissues, the abundances of Chloroflexi, Bacteroidetes, Gemmatimonadetes, Verrucomicrobia and Acidobacteria in the ear and the first stem under the ear were higher than those in other tissues. Our results indicated that the abundances of Sordariomycetes, Mortierellomycetes, Leotiomycetes, Chryseobacterium and Massilia were higher in T. controversa-infected resistant varieties than in their controls, that Dothideomycetes, Bacteroidia, Nocardioides and Pseudomonas showed higher abundances in T. controversa-infected susceptible varieties, and that Curtobacterium, Exiguobacterium, Planococcus, and Pantoea may have higher abundances in both T. controversa-infected susceptible and resistant varieties than in their own controls.
Topics: Bacteria; Biodiversity; Endophytes; Fungi; Microbiota; Plant Diseases; Plant Leaves; Plant Roots; Plant Stems; Principal Component Analysis; Rhizosphere; Sequence Analysis, DNA; Soil Microbiology; Triticum
PubMed: 33707584
DOI: 10.1038/s41598-021-85281-8 -
International Journal of Environmental... Apr 2022Taking into consideration the essential contribution of farming, it is of rising importance to add knowledge regarding bacterial species occurrence in water samples...
Taking into consideration the essential contribution of farming, it is of rising importance to add knowledge regarding bacterial species occurrence in water samples from aquaculture zones from the point of view of both the organism and public health. In the present study, we investigated the bacterial community existing in water samples from six aquaculture areas in the Thermaikos gulf, northern Greece, that may provoke toxicity in aquatic organisms and humans and may indicate environmental pollution in mussel production as well as algal blooms. Bacterial species were identified molecularly by sequencing of a partial 16s rRNA segment and were analyzed phylogenetically for the confirmation of the bacterial taxonomy. The results obtained revealed the presence of four bacterial genera ( sp., sp., sp., and sp.). Members of the and genera have been isolated from highly polluted sites, bacteria have been identified in samples derived directly from plastic debris, and bacteria are in line with microcystin detection. In this context, the monitoring of the bacteria community in mussel aquaculture water samples from the Thermaikos gulf, the largest mussel cultivation area in Greece, represents an indicator of water pollution, microplastics presence, algal blooms, and toxin presence.
Topics: Animals; Cyanobacteria; Greece; Humans; Mytilus; Plastics; RNA, Ribosomal, 16S; Water; Water Pollution
PubMed: 35564680
DOI: 10.3390/ijerph19095285 -
International Journal of Microbiology 2023Zambia has seen rapid development in aquaculture, and in recent years, the industry has experienced disease outbreaks where fish have increasingly become a potential...
Zambia has seen rapid development in aquaculture, and in recent years, the industry has experienced disease outbreaks where fish have increasingly become a potential contributor to emerging bacterial zoonotic diseases. The aim of this study was to identify bacterial pathogens with zoonotic potential in apparently healthy fish and water from their habitat. A total of sixty-three fish were sampled, and fifty-nine water samples were collected from the habitats of these fish. Bacteria were cultured from the internal organs of fish and water, and these were identified through standard bacteriological methods comprising morphological characterization, Gram-staining, and a panel of biochemical tests. The following bacterial pathogens with zoonotic potential were identified at a farm prevalence of (13.2%), (2.1%), (2.1%), (0.7%), (6.9%), (2.1%), (0.7%), (18.1%), and (0.7). Other bacteria with varying significance as fish pathogens identified included (2.1%), (1.4%), (1.4%), (2.1%), (10.4%), (3.5%), (1.4%), (1.4%), (2.1%), (4.2%), (6.9%), (1.4%), (1.4%), (6.3%), (1.4%), (1.4%), (0.7%), and (0.7%). The current study provides baseline information for future reference and the implementation of public health guidelines with regard to potential zoonotic diseases in fish.
PubMed: 37333886
DOI: 10.1155/2023/6650378 -
International Journal of Systematic and... Mar 2024A novel bacterial strain, APC 4016, was previously isolated from the skin of a snub-nosed spiny eel, , from a depth of 1000 m in the northern Atlantic Ocean. Cells...
A novel bacterial strain, APC 4016, was previously isolated from the skin of a snub-nosed spiny eel, , from a depth of 1000 m in the northern Atlantic Ocean. Cells were aerobic, cocci, motile, Gram-positive to Gram-variable staining, and gave rise to orange-pigmented colonies. Growth occurred at 4-40 °C (optimum, 25-28 °C), pH 5.5-12 (optimum, pH 7-7.5), and 0-12 % (w/v) NaCl (optimum, 1 %). 16S rRNA gene phylogenetic analysis confirmed that strain APC 4016 belonged to the genus and was most closely related to IFO 12536 (98.98 % 16S similarity). However, digital DNA-DNA hybridization and average nucleotide identity values between these two strains were low, at 20.1 and 83.8 %, respectively. Major (>10 %) cellular fatty acids of strain APC 4016 were iso-C, anteiso-C and C-ω-Alc. The predominant respiratory quinones were menaquinones 5, 6, 7 and 8. The major cellular polar lipids were phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine, and three unknown lipids were also present. The draft genome sequence is 3.6 Mb with a G+C content of 45.25 mol%. This strain was previously shown to have antimicrobial activity and to encode bacteriocin and secondary metabolite biosynthetic gene clusters. Based on the phylogenetic analysis and its distinct phenotypic characteristics, strain APC 4016 is deemed to represent a novel species of the genus , and for which the name sp. nov. is proposed. The type strain of this species is APC 4016 (=DSM 115753=NCIMB 15463).
Topics: Animals; Fatty Acids; Phospholipids; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Base Composition; Bacterial Typing Techniques; DNA, Bacterial; Planococcus Bacteria; Eels
PubMed: 38512752
DOI: 10.1099/ijsem.0.006298