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RSC Advances Aug 2022Solid waste resource utilization and the treatment of wastewater are two important aspects in environmental protection. Here, biochar (BC) derived from municipal sewage...
Degradation of sulfadiazine in aqueous media by peroxymonosulfate activated with biochar-supported ZnFeO in combination with visible light in an internal loop-lift reactor.
Solid waste resource utilization and the treatment of wastewater are two important aspects in environmental protection. Here, biochar (BC) derived from municipal sewage sludge has been combined with ZnFeO to form the photocatalyst ZnFeO/biochar (ZnFe/BC), and it was used to degrade sulfadiazine (SDZ) in the presence of peroxymonosulfate (PMS) under visible (Vis) light irradiation in an internal loop-airlift reactor (ALR). The surface morphology and structure of ZnFe/BC have been characterized by X-ray diffraction (XRD), scanning electron microscopy equipped with an attachment for energy-dispersive spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS). ZnFe/BC displays outstanding photocatalytic performance and reusability. After four reuse cycles of ZnFe/BC in the Vis/ZnFe/BC/PMS system, the SDZ degradation rate and efficiency still reached 0.082 min and 99.05%, respectively. Reactive species in this system included free radicals SO˙, ˙OH, and ˙O , as well as non-radicals O, e, and h, as established from the results of chemical quenching experiments and electron paramagnetic resonance (EPR) analyses. Moreover, a mechanism of action of the Vis/ZnFe/BC/PMS system for SDZ degradation was proposed. The acute toxicity of the reaction solution towards T3 spp. in the Vis/ZnFe/BC/PMS process increased during the first 40 min and then decreased, illustrating that Vis/ZnFe/BC/PMS provided an effective and safe method for the removal of SDZ.
PubMed: 36128526
DOI: 10.1039/d2ra04573g -
International Journal of Molecular... Aug 2022The genus is known for its ecophysiological versatility encompassing free-living, symbiotic, and pathogenic lifestyles. sp. CCB-ST2H9 was isolated from estuarine...
The genus is known for its ecophysiological versatility encompassing free-living, symbiotic, and pathogenic lifestyles. sp. CCB-ST2H9 was isolated from estuarine sediment collected at Matang Mangrove, Malaysia. In this study, the genome of CCB-ST2H9 was sequenced, and the pan-genome of 37 strains was analysed. Phylogeny based on core genes showed that CCB-ST2H9 clustered with , forming a distinct clade with , , and . The core genome of was conserved in housekeeping functions, while the flexible genome was well represented by environmental genes related to energy production and carbohydrate metabolism. Genomic metrics including 16S rRNA sequence similarity, average nucleotide identity, and digital DNA-DNA hybridization values were below the cut-off for species delineation, implying that CCB-ST2H9 potentially represents a new species. Genome mining revealed that biosynthetic gene clusters (BGCs) involved in producing antimicrobial compounds such as holomycin in CCB-ST2H9 could contribute to the antagonistic potential. Furthermore, the EtOAc extract from the culture broth of CCB-ST2H9 exhibited antagonistic activity against spp. Intriguingly, clustering based on BGCs profiles grouped , , , , and CCB-ST2H9 together in the heatmap by the presence of a large number of BGCs. These BGCs-rich strains represent great potential for bioactive secondary metabolites production and sources for novel compounds.
Topics: Bacterial Typing Techniques; Base Composition; DNA, Bacterial; Fatty Acids; Genomics; Multigene Family; Photobacterium; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA
PubMed: 36077108
DOI: 10.3390/ijms23179712 -
Microbes and Environments 2022Integrative and conjugative elements (ICEs) play a role in the horizontal transfer of antibiotic resistance genes (ARGs). We herein report an ICE from Shewanella...
An Integrative and Conjugative Element (ICE) Found in Shewanella halifaxensis Isolated from Marine Fish Intestine May Connect Genetic Materials between Human and Marine Environments.
Integrative and conjugative elements (ICEs) play a role in the horizontal transfer of antibiotic resistance genes (ARGs). We herein report an ICE from Shewanella halifaxensis isolated from fish intestine with a similar structure to both a clinical bacterial ICE and marine bacterial plasmid. The ICE was designated ICEShaJpn1, a member of the SXT/R391 family of ICEs (SRIs). ICEShaJpn1 has a common core structure with SRIs of clinical and fish origins and an ARG cassette with the pAQU1 plasmid of Photobacterium damselae subsp. damselae, suggesting that the common core of SRIs is widely distributed and ARG cassettes are collected from regional bacteria.
Topics: Animals; Conjugation, Genetic; Humans; Intestines; Photobacterium; Shewanella
PubMed: 36058879
DOI: 10.1264/jsme2.ME22038 -
Environmental Science and Pollution... Sep 2022The Vibrionaceae family groups genetically and metabolically diverse bacteria thriving in all marine environments. Despite often representing a minor fraction of...
The Vibrionaceae family groups genetically and metabolically diverse bacteria thriving in all marine environments. Despite often representing a minor fraction of bacterial assemblages, members of this family can exploit a wide variety of nutritional sources, which makes them important players in biogeochemical dynamics. Furthermore, several Vibrionaceae species are well-known pathogens, posing a threat to human and animal health. Here, we applied the phylogenetic placement coupled with a consensus-based approach using 16S rRNA gene amplicon sequencing, aiming to reach a reliable and fine-level Vibrionaceae characterization and identify the dynamics of blooming, ecologically important, and potentially pathogenic species in different sites of the northern Adriatic Sea. Water samples were collected monthly at a Long-Term Ecological Research network site from 2018 to 2021, and in spring and summer of 2019 and 2020 at two sites affected by depurated sewage discharge. The 41 identified Vibrionaceae species represented generally below 1% of the sampled communities; blooms (up to ~ 11%) mainly formed by Vibrio chagasii and Vibrio owensii occurred in summer, linked to increasing temperature and particulate matter concentration. Pathogenic species such as Vibrio anguilllarum, Vibrio tapetis, and Photobacterium damselae were found in low abundance. Depuration plant samples were characterized by a lower abundance and diversity of Vibrionaceae species compared to seawater, highlighting that Vibrionaceae dynamics at sea are unlikely to be related to wastewater inputs. Our work represents a further step to improve the molecular approach based on short reads, toward a shared, updated, and curated phylogeny of the Vibrionaceae family.
Topics: Animals; Ecosystem; Environmental Monitoring; Genes, rRNA; Humans; Particulate Matter; Phylogeny; RNA, Ribosomal, 16S; Seawater; Sewage; Vibrionaceae; Wastewater; Water
PubMed: 36056283
DOI: 10.1007/s11356-022-22752-z -
Scientific Reports Sep 2022Seaweeds are an important source of nutrients and bioactive compounds and have a high potential as health boosters in aquaculture. This study evaluated the effect of...
Seaweeds are an important source of nutrients and bioactive compounds and have a high potential as health boosters in aquaculture. This study evaluated the effect of dietary inclusion of Gracilaria gracilis biomass or its extract on the European seabass (Dicentrarchus labrax) gut microbial community. Juvenile fish were fed a commercial-like diet with 2.5% or 5% seaweed biomass or 0.35% seaweed extract for 47 days. The gut microbiome was assessed by 16S rRNA amplicon sequencing, and its diversity was not altered by the seaweed supplementation. However, a reduction in Proteobacteria abundance was observed. Random forest analysis highlighted the genera Photobacterium, Staphylococcus, Acinetobacter, Micrococcus and Sphingomonas, and their abundances were reduced when fish were fed diets with algae. SparCC correlation network analysis suggested several mutualistic and other antagonistic relationships that could be related to the predicted altered functions. These pathways were mainly related to the metabolism and biosynthesis of protective compounds such as ectoine and were upregulated in fish fed diets supplemented with algae. This study shows the beneficial potential of Gracilaria as a functional ingredient through the modulation of the complex microbial network towards fish health improvement.
Topics: Animal Feed; Animals; Bass; Diet; Gastrointestinal Microbiome; Gracilaria; Plant Extracts; RNA, Ribosomal, 16S
PubMed: 36050345
DOI: 10.1038/s41598-022-17891-9 -
Applied and Environmental Microbiology Sep 2022The marine bacterium Photobacterium galatheae S2753 produces a group of cyclodepsipeptides, called solonamides, which impede the virulence but not the survival of...
The marine bacterium Photobacterium galatheae S2753 produces a group of cyclodepsipeptides, called solonamides, which impede the virulence but not the survival of Staphylococcus aureus. In addition to their invaluable antivirulence activity, little is known about the biosynthesis and physiological function of solonamides in the native producer. This study generated a solonamide-deficient (Δ) mutant by in-frame deletion of the gene, thereby identifying the core gene for solonamide biosynthesis. By annotation from antiSMASH, the biosynthetic pathway of solonamides in S2753 was also proposed. Mass spectrometry analysis of cell extracts found that deficiency of solonamide production influenced the production of a group of unknown compounds but otherwise did not alter the overall secondary metabolite profile. Physiological comparison between Δ and wild-type S2753 demonstrated that growth dynamics and biofilm formation of both strains were similar; however, the Δ mutant displayed reduced motility rings compared to the wild type. Reintroduction of restored solonamide production and motility to the mutant, indicating that solonamides influence the motility behavior of S2753. Proteomic analysis of the Δ and wild-type strains found that eliminating solonamides influenced many cellular processes, including swimming-related proteins and proteins adjusting the cellular cyclic di-GMP concentration. In conclusion, our results revealed the biosynthetic pathway of solonamides and their ecological benefits to S2753 by enhancing motility, likely by altering the motile physiology. The broad range of bioactive potentials of cyclodepsipeptides makes these compounds invaluable in the pharmaceutical industry. Recently, a few novel cyclodepsipeptides have been discovered in marine ; however, their biosynthetic pathways remain to be revealed. Here, we demonstrated the biosynthetic genetic basis and pathway of the antivirulence compounds known as solonamides in S2753. This can pave the way for the biological overproduction of solonamides on an industrial scale. Moreover, the comparison of a solonamide-deficient mutant and wild-type S2753 demonstrated that solonamides stimulate the swimming behavior of S2753 and also influence a few key physiological processes of the native producers. These results evidenced that, in addition to their importance as novel drug candidates, these compounds play a pivotal role in the physiology of the producing microorganisms and potentially provide the native producer competitive benefits for their survival in nature.
Topics: Bacterial Proteins; Biofilms; Cyclic GMP; Depsipeptides; Gene Expression Regulation, Bacterial; Photobacterium; Proteomics; Virulence
PubMed: 36000852
DOI: 10.1128/aem.01105-22 -
Food Science & Nutrition Aug 2022Severe shrimp disease outbreaks have a destructive impact on shrimp aquaculture and its associated downstream food processing industries. Thus, it is essential to...
Severe shrimp disease outbreaks have a destructive impact on shrimp aquaculture and its associated downstream food processing industries. Thus, it is essential to develop proper methods for shrimp disease control, which emphasizes the importance of food safety. In this study, we performed biochemical tests and gut microbiome analysis using uninfected control and -infected samples. Biochemical tests were performed to assess the phenoloxidase (PO) activity, respiratory Burst (RB) activity, nitrite concentration, superoxide dismutase (SOD) activity, total hemocyte count (THC), and total protein concentrations. Overall, upregulations were detected in these biochemical tests, which showed the activation of the immune response in during acute hepatopancreatic necrosis disease (AHPND) infection, especially at 6 hpi and 12 hpi. Besides that, shrimp gut samples were collected and pooled ( = 3), followed by DNA extraction, PCR amplification targeting the V3/V4 16S ribosomal RNA (rRNA) region, next-generation sequencing (NGS), and bioinformatics analysis. Proteobacteria was the most abundant phylum in both samples. The Rhodobacteraceae family and genus were proposed to be vital forshrimp health maintenance. bacterial colonization and secondary infections were postulated to have occurred based on the higher abundances of Vibrionaceae family and genus in the -infected sample. Firmicutes phylum together with and genera were inferred to be pathogenic or related factors of AHPND infections. In conclusion, physiology (immune response activation) and gut microbiome changes of disease tolerant during AHPND infection were identified. Both biochemical tests and 16S rRNA analysis are proposed as a combined strategy for shrimp health diagnosis for ensuring shrimp health maintenance, disease control, and food safety.
PubMed: 35959249
DOI: 10.1002/fsn3.2873 -
Frontiers in Microbiology 2022The gut microbiome of fish contains core taxa whose relative abundances are modulated in response to diet, environmental factors, and exposure to toxicogenic chemicals,...
The gut microbiome of fish contains core taxa whose relative abundances are modulated in response to diet, environmental factors, and exposure to toxicogenic chemicals, influencing the health of the host fish. Recent advances in genomics and metabolomics have suggested the potential of microbiome analysis as a biomarker for exposure to toxicogenic compounds. In this 35-day laboratory study, 16S RNA sequencing and multivariate analysis were used to explore changes in the gut microbiome of juvenile exposed to dietary sub-lethal doses of three metals: vanadium (20 mg/kg), nickel (480 mg/kg), and iron (470 mg/kg), and to two oils: bunker C heavy fuel oil (HFO) (1% w/w) and Montara, a typical Australian medium crude oil (ACO) (1% w/w). Diversity of the gut microbiome was significantly reduced compared to negative controls in fish exposed to metals, but not petroleum hydrocarbons. The core taxa in the microbiome of negative control fish comprised phyla Proteobacteria (62%), Firmicutes (7%), Planctomycetes (3%), Actinobacteria (2%), Bacteroidetes (1%), and others (25%). Differences in the relative abundances of bacterial phyla of metal-exposed fish were pronounced, with the microbiome of Ni-, V-, and Fe-exposed fish dominated by Proteobacteria (81%), Firmicutes (68%), and Bacteroidetes (48%), respectively. The genus was enriched proportionally to the concentration of polycyclic aromatic hydrocarbons (PAHs) in oil-exposed fish. The probiotic lactic acid bacterium was significantly reduced in the microbiota of fish exposed to metals. Transcription of cytokines IL-1, IL-10, and TNF-a was significantly upregulated in fish exposed to metals but unchanged in oil-exposed fish compared to negative controls. However, IL-7 was significantly downregulated in fish exposed to V, Ni, Fe, and HFOs. Fish gut microbiome exhibits distinctive changes in response to specific toxicants and shows potential for use as biomarkers of exposure to V, Ni, Fe, and to PAHs present in crude oil.
PubMed: 35942316
DOI: 10.3389/fmicb.2022.827371 -
International Journal of Molecular... Jul 2022The evaluation of temperature effects on the structure and function of enzymes is necessary to understand the mechanisms underlying their adaptation to a constantly...
The evaluation of temperature effects on the structure and function of enzymes is necessary to understand the mechanisms underlying their adaptation to a constantly changing environment. In the current study, we investigated the influence of temperature variation on the activity, structural dynamics, thermal inactivation and denaturation of and luciferases belonging to different subfamilies, as well as the role of sucrose in maintaining the enzymes functioning and stability. We used the stopped-flow technique, differential scanning calorimetry and molecular dynamics to study the activity, inactivation rate, denaturation and structural features of the enzymes under various temperatures. It was found that luciferase resembles the properties of cold-adapted enzymes with high activity in a narrow temperature range and slightly lower thermal stability than luciferase, which is less active, but more thermostable. Differences in activity at the studied temperatures can be associated with the peculiarities of the mobile loop conformational changes. The presence of sucrose does not provide an advantage in activity but increases the stability of the enzymes. Differential scanning calorimetry experiments showed that luciferases probably follow different denaturation schemes.
Topics: Luciferases; Luciferases, Bacterial; Structure-Activity Relationship; Sucrose; Temperature
PubMed: 35897698
DOI: 10.3390/ijms23158119 -
Molecules (Basel, Switzerland) Jul 2022This study aimed to evaluate the antibacterial activity in vitro of and extracts against potentially pathogenic bacteria for Pacific white shrimp. Furthermore, the...
This study aimed to evaluate the antibacterial activity in vitro of and extracts against potentially pathogenic bacteria for Pacific white shrimp. Furthermore, the extracts with higher inhibitory activity were analyzed to identify compounds responsible for bacterial inhibition and evaluate their effect on motility and biofilm formation. and extracts were prepared using methanol, acetone, and hexane by ultrasound. The minimum inhibitory concentration (MIC) of the extracts was determined against and . The polyphenol profile of those extracts showing the highest bacterial inhibition were determined. Besides, the bacterial swimming and swarming motility and biofilm formation were determined. The highest inhibitory activity against the four pathogens was found with the acetonic extract of leaf (MIC of 50 mg/mL for spp. and 25 mg/mL for spp.) and the methanol extract of flower (MIC of 50 mg/mL for all pathogens tested). Both extracts affected the swarming and swimming motility and the biofilm formation of the tested bacteria. The main phenolic compounds related to bacteria inhibition were naringin, vanillic acid, and rosmarinic acid, whilst hesperidin, kaempferol pentosyl-rutinoside, and rhamnetin were related to bacteria inhibition.
Topics: Animals; Anti-Bacterial Agents; Methanol; Microbial Sensitivity Tests; Penaeidae; Plant Extracts; Vibrio parahaemolyticus
PubMed: 35889267
DOI: 10.3390/molecules27144397