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1.
Int J Mol Sci ; 24(23)2023 Nov 30.
Article En | MEDLINE | ID: mdl-38069303

Photodynamic inactivation (PDI) is an emerging therapeutic approach that can effectively inactivate diverse microbial forms, including vegetative forms and spores, while preserving host tissues and avoiding the development of resistance to the photosensitization procedure. This study evaluates the antifungal and sporicidal photodynamic activity of two water-soluble amphiphilic tetra- and octa-ß-substituted zinc(II) phthalocyanine (ZnPc) dyes with dimethylaminopyridinium groups at the periphery (ZnPcs 1, 2) and their quaternized derivatives (ZnPcs 1a, 2a). Tetra(1, 1a)- and octa(2, 2a)-ß-substituted zinc(II) phthalocyanines were prepared and assessed as photosensitizers (PSs) for their effects on Fusarium oxysporum conidia. Antimicrobial photoinactivation experiments were performed with each PS at 0.1, 1, 10, and 20 µM under white light irradiation at an irradiance of 135 mW·cm-2, for 60 min (light dose of 486 J·cm-2). High PDI efficiency was observed for PSs 1a, 2, and 2a (10 µM), corresponding to inactivation until the method's detection limit. PS 1 (20 µM) also achieved a considerable reduction of >5 log10 in the concentration of viable conidia. The quaternized PSs (1a, 2a) showed better PDI performance than the non-quaternized ones (1, 2), even at the low concentration of 1 µM, and a light dose of 486 J·cm-2. These cationic phthalocyanines are potent photodynamic drugs for antifungal applications due to their ability to effectively inactivate resistant forms, like conidia, with low concentrations and reasonable energy doses.


Photochemotherapy , Zinc , Spores, Fungal , Zinc/pharmacology , Antifungal Agents/pharmacology , Photosensitizing Agents/pharmacology , Isoindoles
2.
Preprint En | PREPRINT-SCIELO | ID: pps-7276

Background Few studies compared populations with similar genetic and culture background on different continents with standardized methods. Objective To describe methodological issues of the Study of Health in Pomerode - SHIP-Brazil and some characteristics of the participants of the baseline examination. Design and Setting Prospective, population-based cohort study of a representative sample of residents (aged 20 to 79 years) of Pomerode, Santa Catarina, Brazil. Methods Data for the baseline survey (from 2014 to 2018) were collected through interviews and medical examinations, including socio-demographic and lifestyle information, clinical and subclinical conditions, oral and mental health, among others. Biosamples (blood, urine, stool, and saliva) were collected and stored. Methods of data collection and quality control are described. Preliminary descriptive statistics were performed. Results The response rate was 67.6% (n=2,488 individuals). The Kappa test-retest of some variables varied from 0.54 to 1.0. German culture participants are older (46.5 vs 38.7 years), self-declared white (97.3% vs 82.1%), more frequently never smokers (71.4% vs 66.9%) but had higher risk of consuming alcohol (16.9% vs 13.4%) compared to participants with non-German background. Germans were taller (169 cm vs 166 cm), had greater abdominal circumference among men (101.9 cm vs 97.3 cm). Furthermore, they reported more multimorbidity (56.7% vs 43.6%) , had more arterial hypertension (30.7% vs 18.5%), but less depression (15.4% vs 19,1%) than non-Germans. Conclusions The interaction of genetic and social/environmental issues should be examined to understand the role of risk factors on clinical conditions observed.


Introdução Poucos estudos compararam populações com histórico genético e cultural semelhante em diferentes continentes com métodos padronizados. Objetivos Descrever questões metodológicas do estudo de "Vida e Saúde em Pomerode - SHIP-Brazil" e algumas características dos participantes do exame inicial do estudo. Desenho de estudo e local Estudo de coorte prospectivo de base populacional em amostra representativa de moradores (20 a 79 anos) de Pomerode, Santa Catarina. Métodos As informações para a linha de base (de 2014 a 2018) foram coletadas por meio de entrevistas e exames médicos, incluindo dados sociodemográficos, de estilo de vida, condições clínicas e subclínicas, saúde bucal e mental, entre outros. Amostras biológicas (sangue, urina, fezes e saliva) foram coletadas e armazenadas. A coleta de dados e o controle de qualidade foram descritos. Foram realizadas análises descritivas preliminares. Resultados A taxa de resposta foi de 67,6% (n=2.488 indivíduos). O Kappa teste-reteste de algumas variáveis variou  de 0,54 a 1,0. Os participantes de cultura alemã são mais velhos (46,5 vs 38,7 anos ), autodeclarados brancos (97,3% vs 82,1%), com menor número de fumantes (71,4% vs 66,9%), mas tiveram maior risco de consumir álcool (16,9% vs 13,4%), eram mais altos (169 cm vs 166 cm), tinham maior circunferência abdominal entre os homens (101,9 cm vs 97,3 cm) em comparação com participantes "não-alemães". Pessoas de cultura alemã relataram mais multimorbidade (56,7% vs 43,6%), apresentavam mais hipertensão arterial (30,7% vs 18,5%), mas menos depressão (15,4% vs 19,1%). Conclusões A interação genética e social/ambiental devem ser examinadas para melhor entender o papel desses fatores de risco nas condições clínicas observadas.

3.
J Appl Microbiol ; 134(8)2023 Aug 01.
Article En | MEDLINE | ID: mdl-37587019

AIMS: We aim at understanding the effect of domestication on the endophytic microbiome and metabolome of Salicornia europaea and collecting evidence on the potential role of microbial populations and metabolites in the adaptation of plants to different ecological contexts (wild vs crops). METHODS AND RESULTS: Samples were collected from a natural salt marsh (wild) and an intensive crop field (crop). High-throughput sequencing of the 16S rRNA gene, gas chromatography-mass spectrometry (GC-MS) and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) were used to analyze the endophytic bacterial communities and the metabolite profiles of S. europaea roots, respectively. The elemental analysis of the plant shoots was performed by Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS).Overall, significant differences were found between the microbiome of wild and cultivated plants. The later showed a higher relative abundance of the genera Erythrobacter, Rhodomicrobium, and Ilumatobacter than wild plants. The microbiome of wild plants was enriched in Marinobacter, Marixanthomonas, and Thalassospira. The metabolite profile of crop plants revealed higher amounts of saturated and non-saturated fatty acids and acylglycerols. In contrast, wild plants contained comparatively more carbohydrates and most macroelements (i.e. Na, K, Mg, and Ca). CONCLUSIONS: There is a strong correlation between plant metabolites and the endosphere microbiome of S. europaea. In wild populations, plants were enriched in carbohydrates and the associated bacterial community was enriched in genes related to primary metabolic pathways such as nitrogen metabolism and carbon fixation. The endosphere microbiome of crop plants was predicted to have higher gene counts related to pathogenesis. Crop plants also exhibited higher amounts of azelaic acid, an indicator of exposure to phytopathogens.


Chenopodiaceae , Domestication , Chromatography, Liquid , RNA, Ribosomal, 16S/genetics , Tandem Mass Spectrometry , Metabolome
4.
Ciênc. Saúde Colet. (Impr.) ; 28(6): 1863-1872, jun. 2023. tab, graf
Article En | LILACS-Express | LILACS | ID: biblio-1439855

Abstract Professional drivers show a higher prevalence of obstructive sleep apnea (OSA) compared with the general population. OSA has been widely associated with an increased risk of traffic accidents. This article aims to investigate the presence of risk factors for OSA, its prevalence and the value of screening tools in a truck drivers' cohort. Descriptive and analytical prospective study. Demographic, anthropometric, Epworth Sleepiness Scale, STOP-Bang and Berlin Questionnaire were used to select subjects with suspicion of OSA. Polysomnography (PSG) was performed in individuals with positive screening. Mean age was 44.6±7 years, mean body mass index was 28.7±4 kg/m². Of the 281 truck drivers screened, 88 were positive for potential OSA. Of these, 63 completed PSG study and the diagnosis was confirmed in 85.7% (prevalence of 19.2%). The following variables showed a positive correlation with the apnea-hypopnea index: neck circumference and STOP-Bang. The combination of a predominantly male population, obesity, age distribution and lifestyle could account for the high prevalence of OSA in this specific population. Questionnaires proved to be a valuable screening tool. Screening, treatment, and management of OSA should be a priority as a public safety policy.


Resumo A prevalência de Síndrome de Apneia Obstrutiva do Sono (SAOS) em motoristas profissionais é superior à da população geral e esta tem sido amplamente associada ao risco aumentado de acidentes rodoviários. Este artigo tem por objetivos investigar fatores de risco de SAOS, estimar a sua prevalência e o valor de instrumentos de rastreio numa amostra de motoristas de pesados. Estudo prospetivo descritivo e analítico. Rastreio realizado com recurso a dados demográficos, antropométricos, Escala de Sonolência de Epworth, STOP-Bang e Questionário de Berlim. Nos indivíduos com rastreio positivo foi realizada polissonografia (PSG). A idade média era de 44,6±7 anos, índice de massa corporal 28,7±4 kg/m². Dos 281 motoristas incluídos, 88 apresentavam risco elevado de SAOS. Destes, 63 realizaram PSG, com confirmação diagnóstica em 85,7% (prevalência de 19,2%). O perímetro cervical e STOP-Bang apresentaram correlação positiva com o índice de apneia-hipopneia. A combinação de género predominantemente masculino, obesidade, distribuição de idade e estilo de vida pode justificar a elevada prevalência de SAOS nesta população. O uso de questionários é uma medida eficaz de rastreio. Nos motoristas, o rastreio e tratamento de SAOS deveria ser uma medida de saúde pública prioritária.

5.
Am J Orthod Dentofacial Orthop ; 163(6): e152-e161, 2023 Jun.
Article En | MEDLINE | ID: mdl-37125981

INTRODUCTION: In the "appliance first" protocol of miniscrew-assisted rapid palatal expansion, the prefabricated shape of the expanders limits the potential locations for miniscrew placement. Considering the influence of palatal thickness on the selection of the optimal length of miniscrews, this study aimed to evaluate the thickness of both bone and mucosa of the palate of patients aged 6-65 years and suggest optimal lengths of miniscrews for this approach. METHODS: Two hundred and eighty-two cone-beam computed tomography of patients of both sexes were divided into 3 groups according to age. The thicknesses of bone and mucosa were measured in the anterior and posterior regions of the palate. RESULTS: Males showed a greater thickness of palatal bone than females. The thickness of both bone and mucosa was greater in the anterior region of the palate. The young patients showed greater bone thickness than adults and mature adults. The mature adults showed thinner bone thickness in the posterior region of the palate and greater mucosal thickness along the palate than young patients and adults. Development of miniscrews with longer thread lengths is necessary. Miniscrews with a 3-mm thread length would prevent excessive extravasation in the posterior region of the palate. CONCLUSIONS: The thickness of both bone and mucosa of the palate is variable and influenced by sex and age. Manufacturing additional miniscrews with different lengths of thread is suggested to achieve bicortical anchorage in patients undergoing the "appliance first" protocol of miniscrew-assisted rapid palatal expansion.


Orthodontic Anchorage Procedures , Palatal Expansion Technique , Adult , Male , Female , Humans , Bone Screws , Palate/diagnostic imaging , Palate/surgery , Cone-Beam Computed Tomography/methods , Maxilla
6.
Cien Saude Colet ; 28(6): 1863-1872, 2023 Jun.
Article En | MEDLINE | ID: mdl-37255162

Professional drivers show a higher prevalence of obstructive sleep apnea (OSA) compared with the general population. OSA has been widely associated with an increased risk of traffic accidents. This article aims to investigate the presence of risk factors for OSA, its prevalence and the value of screening tools in a truck drivers' cohort. Descriptive and analytical prospective study. Demographic, anthropometric, Epworth Sleepiness Scale, STOP-Bang and Berlin Questionnaire were used to select subjects with suspicion of OSA. Polysomnography (PSG) was performed in individuals with positive screening. Mean age was 44.6±7 years, mean body mass index was 28.7±4 kg/m². Of the 281 truck drivers screened, 88 were positive for potential OSA. Of these, 63 completed PSG study and the diagnosis was confirmed in 85.7% (prevalence of 19.2%). The following variables showed a positive correlation with the apnea-hypopnea index: neck circumference and STOP-Bang. The combination of a predominantly male population, obesity, age distribution and lifestyle could account for the high prevalence of OSA in this specific population. Questionnaires proved to be a valuable screening tool. Screening, treatment, and management of OSA should be a priority as a public safety policy.


Accidents, Traffic , Mass Screening , Sleep Apnea, Obstructive , Adult , Female , Humans , Male , Middle Aged , Mass Screening/methods , Motor Vehicles , Prospective Studies , Risk Factors , Sleep Apnea, Obstructive/diagnosis , Sleep Apnea, Obstructive/epidemiology , Surveys and Questionnaires , Prevalence
7.
Int J Mol Sci ; 24(4)2023 Feb 15.
Article En | MEDLINE | ID: mdl-36835333

Antimicrobial photodynamic therapy (aPDT) has been explored as an innovative therapeutic approach because it can be used to inactivate a variety of microbial forms (vegetative forms and spores) without causing significant damage to host tissues, and without the development of resistance to the photosensitization process. This study assesses the photodynamic antifungal/sporicidal activity of tetra- and octasubstituted phthalocyanine (Pc) dyes with ammonium groups. Tetra- and octasubstituted zinc(II) phthalocyanines (1 and 2) were prepared and tested as photosensitizers (PSs) on Fusarium oxysporum conidia. Photoinactivation (PDI) tests were conducted with photosensitizer (PS) concentrations of 20, 40, and 60 µM under white-light exposure at an irradiance of 135 mW·cm-2, applied during 30 and 60 min (light doses of 243 and 486 J·cm-2). High PDI efficiency corresponding to the inactivation process until the detection limit was observed for both PSs. The tetrasubstituted PS was the most effective, requiring the lowest concentration and the shortest irradiation time for the complete inactivation of conidia (40 µM, 30 min, 243 J·cm-2). Complete inactivation was also achieved with PS 2, but a longer irradiation time and a higher concentration (60 µM, 60 min, 486 J·cm-2) were necessary. Because of the low concentrations and moderate energy doses required to inactivate resistant biological forms such as fungal conidia, these phthalocyanines can be considered potent antifungal photodynamic drugs.


Antifungal Agents , Photochemotherapy , Spores, Fungal , Light , Photosensitizing Agents , Indoles
8.
J Appl Microbiol ; 134(3)2023 Mar 01.
Article En | MEDLINE | ID: mdl-36841232

AIM: The objective of the work was to assess the effect of biostimulation with selected plant growth-promoting bacteria on growth and metabolite profile of Salicornia europaea. METHODS AND RESULTS: Salicornia europaea seeds were inoculated with different combinations of plant growth-promoting bacteria Brevibacterium casei EB3, Pseudomonas oryzihabitans RL18, and Bacillus aryabhattai SP20. Plants germinated from inoculated seeds were grown either in laboratory conditions or in a saline crop field. Fresh and dry weight were determined at the end of the experiment, for biomass quantification. The microbiological quality of fresh shoots for human consumption as salad greens was assessed, and the persistence of the inoculated strains in the plant rhizosphere was confirmed by next-generation sequencing (Illumina) of the 16S rDNA gene. The primary metabolite profile of biostimulated plants was characterized by GC-TOF-MS.In laboratory conditions, inoculation with the two strains Br. casei EB3 and Ps. oryzihabitans RL18 caused the most significant increase in biomass production (fresh and dry weight), and caused a shift in the central metabolic pathways of inoculated plants toward amino acid biosynthesis. In the field experiment, no significant biostimulation effect was detected with any of the tested inoculants. Seed inoculation had no significant effect on the microbiological quality of the edible parts. The persistence of inoculants was confirmed in both experiments. CONCLUSIONS: Manipulation of the plant microbiome can trigger primary metabolic reconfiguration and modulate the plant metabolism while promoting plant growth.


Bacteria , Chenopodiaceae , Humans , Plant Development , Seeds , Crops, Agricultural , Chenopodiaceae/metabolism , Chenopodiaceae/microbiology , Plant Roots/microbiology , Rhizosphere , Soil Microbiology
9.
Org Biomol Chem ; 21(7): 1531-1536, 2023 02 15.
Article En | MEDLINE | ID: mdl-36722743

Fluorescence imaging is a powerful and widely used method to visualize and study living organisms. However, fungi are notoriously difficult to visualize using fluorescence microscopy, given that their cell wall represents a diffusion barrier, and the synthetic organic dyes available are very limited when compared to molecular probes available for other organisms. Moreover, these dyes are usually available in only one colour, preventing co-staining experiments. To fill this gap, curcumin-based molecular probes were designed based on the rationale that curcumin is fluorescent and has moderate toxicity toward fungi, implying its ability to cross the cell wall to reach targets in the intracellular compartments. A family of boron diketonate complexes was synthesized, based on a curcumin backbone, tuning their emission color from blue to red. These probes did not present noticeable toxicity to filamentous fungus and, when applied to their visualization, readily entered the cells and precisely localized in sub-cellular organelles, enabling their visualization.


Curcumin , Curcumin/pharmacology , Molecular Probes , Fluorescent Dyes , Optical Imaging , Fungi
10.
Microorganisms ; 10(12)2022 Dec 13.
Article En | MEDLINE | ID: mdl-36557715

The interactions established between marine microbes, namely phytoplankton-bacteria, are key to the balance of organic matter export to depth and recycling in the surface ocean. Still, their role in the response of phytoplankton to rising CO2 concentrations is poorly understood. Here, we show that the response of the cosmopolitan Emiliania huxleyi (E. huxleyi) to increasing CO2 is affected by the coexistence with bacteria. Specifically, decreased growth rate of E. huxleyi at enhanced CO2 concentrations was amplified in the bloom phase (potentially also related to nutrient concentrations) and with the coexistence with Idiomarina abyssalis (I. abyssalis) and Brachybacterium sp. In addition, enhanced CO2 concentrations also affected E. huxleyi's cellular content estimates, increasing organic and decreasing inorganic carbon, in the presence of I. abyssalis, but not Brachybacterium sp. At the same time, the bacterial isolates only survived in coexistence with E. huxleyi, but exclusively I. abyssalis at present CO2 concentrations. Bacterial species or group-specific responses to the projected CO2 rise, together with the concomitant effect on E. huxleyi, might impact the balance between the microbial loop and the export of organic matter, with consequences for atmospheric carbon dioxide.

11.
Materials (Basel) ; 15(24)2022 Dec 15.
Article En | MEDLINE | ID: mdl-36556783

AISI 420 martensitic stainless steel is widely used in the mould industry due to its high tensile strength, hardness, and corrosion properties. Another requirement concerning any material used for this type of application is high thermal conductivity to minimise the time between consecutive injection cycles. The surfaces of some parts of the mould may be textured and reinforced with a material with higher thermal conductivity to achieve this aim. The results of a detailed study on the texturing of annealed 420 stainless steel using a Nd:YVO4 fibre laser are presented in this work. The influence of the laser's processing parameters (laser power, scanning speed, number of passes, and line spacing) on the dimensions of the track, microstructure, and hardness of the modified surfaces was studied. Based on the continuity and dimensions of the machined grooves, several promising textures could be produced with laser power values from 5 to 30 W, scanning speeds of 500 to 2000 mm/s, 8 passes or more, and line spacings of 40 and 50 µm. High laser powers were responsible for the dissolution of chromium carbides in the laser tracks, the incorporation of chromium in austenite, and the consequent hardening of the microstructure.

12.
World J Microbiol Biotechnol ; 37(12): 199, 2021 Oct 19.
Article En | MEDLINE | ID: mdl-34664127

Citrus are economically important fruit crops to which infectious diseases like citrus canker caused by Xanthomonas citri subs. citri, citrus variegated chlorosis caused by Xylella fastidiosa, "huanglongbing" associated with the presence of Candidatus liberibacter species, anthracnose caused by Colletotrichum gloeosporioides and citrus black spot caused by Phyllosticta citricarpa, impose significant losses. Control measures involve chemical treatment of orchards but often, eradication of infected plants is unavoidable. To circumvent the environmental impacts of pesticides and the socio-economic impacts of eradication, innovative antimicrobial approaches like photodynamic inactivation are being tested. There is evidence of the susceptibility of Xanthomonas citri subs. citri and C. gloeosporioides to photodynamic damage. However, the realistic assessment of perspectives for widespread application of photodynamic inactivation in the control of citrus diseases, necessarily implies that other microorganisms are also considered. This review intends to provide a critical summary of the current state of research on photodynamic inactivation of citrus pathogens and to identify some of the current limitations to the widespread use of photodynamic treatments in citrus crops.


Citrus/microbiology , Crops, Agricultural/microbiology , Photosensitizing Agents , Plant Diseases/microbiology , Anti-Infective Agents , Citrus/physiology , Colletotrichum/radiation effects , Xanthomonas/radiation effects , Xylella
13.
J Mater Chem B ; 9(45): 9285-9294, 2021 11 24.
Article En | MEDLINE | ID: mdl-34709285

Raman spectroscopy coupled with confocal microscopy offers an alternative bioimaging technique overcoming limitations associated with sensitivity, tissue penetration and image resolution. Allied to the surface-enhanced Raman scattering (SERS) properties of gold nanoparticles (AuNP), we designed SERS nanoprobes with enhanced properties and straightforward application as bio-labelling agents for gliomas. The ensuing nanoprobes coated with simple sugar units (galactose or glucose) allowed assessing information about their intracellular localization (vesicular structures), with impressive sensitivity towards complex environments and proved the ability to overcome biological auto-fluorescence and high penetration in tissues. We validate the use of sugars as an all-in-one vector (Raman reporter, conferring high stability, biocompatibility and affinity to glioma cells) as imaging agents using an impressive technique.


Galactose/chemistry , Glucose/chemistry , Gold/chemistry , Metal Nanoparticles/chemistry , Spectrum Analysis, Raman/methods , Galactose/metabolism , Galectins/genetics , Galectins/metabolism , Glucose/metabolism , Monosaccharide Transport Proteins/genetics , Monosaccharide Transport Proteins/metabolism
15.
ACM arq. catarin. med ; 50(1): 81-92, 13/04/2021.
Article Pt | LILACS-Express | LILACS | ID: biblio-1354467

Objetivos: Identificar a prevalência e a frequência do uso de substâncias derivadas do tabaco em estudantes de medicina de uma universidade pública de Santa Catarina e identificar os fatores de risco relacionados. Métodos: Estudo observacional transversal com abordagem quantitativa sobre drogas de abuso em estudantes de medicina. Utilizou-se questionários para identificar a prevalência e a frequência do uso de substâncias derivadas do tabaco, assim como sexo, idade, semestre do curso e doenças psiquiátricas diagnosticadas. Os dados foram tabulados em Excel 2016 e a análise estatística foi realizada por meio do programa Epi Info 7.2. Resultados: Encontrou-se uma prevalência de 29,10% de uso de tabaco nos últimos 3 meses. A população masculina que fumava era de 46,30% e a feminina 19,37%, sendo o sexo masculino o principal fator de risco levantado pelo estudo. Outro fator de risco foi estar nas fases mais iniciais do curso, nas quais o uso era de 35,54% em comparação a fases mais avançadas com uso em somente 24,72% dos acadêmicos. Também houve correlação entre tabagismo e depressão. Conclusões: Pôde-se perceber que o tabagismo em estudantes de medicina é maior do que na população em geral, também é maior o uso por estudantes de medicina da região sul do Brasil em comparação com outras regiões. Identificou-se dois fatores de risco importantes para tabagismo na nossa universidade, que são sexo masculino e pertencer a fases mais iniciais do curso.


Objectives: To identify the prevalence and frequency of the use of tobacco-derived substances in medical students at a public university in Santa Catarina and to identify the related risk factors. Methods: Cross-sectional observational study with a quantitative approach on drugs of abuse in medical students. Questionnaires were used to identify the prevalence and frequency of use of substances derived from tobacco, as well as sex, age, semester of the medical school and diagnosed psychiatric diseases. The data were tabulated in Excel 2016 and a statistical analysis was performed using the Epi Info 7.2 program. Results: The prevalence of tobacco consumption in the last 3 months was 29.10%. The male population who smoked was 46.30% and the female 19.37%, with the male gender being the main risk factor appointed by the study. Another risk factor was being in the earlier semesters of the medical school, in which the usage was 35.54% compared to more advanced semesters, with only 24.72%. There was also a correlation between smoking and depression. Conclusions: Smoking in medical students is more prevalent than the population in general. It is also more used by medical students in the southern region of Brazil when compared to other regions. Two important risk factors for smoking at our university were identified: male gender and belonging to the earlier semesters of the medical school.

20.
Article En | MEDLINE | ID: mdl-32156011

Hydrocarbon bioremediation in anoxic sediment layers is still challenging not only because it involves metabolic pathways with lower energy yields but also because the production of biosurfactants that contribute to the dispersion of the pollutant is limited by oxygen availability. This work aims at screening populations of culturable hydrocarbonoclastic and biosurfactant (BSF) producing bacteria from deep sub-seafloor sediments (mud volcanos from Gulf of Cadiz) and estuarine sub-surface sediments (Ria de Aveiro) for strains with potential to operate in sub-oxic conditions. Isolates were retrieved from anaerobic selective cultures in which crude oil was provided as sole carbon source and different supplements were provided as electron acceptors. Twelve representative isolates were obtained from selective cultures with deep-sea and estuary sediments, six from each. These were identified by sequencing of 16S rRNA gene fragments belonging to Pseudomonas, Bacillus, Ochrobactrum, Brevundimonas, Psychrobacter, Staphylococcus, Marinobacter and Curtobacterium genera. BSF production by the isolates was tested by atomized oil assay, surface tension measurement and determination of the emulsification index. All isolates were able to produce BSFs under aerobic and anaerobic conditions, except for isolate DS27 which only produced BSF under aerobic conditions. These isolates presented potential to be applied in bioremediation or microbial enhanced oil recovery strategies under conditions of oxygen limitation. For the first time, members of Ochrobactrum, Brevundimonas, Psychrobacter, Staphylococcus, Marinobacter and Curtobacterium genera are described as anaerobic producers of BSFs.


Hydrocarbons , Petroleum , Surface-Active Agents , Water Pollutants, Chemical , Bacteria , Biodegradation, Environmental , Geologic Sediments , RNA, Ribosomal, 16S
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