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1.
J Microbiol Biotechnol ; 34(8): 1-6, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-39086223

RESUMEN

A Gram-stain-positive, aerobic, white-coloured, rod-shaped bacteria, designated as a strain dW9T , was isolated from soil. Strain dW9T was catalase-positive and oxidase-negative. Strain dW9T grew at temperature of 20-37°C and at pH of 5.0-7.0. Phylogenetic and 16S rRNA gene analysis indicated that strain dW9T belonged to the genus Paenibacillus with its closest relative being Paenibacillus filicis S4T (97.4% sequence similarity). The genome size of dW9T was 7,787,916 bp with DNA G+C content of 51.3%. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values of dW9T with its closest relatives were found to be <22.0% and <74.0%, respectively. The only respiratory quinone was MK-7, and the major fatty acids were antiso-C15:0 and iso-C16:0. Overall, the comprehensive taxonomic analysis revealed that strain dW9T met all the fundamental criteria to be classified as a novel species within the genus Paenibacillus. Accordingly, we propose the name Paenibacillus gyeongsangnamensis sp. nov., with the type strain dW9T (=KCTC 43431T =NBRC 116022T ).

2.
J Microbiol Biotechnol ; 34(7): 1475-1483, 2024 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-38973386

RESUMEN

Three Gram-stain-positive, aerobic, rod-shaped, and non-motile bacteria, labelled as W11T, SW19T, and YR1T, were isolated from soil, and performed their polyphasic taxonomic investigation. The phylogenetic and 16S rRNA gene sequence analysis showed that strains W11T, SW19T, and YR1T belonged to the genera Agromyces, Rathayibacter, and Nocardioides, respectively. Strain W11T was closely affiliated with Agromyces cavernae SYSU K20354T (98.1%), strain SW19T showed the closest affiliation with Rathayibacter rubneri ZW T2_19T (97.0%), and strain YR1T was most closely related to Nocardioides marmorisolisilvae KIS18-7T (98.0%). The genome sizes of strains W11T, SW19T, and YR1T were 4,181,720 bp, 4,740,677 bp, and 4,228,226 bp, respectively, with DNA G+C contents of 70.5%, 64.2%, and 69.7%, respectively. Average nucleotide identity and digital DNA-DNA hybridization values of W11T, SW19T, and YR1T with their respective reference species were <79.6% and <23.6%, respectively. The predominant cellular fatty acids detected in strain W11T were anteiso-C15:0, iso-C16:0, and anteiso-C17:0. In strain SW19T, they were summed feature 9 (C16:0 10-methyl and/or iso-C17:1ω 9c), anteiso-C17:0, and anteiso-C15:0. Strain YR1T exhibited C18:1ω 9c, C18:0 10-methyl, TBSA, and anteiso-C15:0 as its major cellular fatty acids. Overall, the polyphasic taxonomic comparisons indicated that strains W11T, SW19T, and YR1T represent novel species within the genera Agromyces, Rathayibacter, and Nocardioides, respectively. Accordingly, we propose the names Agromyces silvae sp. nov., with the type strain W11T (=KCTC 49818T =NBRC 115999T), Rathayibacter soli sp. nov., with the type strain SW19T (=KCTC 49860T =NBRC 116108T), and Nocardioides terrisoli sp. nov., with the type strain YR1T (=KCTC 49863T =NBRC 116165T).


Asunto(s)
Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano , Ácidos Grasos , Filogenia , ARN Ribosómico 16S , Análisis de Secuencia de ADN , Microbiología del Suelo , ARN Ribosómico 16S/genética , Ácidos Grasos/análisis , ADN Bacteriano/genética , Hibridación de Ácido Nucleico , Genoma Bacteriano
3.
J Microbiol Biotechnol ; 34(6): 1260-1269, 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38938005

RESUMEN

The gastrointestinal (GI) tract of shrimp, which is comprised of the stomach, hepatopancreas, and intestine, houses microbial communities that play crucial roles in immune defense, nutrient absorption, and overall health. While the intestine's microbiome has been well-studied, there has been limited research investigating the stomach and hepatopancreas. The present study addresses this gap by profiling the bacterial community in these interconnected GI segments of Pacific whiteleg shrimp. To this end, shrimp samples were collected from a local aquaculture farm in South Korea, and 16S rRNA gene amplicon sequencing was performed. The results revealed significant variations in bacterial diversity and composition among GI segments. The stomach and hepatopancreas exhibited higher Proteobacteria abundance, while the intestine showed a more diverse microbiome, including Cyanobacteria, Actinobacteria, Bacteroidetes, Firmicutes, Chloroflexi, and Verrucomicrobia. Genera such as Oceaniovalibus, Streptococcus, Actibacter, Ilumatobacter, and Litorilinea dominated the intestine, while Salinarimonas, Sphingomonas, and Oceaniovalibus prevailed in the stomach and hepatopancreas. It is particularly notable that Salinarimonas, which is associated with nitrate reduction and pollutant degradation, was prominent in the hepatopancreas. Overall, this study provides insights into the microbial ecology of the Pacific whiteleg shrimp's GI tract, thus enhancing our understanding of shrimp health with the aim of supporting sustainable aquaculture practices.


Asunto(s)
Bacterias , Microbioma Gastrointestinal , Hepatopáncreas , Intestinos , Penaeidae , ARN Ribosómico 16S , Animales , Penaeidae/microbiología , Hepatopáncreas/microbiología , ARN Ribosómico 16S/genética , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , República de Corea , Intestinos/microbiología , Filogenia , Estómago/microbiología , Biodiversidad , Acuicultura , ADN Bacteriano/genética
4.
Artículo en Inglés | MEDLINE | ID: mdl-38743058

RESUMEN

Two strictly aerobic and rod-shaped bacteria, labelled as DB1703T and DB2414ST, were obtained from an automobile air conditioning system. Strain DB1703T was Gram-stain-negative, while strain DB2414ST was Gram-stain-positive. Both strains were catalase-positive and oxidase-negative. Strains DB1703T and DB2414ST were able to grow at 18-42 °C. Strain DB1703T grew within a NaCl range of 0-3 % and a pH range of 6.0-8.0; while strain DB2414ST grew at 0-1 % and pH 6.5-8.5. The phylogenetic and 16S rRNA gene sequence analysis indicated that strains DB1703T and DB2414ST belonged to the genera Enterovirga and Knoellia, respectively. Strain DB1703T showed the closest phylogenetic similarity to Enterovirga rhinocerotis YIM 100770T (94.8 %), whereas strain DB2414ST was most closely related to Knoellia remsis ATCC BAA-1496T (97.7 %). The genome sizes of strains DB1703T and DB2414ST were 4 652 148 and 4 282 418 bp, respectively, with DNA G+C contents of 68.8 and 70.5 mol%, respectively. Chemotaxonomic data showed Q-10 as the sole ubiquinone in DB1703T and ML-8 (H4) in DB2414ST. The predominant cellular fatty acid in DB1703T was summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), whereas iso-C16 : 0, C17 : 1 ω8c, and iso-C15 : 0 were dominant in DB2414ST. Overall, the polyphasic taxonomic comparisons showed that strains DB1703T and DB2414ST were distinct from their closest taxa and represent novel species within the genera Enterovirga and Knoellia, respectively. Accordingly, we propose the names Enterovirga aerilata sp. nov., with the type strain DB1703T (=KCTC 72724T=NBRC 114759T), and Knoellia koreensis sp. nov., with the type strain DB2414ST (=KCTC 49355T=NBRC 114620T).


Asunto(s)
Aire Acondicionado , Automóviles , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano , Ácidos Grasos , Filogenia , ARN Ribosómico 16S , Análisis de Secuencia de ADN , Ubiquinona , Ácidos Grasos/análisis , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , República de Corea
5.
J Hazard Mater ; 470: 134167, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38598880

RESUMEN

This study investigated the leaching of phthalate and non-phthalate plasticizers from polyvinyl chloride microplastics (MPs) into sediment and their degradation over a 30-d period via abiotic and biotic processes. The results showed that 3579% of plasticizers were released into the sediment from the MPs and > 99.9% degradation was achieved. Although a significantly higher degradation was found in plasticizer-added microcosms under biotic processes (overall, 94%), there was a noticeable abiotic loss (72%), suggesting that abiotic processes also play a role in plasticizer degradation. Interestingly, when compared with the initial sediment-water partitioning for plasticizers, the partition constants for low-molecular-weight compounds decreased in both microcosms, whereas those for high-molecular-weight compounds increased after abiotic degradation. Furthermore, changes in the bacterial community, abundance of plasticizer-degrading bacterial populations, and functional gene profiles were assessed. In all the microcosms, a decrease in bacterial community diversity and a notable shift in bacterial composition were observed. The enriched potential plasticizer-degrading bacteria were Arthrobacter, Bacillus, Desulfovibrio, Desulfuromonas, Devosia, Gordonia, Mycobacterium, and Sphingomonas, among which Bacillus was recognized as the key plasticizer degrader. Overall, these findings shed light on the factors affecting plasticizer degradation, the microbial communities potentially involved in biodegradation, and the fate of plasticizers in the environment.


Asunto(s)
Bacterias , Sedimentos Geológicos , Microplásticos , Ácidos Ftálicos , Plastificantes , Cloruro de Polivinilo , Contaminantes Químicos del Agua , Cloruro de Polivinilo/química , Plastificantes/metabolismo , Sedimentos Geológicos/microbiología , Sedimentos Geológicos/química , Ácidos Ftálicos/metabolismo , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/metabolismo , Bacterias/metabolismo , Bacterias/clasificación , Biodegradación Ambiental
6.
Mar Pollut Bull ; 202: 116300, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38555803

RESUMEN

This study investigated the contents of total mercury (THg), trace metals, and CH4 and determined the signature microbes involved in various biogeochemical processes in the sediment of the Canadian Beaufort Sea. The THg ranged between 32 and 63 µg/kg and the trace metals such as Fe, Al, Mn, and Zn were significant in distributions. The pH, SO42-, Fe2+, and redox proxy metals were crucial factors in the spatial and vertical heterogeneity of geochemical distributions. CH4 was detected only at the mud volcano site. Microbial analyses identified Clostridium, Desulfosporosinus, Desulfofustis, and Desulftiglans as the predominant Hg methylators and sulfate reducers; Nitrosopumilus and Hyphomicrobium as the major nitrifiers and denitrifiers; Methanosarcina and Methanosaeta as keystone methanogens; and Methyloceanibacter and Methyloprofundus as signature methanotrophs. Altogether, this study expands the current understanding of the microbiological and geochemical features and could be helpful in predicting ecosystem functions in the Canadian Beaufort Sea.


Asunto(s)
Sedimentos Geológicos , Mercurio , Contaminantes Químicos del Agua , Sedimentos Geológicos/química , Sedimentos Geológicos/microbiología , Mercurio/análisis , Mercurio/metabolismo , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , Bacterias , Metano/análisis , Canadá
7.
Arch Microbiol ; 206(3): 119, 2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38396312

RESUMEN

An aerobic bacterium, designated as PT-12T, was isolated from soil collected from agriculture field, and its taxonomic position was validated through a comprehensive polyphasic methodology. The strain was identified as Gram-stain-negative, non-motile, rod-shaped, and catalase- and oxidase-positive. The yellow-colored colonies showed growth ability at temperature range of 18-37 °C, NaCl content of 0-1.0% (w/v), and at a pH of 6.0-8.0. The 16S rRNA gene and phylogenetic analysis showed that strain PT-12T affiliated with the genus Sphingomonas in the family Sphingomonadaceae, and displayed the highest 16S rRNA nucleotide sequence similarity with Sphingomonas limnosediminicola 03SUJ6T (98.4%). The genome size of strain PT-12T was 2,656,862 bp and the DNA G + C content estimated from genome was 63.5%. The highest values of average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) were observed between strain PT-12T and Sphingomonas segetis YJ09T, accounting to 76.2% and 20.2%, respectively. In addition, both ANI and dDDH values between strain PT-12T and other phylogenetically related neighbors ranged between 69.6% and 76.2% and 18.4% and 20.2%, respectively. Chemotaxonomic features exhibited Q-10 as the only ubiquinone; homospermidine as the major polyamine; summed feature 8 (C18:1ω7c and/or C18:1ω6c), C16:0, and 10-methyl C18:0 as the notable fatty acids; and phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine, and sphingoglycolipid as dominating polar lipids. Overall, the comprehensive polyphasic data supported that strain PT-12T represents a novel bacterial species within the genus Sphingomonas. Accordingly, we propose the name Sphingomonas flavescens sp. nov. The type strain is PT-12T (= KCTC 92114T = NBRC 115717T).


Asunto(s)
Fosfolípidos , Sphingomonas , Fosfolípidos/química , Sphingomonas/genética , Filogenia , ARN Ribosómico 16S/genética , Suelo , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Espermidina , Microbiología del Suelo , Ácidos Grasos/química , Análisis de Secuencia de ADN
8.
Arch Microbiol ; 206(1): 42, 2023 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-38147140

RESUMEN

During the study of microbial ecology of forest soil, two circular, white-colored bacterial colonies were isolated and labeled as strains TW38T and TW40T. Both strains were catalase positive and oxidase negative. Strains TW38T and TW40T demonstrated growth within a temperature range of 10-37 °C and 18-37 °C, respectively, and thrived within a pH range of 5.5-9.0 and 6.0-8.0, respectively. Both strains grew at 0-2.0% (w/v) NaCl concentrations. The phylogenetic analysis indicated that strains TW38T and TW40T affiliated to the genus Paenibacillus, with the closest neighbors being Paenibacillus montanisoli RA17T (98.6%) and Paenibacillus arachidis E3T (95.4%), respectively. In both strains, the sole respiratory quinone was MK-7, the signature fatty acid was antiso-C15:0, and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and phosphatidylcholine. The digital DNA-DNA hybridization and the average nucleotide identity values between TW38T, TW40T, and closest reference strains were < 29.0% and < 85.0%, respectively. The DNA G+C content of TW38T and TW40T was 54.5% and 57.1%, respectively. In general, the phylogenetic, genomics, chemotaxonomic, and phenotypic data support the differentiation of TW38T and TW40T from other closest members of the genus Paenibacillus. Thus, we conclude both strains TW38T and TW40T represent novel species of the genus Paenibacillus, for which the name Paenibacillus silvisoli sp. nov. and Paenibacillus humicola sp. nov. are proposed, respectively. The type strain of Paenibacillus silvisoli is TW38T (= KCTC 43468T = NBRC 116015T) and type strain of Paenibacillus humicola is TW40T (= KCTC 43469T = NBRC 116016T).


Asunto(s)
Cardiolipinas , Paenibacillus , Filogenia , Bosques , Paenibacillus/genética , ADN
9.
Int J Syst Evol Microbiol ; 73(11)2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37982814

RESUMEN

A milky-white-coloured, aerobic, Gram-stain-positive, rod-shaped and motile bacterial strain (GW78T) was isolated from forest soil. GW78T was catalase-positive and oxidase-negative. The strain was able to grow optimally at 37 °C and at pH 7.0 in Reasoner's 2A media. The phylogenetic and 16S rRNA gene sequence analysis of GW78T showed its affiliation with the genus Paenibacillus. The 16S rRNA gene sequence of GW78T revealed 98.3 % similarity to its nearest neighbour Paenibacillus mucilaginosus VKPM B-7519T. Its chemotaxonomic properties included MK-7 as the sole menaquinone, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylmonomethylethanolamine and phosphatidylethanolamine as major polar lipids, and anteiso-C15 : 0, C16 : 1 ω11c and anteiso-C17 : 0 as predominant fatty acids. Digital DNA-DNA hybridization and average nucleotide identity results with its closest relatives were <74.0 % and <14.0 %, respectively. Overall, 16S rRNA gene sequence comparisons, phylogenetic and genomic evidence, and phenotypic and chemotaxonomic data allow the differentiation of GW78T from other members of the genus Paenibacillus. Thus, we propose that strain GW78T represents a novel species of the genus Paenibacillus, with the name Paenibacillus caseinilyticus sp. nov. The type strain is GW78T (=KCTC 43430T=NBRC 116023T).


Asunto(s)
Ácidos Grasos , Paenibacillus , Ácidos Grasos/química , Fosfolípidos/química , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Composición de Base , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Microbiología del Suelo , Bosques
10.
Arch Microbiol ; 205(6): 248, 2023 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-37233801

RESUMEN

A white-coloured, rod-shaped, motile, aerobic, and Gram-stain-positive bacterial strain S3N08T was isolated from agricultural soil. The strain grew at temperature 10-40 °C, at 0-1.0% (w/v) NaCl concentration, and at pH 6.5-8.0. Catalase was negative and oxidase was positive. The phylogenetic analysis inferred that the strain S3N08T belonged to the genus Paenibacillus, with the closest relative being Paenibacillus periandrae PM10T (95.6% 16S rRNA gene sequence similarity). The only menaquinone was MK-7 and the major polar lipids were phosphatidylmonomethylethanolamine, phosphatidylglycerol, and phosphatidylethanolamine. The predominant fatty acids were antiso-C15:0, C16:0, and iso-C15:0. The DNA G + C content was 45.1%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain S3N08T and with closest members were < 72.0% and < 19.0%, respectively. Altogether, the phylogenetic, genomics, phenotypic, and chemotaxonomic evidence illustrated in this study suggested that strain S3N08T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus agricola sp. nov. is proposed. The type strain is S3N08T (= KACC 19666 T = NBRC 113430 T).


Asunto(s)
Paenibacillus , Fosfolípidos , Fosfolípidos/química , Suelo , Filogenia , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , Análisis de Secuencia de ADN , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , Ácido Diaminopimélico/química , Ácidos Grasos/química
11.
Environ Pollut ; 320: 121089, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36669717

RESUMEN

Volatile organic compounds (VOCs) have been globally reported at various sites. Currently, limited literature is available on VOC bioremediation using bacterial-immobilized biochar (BC-B). In this study, multiple VOC-degrading bacteria were enriched and isolated using a newly designed diffusion bioreactor. The most effective VOC-degrading bacteria were then immobilized on rice husk-derived pristine biochar (BC) to develop BC-B. Finally, the performances of BC and BC-B for VOCs (benzene, toluene, xylene, and trichloroethane) bioremediation were evaluated by establishing batch microcosm experiments (Control, C; bioconsortium, BS; pristine biochar, BC; and bacterial-immobilized biochar, BC-B). The results revealed that the newly designed diffusion bioreactor effectively simulated native VOC-contaminated conditions, easing the isolation of 38 diverse ranges of VOC-degrading bacterial strains. Members of the genus Pseudomonas were isolated in the highest (26.33%). The most effective bacterial strain was Pseudomonas sp. DKR-23, followed by Rhodococcus sp. Korf-18, which degraded multiple VOCs in the range of 52-75%. The batch microcosm experiment data showed that BC-B remediated the highest >90% of various VOCs, which was comparatively higher than that of BC, BS, and C. In addition, compared with C, the BS, BC, and BC-B microcosms abundantly reduced the half-life of various VOCs, implying a beneficial impact on the degradation behavior of VOCs. Altogether, this study suggests that a diffusion bioreactor system can be used as a cultivation device for the isolation of a wide range of VOC-degrading bacterial strains, and a compatible combination of biochar and bacteria may be an attractive and promising approach for the sustainable bioremediation of multiple VOCs.


Asunto(s)
Compuestos Orgánicos Volátiles , Biodegradación Ambiental , Carbón Orgánico , Bacterias
12.
Mar Pollut Bull ; 185(Pt A): 114319, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36343547

RESUMEN

In this study, total mercury (THg), methylmercury (MeHg), various trace elements, and microbial communities were measured in surface sediments of the East Siberian Sea (ESS). The results showed that the average values of THg and MeHg were 58.8 ± 15.21 µg/kg and 0.50 ± 0.22 µg/kg, respectively. The notable levels of trace elements present in both surface sediment and porewater were Al, Fe, and Mn. The enrichment factor and geoaccumulation index analyses found that both natural phenomena and anthropogenic activities contributed to elevated concentrations of metals in the ESS. The redox proxy metals, pH, and SO42- were the major factors influencing the THg and MeHg distributions. Microbial profiles were substantially affected by metals and other abiotic factors. Proteobacteria and Thaumarchaeota were the most abundant phyla. Overall, the findings presented here facilitate the understanding of the current status of metal contamination, its influencing factors, and metal-microbiota-interactions in ESS.


Asunto(s)
Mercurio , Compuestos de Metilmercurio , Microbiota , Oligoelementos , Contaminantes Químicos del Agua , Mercurio/análisis , Oligoelementos/análisis , Sedimentos Geológicos/análisis , Monitoreo del Ambiente/métodos , Contaminantes Químicos del Agua/análisis , Compuestos de Metilmercurio/análisis
13.
J Hazard Mater ; 438: 129464, 2022 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-35999716

RESUMEN

S-impregnation of biochar through elemental S streaming is known to increase its sorption performance against Hg and methyl mercury (MeHg). However, the effects of %S-loading on biochar's mechanism and sorption capacities for MeHg, and its consequent impact when used as an amendment material for Hg-contaminated sediments, are poorly understood, and thus, were investigated in this work. Our results showed that a minimum sulfur loading of 1% was the most effective in reducing MeHg levels in sediments. At higher %S-loading (3-20%), the reduction in surface area, pore blockage due to unreacted sulfur particles, and presence of poorly bound sulfur species resulted in lowered effectiveness for MeHg control. Increasing S-functionalization during impregnation shifted the sorption process of MeHg from Hg-O to Hg-S in S-impregnated biochar (BCS). Our 60-day slurry experiment showed a significant reduction in pore water THg (40-70%) and MeHg (30-55%), as well as sediment MeHg (50-60%) in biochar-amended sediments. The reduction in the bioavailable Hg resulted in lowered Hg methylation, as supported by the suppression of both the Fe- and SO42--reduction activities in the amended sediments. The microbial community structure in BCS-amended sediments showed a shift towards sulfur-consuming, iron-reducing, thiosulfate-oxidizing, and sulfate-reducing bacterial populations. At the genus level, the overall relative abundance of principal Hg methylators was also lower in the BCS treatment than in the unamended sediments. This study highlights the application of BCS as a promising strategy for remediation of Hg-contaminated sediments.


Asunto(s)
Mercurio , Compuestos de Metilmercurio , Microbiota , Contaminantes Químicos del Agua , Carbón Orgánico , Sedimentos Geológicos/química , Mercurio/análisis , Metilación , Compuestos de Metilmercurio/metabolismo , Azufre , Contaminantes Químicos del Agua/análisis
14.
Environ Res ; 212(Pt C): 113439, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35537496

RESUMEN

This study investigated seasonal trends in bioaccumulation potential and toxic effects of mercury (Hg) in Asian clams (Corbicula fluminea) and microbial community. For this, a clam-exposure experiment was performed during summer, fall, and winter seasons in four different sites (HS1: control/clean site; HS2, HS3, and HS4: contaminated sites) of Hyeongsan River estuary, South Korea. Total mercury (THg) and methylmercury (MeHg) in whole sediments were highest at HS4 site during fall, sustained similar levels during winter, but decreased during summer. Unlike whole sediment, pore water reported higher levels in summer, and gradually declined during fall and winter. Asian clams from HS4 site collected during summer presented highest bioaccumulations of THg (521.52 µg/kg, dry weight) and MeHg (161.04 µg/kg, dry weight), which also correlated with the higher levels of Hg present in pore water in the same season. Moreover, biota-sediment-pore water accumulation factor (BSpAF) were comparatively greater in clams collected from HS2∼HS4 compared to HS1 sites, suggesting that porewater was a better indicator of accumulation of Hg. Upregulation of biomarker genes responsible for detoxifying process (gsts1), scavenging oxidative stress (cat), and protein reparation (hsp70 and hsp90) were observed in clams collected from HS2∼HS4. The overexpression of these biomarkers implied that Asian clams can be considered as promising warning tools for Hg-contamination. Both bacterial and metabolic diversities were negatively affected by higher levels of THg and MeHg. Phylum Proteobacteria was enriched in HS2∼HS4 compared to HS1. In contrast, phylum Bacteroidetes showed a reverse trend. The metabolic profile was highest in HS1 and lowest in HS4, revealing higher stress of Hg in HS4 site. Overall, the outcomes of this field study broaden the information on seasonal trends of bioaccumulation of Hg and its toxic effects. These findings may be helpful in Hg monitoring and management programs in other river systems.


Asunto(s)
Corbicula , Mercurio , Compuestos de Metilmercurio , Microbiota , Contaminantes Químicos del Agua , Animales , Bioacumulación , Corbicula/metabolismo , Monitoreo del Ambiente , Sedimentos Geológicos , Mercurio/análisis , Compuestos de Metilmercurio/toxicidad , Estaciones del Año , Agua , Contaminantes Químicos del Agua/análisis
15.
Curr Microbiol ; 79(5): 156, 2022 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-35397046

RESUMEN

This study investigated the bacterial community structure and metabolic diversity and their relationship with Hg and other environmental variables in sediments collected from different locations (HSR-1-HSR-6) in the Hyeongsan River estuary in South Korea. The results showed that the highest total mercury (THg) and methylmercury (MeHg) concentrations were in HSR-2, with values of 4585.3 µg/kg and 13.4 µg/kg, respectively. The lowest THg (31.9 µg/kg) and MeHg (0.1 µg/kg) concentrations were found in HSR-1. Sulfate and organic matter (OM) were more influential environmental variables, revealing a positive association with THg and MeHg and negatively affecting bacterial and metabolic diversities. Bacterial and metabolic diversities were also negatively impacted by the THg and MeHg concentrations. Proteobacteria and Bacteroidetes were abundantly distributed in all the sediments. The dominance of Proteobacteria was upscaled in all the heavily Hg-contaminated sites (HSR-2-HSR-6), and it was the only phylum that showed a significant positive correlation with THg, MeHg, and OM. The genera Sulfurovum and Sulfurimonas were abundantly observed in sites with high Hg contamination, whereas Congregibacter, Gaetbulibacter, Ilumatobacter, Methylotenera, Nevskia, and Sediminibacter were only detected in low Hg-contaminated sites (HSR-1). The community-level physiological profile data showed the highest (1.0) average well color development (AWCD) value in HSR-1 and the lowest (0.45) AWCD value in HSR-2. Overall, these results demonstrated the inhibitory effects of THg, MeHg, and other environmental variables on microbial communities and metabolic diversity. These findings broaden the current knowledge on the dynamics of bacterial and metabolic diversities in Hg-contaminated sediments and might be useful in the management of Hg pollution.


Asunto(s)
Mercurio , Compuestos de Metilmercurio , Contaminantes Químicos del Agua , Bacterias , Monitoreo del Ambiente/métodos , Sedimentos Geológicos/química , Mercurio/metabolismo , Ríos , Contaminantes Químicos del Agua/análisis
16.
Antonie Van Leeuwenhoek ; 115(5): 563-572, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35305190

RESUMEN

A white-colony-forming, facultative anaerobic, motile and Gram-stain-negative bacterium, designated G-1-2-2 T was isolated from soil of agriculture field near Kyonggi University, Republic of Korea. Strain G-1-2-2 T synthesized the polyhydroxybutyrate and could grow at 10-35 °C. The phylogenetic analysis based on 16S rRNA gene sequence showed that, strain G-1-2-2 T formed a lineage within the family Comamonadaceae and clustered as a member of the genus Ramlibacter. The 16S rRNA gene sequence of strain G-1-2-2 T showed high sequence similarities with Ramlibacter ginsenosidimutans BXN5-27 T (97.9%), Ramlibacter monticola G-3-2 T (97.9%) and Ramlibacter alkalitolerans CJ661T (97.5%). The sole respiratory quinone was ubiquinone-8 (Q-8). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, and an unidentified phospholipid. The principal cellular fatty acids were C16:0, cyclo-C17:0, summed feature 3 (C16:1ω7c and/or C16:1ω6c) and summed feature 8 (C18:1ω7c and/or C18:1ω6c). The genome of strain G-1-2-2 T was 7,200,642 bp long with 13 contigs, 6,647 protein-coding genes, and DNA G + C content of 68.9%. The average nucleotide identity and in silico DNA-DNA hybridization values between strain G-1-2-2 T and close members were ≤ 81.2 and 24.1%, respectively. The genome of strain G-1-2-2 T showed eight putative biosynthetic gene clusters responsible for various secondary metabolites. Genome mining revealed the presence of atoB, atoB2, phaS, phbB, phbC, and bhbD genes in the genome which are responsible for polyhydroxybutyrate biosynthesis. Based on these data, strain G-1-2-2 T represents a novel species in the genus Ramlibacter, for which the name Ramlibacter agri sp. nov. is proposed. The type strain is G-1-2-2 T (= KACC 21616 T = NBRC 114389 T).


Asunto(s)
Comamonadaceae , Suelo , Agricultura , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Ácidos Grasos , Humanos , Fosfolípidos , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Microbiología del Suelo
17.
Arch Microbiol ; 204(1): 118, 2022 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-34988667

RESUMEN

A light yellow-coloured, non-motile, aerobic, Gram-stain-negative, and rod-shaped bacterial strain DKR-2T was isolated from oil-contaminated experimental soil. The strain was catalase and oxidase positive, and grew at 0-1.5% (w/v) NaCl concentration, at temperature 10-35 °C, and at pH 6.0-9.5. The phylogenetic analysis suggested that the strain DKR-2T was affiliated to the genus Kaistella, with the closest species being Kaistella haifensis DSM 19056T (97.6% 16S rRNA gene sequence similarity). The principle fatty acids were iso-C15:0, summed feature 9 (iso-C17:1 ω9c and/or C16:0 10-methyl), and antiso-C15:0. The sole menaquinone was MK-6 and major polar lipid was phosphatidylethanolamin. The DNA G+C content was 39.5%. The dDDH (in silico DNA-DNA hybridization) and ANI (average nucleotide identity) values between strain DKR-2T and K. haifensis DSM 19056T were 22.4% and 79.3%, respectively. In addition, both dDDH and ANI values between strain DKR-2T and other phylogenetically related neighbours were < 25.0% and < 77.0%, respectively. In overall, the polyphasic taxonomic data presented in this study clearly indicated that strain DKR-2T represents a novel species in the genus Kaistella, for which the name Kaistella soli sp. nov. is proposed. The type strain is DKR-2T (=KACC 22070T=NBRC 114725T).


Asunto(s)
Ácidos Grasos , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Ácidos Grasos/análisis , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Suelo
18.
Artículo en Inglés | MEDLINE | ID: mdl-35100105

RESUMEN

A yellow-coloured, Gram-stain-positive, motile, aerobic and rod-shaped bacteria, designated DKR-3T, was isolated from oil-contaminated experimental soil. Strain DKR-3T could grow at pH 5.0-10.5 (optimum, pH 7.0-8.5), at 10-40 °C (optimum, 25-32 °C) and tolerated 3.5 % of NaCl. Phylogenetic analyses based on its 16S rRNA gene sequence indicated that strain DKR-3T formed a lineage within the family Cellulomonadaceae and was clustered with members of the genus Cellulomonas. Strain DKR-3T had highest 16S rRNA gene sequence similarities to Cellulomonas gelida DSM 20111T (98.3 %), Cellulomonas persica JCM 18111T (98.2 %) and Cellulomonas uda DSM 20107T (97.8 %). The predominant respiratory quinone was tetrahydrogenated menaquinone with nine isoprene units [MK-9(H4)]. The principal cellular fatty acids were anteiso-C15 : 0, C16 : 0 and anteiso-C17 : 0. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The cell-wall diamino acid was l-ornithine whereas rhamnose and glucose were the cell-wall sugars. The DNA G+C content was 74.2mol %. The genome of strain DKR-3T was 3.74 Mb and contained three putative biosynthetic gene clusters. The average nucleotide identity and digital DNA-DNA hybridization relatedness values between strain DKR-3T and its phylogenetically related members were below the species threshold values. Based on a polyphasic study, strain DKR-3T represents a novel species belonging to the genus Cellulomonas, for which the name Cellulomonas fulva sp. nov. is proposed. The type strain is DKR-3T (=KACC 22071T=NBRC 114730T).


Asunto(s)
Cellulomonas , Contaminación por Petróleo , Filogenia , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , Composición de Base , Cellulomonas/clasificación , Cellulomonas/aislamiento & purificación , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Fosfolípidos/química , Pigmentación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Contaminantes del Suelo
19.
Bioresour Technol ; 344(Pt B): 126300, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34752882

RESUMEN

The prominent characteristics of the biochar, high porosity, sorption capacity with low density improve the aeration, making it a desirable amendment material for composting process. The composting efficiency was analysed by the impact of rice husk biochar amendment (0, 2, 4, 6, 8 and 10%) in the presence of salts for the co-composting of food waste and swine manure, in composting reactors for 50 days. Results revealed that biochar amendment had improved the degradation rates by microbial activities in comparison with control. The final compost quality was improved by reducing the bulk density (29-53%), C/N ratio (29-57%), gaseous emissions (CO2, CH4, and NH3) and microbial pathogens (Escherichia coli and Salmonella sp.). However, 6% biochar amendment had significant improvement in compost quality, degradation rates and nutritional value which is recommended as the ideal ratio for obtaining mature compost from the feedstock, food waste and swine manure.


Asunto(s)
Compostaje , Eliminación de Residuos , Animales , Carbón Orgánico , Alimentos , Gases , Estiércol , Nitrógeno/análisis , Nutrientes , Sales (Química) , Suelo , Porcinos
20.
Nat Prod Res ; 36(1): 470-473, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32552037

RESUMEN

This study was aimed to determine the phytochemicals and nutritional compositions, antioxidant activity and sensorial properties of Moringa oleifera extracts. The powders prepared from leaves and pods were mixed separately at the ratios of 1:0, 0:1, 0.25:0.75, 0.5:0.5 and 0.75:0.25 and labelled as mixtures A, B, C, D and E, respectively. Mixture A exhibited highest chlorophylls, tannins, phenolics and flavonoids contents (17.8 mg/g, 9.1 mg GAE/g, 91.1 mg GAE/g and 38.1 mg QE/g, respectively). The crude proteins content was higher (18.03%) in mixture A. The fats, fibres and carbohydrates amounts were higher (2.96%, 11.02% and 67.86%, respectively) in mixture B. The highest energy value (335.62 Kcal/100 g) and the highest antioxidant activity (83.2%) were in mixture A. However, most of the sensory attributes were ranked high for mixture D, signifying to use the equal proportion of leaves and pods powder of M. oleifera for the development of food products.


Asunto(s)
Moringa oleifera , Valor Nutritivo , Fitoquímicos/análisis , Antioxidantes , Moringa oleifera/química , Nepal , Extractos Vegetales , Hojas de la Planta
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