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1.
J Med Microbiol ; 73(7)2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38967406

RESUMO

Introduction. Cold plasma is frequently utilized for the purpose of eliminating microbial contaminants. Under optimal conditions, it can function as plasma medicine for treating various diseases, including infections caused by Candida albicans, an opportunistic pathogen that can overgrow in individuals with weakened immune system.Gap Statement. To date, there has been less molecular study on cold plasma-treated C. albicans.Research Aim. The study aims to fill the gap in understanding the molecular response of C. albicans to cold plasma treatment.Methodology. This project involved testing a cold plasma generator to determine its antimicrobial effectiveness on C. albicans' planktonic cells. Additionally, the cells' transcriptomics responses were investigated using RNA sequencing at various treatment durations (1, 3 and 5 min).Results. The results show that our cold plasma effectively eliminates C. albicans. Cold plasma treatment resulted in substantial downregulation of important pathways, such as 'nucleotide metabolism', 'DNA replication and repair', 'cell growth', 'carbohydrate metabolism' and 'amino acid metabolism'. This was an indication of cell cycle arrest of C. albicans to preserve energy consumption under unfavourable conditions. Nevertheless, C. albicans adapted its GSH antioxidant system to cope with the oxidative stress induced by reactive oxygen species, reactive nitrogen species and other free radicals. The treatment likely led to a decrease in cell pathogenicity as many virulence factors were downregulated.Conclusion. The study demonstrated the major affected pathways in cold plasma-treated C. albicans, providing valuable insights into the molecular response of C. albicans to cold plasma treatment. The findings contribute to the understanding of the antimicrobial efficiency of cold plasma and its potential applications in the field of microbiology.


Assuntos
Candida albicans , Perfilação da Expressão Gênica , Gases em Plasma , Candida albicans/genética , Candida albicans/efeitos dos fármacos , Gases em Plasma/farmacologia , Plâncton/genética , Transcriptoma , Estresse Oxidativo , Regulação Fúngica da Expressão Gênica , Espécies Reativas de Oxigênio/metabolismo , Humanos
2.
Artigo em Inglês | MEDLINE | ID: mdl-38842626

RESUMO

Halophilic bacteria are extremophiles that thrive in saline environment. Their ability to withstand such harsh conditions makes them an ideal choice for industrial applications such as lignocellulosic biomass degradation. In this study, a halophilic bacterium with the ability to produce extracellular cellulases and hemicellulases, designated as Nesterenkonia sp. CL21, was isolated from mangrove sediment in Tanjung Piai National Park, Malaysia. Thus far, studies on lignocellulolytic enzymes concerning bacterial species under this genus are limited. To gain a comprehensive understanding of its lignocellulose-degrading potential, the whole genome was sequenced using the Illumina NovaSeq 6000 platform. The genome of strain CL21 was assembled into 25 contigs with 3,744,449 bp and a 69.74% GC content and was predicted to contain 3,348 coding genes. Based on taxonomy analysis, strain CL21 shares 73.8 to 82.0% average nucleotide identity with its neighbouring species, below the 95% threshold, indicating its possible status as a distinct species in Nesterenkonia genus. Through in-depth genomic mining, a total of 81 carbohydrate-active enzymes were encoded. Among these, 24 encoded genes were identified to encompass diverse cellulases (GH3), xylanases (GH10, GH11, GH43, GH51, GH127 and CE4), mannanases (GH38 and GH106) and pectinases (PL1, PL9, and PL11). The production of lignocellulolytic enzymes was tested in the presence of several substrates. This study revealed that strain CL21 can produce a diverse array of enzymes which are active at different time points. By combining experimental data with genomic information, the ability of strain CL21 to produce lignocellulolytic enzymes has been elucidated, with potential applications in biorefinery industry.

3.
Arch Microbiol ; 205(8): 278, 2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37420023

RESUMO

Hahella is a genus that has not been well-studied, with only two identified species. The potential of this genus to produce cellulases is yet to be fully explored. The present study isolated Hahella sp. CR1 from mangrove soil in Tanjung Piai National Park, Malaysia, and performed whole genome sequencing (WGS) using NovaSeq 6000. The final assembled genome consists of 62 contigs, 7,106,771 bp, a GC ratio of 53.5%, and encoded for 6,397 genes. The CR1 strain exhibited the highest similarity with Hahella sp. HN01 compared to other available genomes, where the ANI, dDDH, AAI, and POCP were 97.04%, 75.2%, 97.95%, and 91.0%, respectively. In addition, the CAZymes analysis identified 88 GTs, 54 GHs, 11 CEs, 7 AAs, 2 PLs, and 48 CBMs in the genome of strain CR1. Among these proteins, 11 are related to cellulose degradation. The cellulases produced from strain CR1 were characterized and demonstrated optimal activity at 60 ℃, pH 7.0, and 15% (w/v) sodium chloride. The enzyme was activated by K+, Fe2+, Mg2+, Co2+, and Tween 40. Furthermore, cellulases from strain CR1 improved the saccharification efficiency of a commercial cellulase blend on the tested agricultural wastes, including empty fruit bunch, coconut husk, and sugarcane bagasse. This study provides new insights into the cellulases produced by strain CR1 and their potential to be used in lignocellulosic biomass pre-treatment.


Assuntos
Celulase , Celulases , Saccharum , Celulases/genética , Celulases/metabolismo , Celulose/metabolismo , Biomassa , Saccharum/química , Celulase/metabolismo
4.
Microbiol Resour Announc ; 12(5): e0006823, 2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37017536

RESUMO

Zhouia amylolytica CL16 was isolated from the mangrove soil of Tanjung Piai, Malaysia. The present work reports the draft genome sequence of this bacterium. The genome consists of 113 glycoside hydrolases, 40 glycosyltransferases, 4 polysaccharide lyases, 23 carbohydrate esterases, 5 auxiliary activities, and 27 carbohydrate-binding modules, which warrant further investigation.

5.
3 Biotech ; 13(2): 50, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36685320

RESUMO

The halophilic genus Joostella is one of the least-studied genera in the family of Flavobacteriaceae. So far, only two species were taxonomically identified with limited genomic analysis in the aspect of application has been reported. Joostella atrarenae M1-2T was previously isolated from a seashore sample and it is the second discovered species of the genus Joostella. In this project, the genome of J. atrarenae M1-2T was sequenced using NovaSeq 6000. The final assembled genome is comprised of 71 contigs, a total of 3,983,942 bp, a GC ratio of 33.2%, and encoded for 3,416 genes. The 16S rRNA gene sequence of J. atrarenae M1-2T shows 97.3% similarity against J. marina DSM 19592T. Genome-genome comparison between the two strains by ANI, dDDH, AAI, and POCP shows values of 80.8%, 23.3%, 83.4%, and 74.1% respectively. Pan-genome analysis shows that strain M1-2T and J. marina DSM 19592T shared a total of 248 core genes. Taken together, strain M-2T and J. marina DSM 19592T belong to the same genus but are two different species. CAZymes analysis revealed that strain M1-2T harbors 109 GHs, 40 GTs, 5 PLs, 9 CEs, and 6 AAs. Among these CAZymes, while 5 genes are related to cellulose degradation, 12 and 24 genes are found to encode for xylanolytic enzymes and other hemicellulases that involve majorly in the side chain removal of the lignocellulose structure, respectively. Furthermore, both the intracellular and extracellular crude extracts of strain M1-2T exhibited enzymatic activities against CMC, xylan, pNPG, and pNPX substrates, which corresponding to endoglucanase, xylanase, ß-glucosidase, and ß-xylosidase, respectively. Collectively, description of genome coupled with the enzyme assay results demonstrated that J. atrarenae M1-2T has a role in lignocellulosic biomass degradation, and the strain could be useful for lignocellulosic biorefining.

6.
Genes (Basel) ; 13(11)2022 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-36421811

RESUMO

Robertkochia solimangrovi is a proposed marine bacterium isolated from mangrove soil. So far, the study of this bacterium is limited to taxonomy only. In this report, we performed a genomic analysis of R. solimangrovi that revealed its lignocellulose degrading ability. Genome mining of R. solimangrovi revealed a total of 87 lignocellulose degrading enzymes. These enzymes include cellulases (GH3, GH5, GH9 and GH30), xylanases (GH5, GH10, GH43, GH51, GH67, and GH115), mannanases (GH2, GH26, GH27 and GH113) and xyloglucanases (GH2, GH5, GH16, GH29, GH31 and GH95). Most of the lignocellulolytic enzymes encoded in R. solimangrovi were absent in the genome of Robertkochia marina, the closest member from the same genus. Furthermore, current work also demonstrated the ability of R. solimangrovi to produce lignocellulolytic enzymes to deconstruct oil palm empty fruit bunch (EFB), a lignocellulosic waste found abundantly in palm oil industry. The metabolic pathway taken by R. solimangrovi to transport and process the reducing sugars after the action of lignocellulolytic enzymes on EFB was also inferred based on genomic data. Collectively, genomic analysis coupled with experimental studies elucidated R. solimangrovi to serve as a promising candidate in seawater based-biorefinery industry.


Assuntos
Celulases , Lignina , Lignina/metabolismo , Celulases/genética , Óleo de Palmeira , Bactérias/metabolismo , Genômica
7.
Protein Pept Lett ; 29(5): 379-383, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35345988

RESUMO

Bioactive peptides with potential health benefits and metabolic functionality have been identified from plant-based food. The aim of this perspective is to report the recent progress in the research of plant-derived bioactive peptides using the combination of omics technologies and bioinformatics tools. Studies examining bioactive peptides with identified amino acid sequences and well-characterized biological functionalities are highlighted. Various software, webtools and workflows for analyzing and interpreting the biological data acquired from different omics approaches are discussed. The emerging evidence from the integration of proteomics and metabolomics data with advanced laboratory analytical methods supports more potential applications in the envisioned development of nutraceutical and therapeutic products. Notwithstanding, much works are mandatory to resolve those lied-ahead challenges before realizing the proposed applications of plant peptides.


Assuntos
Peptídeos , Proteômica , Sequência de Aminoácidos , Biologia Computacional/métodos , Metabolômica , Peptídeos/química , Plantas/genética
8.
Braz J Microbiol ; 52(1): 251-256, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33141351

RESUMO

The wide use of whole-genome sequencing approach in the modern genomic era has opened a great opportunity to reveal the prospective applications of halophilic bacteria. Robertkochia marina CC-AMO-30DT is one of the halophilic bacteria that was previously taxonomically identified without any inspection on its biotechnological potential from a genomic aspect. In this study, we present the whole-genome sequence of R. marina and demonstrated the ability of this bacterium in solubilizing phosphate by producing phosphatase. The genome of R. marina has 3.57 Mbp and contains 3107 predicted genes, from which 3044 are protein coding, 52 are non-coding RNAs, and 11 are pseudogenes. Several phosphatases such as alkaline phosphatases and pyrophosphatases were mined from the genome. Further genomic study (phylogenetics, sequence analysis, and functional mechanism) and experimental data suggested that the alkaline phosphatase produced by R. marina could potentially be utilized in promoting plant growth, particularly for plants on saline-based agricultural land.


Assuntos
Flavobacteriaceae/genética , Flavobacteriaceae/metabolismo , Genoma Bacteriano , Fosfatos/metabolismo , Sequenciamento Completo do Genoma , Agricultura/métodos , Flavobacteriaceae/enzimologia , Fosfodiesterase I/genética , Filogenia , Pirofosfatases/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Solubilidade
9.
Microorganisms ; 8(7)2020 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-32610703

RESUMO

The majority of the members in order Rhodothermales are underexplored prokaryotic extremophiles. Roseithermus, a new genus within Rhodothermales, was first described in 2019. Roseithermus sacchariphilus is the only species in this genus. The current report aims to evaluate the transcriptomic responses of R. sacchariphilus strain RA when cultivated on beechwood xylan. Strain RA doubled its growth in Marine Broth (MB) containing xylan compared to Marine Broth (MB) alone. Strain RA harbors 54 potential glycosyl hydrolases (GHs) that are affiliated with 30 families, including cellulases (families GH 3, 5, 9, and 44) and hemicellulases (GH 2, 10, 16, 29, 31,43, 51, 53, 67, 78, 92, 106, 113, 130, and 154). The majority of these GHs were upregulated when the cells were grown in MB containing xylan medium and enzymatic activities for xylanase, endoglucanase, ß-xylosidase, and ß-glucosidase were elevated. Interestingly, with the introduction of xylan, five out of six cellulolytic genes were upregulated. Furthermore, approximately 1122 genes equivalent to one-third of the total genes for strain RA were upregulated. These upregulated genes were mostly involved in transportation, chemotaxis, and membrane components synthesis.

10.
Arch Microbiol ; 202(9): 2591-2597, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32607725

RESUMO

To date, the genus Parvularcula consists of 6 species and no potential application of this genus was reported. Current study presents the genome sequence of Parvularcula flava strain NH6-79 T and its cellulolytic enzyme analysis. The assembled draft genome of strain NH6-79 T consists of 9 contigs and 7 scaffolds with 3.68 Mbp in size and GC content of 59.87%. From a total of 3,465 genes predicted, 96 of them are annotated as glycoside hydrolases (GHs). Within these GHs, 20 encoded genes are related to cellulosic biomass degradation, including 12 endoglucanases (5 GH10, 4 GH5, and 3 GH51), 2 exoglucanases (GH9) and 6 ß-glucosidases (GH3). In addition, highest relative enzyme activities (endoglucanase, exoglucanase, and ß-glucosidase) were observed at 27th hour when the strain was cultured in the carboxymethyl cellulose/Avicel®-containing medium for 45 h. The combination of genome analysis with experimental studies indicated the ability of strain NH6-79 T to produce extracellular endoglucanase, exoglucanase, and ß-glucosidase. These findings suggest the potential of Parvularcula flava strain NH6-79 T in cellulose-containing biomass degradation and that the strain could be used in cellulosic biorefining process.


Assuntos
Alphaproteobacteria/enzimologia , Alphaproteobacteria/genética , Genoma Bacteriano/genética , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Composição de Bases , Biomassa , Celulase/genética , Celulase/metabolismo , Celulose/metabolismo , beta-Glucosidase/genética , beta-Glucosidase/metabolismo
11.
Data Brief ; 30: 105658, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32426431

RESUMO

Mangrovimonas sp. strain CR14 is a halophilic bacterium affiliated with family Flavobacteriaceae which was successfully isolated from mangrove soil samples obtained from Tanjung Piai National Park, Johor. The whole genome of strain CR14 was sequenced on an Illumina HiSeq 2500 platform (2 × 150 bp paired end). Herein, we report the genome sequence of Mangrovimonas sp. strain CR14 in which its assembled genome consisted 20 contigs with a total size of 3,590,195 bp, 3209 coding sequences, and an average 36.08% G + C content. Genome annotation and gene mining revealed that this bacterium demonstrated proteolytic activity which could be potentially applied in detergent industry. This whole-genome shotgun data of Mangrovimonas sp. strain CR14 has been deposited at DDBJ/ENA/GenBank under the accession JAAFZY000000000. The version described in this paper is version JAAFZY010000000.

12.
3 Biotech ; 10(4): 160, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32206494

RESUMO

In this study, a bacterial strain CP22 with ability to produce cellulase, xylanase and mannanase was isolated from the oil palm compost. Based on the 16S rRNA gene analysis, the strain was affiliated to genus Micromonospora. To further investigate genes that are related to cellulose and hemicellulose degradation, the genome of strain CP22 was sequenced, annotated and analyzed. The de novo assembled genome of strain CP22 featured a size of 5,856,203 bp with G + C content of 70.84%. Detailed genome analysis on lignocellulose degradation revealed a total of 60 genes consisting of 47 glycoside hydrolase domains and 16 carbohydrate esterase domains predicted to be involved in cellulolytic and hemicellulolytic deconstruction. Particularly, 20 genes encode for cellulases (8 endoglucanases, 3 exoglucanases and 9 ß-glucosidases) and 40 genes encode for hemicellulases (15 endo-1,4-ß-xylanase, 3 ß-xylosidase, 3 α-arabinofuranosidase, 10 acetyl xylan esterase, 6 polysaccharide deacetylase, 1 ß-mannanase, 1 ß-mannosidase and 1 α-galactosidase). Thirty-two genes encoding carbohydrate-binding modules (CBM) from six different families (CBM2, CBM4, CBM6, CBM9, CBM13 and CBM22) were present in the genome of strain CP22. These CBMs were found in 27 cellulolytic and hemicellulolytic genes, indicating their potential role in enhancing the substrate-binding capability of the enzymes. CBM2 and CBM13 are the major CBMs present in cellulases and hemicellulases (xylanases and mannanases), respectively. Moreover, a GH10 xylanase was found to contain 3 CBMs (1 CBM9 and 2 CBM22) and these CBMs were reported to bind specifically to xylan. This genome-based analysis could facilitate the exploration of this strain for lignocellulosic biomass degradation.

13.
Int J Syst Evol Microbiol ; 70(3): 1769-1776, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31976852

RESUMO

To date, there is sparse information for the genus Robertkochia with Robertkochia marina CC-AMO-30DT as the only described member. We report here a new species isolated from mangrove soil collected at Malaysia Tanjung Piai National Park and perform polyphasic characterization to determine its taxonomic position. Strain CL23T is a Gram-negative, yellow-pigmented, strictly aerobic, catalase-positive and oxidase-positive bacterium. The optimal growth conditions were determined to be at pH 7.0, 30-37 °C and in 1-2 % (w/v) NaCl. The major respiratory quinone was menaquinone-6 (MK-6) and the highly abundant polar lipids were four unidentified lipids, a phosphatidylethanolamine and two unidentified aminolipids. The 16S rRNA gene similarity between strain CL23T and R. marina CC-AMO-30DT is 96.67 %. Strain CL23T and R. marina CC-AMO-30DT clustered together and were distinguished from taxa of closely related genera in 16S rRNA gene phylogenetic analysis. Genome sequencing revealed that strain CL23T has a genome size of 4.4 Mbp and a G+C content of 40.72 mol%. Overall genome related indexes including digital DNA-DNA hybridization value and average nucleotide identity are 17.70 % and approximately 70%, below the cutoffs of 70 and 95%, respectively, indicated that strain CL23T is a distinct species from R. marina CC-AMO-30DT. Collectively, based on the phenotypic, chemotaxonomic, phylogenetic and genomic evidences presented here, strain CL23T is proposed to represent a new species with the name Robertkochia solimangrovi sp. nov. (KCTC 72252T=LMG 31418T). An emended description of the genus Robertkochia is also proposed.


Assuntos
Flavobacteriaceae/classificação , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Flavobacteriaceae/isolamento & purificação , Tamanho do Genoma , Malásia , Hibridização de Ácido Nucleico , Fosfolipídeos/química , Pigmentação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
14.
Genomics ; 112(1): 952-960, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31201854

RESUMO

The genus Meridianimaribacter is one of the least-studied genera within Cytophaga-Flavobacteria. To date, no genomic analysis of Meridianimaribacter has been reported. In this study, Meridianimaribacter sp. strain CL38, a lignocellulose degrading halophile was isolated from mangrove soil. The genome of strain CL38 was sequenced and analyzed. The assembled genome contains 17 contigs with 3.33 Mbp, a GC content of 33.13% and a total of 2982 genes predicted. Lignocellulose degrading enzymes such as cellulases (GH3, 5, 9, 16, 74 and 144), xylanases (GH43 and CE4) and mannanases (GH5, 26, 27 and 130) are encoded in the genome. Furthermore, strain CL38 demonstrated its ability to decompose empty fruit bunch, a lignocellulosic waste residue arising from palm oil industry. The genome information coupled with experimental studies confirmed the ability of strain CL38 to degrade lignocellulosic biomass. Therefore, Meridianimaribacter sp. strain CL38, with its halotolerance, could be useful for seawater based lignocellulosic biorefining.


Assuntos
Flavobacteriaceae/genética , Genoma Bacteriano , Lignina/metabolismo , Flavobacteriaceae/classificação , Flavobacteriaceae/enzimologia , Genômica , Redes e Vias Metabólicas/genética , Filogenia , Polissacarídeos/metabolismo
15.
3 Biotech ; 9(10): 364, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31588388

RESUMO

Empty fruit bunch (EFB) and palm oil mill effluent (POME) are the major wastes generated by the oil palm industry in Malaysia. The practice of EFB and POME digester sludge co-composting has shown positive results, both in mitigating otherwise environmentally damaging waste streams and producing a useful product (compost) from these streams. In this study, the bacterial ecosystems of 12-week-old EFB-POME co-compost and POME biogas sludge from Felda Maokil, Johor were analysed using 16S metagenome sequencing. Over ten phyla were detected, with Chloroflexi being the predominant phylum, representing approximately 53% of compost and 23% of the POME microbiome reads. The main bacterial lineage found in the compost and POME was Anaerolinaceae (Chloroflexi) with 30% and 18% of the total gene fragments, respectively. The significant differences between compost and POME communities were abundances of Syntrophobacter, Sulfuricurvum and Coprococcus. No methanogens were identified due to the bias in general 16S primers to eubacteria. The preponderance of anaerobic species in the compost and high abundance of secondary metabolite fermenting bacteria is due to an extended composting time, with anaerobic collapse of the pile due to the tropical heat. Predictive functional profiles of the metagenomes using 16S rRNA marker genes suggest that the presence of enzymes involved in degradation of polysaccharides such as glucoamylase, endoglucanase and arabinofuranosidase, all of which were strongly active in POME. Eubacterial species associated with cellulytic methanogenesis were present in both samples.

16.
Microorganisms ; 7(10)2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-31635256

RESUMO

Thousands of prokaryotic genera have been published, but methodological bias in the study of prokaryotes is noted. Prokaryotes that are relatively easy to isolate have been well-studied from multiple aspects. Massive quantities of experimental findings and knowledge generated from the well-known prokaryotic strains are inundating scientific publications. However, researchers may neglect or pay little attention to the uncommon prokaryotes and hard-to-cultivate microorganisms. In this review, we provide a systematic update on the discovery of underexplored culturable and unculturable prokaryotes and discuss the insights accumulated from various research efforts. Examining these neglected prokaryotes may elucidate their novelties and functions and pave the way for their industrial applications. In addition, we hope that this review will prompt the scientific community to reconsider these untapped pragmatic resources.

17.
Protein Expr Purif ; 164: 105464, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31376486

RESUMO

Xylanases (EC 3.2.1.8) are essential enzymes due to their applications in various industries such as textile, animal feed, paper and pulp, and biofuel industries. Halo-thermophilic Rhodothermaceae bacterium RA was previously isolated from a hot spring in Malaysia. Genomic analysis revealed that this bacterium is likely to be a new genus of the family Rhodothermaceae. In this study, a xylanase gene (1140 bp) that encoded 379 amino acids from the bacterium was cloned and expressed in Escherichia coli BL21(DE3). Based on InterProScan, this enzyme XynRA1 contained a GH10 domain and a signal peptide sequence. XynRA1 shared low similarity with the currently known xylanases (the closest is 57.2-65.4% to Gemmatimonadetes spp.). The purified XynRA1 achieved maximum activity at pH 8 and 60 °C. The protein molecular weight was 43.1 kDa XynRA1 exhibited an activity half-life (t1/2) of 1 h at 60 °C and remained stable at 50 °C throughout the experiment. However, it was NaCl intolerant, and various types of salt reduced the activity. This enzyme effectively hydrolyzed xylan (beechwood, oat spelt, and Palmaria palmata) and xylodextrin (xylotriose, xylotetraose, xylopentaose, and xylohexaose) to produce predominantly xylobiose. This xylanase is the first functionally characterized enzyme from the bacterium, and this work broadens the knowledge of GH10 xylanases.


Assuntos
Proteínas de Bactérias/genética , Endo-1,4-beta-Xilanases/genética , Rhodothermus/genética , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/metabolismo , Endo-1,4-beta-Xilanases/química , Endo-1,4-beta-Xilanases/isolamento & purificação , Endo-1,4-beta-Xilanases/metabolismo , Escherichia coli/genética , Expressão Gênica , Vetores Genéticos/genética , Filogenia , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Rhodothermus/química , Rhodothermus/isolamento & purificação , Rhodothermus/metabolismo , Alinhamento de Sequência , Especificidade por Substrato
18.
Int J Mol Sci ; 20(9)2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-31075847

RESUMO

A halo-thermophilic bacterium, Roseithermus sacchariphilus strain RA (previously known as Rhodothermaceae bacterium RA), was isolated from a hot spring in Langkawi, Malaysia. A complete genome analysis showed that the bacterium harbors 57 glycoside hydrolases (GHs), including a multi-domain xylanase (XynRA2). The full-length XynRA2 of 813 amino acids comprises a family 4_9 carbohydrate-binding module (CBM4_9), a family 10 glycoside hydrolase catalytic domain (GH10), and a C-terminal domain (CTD) for type IX secretion system (T9SS). This study aims to describe the biochemical properties of XynRA2 and the effects of CBM truncation on this xylanase. XynRA2 and its CBM-truncated variant (XynRA2ΔCBM) was expressed, purified, and characterized. The purified XynRA2 and XynRA2ΔCBM had an identical optimum temperature at 70 °C, but different optimum pHs of 8.5 and 6.0 respectively. Furthermore, XynRA2 retained 94% and 71% of activity at 4.0 M and 5.0 M NaCl respectively, whereas XynRA2ΔCBM showed a lower activity (79% and 54%). XynRA2 exhibited a turnover rate (kcat) of 24.8 s-1, but this was reduced by 40% for XynRA2ΔCBM. Both the xylanases hydrolyzed beechwood xylan predominantly into xylobiose, and oat-spelt xylan into a mixture of xylo-oligosaccharides (XOs). Collectively, this work suggested CBM4_9 of XynRA2 has a role in enzyme performance.


Assuntos
Bactérias/enzimologia , Endo-1,4-beta-Xilanases/química , Endo-1,4-beta-Xilanases/metabolismo , Variação Genética , Proteínas Mutantes/metabolismo , Tolerância ao Sal , Sequência de Aminoácidos , Endo-1,4-beta-Xilanases/genética , Cinética , Proteínas Mutantes/química , Filogenia , Domínios Proteicos , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Eletricidade Estática , Especificidade por Substrato , Xilanos/metabolismo
19.
3 Biotech ; 8(8): 376, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30105201

RESUMO

Rhodothermaceae bacterium RA is a halo-thermophile isolated from a saline hot spring. Previously, the genome of this bacterium was sequenced using a HiSeq 2500 platform culminating in 91 contigs. In this report, we report on the resequencing of its complete genome using a PacBio RSII platform. The genome has a GC content of 68.3%, is 4,653,222 bp in size, and encodes 3711 genes. We are interested in understanding the carbohydrate metabolic pathway, in particular the lignocellulosic biomass degradation pathway. Strain RA harbors 57 glycosyl hydrolase (GH) genes that are affiliated with 30 families. The bacterium consists of cellulose-acting (GH 3, 5, 9, and 44) and hemicellulose-acting enzymes (GH 3, 10, and 43). A crude cell-free extract of the bacterium exhibited endoglucanase, xylanase, ß-glucosidase, and ß-xylosidase activities. The complete genome information coupled with biochemical assays confirms that strain RA is able to degrade cellulose and xylan. Therefore, strain RA is another excellent member of family Rhodothermaceae as a repository of novel and thermostable cellulolytic and hemicellulolytic enzymes.

20.
Microbiologyopen ; 7(6): e00615, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29602271

RESUMO

The ability of thermophilic microorganisms and their enzymes to decompose biomass have attracted attention due to their quick reaction time, thermostability, and decreased risk of contamination. Exploitation of efficient thermostable glycoside hydrolases (GHs) could accelerate the industrialization of biofuels and biochemicals. However, the full spectrum of thermophiles and their enzymes that are important for biomass degradation at high temperatures have not yet been thoroughly studied. We examined a Malaysian Y-shaped Sungai Klah hot spring located within a wooded area. The fallen foliage that formed a thick layer of biomass bed under the heated water of the Y-shaped Sungai Klah hot spring was an ideal environment for the discovery and analysis of microbial biomass decay communities. We sequenced the hypervariable regions of bacterial and archaeal 16S rRNA genes using total community DNA extracted from the hot spring. Data suggested that 25 phyla, 58 classes, 110 orders, 171 families, and 328 genera inhabited this hot spring. Among the detected genera, members of Acidimicrobium, Aeropyrum, Caldilinea, Caldisphaera, Chloracidobacterium, Chloroflexus, Desulfurobacterium, Fervidobacterium, Geobacillus, Meiothermus, Melioribacter, Methanothermococcus, Methanotorris, Roseiflexus, Thermoanaerobacter, Thermoanaerobacterium, Thermoanaerobaculum, and Thermosipho were the main thermophiles containing various GHs that play an important role in cellulose and hemicellulose breakdown. Collectively, the results suggest that the microbial community in this hot spring represents a good source for isolating efficient biomass degrading thermophiles and thermozymes.


Assuntos
Bactérias/isolamento & purificação , Biodiversidade , Fontes Termais/microbiologia , Bactérias/classificação , Bactérias/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biomassa , Celulose/metabolismo , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Temperatura Alta , Filogenia
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