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1.
Int J Mol Sci ; 22(9)2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-34068779

RESUMO

Bacillus volatiles to control plant nematodes is a topic of great interest among researchers due to its safe and environmentally friendly nature. Bacillus strain GBSC56 isolated from the Tibet region of China showed high nematicidal activity against M. incognita, with 90% mortality as compared with control in a partition plate experiment. Pure volatiles produced by GBSC56 were identified through gas chromatography and mass spectrometry (GC-MS). Among 10 volatile organic compounds (VOCs), 3 volatiles, i.e., dimethyl disulfide (DMDS), methyl isovalerate (MIV), and 2-undecanone (2-UD) showed strong nematicidal activity with a mortality rate of 87%, 83%, and 80%, respectively, against M. incognita. The VOCs induced severe oxidative stress in nematodes, which caused rapid death. Moreover, in the presence of volatiles, the activity of antioxidant enzymes, i.e., SOD, CAT, POD, and APX, was observed to be enhanced in M. incognita-infested roots, which might reduce the adverse effect of oxidative stress-induced after infection. Moreover, genes responsible for plant growth promotion SlCKX1, SlIAA1, and Exp18 showed an upsurge in expression, while AC01 was downregulated in infested plants. Furthermore, the defense-related genes (PR1, PR5, and SlLOX1) in infested tomato plants were upregulated after treatment with MIV and 2-UD. These findings suggest that GBSC56 possesses excellent biocontrol potential against M. incognita. Furthermore, the study provides new insight into the mechanism by which GBSC56 nematicidal volatiles regulate antioxidant enzymes, the key genes involved in plant growth promotion, and the defense mechanism M. incognita-infested tomato plants use to efficiently manage root-knot disease.


Assuntos
Bacillus/genética , Resistência à Doença/genética , Lycopersicon esculentum/genética , Tylenchoidea/patogenicidade , Animais , Antinematódeos/metabolismo , Bacillus/metabolismo , China , Cromatografia Gasosa-Espectrometria de Massas , Lycopersicon esculentum/microbiologia , Lycopersicon esculentum/parasitologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Tylenchoidea/genética , Compostos Orgânicos Voláteis/metabolismo
2.
Int J Mol Sci ; 22(9)2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-34066922

RESUMO

Human gut microbiota harbors numerous microbial species with molecular enzymatic potential that impact on the eubiosis/dysbiosis and health/disease balances. Microbiota species isolation and description of their specific molecular features remain largely unexplored. In the present study, we focused on the cultivation and selection of species able to tolerate or biodegrade the endocrine disruptor bisphenol A (BPA), a xenobiotic extensively found in food plastic containers. Chemical xenobiotic addition methods for the directed isolation, culturing, Whole Genome Sequencing (WGS), phylogenomic identification, and specific gene-encoding searches have been applied to isolate microorganisms, assess their BPA metabolization potential, and describe encoded catabolic pathways. BPA-tolerant strains were isolated from 30% of infant fecal microbial culture libraries analyzed. Most isolated strains were phylogenetically related to the operational taxonomic group Bacillus amyloliquefaciens spp. Importantly, WGS analysis of microbial representative strain, Bacillus sp. AM1 identified the four complete molecular pathways involved on BPA degradation indicating its versatility and high potential to degrade BPA. Pathways for Exopolysaccharide (EPS) and Polyhydroxyalkanates (PHA) biopolymer synthesis were also identified and phenotypically confirmed by transmission electronic microscopy (TEM). These microbial biopolymers could generally contribute to capture and/or deposit xenobiotics.


Assuntos
Bacillus/metabolismo , Compostos Benzidrílicos/metabolismo , Microbioma Gastrointestinal , Fenóis/metabolismo , Transdução de Sinais , Antibacterianos/farmacologia , Bacillus/citologia , Bacillus/genética , Bacillus/ultraestrutura , Compostos Benzidrílicos/química , Biodegradação Ambiental , Genoma Bacteriano , Humanos , Testes de Sensibilidade Microbiana , Fenóis/química , Filogenia , RNA Ribossômico 16S/genética
3.
Int J Mol Sci ; 22(9)2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33925231

RESUMO

Genome-wide transcriptomic data obtained in RNA-seq experiments can serve as a reliable source for identification of novel regulatory elements such as riboswitches and promoters. Riboswitches are parts of the 5' untranslated region of mRNA molecules that can specifically bind various metabolites and control gene expression. For that reason, they have become an attractive tool for engineering biological systems, especially for the regulation of metabolic fluxes in industrial microorganisms. Promoters in the genomes of prokaryotes are located upstream of transcription start sites and their sequences are easily identifiable based on the primary transcriptome data. Bacillus methanolicus MGA3 is a candidate for use as an industrial workhorse in methanol-based bioprocesses and its metabolism has been studied in systems biology approaches in recent years, including transcriptome characterization through RNA-seq. Here, we identify a putative lysine riboswitch in B. methanolicus, and test and characterize it. We also select and experimentally verify 10 putative B. methanolicus-derived promoters differing in their predicted strength and present their functionality in combination with the lysine riboswitch. We further explore the potential of a B. subtilis-derived purine riboswitch for regulation of gene expression in the thermophilic B. methanolicus, establishing a novel tool for inducible gene expression in this bacterium.


Assuntos
Bacillus/genética , Engenharia Genética/métodos , Riboswitch/genética , Bacillus/metabolismo , Proteínas de Bactérias/metabolismo , Biologia Computacional/métodos , Genoma Bacteriano/genética , Análise do Fluxo Metabólico/métodos , Regiões Promotoras Genéticas/genética , Sequências Reguladoras de Ácido Nucleico , Sítio de Iniciação de Transcrição/fisiologia , Transcriptoma/genética
4.
Molecules ; 26(4)2021 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-33672446

RESUMO

Over the past decade, reckless usage of synthetic pesticides and fertilizers in agriculture has made the environment and human health progressively vulnerable. This setting leads to the pursuit of other environmentally friendly interventions. Amongst the suggested solutions, the use of chitin and chitosan came about, whether alone or in combination with endophytic bacterial strains. In the framework of this research, we reported an assortment of studies on the physico-chemical properties and potential applications in the agricultural field of two biopolymers extracted from shrimp shells (chitin and chitosan), in addition to their uses as biofertilizers and biostimulators in combination with bacterial strains of the genus Bacillus sp. (having biochemical and enzymatic properties).


Assuntos
Bacillus/metabolismo , Quitina/metabolismo , Quitosana/metabolismo , Produtos Agrícolas/metabolismo , Exoesqueleto/química , Animais , Configuração de Carboidratos , Quitina/química , Quitina/isolamento & purificação , Quitosana/química , Quitosana/isolamento & purificação , Crustáceos
5.
Int J Mol Sci ; 22(4)2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33671687

RESUMO

Our observations of predatory fungi trapping rotifers in activated sludge and laboratory culture allowed us to discover a complicated trophic network that includes predatory fungi armed with bacteria and bacteriophages and the rotifers they prey on. Such a network seems to be common in various habitats, although it remains mostly unknown due to its microscopic size. In this study, we isolated and identified fungi and bacteria from activated sludge. We also noticed abundant, virus-like particles in the environment. The fungus developed absorptive hyphae within the prey. The bacteria showed the ability to enter and exit from the hyphae (e.g., from the traps into the caught prey). Our observations indicate that the bacteria and the fungus share nutrients obtained from the rotifer. To narrow the range of bacterial strains isolated from the mycelium, the effects of bacteria supernatants and lysed bacteria were studied. Bacteria isolated from the fungus were capable of immobilizing the rotifer. The strongest negative effect on rotifer mobility was shown by a mixture of Bacillus sp. and Stenotrophomonas maltophilia. The involvement of bacteriophages in rotifer hunting was demonstrated based on molecular analyses and was discussed. The described case seems to be an extraordinary quadruple microbiological puzzle that has not been described and is still far from being understood.


Assuntos
Fagos Bacilares/fisiologia , Fungos/patogenicidade , Rotíferos/microbiologia , Animais , Bacillus/metabolismo , Fagos Bacilares/genética , Bactérias , Quitinases/metabolismo , Técnicas de Cocultura , Consórcios Microbianos , Esgotos/microbiologia , Simbiose , Eliminação de Resíduos Líquidos
6.
Molecules ; 26(4)2021 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-33562111

RESUMO

Microbial polyhydroxyalkanoates (PHA) are proteinaceous storage granules ranging from 100 nm to 500 nm. Bacillus sp. serve as unique bioplastic sources of short-chain length and medium-chain length PHA showcasing properties such as biodegradability, thermostability, and appreciable mechanical strength. The PHA can be enhanced by adding functional groups to make it a more industrially useful biomaterial. PHA blends with hydroxyapatite to form nanocomposites with desirable features of compressibility. The reinforced matrices result in nanocomposites that possess significantly improved mechanical and thermal properties both in solid and melt states along with enhanced gas barrier properties compared to conventional filler composites. These superior qualities extend the polymeric composites' applications to aggressive environments where the neat polymers are likely to fail. This nanocomposite can be used in different industries as nanofillers, drug carriers for packaging essential hormones and microcapsules, etc. For fabricating a bone scaffold, electrospun nanofibrils made from biocomposite of hydroxyapatite and polyhydroxy butyrate, a form of PHA, can be incorporated with the targeted tissue. The other methods for making a polymer scaffold, includes gas foaming, lyophilization, sol-gel, and solvent casting method. In this review, PHA as a sustainable eco-friendly NextGen biomaterial from bacterial sources especially Bacillus cereus, and its application for fabricating bone scaffold using different strategies for bone regeneration have been discussed.


Assuntos
Bacillus/metabolismo , Biopolímeros/metabolismo , Osso e Ossos/efeitos dos fármacos , Poli-Hidroxialcanoatos/biossíntese , Poli-Hidroxialcanoatos/farmacologia , Tecidos Suporte/química , Animais , Osso e Ossos/citologia , Osso e Ossos/fisiologia , Humanos , Poli-Hidroxialcanoatos/química
7.
Biomed Res Int ; 2021: 3904120, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33604372

RESUMO

An endophytic bacterium Bacillus velezensis BY6 was isolated from the wood stems of healthy Populus davidiana × P. alba var. pyramidalis (PdPap). The BY6 strain can inhibit pathogenic fungus Alternaria alternate in PdPap and promote growth of PdPap seedlings. In the present study, we used the Pacific Biosciences long-read sequencing platform, a single-molecule real-time (SMRT) technology for strain BY6, to perform complete genome sequencing. The genome size was 3,898,273 bp, the number of genes was 4,045, and the average GC content was 47.33%. A complete genome of strain BY6 contained 110 secondary metabolite gene clusters. Nine of the secondary metabolite gene clusters exhibited antifungal activity and promoted growth functions primarily involved in the synthesis of surfactin, bacteriocins, accumulated iron ions, and related antibiotics. Gene clusters provide genetic resources for biotechnology and genetic engineering, and enhance understanding of the relationship between microorganisms and plants.


Assuntos
Antifúngicos , Bacillus/genética , Genoma Bacteriano/genética , Reguladores de Crescimento de Plantas , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Bacillus/metabolismo , Bacillus/fisiologia , Composição de Bases/genética , Endófitos/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Populus/microbiologia , Madeira/microbiologia
8.
J Chromatogr A ; 1640: 461929, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33610132

RESUMO

Imaging high-performance thin-layer chromatography (HPTLC) was explored with regard to its ability to visualize changes in the metabolite profile of bacteria. Bacillus subtilis has become a model organism in many fields. The increasing interest in these bacteria is driven by their attributed probiotic activity. However, growth behavior and metabolism of Bacillus species have a considerable influence on their activity and secondary metabolite profile. On the HPTLC plate, cultivation broths of Bacillus species (B. subtilis, B. licheniformis, B. pumilus and B. amyloliquefaciens) and some B. subtilis strains of high genetic similarity up to 99.5% were applied directly and compared with their respective liquid-liquid extracts. The latter as well as the cultivation in a minimal medium reduced the matrix load and improved the zone resolution. Cultivation parameters such as nutrient supply, cultivation temperature, cultivation time and rotational speed (oxygen level) as well as medium change were shown to have a considerable influence on the growth behavior and resulting metabolite profiles. Imaging HPTLC turned out to be an efficient and affordable tool to visualize such influences of cultivation parameters on the metabolite profiles. It converts the complexity of reaction processes occurring during cell cultivation in easy-to-understand images, which are helpful to figure out factors of influence and understand activity changes. The results highlighted that optimal cultivation conditions need to be found for the intended bacterial application, and in particular, these conditions have to be kept constant. It must be ensured that small variations in cultivation parameters of bacteria do not change the specified (probiotic) effect on the health of animals and humans. The HPTLC metabolite profiles represented the cultivation conditions of specific bacteria and were found to be a proof of the activity of distinct bacteria. In addition, HPTLC can also be used to optimize and streamline the culture media. The quality control of cultivation or fermentation processes can benefit from such a powerful tool, as a picture is worth a thousand words.


Assuntos
Bacillus/crescimento & desenvolvimento , Bacillus/metabolismo , Cromatografia em Camada Delgada/métodos , Metabolômica , Meios de Cultura , Humanos
9.
Int J Food Microbiol ; 341: 109072, 2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33524880

RESUMO

Proper elimination of bacterial endospores in foods and food processing environment is challenging because of their extreme resistance to various stresses. Often, sporicidal treatments prove insufficient to eradicate the contaminating endospore population as a whole, and might therefore serve as a selection pressure for enhanced endospore resistance. In the sporeforming Bacillus cereus group, Bacillus weihenstephanensis is an important food spoilage organism and potential cereulide producing pathogen, due to its psychrotolerant growth ability at 7 °C. Although the endospores of B. weihenstephanensis are generally less heat resistant compared to their mesophilic or thermotolerant relatives, our data now show that non-emetic B. weihenstephanensis strain LMG 18989T can readily and reproducibly evolve to acquire much enhanced endospore heat resistance. In fact, one of the B. weihenstephanensis mutants from directed evolution by wet heat in this study yielded endospores displaying a > 4-fold increase in D-value at 91 °C compared to the parental strain. Moreover, these mutant endospores retained their superior heat resistance even when sporulation was performed at 10 °C. Interestingly, increased endospore heat resistance did not negatively affect the vegetative growth capacities of the evolved mutants at lower (7 °C) and upper (37 °C) growth temperature boundaries, indicating that the correlation between cardinal growth temperatures and endospore heat resistance which is observed among bacterial sporeformers is not necessarily causal.


Assuntos
Bacillus/crescimento & desenvolvimento , Bacillus/metabolismo , Esporos Bacterianos/crescimento & desenvolvimento , Evolução Biológica , Depsipeptídeos/biossíntese , Manipulação de Alimentos , Temperatura Alta
10.
Sci Total Environ ; 774: 145002, 2021 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-33609820

RESUMO

Polystyrene (PS) films were subjected to in vitro biodegradation by Bacillus paralicheniformis G1 (MN720578) isolated from 3538 m depth sediments of the Arabian Sea. The growth of the isolate was most favourable at pH 7.5, 30 °C and 4% salinity. A series of batch experiments were conducted to investigate the degradation of PS films up to 60 days. The results of this study indicated that the strain degraded 34% of PS film within 60 days of incubation. The complete genome sequence consists of 4,281,959 bp with 45.88% GC content and encodes 4213 protein coding genes. A high number of genes encoding monooxygenase, dioxygenase, peroxidase, esterase and hydrolase involved in the degradation of synthetic polymers were identified. Also genes associated with flagellum dependent motility, chemotaxis, biofilm formation and siderophores biosynthesis were identified in this deep-sea strain G1. This study suggests that B. paralicheniformis G1 could be a potential species for degradation of PS and its genome analysis provides insight into the molecular basis of biodegradation.


Assuntos
Bacillus , Poliestirenos , Bacillus/genética , Bacillus/metabolismo , Biodegradação Ambiental , Poliestirenos/metabolismo , Metabolismo Secundário
11.
Int J Mol Sci ; 22(4)2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33578992

RESUMO

In this study, endophytic bacteria belonging to the Bacillus genus were isolated from in vitro bulblets of Leucojum aestivum and their ability to produce Amaryllidaceae alkaloids was studied. Proton Nuclear Magnetic Resonance (1H NMR)-based metabolomics combined with multivariate data analysis was chosen to compare the metabolism of this plant (in vivo bulbs, in vitro bulblets) with those of the endophytic bacteria community. Primary metabolites were quantified by quantitative 1H NMR (qNMR) method. The results showed that tyrosine, one precursor of the Amaryllidaceae alkaloid biosynthesis pathway, was higher in endophytic extract compared to plant extract. In total, 22 compounds were identified including five molecules common to plant and endophyte extracts (tyrosine, isoleucine, valine, fatty acids and tyramine). In addition, endophytic extracts were analyzed using Liquid Chromatography-Mass Spectrometry (LC-MS) and Gas Chromatography-Mass Spectrometry (GC-MS) for the identification of compounds in very low concentrations. Five Amaryllidaceae alkaloids were detected in the extracts of endophytic bacteria. Lycorine, previously detected by 1H NMR, was confirmed with LC-MS analysis. Tazettine, pseudolycorine, acetylpseudolycorine, 1,2-dihydro-chlidanthine were also identified by LC-MS using the positive ionization mode or by GC-MS. In addition, 11 primary metabolites were identified in the endophytic extracts such as tyramine, which was obtained by decarboxylation of tyrosine. Thus, Bacillus sp. isolated from L. aestivum bulblets synthesized some primary and specialized metabolites in common with the L.aestivum plant. These endophytic bacteria are an interesting new approach for producing the Amaryllidaceae alkaloid such as lycorine.


Assuntos
Alcaloides de Amaryllidaceae/metabolismo , Amaryllidaceae/microbiologia , Bacillus/metabolismo , Endófitos/metabolismo , Alcaloides de Amaryllidaceae/análise , Bacillus/química , Bacillus/isolamento & purificação , Cromatografia Líquida , Endófitos/química , Endófitos/isolamento & purificação , Microbiologia Industrial/métodos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Metabolômica
12.
Appl Microbiol Biotechnol ; 105(2): 707-723, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33386896

RESUMO

A novel protease-producing Bacillus sp. CN2 isolated from chicken manure composts exhibited a relatively high proteolytic specific activity. The strain CN2 degradome consisted of at least 149 proteases and homolog candidates, which were distributed into 4 aspartic, 30 cysteine, 55 metallo, 56 serine, and 4 threonine proteases. Extracellular proteolytic activity was almost completely inhibited by PMSF (phenylmethylsulfonyl fluoride) rather than o-P, E-64, or pepstatin A, suggesting that strain CN2 primarily secreted serine protease. More importantly, analysis of the extracellular proteome of strain CN2 revealed the presence of a highly efficient protein degradation system. Three serine proteases of the S8 family with different active site architectures firstly fragmented protein substrates which were then degraded to smaller peptides by a M4 metalloendopeptidase that prefers to degrade hydrophobic peptides and by a S13 carboxypeptidase. Those enzymes acted synergistically to degrade intact substrate proteins outside the cell. Furthermore, highly expressed sequence-specific intracellular aminopeptidases from multiple families (M20, M29, and M42) accurately degraded peptides into oligopeptides or amino acids, thus realizing the rapid acquisition and utilization of nitrogen sources. In this paper, a systematic study of the functional-degradome provided a new perspective for understanding the complexity of the protease hydrolysis system of Bacillus, and laid a solid foundation for further studying the precise degradation of proteins with the cooperative action of different family proteases. KEY POINTS: • Bacillus sp. CN2 has relatively high proteolytic specific activity. • Bacillus sp. CN2 harbors a highly efficient protein degradation system. • The site-specific endopeptidases were secreted extracellular, while the sequence-specific aminopeptidases played a role in the cell.


Assuntos
Bacillus , Bacillus/metabolismo , Hidrólise , Peptídeo Hidrolases/metabolismo , Proteólise , Serina Endopeptidases/metabolismo
13.
Arch Microbiol ; 203(4): 1743-1752, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33471134

RESUMO

Beneficial rhizobacteria can inhibit soilborne pathogens by secreting an array of polyketides, lipopeptides and dipeptides, but the effect of polyketides on crown gall disease caused by Agrobacterium tumefaciens C58 is unclear. In this study, the antagonistic compounds of the plant growth-promoting rhizobacterium Bacillus velezensis CLA178 was sorted with different organic phases, purified by high-pressure liquid chromatography, and detected by a liquid chromatography ionization-mass spectrometry system. Macrolactins were found to be the compounds with antagonistic activity against A. tumefaciens C58. When the macrolactin synthesis pathway was disrupted, the mutant △mlnA only showed slight antagonistic activity against A. tumefaciens C58. Transmission electron microscopy showed that the inhibition of C58 cell division by cell-free culture from the mutant △mlnA was weaker than that by cell-free culture from CLA178. The mutant deficient in production of macrolactin showed a weaker transcription of genes involved in attachment of C58 to plant and lower biocontrol of crown gall disease in rose than the wild-type strain CLA178. The effect of macrolactins on pathogen C58 has been also confirmed by the purified macrolactins. These results reveal that macrolactins contribute to the biocontrol activity of C58 by inhibiting cell division and downregulating the transcription of chvB and chvE.


Assuntos
Agrobacterium tumefaciens/crescimento & desenvolvimento , Antibiose/fisiologia , Bacillus/metabolismo , Tumores de Planta/microbiologia , Agrobacterium tumefaciens/genética , Divisão Celular/fisiologia , Lipopeptídeos/metabolismo , Espectrometria de Massas , Microscopia Eletrônica de Transmissão , Doenças das Plantas/microbiologia , Plantas/metabolismo , Rosa/microbiologia
14.
PLoS One ; 16(1): e0243976, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33493159

RESUMO

Due to the inefficient reproduction of microorganisms in oxygen-deprived environments of the reservoir, the applications of microbial enhanced oil recovery (MEOR) are restricted. To overcome this problem, a new type of air-assisted MEOR process was investigated. Three compounding oil degradation strains were screened using biochemical experiments. Their performances in bacterial suspensions with different amounts of dissolved oxygen were evaluated. Water flooding, microbial flooding and air-assisted microbial flooding core flow experiments were carried out. Carbon distribution curve of biodegraded oil with different oxygen concentration was determined by chromatographic analysis. The long-chain alkanes are degraded by microorganisms. A simulation model was established to take into account the change in oxygen concentration in the reservoir. The results showed that the optimal dissolved oxygen concentration for microbial growth was 4.5~5.5mg/L. The main oxygen consumption in the reservoir happened in the stationary and declining phases of the microbial growth systems. In order to reduce the oxygen concentration to a safe level, the minimum radius of oxygen consumption was found to be about 145m. These results demonstrate that the air-assisted MEOR process can overcome the shortcomings of traditional microbial flooding techniques. The findings of this study can help for better understanding of microbial enhanced oil recovery and improving the efficiency of microbial oil displacement.


Assuntos
Alcanos/metabolismo , Bactérias , Biodegradação Ambiental , Campos de Petróleo e Gás/microbiologia , Petróleo/microbiologia , Bacillus/crescimento & desenvolvimento , Bacillus/isolamento & purificação , Bacillus/metabolismo , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Bactérias/metabolismo , Enterobacter/crescimento & desenvolvimento , Enterobacter/isolamento & purificação , Enterobacter/metabolismo , Fermentação , Oxigênio/metabolismo , Pseudomonas/crescimento & desenvolvimento , Pseudomonas/isolamento & purificação , Pseudomonas/metabolismo
15.
Food Chem ; 347: 129036, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33508589

RESUMO

3-(Methylthio)-1-propanol, reminiscent of cauliflower and cooked vegetable aroma, is an important sulfur compound in Baijiu. It is important to develop a method to increase 3-(methylthio)-1-propanol content to improve flavor quality of products. In this study, a synthetic microbial community was employed to enhance the content of 3-(methylthio)-1-propanol by multi-module division of labor approach. Firstly, the synthetic pathway of 3-(methylthio)-1-propanol was reconstructed and classified into three modules. Later, the hyper producers in each module were isolated and negative interaction between the members was relieved. Finally, a synthetic microbial community was constructed using three species containing one hyper producer from each module. Furthermore, the transcription characteristics of the species in each module were validated by metatranscriptomic analysis. The constructed synthetic microbial community can be used to biosynthesize 3-(methylthio)-1-propanol for Baijiu. This work provided a novel and workable strategy to design synthetic microbial community to enhance the flavor feature of other fermented foods.


Assuntos
Bacillus/metabolismo , Compostos de Enxofre/metabolismo , Bacillus/genética , Técnicas de Cultura Celular por Lotes , Biomassa , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Lactobacillus/genética , Lactobacillus/metabolismo , Metionina/análise , Metionina/metabolismo , RNA Bacteriano/química , RNA Bacteriano/isolamento & purificação , RNA Bacteriano/metabolismo , RNA Fúngico/química , RNA Fúngico/isolamento & purificação , RNA Fúngico/metabolismo , Saccharomyces/genética , Saccharomyces/metabolismo , Compostos de Enxofre/química
16.
J Agric Food Chem ; 69(1): 146-158, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33356234

RESUMO

The aim of this study was to isolate the angiotensin I-converting enzyme (ACE) inhibitory peptides from the skirt of Chlamys farreri fermented with Bacillus natto and to explore the antihypertension effect through in vivo studies. ACE inhibitory peptides were purified from the fermentation mixture by ultrafiltration, gel filtration chromatography, and reversed-phase high-performance liquid chromatography sequentially. The amino acids' sequence of the five novel ACE inhibitory peptides were identified by liquid chromatography-tandem mass spectrometry. Animal experiments demonstrated that the novel ACE inhibitory peptides significantly reduced the blood pressure in spontaneously hypertensive rats after a single or long-time treatment. Potential mechanisms were explored, and the results indicated that the novel peptides could regulate the renal renin-angiotensin system, improve vascular remodeling, inhibit myocardial fibrosis, and rebalance the gut microbial dysbiosis. Our results suggest that the fermentation products of the Chlamys farreri skirt by B. natto are potential sources of active peptides processing antihypertension activities.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/química , Anti-Hipertensivos/química , Bacillus/metabolismo , Hipertensão/tratamento farmacológico , Pectinidae/microbiologia , Peptídeos/química , Sequência de Aminoácidos , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Inibidores da Enzima Conversora de Angiotensina/isolamento & purificação , Inibidores da Enzima Conversora de Angiotensina/metabolismo , Animais , Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/metabolismo , Cromatografia em Gel , Cromatografia de Fase Reversa , Fermentação , Alimentos e Bebidas Fermentados/análise , Alimentos e Bebidas Fermentados/microbiologia , Humanos , Hipertensão/enzimologia , Masculino , Espectrometria de Massas , Pectinidae/metabolismo , Peptídeos/administração & dosagem , Peptídeos/isolamento & purificação , Peptídeos/metabolismo , Peptidil Dipeptidase A/química , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY
17.
Int J Biol Macromol ; 170: 232-238, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33340630

RESUMO

Laccases are multicoopper oxidases catalyzing the oxidation of phenolic as well as non-phenolic compounds. Laccases show typical blue color due to the presence of covalent Type 1 Cu-Cys bond which absorbs at 600 nm. However, recently some white laccases have also been identified which lacks typical spectra of blue laccases and do not show peak at 600 nm. In the present study, a novel white laccase was isolated from Bacillus sp. MSK-01. MSK laccase was purified and characterized in detail and the purified laccase was referred to MSKLAC. It has a molecular weight of 32 KDa. UV-visible spectrum of purified MSKLAC do not show characteristic peak at 600 nm and bend at 330 nm. The enzyme was repressed by conventional inhibitors of laccase like sodium azide, cysteine, dithiothreitol and ß-mercaptoethanol. The laccase was highly thermo-stable enzyme having optimum temperature of 75 °C and could treasure more than 50% activity even at 100 °C. The optimum pH for ABTS and guaiacol was 4.5 and 8.0 respectively. MSKLAC was stable in the presence of most of the metal ions and surfactants. The effect of MSKLAC on lung cancer cell line was also assessed. It was observed that MSKLAC is inhibitory to lung cell cancer line. Thus, MSKLAC has potential to be used as an anti-proliferative agent to cancer cells.


Assuntos
Bacillus/enzimologia , Lacase/química , Lacase/isolamento & purificação , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Bacillus/metabolismo , Cor , Corantes/metabolismo , Concentração de Íons de Hidrogênio , Lacase/metabolismo , Oxirredução , Especificidade por Substrato , Temperatura
18.
Int J Biol Macromol ; 170: 298-306, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33347931

RESUMO

Laccases are enzymes able to catalyze the oxidation of a wide array of phenolic and non-phenolic compounds using oxygen as co-substrate and releasing water as by-product. They are well known to have wide substrate specificity and in recent years, have gained great biotechnological importance. To date, most well studied laccases are from fungal and mesophilic origin, however, enzymes from extremophiles possess an even greater potential to withstand the extreme conditions present in many industrial processes. This research work presents the heterologous production and characterization of a novel laccase from a thermoalkaliphilic bacterium isolated from a hot spring in a geothermal site. This recombinant enzyme exhibits remarkably high specific activity (>450,000 U/mg) at 70 °C, pH 6.0, using syringaldazine substrate, it is active in a wide range of temperature (20-90 °C) and maintains over 60% of its activity after 2 h at 60 °C. Furthermore, this novel spore-coat laccase is able to biodecolorize eight structurally different recalcitrant synthetic dyes (Congo red, methyl orange, methyl red, Coomassie brilliant blue R250, bromophenol blue, malachite green, crystal violet and Remazol brilliant blue R), in just 30 min at 40 °C in the presence of the natural redox mediator acetosyringone.


Assuntos
Corantes/química , Lacase/química , Lacase/isolamento & purificação , Antraquinonas/química , Compostos Azo/química , Bacillus/enzimologia , Bacillus/metabolismo , Bactérias/metabolismo , Biodegradação Ambiental , Concentração de Íons de Hidrogênio , Lacase/metabolismo , Oxirredução , Esporos/metabolismo , Águas Residuárias/química
19.
Nat Commun ; 11(1): 5388, 2020 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-33097692

RESUMO

The alarmone nucleotides guanosine tetraphosphate and pentaphosphate, commonly referred to as (p)ppGpp, regulate bacterial responses to nutritional and other stresses. There is evidence for potential existence of a third alarmone, guanosine-5'-monophosphate-3'-diphosphate (pGpp), with less-clear functions. Here, we demonstrate the presence of pGpp in bacterial cells, and perform a comprehensive screening to identify proteins that interact respectively with pGpp, ppGpp and pppGpp in Bacillus species. Both ppGpp and pppGpp interact with proteins involved in inhibition of purine nucleotide biosynthesis and with GTPases that control ribosome assembly or activity. By contrast, pGpp interacts with purine biosynthesis proteins but not with the GTPases. In addition, we show that hydrolase NahA (also known as YvcI) efficiently produces pGpp by hydrolyzing (p)ppGpp, thus modulating alarmone composition and function. Deletion of nahA leads to reduction of pGpp levels, increased (p)ppGpp levels, slower growth recovery from nutrient downshift, and loss of competitive fitness. Our results support the existence and physiological relevance of pGpp as a third alarmone, with functions that can be distinct from those of (p)ppGpp.


Assuntos
Bacillus/metabolismo , Proteínas de Bactérias/metabolismo , Nucleotídeos de Guanina/metabolismo , Nucleotídeos/metabolismo , Bacillus/genética , Bacillus anthracis/metabolismo , Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica , Guanosina Tetrafosfato/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Ligação Proteica , Biossíntese de Proteínas
20.
PLoS One ; 15(8): e0236745, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785276

RESUMO

Mineral precipitation via microbial activity is a well-known process with applications in various fields. This relevance of microbially induced calcite precipitation (MICP) has pushed researchers to explore various naturally occurring MICP capable bacterial strains. The present study was performed to explore the efficiency of microbially induced calcite precipitation (MICP) via locally isolated bacterial strains and role of guar gum, which is a naturally occurring polymer, on the MICP process. The strains were isolated from local soil and screened for urease activity Further, the urease positive strain was subjected to urea and calcium chloride based medium to investigate the efficacy of isolated strain for microbial induced precipitation. Among screened isolates, the soil bacterium that showed urease positive behaviour and precipitated calcium carbonate was subjected to 16S rRNA gene sequencing. This strain was identified as Bacillus velezensis. Guar gum-a natural polymer, was used as a sole carbon source to enhance the MICP process. It was observed that the isolated strain was able to breakdown the guar gum into simple sugars resulting in two-fold increase in calcium carbonate precipitate. Major bio-chemical activities of isolated strain pertaining to MICP such as ammonium ion concentration, pH profiling, and total reducing sugar with time were explored under four different concentrations of guar gum (0.25%, 0.5%, 0.75% and 1% w/v). Maximum ammonium ion concentration (17.5 µg/ml) and increased pH was observed with 1% guar gum supplementation, which confirms augmented MICP activity of the bacterial strain. Microstructural analysis of microbial precipitation was performed using scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques, which confirmed the presence of calcium carbonate in different phases. Further, XRD and SEM based studies corroborated that guar gum supplemented media showed significant increase in stable calcite phase as compared to media without guar gum supplementation. Significant diverse group of nitrogenous compounds were observed in guar gum supplemented medium when subjected to Gas Chromatography-Mass spectrometry (GC-MS) profiling.


Assuntos
Bacillus/metabolismo , Carbonato de Cálcio/química , Carbonato de Cálcio/metabolismo , Galactanos/química , Mananas/química , Gomas Vegetais/química , Precipitação Química
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