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1.
In Vivo ; 34(5): 3023-3026, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32871846

RESUMO

BACKGROUND/AIM: Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). One drug that has attracted interest is the antiparasitic compound ivermectin, a macrocyclic lactone derived from the bacterium Streptomyces avermitilis. We carried out a docking study to determine if ivermectin might be able to attach to the SARS-CoV-2 spike receptor-binding domain bound with ACE2. MATERIALS AND METHODS: We used the program AutoDock Vina Extended to perform the docking study. RESULTS: Ivermectin docked in the region of leucine 91 of the spike and histidine 378 of the ACE2 receptor. The binding energy of ivermectin to the spike-ACE2 complex was -18 kcal/mol and binding constant was 5.8 e-08. CONCLUSION: The ivermectin docking we identified may interfere with the attachment of the spike to the human cell membrane. Clinical trials now underway should determine whether ivermectin is an effective treatment for SARS-Cov2 infection.


Assuntos
Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Ivermectina/química , Peptidil Dipeptidase A/química , Pneumonia Viral/tratamento farmacológico , Betacoronavirus/química , Betacoronavirus/patogenicidade , Sítios de Ligação/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Infecções por Coronavirus/virologia , Reposicionamento de Medicamentos , Histidina/química , Humanos , Ivermectina/uso terapêutico , Leucina/química , Simulação de Acoplamento Molecular , Pandemias , Peptidil Dipeptidase A/efeitos dos fármacos , Pneumonia Viral/virologia , Streptomyces/química
2.
Nat Commun ; 11(1): 4022, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32782248

RESUMO

One major bottleneck in natural product drug development is derivatization, which is pivotal for fine tuning lead compounds. A promising solution is modifying the biosynthetic machineries of middle molecules such as macrolides. Although intense studies have established various methodologies for protein engineering of type I modular polyketide synthase(s) (PKSs), the accurate targeting of desired regions in the PKS gene is still challenging due to the high sequence similarity between its modules. Here, we report an innovative technique that adapts in vitro Cas9 reaction and Gibson assembly to edit a target region of the type I modular PKS gene. Proof-of-concept experiments using rapamycin PKS as a template show that heterologous expression of edited biosynthetic gene clusters produced almost all the desired derivatives. Our results are consistent with the promiscuity of modular PKS and thus, our technique will provide a platform to generate rationally designed natural product derivatives for future drug development.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes/métodos , Policetídeo Sintases/genética , Produtos Biológicos/química , Produtos Biológicos/metabolismo , Estrutura Molecular , Família Multigênica/genética , Policetídeo Sintases/metabolismo , Sirolimo/química , Sirolimo/metabolismo , Estereoisomerismo , Streptomyces/enzimologia , Streptomyces/genética , Streptomyces/metabolismo
3.
Nat Protoc ; 15(8): 2470-2502, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32651565

RESUMO

Streptomycetes are prominent sources of bioactive natural products, but metabolic engineering of the natural products of these organisms is greatly hindered by relatively inefficient genetic manipulation approaches. New advances in genome editing techniques, particularly CRISPR-based tools, have revolutionized genetic manipulation of many organisms, including actinomycetes. We have developed a comprehensive CRISPR toolkit that includes several variations of 'classic' CRISPR-Cas9 systems, along with CRISPRi and CRISPR-base editing systems (CRISPR-BEST) for streptomycetes. Here, we provide step-by-step protocols for designing and constructing the CRISPR plasmids, transferring these plasmids to the target streptomycetes, and identifying correctly edited clones. Our CRISPR toolkit can be used to generate random-sized deletion libraries, introduce small indels, generate in-frame deletions of specific target genes, reversibly suppress gene transcription, and substitute single base pairs in streptomycete genomes. Furthermore, the toolkit includes a Csy4-based multiplexing option to introduce multiple edits in a single experiment. The toolkit can be easily extended to other actinomycetes. With our protocol, it takes <10 d to inactivate a target gene, which is much faster than alternative protocols.


Assuntos
Sistemas CRISPR-Cas/genética , Edição de Genes/métodos , Streptomyces/genética , Sequência de Bases , Plasmídeos/genética
4.
J Med Microbiol ; 69(8): 1040-1048, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32692643

RESUMO

Given the increased reporting of multi-resistant bacteria and the shortage of newly approved medicines, researchers have been looking towards extreme and unusual environments as a new source of antibiotics. Streptomyces currently provides many of the world's clinical antibiotics, so it comes as no surprise that these bacteria have recently been isolated from traditional medicine. Given the wide array of traditional medicines, it is hoped that these discoveries can provide the much sought after core structure diversity that will be required of a new generation of antibiotics. This review discusses the contribution of Streptomyces to antibiotics and the potential of newly discovered species in traditional medicine. We also explore how knowledge of traditional medicines can aid current initiatives in sourcing new and chemically diverse antibiotics.


Assuntos
Antibacterianos/isolamento & purificação , Descoberta de Drogas/tendências , Microbiologia do Solo , Streptomyces/metabolismo , Animais , Antibacterianos/biossíntese , Cavernas/química , Invertebrados/química , Medicina Tradicional , Peptídeo Sintases/metabolismo , Plantas Medicinais/química , Policetídeo Sintases/metabolismo , Poríferos/química , Streptomyces/química , Streptomyces/enzimologia
5.
BMC Infect Dis ; 20(1): 499, 2020 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-32652948

RESUMO

BACKGROUND: Streptomyces cacaoi, Gram-positive, branched, filamentous bacillus forms without fragmentation, are saprophytic soil organisms rarely known to cause invasive infections other than mycetoma. Here we describe a case of chronic suppurative otitis media caused by Streptomyces cacaoi in a patient with hyperlipidemia in China. CASE PRESENTATION: A 62-year-old female patient with hyperlipidemia suffered chronic suppurative otitis media caused by Streptomyces cacaoi. She had a favorable outcome with a 4-week course of ofloxacin ear drops. CONCLUSIONS: Streptomyces cacaoi is rarely reported to cause human infection. The introduction of molecular techniques improves the ability to identify rare species such as Streptomyces considerably. We report the case improve our ability to identify this pathogen and expand the range of known bacterial causes of human infection.


Assuntos
Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/microbiologia , Otite Média Supurativa/tratamento farmacológico , Otite Média Supurativa/microbiologia , Streptomyces/patogenicidade , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , China , Feminino , Humanos , Pessoa de Meia-Idade , Ofloxacino/administração & dosagem , Ofloxacino/uso terapêutico , Streptomyces/genética , Streptomyces/isolamento & purificação , Resultado do Tratamento , Timpanoplastia/métodos
6.
Int J Syst Evol Microbiol ; 70(7): 4398-4405, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32618557

RESUMO

We investigated the taxonomic relationships among Streptomyces hygroscopicus subsp. glebosus, Streptomyces libani subsp. rufus and Streptomyces platensis. The three species formed a single clade in the phylogenetic trees based on 16S rRNA gene sequence and multilocus sequence analyses. Digital DNA-DNA hybridization using whole genome sequences suggested that S. hygroscopicus subsp. glebosus, S. libani subsp. rufus and S. platensis belong to the same genomospecies. Previously reported phenotypic data also supported this synonymy. Therefore, S. hygroscopicus subsp. glebosus and S. libani subsp. rufus should be reclassified as later heterotypic synonyms of S. platensis.


Assuntos
Filogenia , Streptomyces/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Tipagem de Sequências Multilocus , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
7.
Int J Syst Evol Microbiol ; 70(7): 4291-4297, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32644916

RESUMO

We investigated the taxonomic relationships among Streptomyces diastaticus subsp. ardesiacus, Streptomyces diastaticus subsp. diastaticus, Streptomyces gougerotii and Streptomyces rutgersensis. The 16S rRNA gene sequence similarity between S. diastaticus subsp. ardesiacus and S. diastaticus subsp. diastaticus was 97.7 %, whereas S. diastaticus subsp. diastaticus, S. gougerotii and S. rutgersensis showed 100 % nucleotide sequence identity. In addition, S. diastaticus subsp. diastaticus, S. gougerotii and S. rutgersensis formed a single clade in the phylogenetic tree. Digital DNA-DNA relatedness between S. diastaticus subsp. diastaticus and S. diastaticus subsp. ardesiacus was only 22.8%, indicative of different species. In comparison, DNA-DNA relatedness values for S. diastaticus subsp. diastaticus, S. gougerotii and S. rutgersensis ranged from 95.8 to 97.2 %, suggesting the three taxa belong to the same genomospecies. Previously reported phenotypic data also supported synonymy. Therefore, we propose that S. diastaticus subsp. ardesiacus should be classified as an independent species, Streptomyces ardesiacus sp. nov. The type strain is NBRC 13412T (=ATCC 3315T=CBS 713.72T=DSM 40496T=ISP 5496T=JCM 4745T=NBRC 3714T=NRRL B-1241T=RIA 1373T). Our data also suggests that S. rutgersensis and S. gougerotii should be reclassified as later heterotypic synonyms of S. diastaticus.


Assuntos
Filogenia , Streptomyces/classificação , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
8.
Chimia (Aarau) ; 74(5): 382-390, 2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32482215

RESUMO

Actinomycetes strains isolated from different habitats in Switzerland were investigated for production of antibacterial and antitumoral compounds. Based on partial 16S rRNA gene sequences, the isolated strains were identified to genus level. Streptomyces as the largest genus of Actinobacteriawas isolated the most frequently. A screening assay using the OmniLog instrument was established to facilitate the detection of active compounds from actinomycetes. Extracts prepared from the cultivated strains able to inhibit Staphylococcus aureusand Escherichia coliwere further analysed by HPLC and MALDI-TOF MS to identify the produced antibiotics. In this study, the bioactive compound echinomycin was identified from two isolated Streptomycesstrains. Natural compounds similar to TPU-0037-C, azalomycin F4a 2-ethylpentyl ester, a derivative of bafilomycin A1, milbemycin-α8 and dihydropicromycin were detected from different isolated Streptomyces strains. Milbemycin-α8 showed cytotoxic activity against HT-29 colon cancer cells. The rare actinomycete,Micromonospora sp. Stup16_C148 produced a compound that matches with the antibiotic bottromycin A2. The draft genome sequence from Actinokineospora strain B136.1 was determined using Illumina and nanopore-based technologies. The isolated strain was not able to produce antibacterial compounds under standard cultivation conditions. The antiSMASH bioinformatics analyses of the genome from strain B136.1 identified biosynthetic gene clusters with identity values between 4% to 90% to known gene clusters encoding antibiotics. The combinations of cultivation conditions, screening assays, analytical methods and genome mining are important tools to characterize strains of actinomycetes for the identification of their potential to produce natural compounds with antimicrobial activity.


Assuntos
Actinobacteria , RNA Ribossômico 16S , Streptomyces , Suíça
9.
Bioresour Technol ; 313: 123692, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32570080

RESUMO

The effect of Streptomyces griseorubens JSD-1 inoculant on composting performance and bacterial community assembly during the swine manure and rice straw co-composting was studied by a high-throughput pyrosequencing technology. The JSD-1 inoculant contributed to a higher temperature (maximum 66.8 °C), a longer thermophilic phase (46 days), and a lower bacterial diversity in JSD-1 compost. The principle component analysis confirmed that JSD-1 inoculant significantly reshaped the microbial communities. The difference in genera significantly increased during both composting processes. The predominant biomarkers were members of Bacteroidetes in JSD-1 composting. The network analysis also showed different chief "connecting" genera in both composts. Moreover, JSD-1 inoculant increased the total nitrogen, phosphorus, and potassium content in composts. The redundancy analysis showed that the bacterial community was mainly influenced by temperature; additionally, the nutrient contents were positively correlated with temperature. These results demonstrated that JSD-1 inoculant drove the bacterial assembly to induce physicochemical property changes in co-composting.


Assuntos
Compostagem , Oryza , Streptomyces , Animais , Esterco , Solo , Suínos
10.
Sheng Wu Gong Cheng Xue Bao ; 36(5): 932-941, 2020 May 25.
Artigo em Chinês | MEDLINE | ID: mdl-32567276

RESUMO

Endo-ß-N-acetylglucosaminidase is used widely in the glycobiology studies and industries. In this study, a new endo-ß-N-acetylglucosaminidase, designated as Endo SA, was cloned from Streptomyces alfalfae ACCC 40021 and expressed in Escherichia coli BL21 (DE3). The purified recombinant Endo SA exhibited the maximum activity at 35 ºC and pH 6.0, good thermo/pH stability and high specific activity (1.0×106 U/mg). It displayed deglycosylation activity towards different protein substrates. These good properties make EndoSA a potential tool enzyme and industrial biocatalyst.


Assuntos
Manosil-Glicoproteína Endo-beta-N-Acetilglucosaminidase , Streptomyces , Clonagem Molecular , Estabilidade Enzimática , Escherichia coli/genética , Expressão Gênica , Manosil-Glicoproteína Endo-beta-N-Acetilglucosaminidase/genética , Manosil-Glicoproteína Endo-beta-N-Acetilglucosaminidase/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Streptomyces/enzimologia , Streptomyces/genética
11.
Arch Microbiol ; 202(7): 2013-2017, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32474644

RESUMO

Streptomyces strains are well known as promising source of bioactive secondary metabolites, important in ecology, biotechnology and medicine. In this study, we present the draft genome of the new type strain Streptomyces tunisialbus DSM 105760T (= JCM 32165T), a rhizospheric bacterium with antimicrobial activity. The genome is 6,880,753 bp in size (average GC content, 71.85%) and encodes 5802 protein-coding genes. Preliminary analysis with antiSMASH 5.1.2. reveals 34 predicted gene clusters for the synthesis of potential secondary metabolites, which was compared with those of Streptomyces varsoviensis NRRL ISP-5346.


Assuntos
Genoma Bacteriano/genética , Streptomyces/genética , Composição de Bases , Sequência de Bases
12.
Arch Microbiol ; 202(7): 1977-1984, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32476046

RESUMO

Biofilm-mediated multidrug resistance has turned into major challenge for the treatment of C. albicans infections. In the present study, actinomycetes (SS5) isolated from marine crustacean were investigated for their ability to inhibit C. albicans biofilm formation. Cultural, morphological and 16S rRNA analysis revealed that the isolated strain was Streptomyces diastaticus. Ethyl acetate bioactive fractions (6 µg mL-1) from SS5 showed potent antibiofilm activity against C. albicans. Light microscopic and CLSM analysis further substantiated the antibiofilm activity of the bioactive fraction against C. albicans. The bioactive fraction was subjected to FTIR and GC-MS for characterization. From GC-MS analysis, the presence of 31 compounds were revealed, among which the alkanes are predominantly present. Hence, further investigation for the potential of these bioactive compounds against C. albicans biofilm will help in the identification of promising candidate for the prevention of biofilm-mediated infection.


Assuntos
Antibiose/fisiologia , Biofilmes , Candida albicans/fisiologia , Streptomyces/fisiologia , Antifúngicos , Testes de Sensibilidade Microbiana , RNA Ribossômico 16S/genética , Streptomyces/classificação , Streptomyces/isolamento & purificação
13.
Environ Pollut ; 265(Pt B): 114867, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32504977

RESUMO

The present work was done to explore the joint effect of Streptomyces pactum (Act12) and plant nutrients on phytoremediation of smelter-contaminated soils. The physiological indicators and phytoextraction indices of potherb mustard (Brassica juncea, Coss) grown in Act12 inoculated soil with or without Hoagland's solution (H), humic acid (HA) and peat (PS) were evaluated. The results indicated that H, HA and PS acted synergistically with Act12, notably increasing chlorophyll and soluble protein contents and thereby promoting plant growth. Soil nutrient treatments reduced the antioxidant activities (PPO, CAT and POD) by 28.2-41.4%, 22.3-90.1% and 15.2-59.4% compared to control, respectively. Act12 and H treatments markedly facilitated plant to accumulate more cadmium (Cd) and zinc (Zn), but it was observed decreases when applied with HA and PS. Metal uptake (MU) values further indicated the differences in phytoextraction efficiency, i.e., H > PS > Control > HA. Taken together, Act12 combined with plant nutrients contributed to alleviating metal toxicity symptoms of plant. Hoagland's solution and peat were highlighted in the present phytoextraction trial, and recommended as soil additives.


Assuntos
Poluentes do Solo/análise , Streptomyces , Biodegradação Ambiental , Cádmio/análise , Biomarcadores Ambientais , Mostardeira , Nutrientes , Solo
14.
Int J Syst Evol Microbiol ; 70(5): 3226-3233, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32375929

RESUMO

A novel actinomycete, designated strain NEAU-C151T, was isolated from soil collected from Mount Song and characterized using a polyphasic approach. Analysis of the 16S rRNA gene sequence indicated that strain NEAU-C151T belongs to the genus Streptomyces and exhibited 97.5, 97.4 and 97.4 % similarities to Streptomyces lincolnensis NRRL 2936T, Streptomyces coacervatus AS-0823T, and Streptomyces longisporus ISP 5166T, respectively. The assignment of strain NEAU-C151T to the genus Streptomyces was confirmed by chemotaxonomic data: anteiso-C15 : 0, C16 : 0, iso-C16 : 0, C16 : 1 (ω7c) and anteiso-C17 : 0 as the major cellular fatty acids; whole-cell sugars contained ribose and glucose; phospholipid profile consisted of diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), unidentified phospholipid (PL), unidentified lipids (L) and phosphatidylinositol mannoside (PIM); the menaquinones were MK-9(H4), MK-9(H6), MK-10(H2) and MK-9(H8). However, multilocus sequence analysis based on five other house-keeping genes (atpD, gyrB, recA, rpoB, and trpB), DNA-DNA relatedness and phenotypic data showed that strain NEAU-C151T could be distinguished from its closest relatives. Consequently, strain NEAU-C151T represents a novel species of the genus Streptomyces, for which the name Streptomyces montanus sp. nov. is proposed. The type strain is NEAU-C151T (=CGMCC 4.7498T=DSM 107808T).


Assuntos
Filogenia , Microbiologia do Solo , Streptomyces/classificação , Actinobacteria/genética , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Genes Bacterianos , Tipagem de Sequências Multilocus , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Streptomyces/isolamento & purificação , Vitamina K 2/análogos & derivados , Vitamina K 2/química
15.
Int J Syst Evol Microbiol ; 70(5): 3316-3322, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32375984

RESUMO

An endophytic actinomycete, strain 3MP-10T, isolated from the root of Mimosa pudica was taxonomically studied based upon polyphasic approaches. This strain formed spiral spore chains on aerial mycelia. ll-Diaminopimelic acid, glucose and ribose were found in the whole-cell hydrolysates. It belonged to the genus Streptomyces and was closely related to Streptomyces zhaozhouensis DSM 42101T (98.9 %) and Streptomyces sedi JCM 16909T (98.6 %) based on 16S rRNA gene sequence analysis results. The major menaquinones were MK-10(H8), MK-10(H6) and MK-9(H8). The predominant cellular fatty acids were iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. The detected phospholipids were diphosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol, phosphatidylethanolamine and phosphatidylglycerol. Strain 3MP-10T had a genome size of 7.2 Mb with a genome G+C content of 73.4 mol%. Results of in silico genome-based similarity analysis revealed ANIb values of 84.94 and 84.77 %, ANIm values of 88.01 and 87.92 %, and dDDH values of 29.9 and 29.6 % when compared with S. zhaozhouensis DSM 42101T and S. sedi JCM 16909T, respectively. Based on the polyphasic approach, digital DNA-DNA relatedness and average nucleotide identity, we propose that the novel actinomycete represents a novel species, Streptomyces mimosae, with type strain 3MP-10T (=JCM 33328T=TISTR 2646T).


Assuntos
Mimosa/microbiologia , Filogenia , Raízes de Plantas/microbiologia , Streptomyces/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Streptomyces/isolamento & purificação , Tailândia , Vitamina K 2/química
16.
Proc Natl Acad Sci U S A ; 117(19): 10265-10270, 2020 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-32350138

RESUMO

Coformycin and pentostatin are structurally related N-nucleoside inhibitors of adenosine deaminase characterized by an unusual 1,3-diazepine nucleobase. Herein, the cof gene cluster responsible for coformycin biosynthesis is identified. Reconstitution of the coformycin biosynthetic pathway in vitro demonstrates that it overlaps significantly with the early stages of l-histidine biosynthesis. Committed entry into the coformycin pathway takes place via conversion of a shared branch point intermediate to 8-ketocoformycin-[Formula: see text]-monophosphate catalyzed by CofB, which is a homolog of succinylaminoimidazolecarboxamide ribotide (SAICAR) synthetase. This reaction appears to proceed via a Dieckmann cyclization and a retro-aldol elimination, releasing ammonia and D-erythronate-4-phosphate as coproducts. Completion of coformycin biosynthesis involves reduction and dephosphorylation of the CofB product, with the former reaction being catalyzed by the NADPH-dependent dehydrogenase CofA. CofB also shows activation by adenosine triphosphate (ATP) despite the reaction requiring neither a phosphorylated nor an adenylated intermediate. This may serve to help regulate metabolic partitioning between the l-histidine and coformycin pathways.


Assuntos
Adenosina Desaminase/química , Trifosfato de Adenosina/metabolismo , Proteínas de Bactérias/genética , Coformicina/biossíntese , Família Multigênica , Streptomyces/genética , Adenosina Desaminase/metabolismo , Monofosfato de Adenosina/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Vias Biossintéticas , Fosforilação , Streptomyces/metabolismo
17.
Arch Microbiol ; 202(7): 1597-1615, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32451592

RESUMO

Extracellular enzymes produced from Streptomyces have the potential to replace toxic chemicals that are being used in various industries. The endorsement of this replacement has not received a better platform in developing countries. In this review, we have discussed the impact of chemicals and conventional practices on environmental health, and the role of extracellular enzymes to replace these practices. Burning of fossil fuels and agriculture residue is a global issue, but the production of biofuel using extracellular enzymes may be the single key to solve all these issues. We have discussed the replacement of hazardous chemicals with the use of xylanase, cellulase, and pectinase in food industries. In paper industries, delignification was done by the chemical treatment, but xylanase and laccase have the efficient potential to remove the lignin from pulp. In textile industries, the conventional method includes the chemicals which affect the nervous system and other organs. The use of xylanase, cellulase, and pectinase in different processes can give a safe and environment-friendly option to textile industries. Hazardous chemical pesticides can be replaced by the use of chitinase as an insecticide and fungicide in agricultural practices.


Assuntos
Proteínas de Bactérias/metabolismo , Enzimas/metabolismo , Microbiologia Industrial/tendências , Streptomyces/enzimologia , Agricultura , Biocombustíveis , Lignina/metabolismo
18.
PLoS One ; 15(5): e0232927, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32396566

RESUMO

Tetraene macrolides remain one of the most reliable fungicidal agents as resistance of fungal pathogens to these antibiotics is relatively rare. The modes of action and biosynthesis of polyene macrolides had been the focus of research over the past few years. However, few studies have been carried out on the overproduction of polyene macrolides. In the present study, cumulative drug-resistance mutation was used to obtain a quintuple mutant G5-59 with huge tetraene macrolide overproduction from the starting strain Streptomyces diastatochromogenes 1628. Through DNA sequence analysis, the mutation points in the genes of rsmG, rpsL and rpoB were identified. Additionally, the growth characteristic and expression level of tetrRI gene (belonging to the large ATP binding regulator of LuxR family) involved in the biosynthesis of tetraene macrolides were analyzed. As examined with 5L fermentor, the quintuple mutant G5-59 grew very well and the maximum productivity of tetramycin A, tetramycin P and tetrin B was as high as 1735, 2811 and 1500 mg/L, which was 8.7-, 16- and 25-fold higher than that of the wild-type strain 1628, respectively. The quintuple mutant G5-59 could be useful for further improvement of tetraene macrolides production at industrial level.


Assuntos
Proteínas de Bactérias/genética , Reatores Biológicos/microbiologia , Macrolídeos/metabolismo , Mutação , Streptomyces/crescimento & desenvolvimento , RNA Polimerases Dirigidas por DNA/genética , Farmacorresistência Bacteriana , Fermentação , Engenharia Metabólica , Metiltransferases/genética , Proteínas Ribossômicas/genética , Análise de Sequência de DNA , Streptomyces/genética , Streptomyces/metabolismo
19.
Int J Syst Evol Microbiol ; 70(6): 3924-3929, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32441614

RESUMO

Phylogenetic analysis based on 16S rRNA gene sequences of the genus Streptomyces showed the presence of six distinguishable clusters, with 100 % sequence similarity values among strains in each cluster; thus they shared almost the same evolutionary distance. This result corroborated well with the outcome of core gene (orthologous gene clusters) based genome phylogeny analysis of 190 genomes including the Streptomyces species in those six clusters. These preeminent results led to an investigation of genome-based indices such as digital DNA-DNA hybridization (dDDH), average nucleotide identity (ANI) and average amino acid identity (AAI) for the strains in those six clusters. Certain strains recorded genomic indices well above the threshold values (70 %, 95-96 % and >95 % for dDDH, ANI and AAI, respectively) determined for species affiliation, suggesting only one type strain belongs to described species and the other(s) may need to be reduced in taxa to a later heterotypic synonym. To conclude, the results of comprehensive analyses based on phylogenetic and genomic indices suggest that the following six reclassifications are proposed: Streptomyces flavovariabilis as a later heterotypic synonym of Streptomyces variegatus; Streptomyces griseofuscus as a later heterotypic synonym of Streptomyces murinus; Streptomyces kasugaensis as a later heterotypic synonym of Streptomyces celluloflavus; Streptomyces luridiscabiei as a later heterotypic synonym of Streptomyces fulvissimus; Streptomyces pharetrae as a later heterotypic synonym of Streptomyces glaucescens; and Streptomyces stelliscabiei as a later heterotypic synonym of Streptomyces bottropensis.


Assuntos
Filogenia , Streptomyces/classificação , DNA Bacteriano/genética , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética
20.
Plant Dis ; 104(7): 1986-1993, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32441579

RESUMO

Potato common scab is an important soilborne disease worldwide that can significantly reduce the quality and economic values of potato. The disease is caused by multiple species of Streptomyces, which are not well controlled due to lack of effective strategies. Streptomyces galilaeus has been recently identified as a dominant species causing potato common scab in Inner Mongolia, China. This study was focused on screening and characterizing antagonists for biological control against pathogenic S. galilaeus. Bacterial strain PBSH9 was isolated from a potato tuber. PBSH9 was identified as a Streptomyces sp. on the basis of morphological, physiological, and biochemical characteristics, as well as DNA sequence analysis. PBSH9 inhibited S. galilaeus with a diameter of inhibitory zone of 19.8 mm on agar plates. The extracellular filtrate of PBSH9 also inhibited S. galilaeus growth with a diameter of inhibition zone of 10.0 mm. Furthermore, PBSH9 promoted potato sprouting and emergence. Disease control was up to 81.88% in greenhouse trials, and from 47.64 to 73.97% in 3-year field trials. Among the tested inoculation methods, seed treatment was more effective than soil drenching for PBSH9 application. PBSH9 not only effectively controlled potato common scab but also increased potato growth. Thus, it can be a potential candidate for biocontrol agent.


Assuntos
Solanum tuberosum , Streptomyces , China , Doenças das Plantas
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