RESUMO
Collective cellular behavior plays a crucial role in various biological processes, ranging from developmental morphogenesis to pathological processes such as cancer metastasis. Our previous research has revealed that a mutant cell of Dictyostelium discoideum exhibits collective cell migration, including chain migration and traveling band formation, driven by a unique tail-following behavior at contact sites, which we term "contact following locomotion" (CFL). Here, we uncover an imbalance of forces between the front and rear cells within cell chains, leading to an additional propulsion force in the rear cells. Drawing inspiration from this observation, we introduce a theoretical model that incorporates non-reciprocal cell-cell interactions. Our findings highlight that the non-reciprocal interaction, in conjunction with self-alignment interactions, significantly contributes to the emergence of the observed collective cell migrations. Furthermore, we present a comprehensive phase diagram, showing distinct phases at both low and intermediate cell densities. This phase diagram elucidates a specific regime that corresponds to the experimental system.
Assuntos
Dictyostelium , Comunicação Celular , Movimento Celular , Locomoção , MorfogêneseRESUMO
The unique Akebono soybeans are cultivated in Minobu Town, Yamanashi Prefecture, Japan. The biogeography of Akebono soybeans and the microbial diversity associated with their root nodules remain unexplored. This study investigated the nodule-associated microbial community of Akebono soybeans using molecular techniques. The results showed that the family Bradyrhizobiaceae was dominant in soybeans obtained from Minobu town Imata (MI), Minobu town IItomi (MS), and Minobu town Hirase (MN). In contrast, members of the family Pseudonocardiaceae were isolated from the nodule samples from Minobu town Yasaiku (MY). The community structure of MY was different from that of the other sites and the genus Amycolatopsis was dominant. The bacterial community in the nodule associated soil obtained from the Minobu area was different from that of soybeans cultivated in Kofu City (approximately 35 km away from Minobu Town). The MY1 strain of Amycolatopsis spp. was isolated from the nodule associated soil in MY and was found to produce antibiotics. This study showed that the bacterial community in the nodules and the adjacent rhizosphere may be a regional characteristic of Akebono soybeans and the specific Amycolatopsis spp. dominant in the nodule associated soil of MY was implicated in determining the bacterial community structure. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-022-00999-x.
RESUMO
Linear azole-containing peptides are a class of ribosomally synthesized and post-translationally modified peptides. We performed a chemical investigation on marine actinomycetes, and new linear azole-containing peptides named spongiicolazolicins A and B were found in the MeOH extracts of a newly isolated strain Streptomyces sp. CWH03 (NBRC 114659) and two strains of S. spongiicola (strain HNM0071T: DSM 103383T and strain 531S: NBRC 113560). The strain Streptomyces sp. CWH03 was indicated to be a new species closely related to S. spongiicola by phylogenetic analysis using the genome sequence. The new peptides named spongiicolazolicins A and B were isolated from the cell of Streptomyces sp. CWH03. The partial structure of spongiicolazolicin A was determined by 2D NMR experiments. Based on data of MS/MS experiments, the chemical structures of spongiicolazolicins A and B were proposed using the amino acid sequence deduced from the precursor-encoding gene, which was found from whole-genome sequence data of Streptomyces sp. CWH03. The biosynthetic gene cluster of spongiicolazolicins was proposed based on comparative analysis with that of a known linear azole peptide goadsporin. KEY POINTS: ⢠Streptomyces sp. CWH03 was a new species isolated from marine sediment. ⢠New linear azole-containing peptides named spongiicolazolicins A and B were isolated. ⢠Biosynthetic pathway of spongiicolazolicins was proposed.
Assuntos
Streptomyces , Azóis , DNA Bacteriano , Ácidos Graxos , Peptídeos/genética , Filogenia , RNA Ribossômico 16S , Análise de Sequência de DNA , Streptomyces/genética , Espectrometria de Massas em TandemRESUMO
An actinomycete strain, TKZ-21T, was isolated from a freshwater alga (Chetophoraceae) collected from the Takizawa River, Yamanashi, Japan, and examined using a polyphasic taxonomic approach. Cells were Gram-stain positive, aerobic, non-sporulating, motile, and coccoid or short rod-shaped. The strain grew in the presence of 0-4â% (w/v) NaCl, between pH 6-9.4, and over a temperature range of 15-40 °C, with optimum growth at 30 °C. The peptidoglycan type of strain TKZ-21T was A4ß, containing l-ornithine as diagnostic diamino acid and d-glutamic acid as the interpeptide bridge. The predominant menaquinone was MK-9(H4). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, ninhydrin-positive glycolipid, and unidentified phospholipids. The major cellular fatty acids were anteiso-C15â:â0 and anteiso-C17â:â0, and the DNA G+C content was 75.6 mol%. On the basis of 16S rRNA gene sequence analysis, strain TKZ-21T was closely related to Cellulomonas fimi (98.5â% sequence similarity) and Cellulomonas biazotea (98.3â%). The genome orthoANI value between strain TKZ-21T and C. biazotea and C. fimi were 84.7 and 84.2â%, respectively. On the basis of fatty acid and MALDI-TOF MS profile analysis, phylogenetic analyses, genomic analysis, and phenotypic data, it is proposed that the isolate be classified as a representative of a novel species of the genus Cellulomonas, with the name Cellulomonas algicola sp. nov. The type strain is TKZ-21T (=NBRC 112905T=TBRC 8129T).
Assuntos
Cellulomonas/classificação , Clorofíceas/microbiologia , Filogenia , Técnicas de Tipagem Bacteriana , Composição de Bases , Cellulomonas/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/química , Glicolipídeos/química , Japão , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Rios , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMO
This paper reports a twisting microfluidic method utilising a centrifuge-based fluid extruding system in a planetary centrifuge which simultaneously generates an orbital rotation and an axial spin. In this method, fluid extrusion from a micro-scale capillary to an 'open-space' solution or air enables release of the fluid from the capillary-based microchannel, which physically means that there is a release of fluids from a confined low-Reynolds-number environment to an open non-low-Reynolds-number environment. As a result, the extruded fluids are separated from the axial spin of the capillary, and the difference in the angular rates of the axial spin between the capillary and the extruded fluids produces the 'twisting' of the fluid. In this study, we achieve control of the twist of highly viscous fluids, and we construct a simple physical model for the fluid twist. In addition, we demonstrate the formation of twisted hydrogel microstructures (stripe-patterned microbeads and multi-helical microfibres) with control over the stripe pattern and the helical pitch length. We believe that this method will enable the generation of more sophisticated microstructures which cannot easily be formed by usual channel-based microfluidic devices. This method can also provide advanced control of microfluids, as in the case of rapid mixing of highly viscous fluids. This method can contribute to a wide range of applications in materials science, biophysics, biomedical science, and microengineering in the future.
RESUMO
The magnetic actuation of deposited drops has mainly relied on volume forces exerted on the liquid to be transported, which is poorly efficient with conventional diamagnetic liquids such as water and oil, unless magnetosensitive particles are added. Herein, we describe a new and additive-free way to magnetically control the motion of discrete liquid entities. Our strategy consists of using a paramagnetic liquid as a deformable substrate to direct, using a magnet, the motion of various floating liquid entities, ranging from naked drops to liquid marbles. A broad variety of liquids, including diamagnetic (water, oil) and nonmagnetic ones, can be efficiently transported using the moderate magnetic field (ca. 50â mT) produced by a small permanent magnet. Complex trajectories can be achieved in a reliable manner and multiplexing potential is demonstrated through on-demand drop fusion. Our paramagnetofluidic method advantageously works without any complex equipment or electric power, in phase with the necessary development of robust and low-cost analytical and diagnostic fluidic devices.
RESUMO
UNLABELLED: Actinoplanes missouriensis, a Gram-positive and soil-inhabiting bacterium, is a member of the rare actinomycetes. The filamentous cells produce sporangia, which contain hundreds of flagellated spores that can swim rapidly for a short period of time until they find niches for germination. These swimming cells are called zoospores, and the mechanism of this unique temporal flagellation has not been elucidated. Here, we report all of the flagellar genes in the bacterial genome and their expected function and contribution for flagellar morphogenesis. We identified a large flagellar gene cluster composed of 33 genes that encode the majority of proteins essential for assembling the functional flagella of Gram-positive bacteria. One noted exception to the cluster was the location of the fliQ gene, which was separated from the cluster. We examined the involvement of four genes in flagellar biosynthesis by gene disruption, fliQ, fliC, fliK, and lytA Furthermore, we performed a transcriptional analysis of the flagellar genes using RNA samples prepared from A. missouriensis grown on a sporangium-producing agar medium for 1, 3, 6, and 40 days. We demonstrated that the transcription of the flagellar genes was activated in conjunction with sporangium formation. Eleven transcriptional start points of the flagellar genes were determined using the rapid amplification of cDNA 5' ends (RACE) procedure, which revealed the highly conserved promoter sequence CTCA(N15-17)GCCGAA. This result suggests that a sigma factor is responsible for the transcription of all flagellar genes and that the flagellar structure assembles simultaneously. IMPORTANCE: The biology of a zoospore is very interesting from the viewpoint of morphogenesis, survival strategy, and evolution. Here, we analyzed flagellar genes in A. missouriensis, which produces sporangia containing hundreds of flagellated spores each. Zoospores released from the sporangia swim for a short time before germination occurs. We identified a large flagellar gene cluster and an orphan flagellar gene (fliQ). These findings indicate that the zoospore flagellar components are typical of Gram-positive bacteria. However, the transcriptional analysis revealed that all flagellar genes are transcribed simultaneously during sporangium formation, a pattern differing from the orderly, regulated expression of flagellar genes in other bacteria, such as Salmonella and Escherichia coli These results suggest a novel regulatory mechanism for flagellar formation in A. missouriensis.
Assuntos
Proteínas de Bactérias/metabolismo , Flagelos/metabolismo , Regulação Bacteriana da Expressão Gênica/fisiologia , Micromonosporaceae/genética , Micromonosporaceae/metabolismo , Proteínas de Bactérias/genética , Sequência de Bases , DNA Bacteriano/genética , Flagelos/genética , Glicosiltransferases/genética , Glicosiltransferases/metabolismoRESUMO
To date, no plasmid vector has been developed for the rare actinomycete Actinoplanes missouriensis. Moreover, no small circular plasmid has been reported to exist in the genus Actinoplanes. Here, a novel plasmid, designated pCAZ1, was isolated from Couchioplanes caeruleus subsp. azureus via screening for small circular plasmids in Actinoplanes (57 strains) and Couchioplanes (2 strains). Nucleotide sequencing revealed that pCAZ1 is a 5845-bp circular molecule with a G + C content of 67.5%. The pCAZ1 copy number was estimated at 30 per chromosome. pCAZ1 contains seven putative open reading frames, one of which encodes a protein containing three motifs conserved among plasmid-encoded replication proteins that are involved in the rolling-circle mechanism of replication. Detection of single-stranded DNA intermediates in C. caeruleus confirmed that pCAZ1 replicates by this mechanism. The ColE1 origin from pBluescript SK(+) and the oriT sequence with the apramycin resistance gene aac(3)IV from pIJ773 were inserted together into pCAZ1, to construct the Escherichia coli-A. missouriensis shuttle vectors, pCAM1 and pCAM2, in which the foreign DNA fragment was inserted into pCAZ1 in opposite directions. pCAM1 and pCAM2 were successfully transferred to A. missouriensis through the E. coli-mediated conjugative transfer system. The copy numbers of pCAM1 and pCAM2 in A. missouriensis were estimated to be one and four per chromosome, respectively. Thus, these vectors can be used as effective genetic tools for homologous and heterologous gene expression studies in A. missouriensis.
Assuntos
Actinobacteria/genética , Expressão Gênica , Vetores Genéticos/genética , Plasmídeos/genética , Plasmídeos/isolamento & purificação , Sequência de Aminoácidos , Sequência de Bases , Replicação do DNA , DNA Circular/metabolismo , DNA de Cadeia Simples/genética , Dosagem de Genes , Vetores Genéticos/isolamento & purificação , Dados de Sequência Molecular , Fases de Leitura Aberta/genética , Alinhamento de Sequência , Análise de Sequência de DNARESUMO
Thirteen novel Gram-stain-positive bacteria were isolated from various samples collected from mangrove forests in Japan, and their taxonomic positions were investigated by a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequence comparisons showed that the 13 isolates formed a single clade with Lysinimicrobium mangrovi HI08-69T, with a similarity range of 97.6-99.5 %. The peptidoglycan of the isolates was of the A4α type with an interpeptide bridge comprising Ser-Glu and an l-Ser residue at position 1 of the peptide subunit. The predominant menaquinone was demethylmenaquinone DMK-9(H4) and the major fatty acid was anteiso-C15 : 0. These chemotaxonomic characteristics corresponded to those of the genus Lysinimicrobium. On the basis of the phenotypic and phylogenetic data, along with average nucleotide identity values among the isolates, we concluded that the 13 isolates should be assigned to the following nine novel species of the genus Lysinimicrobium: Lysinimicrobium aestuarii sp. nov. (type strain HI12-104T = NBRC 109392T = DSM 28144T), Lysinimicrobium flavum sp. nov. (type strain HI12-45T = NBRC 109391T = DSM 28150T), Lysinimicrobium gelatinilyticum sp. nov. (type strain HI12-44T = NBRC 109390T = DSM 28149T), Lysinimicrobium iriomotense sp. nov. (type strain HI12-143T = NBRC 109399T = DSM 28146T), Lysinimicrobium luteum sp. nov. (type strain HI12-123T = NBRC 109395T = DSM 28147T), Lysinimicrobium pelophilum sp. nov. (type strain HI12-111T = NBRC 109393T = DSM 28148T), Lysinimicrobium rhizosphaerae sp. nov. (type strain HI12-135T = NBRC 109397T = DSM 28152T), Lysinimicrobium soli sp. nov. (type strain HI12-122T = NBRC 109394T = DSM 28151T) and Lysinimicrobium subtropicum sp. nov. (type strain HI12-128T = NBRC 109396T = DSM 28145T). In addition, an emended description of the genus Lysinimicrobium is proposed.
Assuntos
Actinomycetales/classificação , Avicennia/microbiologia , Filogenia , Actinomycetales/genética , Actinomycetales/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Japão , Dados de Sequência Molecular , Peptidoglicano/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química , Áreas AlagadasRESUMO
The planar and stereostructures of JBIR-108 isolated from Streptomyces gramineus IR087Pi-4 were determined partly by spectral analysis, and these structural assignments were confirmed and completed by the total synthesis of both 1-epimers. The key stereocenters in JBIR-108 were constructed via a Corey-Bakshi-Shibata (CBS) reduction (C-1), vinylogous Mukaiyama aldol reaction (C-7), and Brown crotylation (C-14 and C-15). Although it was difficult to determine the stereochemistries at the C-1 and C-7 positions in the natural product using the modified Mosher's method, the synthesis of two possible C-1 diastereomers enabled the identification of the configurations at the hitherto unknown stereocenters.
Assuntos
Furanos/síntese química , Furanos/isolamento & purificação , Streptomyces/química , Furanos/química , Conformação Molecular , Estrutura MolecularRESUMO
Three novel Gram-stain-positive bacteria, designated IY07-20(T), IY07-56(T) and IY07-113, were isolated from soil samples from Iriomote Island, Okinawa, Japan, and their taxonomic positions were investigated by a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequence comparisons showed that the three isolates were closely related to the members of the genus Agromyces, with similarity range of 95.6-98.7%. The isolates contained l-2,4-diaminobutylic acid, d-alanine, d-glutamic acid and glycine in their peptidoglycans. The predominant menaquinone was MK-12 and the major fatty acids were anteiso-C15:0 and anteiso-C17:0. The DNA G+C contents were 70.9-72.9 mol%. The chemotaxonomic characteristics of the isolates matched those described for members of the genus Agromyces. The results of phylogenetic analysis and DNA-DNA hybridization, along with differences in phenotypic characteristics between strains IY07-20(T), IY07-56(T) and IY07-113 and the species of the genus Agromyces with validly published names, indicate that the three isolates merit classification as representatives of two novel species of the genus Agromyces, for which the names Agromyces iriomotensis sp. nov. and Agromyces subtropica sp. nov. are proposed; the type strains are IY07-20(T) (â=âNBRC 106452(T)â=âDSM 26155(T)) and IY07-56(T) (â=âNBRC 106454(T)â=âDSM 26153(T)), respectively.
Assuntos
Actinomycetales/classificação , Filogenia , Microbiologia do Solo , Actinomycetales/genética , Actinomycetales/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Japão , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Peptidoglicano/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/químicaRESUMO
We constructed a plasmid that expresses FLO11 encoding a cell surface glycoprotein of Saccharomyces cerevisiae under the control of a constitutive promoter. This plasmid conferred pellicle-forming ability on the non-pellicle-forming industrial strain of S. cerevisiae at the air-liquid interface of the glucose-containing liquid medium. The induced pellicle-forming cells exhibited tolerance to furfural, which is a key toxin in lignocellulosic hydrolysates, in ethanol production.
Assuntos
Etanol/metabolismo , Furaldeído/farmacologia , Engenharia Genética/métodos , Glicoproteínas de Membrana/genética , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Fermentação , Glucose/farmacologia , Plasmídeos/genética , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/fisiologiaRESUMO
Collective cell migration occurs when the orientation of cell polarity is aligned with each other in a group of cells. Such collective polarization depends on a reciprocal process between cell intrinsic mechanisms such as cell-cell adhesion and extracellular guidance mechanism such as wound healing and chemotaxis. As part of its development life cycle, individual single cells of Dictyostelium discoideum exhibit chemotaxis toward cAMP, which is secreted from a certain population of cells. During the formation of multicellular body by chemotaxis-dependent cell aggregation, D. discoideum is also known to relay on multiple cell-cell adhesion mechanisms. In particular, tail-following behavior at the contact site, called contact following of locomotion (CFL), plays a pivotal role on the formation of the multicellular body. However, whether and how CFL alone can lead to a formation of collective behavior was not well understood. KI cell is a mutant of D. discoideum that lacks all chemotactic activity. Yet, it can exhibit the CFL activity and show nontrivial collective cell migration. This mutant provides an excellent model system to analyze the mechanism of the CFL and the macroscopic phenomena brought by the CFL. This chapter describes protocols for using KI cell to understand the biophysics and cell biology behind the collective cell migration induced by CFL.
Assuntos
Movimento Celular , Quimiotaxia , Dictyostelium , Dictyostelium/genética , Dictyostelium/fisiologia , Dictyostelium/citologia , Quimiotaxia/genética , Movimento Celular/genética , Mutação , AMP Cíclico/metabolismo , Polaridade Celular/genética , Adesão Celular , Modelos BiológicosRESUMO
Two novel Gram-stain-positive bacteria, designated HR08-7(T) and HR08-43(T), were isolated from a sea sediment sample from Rishiri Island, Hokkaido, Japan, and their taxonomic positions were investigated by a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strains HR08-7(T) and HR08-43(T) and the members of the genus Demequina formed a monophyletic cluster with similarity range of 95.5-99.0 %. The peptidoglycan type of strains HR08-7(T) and HR08-43(T) was A4ß. The predominant menaquinone of both strains was demethylmenaquinone DMK-9(H(4)) and the major fatty acid was anteiso-C(15 : 0). The DNA G+C contents of strains HR08-7(T) and HR08-43(T) were 64.5 and 62.4 mol%, respectively. The results of phylogenetic analysis and DNA-DNA hybridization, along with differences of strains HR08-7(T) and HR08-43(T) from the recognized Demequina species in phenotypic characteristics, indicate that the two strains merit classification as representatives of two novel species of the genus Demequina, for which the names Demequina flava sp. nov. and Demequina sediminicola sp. nov. are proposed; the type strains are HR08-7(T) (= NBRC 105854(T) = DSM 24865(T)) and HR08-43(T) (= NBRC 105855(T) = DSM 24867(T)), respectively.
Assuntos
Actinomycetales/classificação , Sedimentos Geológicos/microbiologia , Filogenia , Actinomycetales/genética , Actinomycetales/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/análise , Japão , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Água do Mar/microbiologia , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/análise , Microbiologia da ÁguaRESUMO
A novel Gram-stain-positive actinobacterium, designated HR08-44(T), was isolated from a sea-sediment sample collected from the foreshore of Rishiri Island, Japan, and its taxonomic position was investigated by a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain HR08-44(T) was closely related to the members of the genus Janibacter, with pairwise sequence similarities of 97.3-98.8â%. Strain HR08-44(T) had peptidoglycan type A1γ, with meso-diaminopimelic acid as the diagnostic diamino acid. The predominant menaquinone was MK-8(H4) and the major fatty acids were iso-C16â:â0, C17â:â1ω8c, C17â:â0 and C18â:â1ω9c. These data supported the affiliation of the novel strain to the genus Janibacter. Meanwhile, the results of DNA-DNA hybridization and physiological and biochemical tests indicated that strain HR08-44(T) can be distinguished from recognized species of the genus Janibacter. Therefore, strain HR08-44(T) represents a novel species of the genus Janibacter, for which the name Janibacter cremeus sp. nov. is proposed; the type strain is HR08-44(T) (â=âNBRC 107693(T)â=âDSM 26154(T)).
Assuntos
Actinomycetales/classificação , Sedimentos Geológicos/microbiologia , Filogenia , Água do Mar/microbiologia , Microbiologia da Água , Actinomycetales/genética , Actinomycetales/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/análise , Japão , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Peptidoglicano/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/análiseRESUMO
A novel Gram-stain-positive actinobacterium, designated H25-14(T), was isolated from a sea sediment sample, and its taxonomic position was investigated by a polyphasic approach. The peptidoglycan type of strain H25-14(T) was A4α and lysine was the diagnostic diamino acid of the peptidoglycan. The predominant menaquinone was MK-9(H4) and the major fatty acids were anteiso-C15 : 0 and iso-C15 : 0. The DNA G+C content was 73.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain H25-14(T) was closely related to Paraoerskovia marina NBRC 104352(T) (98.3 %). However, DNA-DNA hybridization data and phenotypic characteristics revealed that strain H25-14(T) differed from P. marina NBRC 104352(T). Therefore, strain H25-14(T) represents a novel species of the genus Paraoerskovia, for which the name Paraoerskovia sediminicola sp. nov. is proposed. The type strain is H25-14(T) ( = NBRC 108565(T) = DSM 25477(T)). An emended description of the genus Paraoerskovia is also proposed.
Assuntos
Actinomycetales/classificação , Sedimentos Geológicos/microbiologia , Filogenia , Água do Mar/microbiologia , Actinomycetales/genética , Actinomycetales/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/análise , Japão , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Peptidoglicano/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/análiseRESUMO
Tolerance of microorganisms to diverse stresses (i.e., multistress tolerance) is a very useful property with industrial applications. We have developed a simple method for isolating multistress-tolerant semidominant mutants of the budding yeast Saccharomyces cerevisiae by one-step selection under lethal hydrogen peroxide (H(2)O(2)) stress condition, which we named the lethal concentration of H(2)O(2) (LCH) method. This method involves simply isolating colonies after plating of mutagenized S. cerevisiae cells, which are cultivated overnight in liquid media, on agar plates containing a lethal concentration of H(2)O(2) for the wild-type strain. Phenotypic and genetic analyses of the ten strains isolated by this method revealed that two strains exhibiting stress tolerance to H(2)O(2), ethanol, heat shock, salt, organic solvent, freeze-thaw, chronological aging, and high concentrations of glucose possess semidominant and distinct single-gene mutations designated as MLT1-1 (multistress tolerance) and MLT2-1, which are responsible for multistress tolerance. From these results, we expect this method to confer multistress tolerance on industrial yeasts.
Assuntos
Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Genes Fúngicos , Peróxido de Hidrogênio/farmacologia , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/efeitos dos fármacos , Seleção Genética , Etanol/farmacologia , Congelamento , Genes Dominantes , Glucose/farmacologia , Resposta ao Choque Térmico , Temperatura Alta , Mutação , Concentração Osmolar , Saccharomyces cerevisiae/fisiologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Estresse FisiológicoRESUMO
A polyphasic approach was used to determine the taxonomic position of a marine actinomycete, designated isolate CWH03T, which we previously reported to produce new linear azole-containing peptides spongiicolazolicins A and B. Strain CWH03T is mesophilic, neutrophilic, and halotolerant streptomycete that forms spiral spore chains on aerial mycelium. Comparative 16S rRNA gene sequencing showed that CWH03T was most closely related to Streptomyces tirandamycinicus HNM0039T (99.7%), Streptomyces spongiicola HNM0071T (99.4%), 'Streptomyces marianii' ICN19T (99.1%) and Streptomyces wuyuanensis CGMCC4.7042T (99.0%). The phylogenetic tree prepared using the 16S rRNA gene, as well as the phylogenomic tree using the genome BLAST distance phylogeny method and 81 core housekeeping genes, respectively, showed that the closest relative of strain CWH03T was S. spongiicola HNM0071T. The average nucleotide identity and digital DNA-DNA hybridization values between strains CWH03T and S. spongiicola HNM0071T were 91.46% and 44.2%, respectively, which were below the thresholds of 96% and 70% for prokaryotic conspecific assignation. The G+C content of the genomic DNA of strain CWH03T was 72.3%. Whole-cell hydrolysates of strain CWH03T contained LL-diaminopimelic acid. The predominant menaquinone was MK-9(H8) (88.3%), and the major fatty acids were iso-C16:0 (28.4%), anteiso-C15:0 (15.0%) and iso-C15:0 (12.9%). The major phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid. Based on data obtained from phenotypic, phylogenetic, genomic, and chemotaxonomic analyses, strain CWH03T represents a novel species of the genus Streptomyces, for which the proposed name is Streptomyces pacificus sp. nov. The type strain is CWH03T ( = NBRC 114659T = TBRC 15780T).
Assuntos
Actinobacteria , Streptomyces , Actinobacteria/genética , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfolipídeos/química , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/químicaRESUMO
A novel strain of Gram-staining-positive bacterium, designated HI08-69(T), was isolated from the rhizosphere of a mangrove on Iriomote Island, Japan, and its taxonomic position was investigated by a polyphasic approach. The strain had peptidoglycan of the A4α type, with lysine as the diagnostic diamino acid. The predominant menaquinone was demethylmenaquinone DMK-9(H(4)) and the major fatty acids were anteiso-C(15:0), anteiso-C(17:0) and C(16:0). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and an unidentified polar lipid but minor amounts of other polar lipids were also detected. The genomic DNA G+C content of strain HI08-69(T) was 71.7 mol%. In phylogenetic analyses based on 16S rRNA gene sequences, the novel strain and members of the genus Demequina formed a monophyletic cluster, with pairwise sequence similarities of 95.6-96.8%. However, strain HI08-69(T) was clearly distinguishable from all established members of the genus Demequina in terms of several chemotaxonomic characteristics. On the basis of the phenotypic and genotypic characteristics, strain HI08-69(T) represents a novel species in a new genus for which the name Lysinimicrobium mangrovi gen. nov., sp. nov. is proposed. The type strain of the type species is HI08-69(T) (â=âNBRC 105856(T)â=âDSM 24868(T)).
Assuntos
Actinobacteria/classificação , Actinobacteria/isolamento & purificação , Filogenia , Rhizophoraceae/microbiologia , Rizosfera , Microbiologia da Água , Actinobacteria/genética , Composição de Bases , DNA Bacteriano/genética , Japão , Dados de Sequência Molecular , Peptidoglicano/análise , Fosfolipídeos/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
Two phenolic compounds, JBIR-94 (1) and JBIR-125 (2), were isolated from the fermentation broth of strain R56-07, which was identified by phylogenetic methods as a novel species of Streptomyces. The structures of 1 and 2 were assigned on the basis of 1D and 2D NMR spectroscopy and MS analyses. Compounds 1 and 2 exhibited 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity with an IC(50) value of 11.4 and 35.1 µM, respectively. These compounds are the first examples of hydroxycinnamic acid amides containing putrescine or spermidine produced by actinomycetes.