-
Microbiology and Molecular Biology... Mar 2016Actinobacteria are Gram-positive bacteria with high G+C DNA content that constitute one of the largest bacterial phyla, and they are ubiquitously distributed in both... (Review)
Review
Actinobacteria are Gram-positive bacteria with high G+C DNA content that constitute one of the largest bacterial phyla, and they are ubiquitously distributed in both aquatic and terrestrial ecosystems. Many Actinobacteria have a mycelial lifestyle and undergo complex morphological differentiation. They also have an extensive secondary metabolism and produce about two-thirds of all naturally derived antibiotics in current clinical use, as well as many anticancer, anthelmintic, and antifungal compounds. Consequently, these bacteria are of major importance for biotechnology, medicine, and agriculture. Actinobacteria play diverse roles in their associations with various higher organisms, since their members have adopted different lifestyles, and the phylum includes pathogens (notably, species of Corynebacterium, Mycobacterium, Nocardia, Propionibacterium, and Tropheryma), soil inhabitants (e.g., Micromonospora and Streptomyces species), plant commensals (e.g., Frankia spp.), and gastrointestinal commensals (Bifidobacterium spp.). Actinobacteria also play an important role as symbionts and as pathogens in plant-associated microbial communities. This review presents an update on the biology of this important bacterial phylum.
Topics: Actinobacteria; Anti-Bacterial Agents; Antifungal Agents; Biological Products; Herbicides; Insecticides; Microbial Interactions; Phylogeny; Pigments, Biological; Spores, Bacterial
PubMed: 26609051
DOI: 10.1128/MMBR.00019-15 -
Annual Review of Genetics 2011Sexual reproduction enables genetic exchange in eukaryotic organisms as diverse as fungi, animals, plants, and ciliates. Given its ubiquity, sex is thought to have... (Review)
Review
Sexual reproduction enables genetic exchange in eukaryotic organisms as diverse as fungi, animals, plants, and ciliates. Given its ubiquity, sex is thought to have evolved once, possibly concomitant with or shortly after the origin of eukaryotic organisms themselves. The basic principles of sex are conserved, including ploidy changes, the formation of gametes via meiosis, mate recognition, and cell-cell fusion leading to the production of a zygote. Although the basic tenants are shared, sex determination and sexual reproduction occur in myriad forms throughout nature, including outbreeding systems with more than two mating types or sexes, unisexual selfing, and even examples in which organisms switch mating type. As robust and diverse genetic models, fungi provide insights into the molecular nature of sex, sexual specification, and evolution to advance our understanding of sexual reproduction and its impact throughout the eukaryotic tree of life.
Topics: Aneuploidy; Chromosomes, Fungal; Evolution, Molecular; Fungi; Genes, Mating Type, Fungal; Genetic Loci; Germ Cells; Inheritance Patterns; Mitochondria; Mycelium; Recombination, Genetic; Reproduction; Sex Chromosomes; Signal Transduction; Spores, Fungal
PubMed: 21942368
DOI: 10.1146/annurev-genet-110410-132536 -
Trends in Microbiology Jun 2022In recent years, microfluidic technologies have become widespread in biological science. However, the suitability of this technique for understanding different aspects... (Review)
Review
In recent years, microfluidic technologies have become widespread in biological science. However, the suitability of this technique for understanding different aspects of spore research has hardly been considered. Herein, we review recent developments in 'spores-on-a-chip' technologies, highlighting how they could be exploited to drive new frontiers in spore research.
Topics: Lab-On-A-Chip Devices; Spores; Spores, Bacterial
PubMed: 35346553
DOI: 10.1016/j.tim.2022.03.003 -
International Journal of Nanomedicine 2022To present a safer tumor therapy based on bacteria and identify in detail how the activation and infection behavior of spores can be controlled remotely by near-infrared...
INTRODUCTION
To present a safer tumor therapy based on bacteria and identify in detail how the activation and infection behavior of spores can be controlled remotely by near-infrared light (NIR-irradiation) based on nanoheaters' modification.
METHODS
Spores bring a better tolerance to surface modification. Transitive gold-nanorods-allied-nanoclusters-modified spores (Spore@NRs/NCs) were constructed by covalent glutaraldehyde crosslink. The photothermal properties of nanoheaters before and after attachment to spores were studied by recording temperature-irradiation time curves. The controlled viability and infection behavior of Spore@NRs/NCs were investigated by NIR-irradiation.
RESULTS
In this work, a controllable sterilizing effect to activated vegetative bacteria was obtained obviously. When met with a suitable growth-environment, Spore@NRs/NCs could germinate, activate into vegetative bacteria and continue to reproduce. Without NIR-irradiation, nanoheaters could not affect the activity of both spores and vegetative bacterial cells. However, with NIR-irradiation after incubating in growth medium, nanoheaters on spores could control the spores' germination and affect the growth curve as well as the viability of the vegetative bacterial cells. For Spore@NRs/NCs (Spore:NCs:NRs=1:1:4, 67.5 μg mL), a ~98% killing rate of vegetative bacterial cells was obtained with NIR-irradiation (2.8 W cm, 20 min) after 2 h-incubation. In addition, these nanoheaters modified on spores could be taken not only to the vegetative bacteria cells, but also to the first-generation bacteria cells with their excellent photothermal and bactericidal performance, as well as synergetic anticancer effect. NIR-irradiation after 2 h-incubation could also trigger Spore@NRs/NCs (1:1:4, 6 μL) to synergistically reduce the viability of HCT116 cells to 15.63±2.90%.
CONCLUSION
By using NIR-irradiation, the "transitive" nanoheaters can remotely control the activity of both bacteria (germinated from spore) and cancer cells. This discovery provides basis and a feasible plan for controllable safer treatment of bacteria therapy, especially anaerobes with spores in hypoxic areas of the malignant solid tumors.
Topics: Humans; Spores; Bacteria; Temperature; Spores, Bacterial; Neoplasms
PubMed: 36545219
DOI: 10.2147/IJN.S385269 -
Journal of Applied Microbiology Feb 2019The purpose of this article is to highlight some areas of research with spores of bacteria of Firmicute species in which the methodology too commonly used is not optimal... (Review)
Review
The purpose of this article is to highlight some areas of research with spores of bacteria of Firmicute species in which the methodology too commonly used is not optimal and generates misleading results. As a consequence, conclusions drawn from data obtained are often flawed or not appropriate. Topics covered in the article include the following: (i) the importance of using well-purified bacterial spores in studies on spore resistance, composition, killing, disinfection and germination; (ii) methods for obtaining good purification of spores of various species; (iii) appropriate experimental approaches to determine mechanisms of spore resistance and spore killing by a variety of agents, as well as known mechanisms of spore resistance and killing; (iv) common errors made in drawing conclusions about spore killing by various agents, including failure to neutralize chemical agents before plating for viable spore enumeration, and equating correlations between changes in spore properties accompanying spore killing with causation. It is hoped that a consideration of these topics will improve the quality of spore research going forward.
Topics: Bacillales; Clostridiales; Drug Resistance, Bacterial; Spores, Bacterial
PubMed: 30106202
DOI: 10.1111/jam.14067 -
American Journal of Botany Dec 2022Approximately 14% of all fern species have physiologically active chlorophyllous spores that are much more short-lived than the more common and dormant achlorophyllous...
PREMISE
Approximately 14% of all fern species have physiologically active chlorophyllous spores that are much more short-lived than the more common and dormant achlorophyllous spores. Most chlorophyllous-spored species (70%) are epiphytes and account for almost 37% of all epiphytic ferns. Chlorophyllous-spored ferns are also overrepresented among fern species in habitats with waterlogged soils, of which nearly 60% have chlorophyllous spores. Ferns in these disparate habitat types also have a low incidence of mycorrhizal associations. We therefore hypothesized that autotrophic chlorophyllous spores represent an adaptation of ferns to habitats with scarce mycorrhizal associations.
METHODS
We evaluated the coevolution of chlorophyllous spores and mycorrhizal associations in ferns and their relation to habitat type using phylogenetic comparative methods.
RESULTS
Although we did not find support for the coevolution of spore type and mycorrhizal associations, we did find that chlorophyllous spores and the absence of mycorrhizal associations have coevolved with epiphytic and waterlogged habitats. Transition rates to epiphytic and waterlogged habitats were significantly higher in species with chlorophyllous spores compared to achlorophyllous lineages.
CONCLUSIONS
Spore type and mycorrhizal associations appear to play important roles in the radiation of ferns into different habitat types. Future work should focus on clarifying the functional significance of these associations.
Topics: Mycorrhizae; Ferns; Phylogeny; Spores, Fungal; Biological Evolution; Spores
PubMed: 36310350
DOI: 10.1002/ajb2.16094 -
Comptes Rendus Biologies 2011Over the decades, basic research in life sciences has profited greatly from the study of the small unicellular fungal species Saccharomyces cerevisiae. This yeast turned... (Review)
Review
Over the decades, basic research in life sciences has profited greatly from the study of the small unicellular fungal species Saccharomyces cerevisiae. This yeast turned out to be key for the identification and understanding of molecular mechanisms that underlay the basic functions of all eukaryotic cells. These include, but are not limited to, the regulatory mechanisms behind cellular reproduction (cell cycle control), cellular morphogenesis (cell polarity, cytoskeleton and membrane trafficking) and the management of cellular information (chromosome biology, transcription and translation). Rapid access to genomic information of many yeast species, combined with bioinformatics analyses, provide information on the evolutionary history of yeasts and the molecular ancestry of their constituents. The availability of a comprehensive list of experimental procedures for these organisms presents now a unique opportunity to learn about variations of molecular processes on an evolutionary scale. Yeast cell morphology is another interesting factor, since cellular shapes influence the interactions with the environment on all levels. In this overview article I provide a short summary of the relevant aspects of yeast cell morphology, in particular in relation to one of the most influencing processes, cellular reproduction by mating and meiosis.
Topics: Animals; Cell Division; Genes, Mating Type, Fungal; Humans; Morphogenesis; Saccharomycetales; Spores, Fungal; Yeasts
PubMed: 21819940
DOI: 10.1016/j.crvi.2011.05.007 -
Annual Review of Genetics Dec 2019species utilize a variety of sexual reproduction mechanisms, which generate genetic diversity, purge deleterious mutations, and contribute to their ability to occupy... (Review)
Review
species utilize a variety of sexual reproduction mechanisms, which generate genetic diversity, purge deleterious mutations, and contribute to their ability to occupy myriad environmental niches and exhibit a range of pathogenic potential. The bisexual and unisexual cycles of pathogenic species are stimulated by properties associated with their environmental niches and proceed through well-characterized signaling pathways and corresponding morphological changes. Genes governing mating are encoded by the mating-type () loci and influence pathogenesis, population dynamics, and lineage divergence in . has undergone significant evolutionary changes within the genus, including transition from the ancestral tetrapolar state in nonpathogenic species to a bipolar mating system in pathogenic species, as well as several internal reconfigurations. Owing to the variety of established sexual reproduction mechanisms and the robust characterization of the evolution of mating and in this genus, species provide key insights into the evolution of sexual reproduction.
Topics: Biological Evolution; Cryptococcus; Fungal Proteins; Genes, Mating Type, Fungal; Genetics, Population; Host-Pathogen Interactions; Humans; Reproduction; Spores, Fungal
PubMed: 31537103
DOI: 10.1146/annurev-genet-120116-024755 -
Journal of Applied Microbiology Sep 2006Bacterial endospores were first studied 130 years ago by Cohn in 1876 and independently by Koch in the same year. Although spore dormancy and resistance have been much...
Bacterial endospores were first studied 130 years ago by Cohn in 1876 and independently by Koch in the same year. Although spore dormancy and resistance have been much studied since then, questions still remain concerning the basic mechanisms and the kinetics of heat inactivation in particular. Likewise, the extreme dormancy and longevity of spores was recognized early on and later greatly extended but still evade complete understanding. Evidence has accumulated for the involvement of specific spore components such as calcium, dipicolinic acid, small acid soluble proteins in the core and peptidoglycan in the cortex. Involvement of physical factors too, such as the relative dehydration of the core, maybe in a high-viscosity state or even in a glassy state, has added to appreciation of the multicomponent nature of dormancy and resistance. Spore-former morphology formed the basis for early classification systems of sporeformers from about 1880 and consolidated in the mid-1900s, well prior to the use of modern genetic procedures. With respect to sporulation, groundbreaking sequence studies in the 1950s provided the basis for later elucidation of the genetic control widely relevant to many cell differentiation mechanisms. With respect to the breaking of dormancy (activation and germination), the elucidation of mechanisms began in the 1940s following the observations of Hills at Porton who identified specific amino acid and riboside 'germinants', and laid the basis for the later genetic analyses, the identification of germinant receptor genes and the elucidation of key germination reactions. The nonexponential nature of germination kinetics has thwarted the development of practical Tyndallization-like processing. So inactivation by heat remains the premier method of spore control, the basis of a huge worldwide industry, and still relying on the basic kinetics of inactivation of Clostridium botulinum spores, and the reasoning regarding safety first evolved by Bigelow et al. in 1920 and Esty and Meyer in 1922. 'Newer' processes such as treatment with ionizing radiation (first proposed in 1905) and high hydrostatic pressure (first proposed in 1899) may be introduced if consumer resistance and some remaining technical barriers could be overcome.
Topics: Cell Death; Genes, Bacterial; History, 19th Century; History, 20th Century; Hot Temperature; Hydrostatic Pressure; Radiation, Ionizing; Spores, Bacterial
PubMed: 16907801
DOI: 10.1111/j.1365-2672.2006.02888.x -
Acta Biochimica Et Biophysica Sinica Mar 2016Nosema bombycis is an obligate intracellular parasitic fungus that utilizes a distinctive mechanism to infect Bombyx mori. Germination, an indispensible process through...
Nosema bombycis is an obligate intracellular parasitic fungus that utilizes a distinctive mechanism to infect Bombyx mori. Germination, an indispensible process through which microsporidia infect the host cells, is regarded as a key developmental turning point for microsporidia from dormant state to reproduction state. Thus, elucidating the transcriptome changes before and after germination is crucial for parasite control. However, the molecular basis of germination of microsporidia remains unknown. To investigate this germination process, the transcriptome of N. bombycis ungerminated spores and germinated spores were sequenced and analyzed. More than 60 million high-quality transcript reads were generated from these two groups using RNA-Seq technology. After assembly, 2756 and 2690 unigenes were identified, respectively, and subsequently annotated based on known proteins. After analysis of differentially expressed genes, 66 genes were identified to be differentially expressed (P ≤ 0.05) between these two groups. A protein phosphatase-associated gene was first identified to be significantly up-regulated as determined by RNA-Seq and immunoblot analysis, indicating that dephosphorylation might potentially contribute to microsporidia germination. The DEGs that encode proteins involved in glycometabolism, spore wall proteins and ricin B lectin of N. bombycis were also analyzed. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses revealed genes responsible for some specific biological functions and processes. The datasets generated in this study provide a basic characterization of the transcriptome changes in N. bombycis during germination. The analysis of transcriptome data and identification of certain functional genes which are robust candidate genes related to germination will help to provide a deep understanding of spore germination and invasion.
Topics: Genes, Fungal; Germination; Nosema; Spores, Fungal; Transcriptome
PubMed: 26837419
DOI: 10.1093/abbs/gmv140