Proposals to revise the Statutes of the International Committee on Systematics of Prokaryotes.

The International Committee on Systematics of Prokaryotes serves to administer the rules of prokaryotic nomenclature via the International Code of Nomenclature of Prokaryotes, ensures the publication of the International Journal of Systematic and Evolutionary Microbiology, and works to represent the interests of the microbiological disciplines regarding prokaryotic nomenclature. The functions and mechanisms of operation of the International Committee on Systematics of Prokaryotes (ICSP) are defined in its Statutes, which were last revised in 2019. As members of the 2020-2023 and the 2023-2026 ICSP Executive Board and the Judicial Commission, we propose here some further revisions to help improve the clarity and functionality of the Statutes.

Judicial Opinion 130.

Opinion 130 deals with a Request for an Opinion asking the Judicial Commission to clarify whether the genus name Rhodococcus Zopf 1891 (Approved Lists 1980) is illegitimate. The Request is approved and an answer is given. The name Rhodococcus Zopf 1891 (Approved Lists 1980) is illegitimate because it is a later homonym of the validly published cyanobacterial name Rhodococcus Hansgirg 1884. The Judicial Commission also clarifies that it has the means to resolve such cases by conserving a name over an earlier homonym. It is concluded that the name Rhodococcus Zopf 1891 (Approved Lists 1980) is significantly more important than the name Rhodococcus Hansgirg 1884 and therefore the former is conserved over the latter. This makes the name Rhodococcus Zopf 1891 (Approved Lists 1980) legitimate.

Formation of compound generic names based on personal names: a proposal for emendation of Appendix 9 of the International Code of Nomenclature of Prokaryotes.

Appendix 9, the orthography appendix of the International Code of Nomenclature of Prokaryotes, provides guidelines for the correct formation of generic names and specific epithets to honour famous microbiologists and other persons connected with natural science. However, no guidelines are given for the correct formation of compound generic names in which the first word element is derived from a personal name. Currently there are 16 such names validly published under the Rules of the Code, but the ways they were formed are inconsistent. We therefore propose an emendation of Appendix 9 to provide uniform guidelines for the formation of such names in the future.

Naming classes of prokaryotes based on the rules of Latin grammar.

Recently a proposal was published to unify Rules 7, 8 and 9 of the International Code of Nomenclature of Prokaryotes. Based on this proposal, all names of taxa above the rank of genus must be in the feminine gender, the plural number. For the rank of class, this proposal contravenes Principle 3 of the Code, which states that the scientific names of all taxa are treated as Latin. The -ia ending of most names of classes belongs to nominative plural nouns of the neuter gender.

Request for revision of the Statutes of the International Committee on Systematics of Prokaryotes.

At the Valencia Plenary meeting on 7-9 July, 2017, the Working Group on the organization and structure of the ICSP recommended amendment of the Statutes of the ICSP (Dijkshoorn L. Int J Syst Evol Microbiol 2018; 68: 2104-2110). In October 2017, our Executive-Secretary, Lenie Dijkshoorn, sent out a call for participation in this working group, which began work in December, 2017. The members included William B. Whitman, Carolee Bull, Hans-Jürgen Busse, Pierre-Edouard Fournier, Aharon Oren, and Stefano Ventura. During the Winter and Spring, 2018, a large number of revisions were discussed by the working group. In addition, comments were solicited from Dan Brown [Secretary for Subcommittees on Taxonomy], Iain Sutcliffe [Chair ICSP], Fanus Venter [Member at Large, EB-ICSP], and Martha Trujillo [Editor-in-Chief of IJSEM]. The draft Statutes were then presented to the Executive Board [EB] at its online meeting on May 31, 2018. The EB asked that the working group circulate the draft to the members of the ICSP for comments for 45 days and that comments be returned by July 27, 2018. After that time, the working group incorporated additional suggestions before the final submission to IJSEM for publication. According to our current statutes, there will then be a period of 90 days following publication for further deliberation before a vote by the ICSP members.

Taxonomic resolution of the genus Cyanothece (Chroococcales, Cyanobacteria), with a treatment on Gloeothece and three new genera, Crocosphaera, Rippkaea, and Zehria.

The systematics of single-celled cyanobacteria represents a major challenge due to morphological convergence and application of various taxonomic concepts. The genus Cyanothece is one of the most problematic cases, as the name has been applied to oval-shaped coccoid cyanobacteria lacking sheaths with little regard to their phylogenetic position and details of morphology and ultrastructure. Hereby we analyze an extensive set of complementary genetic and phenotypic evidence to disentangle the relationships among these cyanobacteria. We provide diagnostic characters to separate the known genera Cyanothece, Gloeothece, and Aphanothece, and provide a valid description for Crocosphaera gen. nov. We describe two new genera, Rippkaea and Zehria, to characterize two distinct phylogenetic lineages outside the previously known genera. We further describe 13 new species in total including Cyanothece svehlovae, Gloeothece aequatorialis, G. aurea, G. bryophila, G. citriformis, G. reniformis, Gloeothece tonkinensis, G. verrucosa, Crocosphaera watsonii, C. subtropica, C. chwakensis, Rippkaea orientalis, and Zehria floridana to recognize the intrageneric diversity as rendered by polyphasic analysis. We discuss the close relationship of free-living cyanobacteria from the Crocosphaera lineage to nitrogen-fixing endosymbionts of marine algae. The current study includes several experimental strains (Crocosphaera and "Cyanothece") important for the study of diazotrophy and the global oceanic nitrogen cycle, and provides evidence suggesting ancestral N2 -fixing capability in the chroococcalean lineage.

Proposal of the suffix -ota to denote phyla. Addendum to 'Proposal to include the rank of phylum in the International Code of Nomenclature of Prokaryotes'.

As an addendum to the earlier proposal to include the rank of phylum in the International Code of Nomenclature of Prokaryotes (Oren et al., Int J Syst Evol Microbiol 2015;65:4284-4287) we propose the suffix -ota to denote phyla, replacing the somewhat awkward -aeota. We therefore present a new draft modified version of Rule 8 of the International Code of Nomenclature of Prokaryotes and a corrected list of names of phyla to be considered for validation after approval of the proposal to include the rank of phylum in the Code.

'Localimania' revisited: guidelines for the formation of specific epithets for names of prokaryotes based on names of institutions or their acronyms. A proposal for emendation of Appendix 9 to the International Code of Nomenclature of Prokaryotes.

We here present a survey of the increasing use of the -ensis (-ense) ending for the formation of specific epithets that do not refer to geographical locations but to names of research institutes or their acronyms. To our opinion the use of the -ensis (-ense) ending must be discouraged for such purposes, the formation of nouns in the genitive case being preferred for the formation of such arbitrary epithets. Emendation of Appendix 9 - Orthography to the International Code of Nomenclature of Prokaryotes is proposed with guidelines for the formation of such names.

The current status of cyanobacterial nomenclature under the "prokaryotic" and the "botanical" code.

Cyanobacterial taxonomy developed in the botanical world because Cyanobacteria/Cyanophyta have traditionally been identified as algae. However, they possess a prokaryotic cell structure, and phylogenetically they belong to the Bacteria. This caused nomenclature problems as the provisions of the International Code of Nomenclature for algae, fungi, and plants (ICN; the "Botanical Code") differ from those of the International Code of Nomenclature of Prokaryotes (ICNP; the "Prokaryotic Code"). While the ICN recognises names validly published under the ICNP, Article 45(1) of the ICN has not yet been reciprocated in the ICNP. Different solutions have been proposed to solve the current problems. In 2012 a Special Committee on the harmonisation of the nomenclature of Cyanobacteria was appointed, but its activity has been minimal. Two opposing proposals to regulate cyanobacterial nomenclature were recently submitted, one calling for deletion of the cyanobacteria from the groups of organisms whose nomenclature is regulated by the ICNP, the second to consistently apply the rules of the ICNP to all cyanobacteria. Following a general overview of the current status of cyanobacterial nomenclature under the two codes we present five case studies of genera for which nomenclatural aspects have been discussed in recent years: Microcystis, Planktothrix, Halothece, Gloeobacter and Nostoc.

Cytotoxicity evaluation of large cyanobacterial strain set using selected human and murine in vitro cell models.

The production of cytotoxic molecules interfering with mammalian cells is extensively reported in cyanobacteria. These compounds may have a use in pharmacological applications; however, their potential toxicity needs to be considered. We performed cytotoxicity tests of crude cyanobacterial extracts in six cell models in order to address the frequency of cyanobacterial cytotoxicity to human cells and the level of specificity to a particular cell line. A set of more than 100 cyanobacterial crude extracts isolated from soil habitats (mainly genera Nostoc and Tolypothrix) was tested by MTT test for in vitro toxicity on the hepatic and non-hepatic human cell lines HepG2 and HeLa, and three cell systems of rodent origin: Yac-1, Sp-2 and Balb/c 3T3 fibroblasts. Furthermore, a subset of the extracts was assessed for cytotoxicity against primary cultures of human hepatocytes as a model for evaluating potential hepatotoxicity. Roughly one third of cyanobacterial extracts caused cytotoxic effects (i.e. viability<75%) on human cell lines. Despite the sensitivity differences, high correlation coefficients among the inhibition values were obtained for particular cell systems. This suggests a prevailing general cytotoxic effect of extracts and their constituents. The non-transformed immortalized fibroblasts (Balb/c 3T3) and hepatic cancer line HepG2 exhibited good correlations with primary cultures of human hepatocytes. The presence of cytotoxic fractions in strongly cytotoxic extracts was confirmed by an activity-guided HPLC fractionation, and it was demonstrated that cyanobacterial cytotoxicity is caused by a mixture of components with similar hydrophobic/hydrophilic properties. The data presented here could be used in further research into in vitro testing based on human models for the toxicological monitoring of complex cyanobacterial samples.

Bacterial communities involved in soil formation and plant establishment triggered by pyrite bioweathering on arctic moraines.

In arctic glacier moraines, bioweathering primed by microbial iron oxidizers creates fertility gradients that accelerate soil development and plant establishment. With the aim of investigating the change of bacterial diversity in a pyrite-weathered gradient, we analyzed the composition of the bacterial communities involved in the process by sequencing 16S rRNA gene libraries from different biological soil crusts (BSC). Bacterial communities in three BSC of different morphology, located within 1 m distance downstream a pyritic conglomerate rock, were significantly diverse. The glacier moraine surrounding the weathered site showed wide phylogenetic diversity and high evenness with 15 represented bacterial classes, dominated by Alphaproteobacteria and pioneer Cyanobacteria colonizers. The bioweathered area showed the lowest diversity indexes and only nine bacterial families, largely dominated by Acidobacteriaceae and Acetobacteraceae typical of acidic environments, in accordance with the low pH of the BSC. In the weathered BSC, iron-oxidizing bacteria were cultivated, with counts decreasing along with the increase of distance from the rock, and nutrient release from the rock was revealed by environmental scanning electron microscopy-energy dispersive X-ray analyses. The vegetated area showed the presence of Actinomycetales, Verrucomicrobiales, Gemmatimonadales, Burkholderiales, and Rhizobiales, denoting a bacterial community typical of developed soils and indicating that the lithoid substrate of the bare moraine was here subjected to an accelerated colonization, driven by iron-oxidizing activity.

Cytotoxicity and secondary metabolites production in terrestrial Nostoc strains, originating from different climatic/geographic regions and habitats: is their cytotoxicity environmentally dependent?

Extensive selection of cyanobacterial strains (82 isolates) belonging to the genus Nostoc, isolated from different climatic regions and habitats, were screened for both their secondary metabolite content and their cytotoxic effects to mammalian cell lines. The overall occurrence of cytotoxicity was found to be 33%, which corresponds with previously published data. However, the frequency differs significantly among strains, which originate from different climatic regions and microsites (particular localities). A large fraction of intensely cytotoxic strains were found among symbiotic strains (60%) and temperate and continental climatic isolates (45%); compared with the less significant incidences in strains originating from cold regions (36%), deserts (14%), and tropical habitats (9%). The cytotoxic strains were not randomly distributed; microsites that clearly had a higher occurrence of cytotoxicity were observed. Apparently, certain natural conditions lead to the selection of cytotoxic strains, resulting in a high cytotoxicity occurrence, and vice versa. Moreover, in strains isolated from a particular microsite, the cytotoxic effects were caused by different compounds. This result supports our hypothesis for the environmental dependence of cytotoxicity. It also contradicts the hypothesis that clonality and lateral gene transfer could be the reason for this phenomenon. Enormous variability in the secondary metabolites was detected within the studied Nostoc extracts. According to their molecular masses, only 26% of these corresponded to any known structures; thus, pointing to the high potential for the use of many terrestrial cyanobacteria in both pharmacology and biotechnology.

Non-reducible knee dislocation with interposition of the vastus medialis muscle.

Irreducibility of the knee following complete dislocation is a rare event determined by the interposition of various capsulo-ligamentous structures in the joint space. Such cases often require urgent surgical treatment. We report the case of a healthy 70-year-old man with a sprain of the left knee that occurred after a sports trauma. The patient showed knee dislocation with multiple ligamentous injuries and articular block due to interposition of a portion of the vastus medialis muscle. After arthroscopic evaluation, we performed surgical treatment to free the muscle, regularize the medial meniscus and suture the posterior and medial capsule and ligaments; the cruciate ligaments were not treated. The most interesting aspect of the articular damage in this case was a wide detachment of the vastus medialis muscle with intra-articular dislocation. The decision to treat only the posterior lesions and allow the healing of the front ones by rehabilitation treatment was supported by full functional recovery and return to sports activity.

Highly differentiated soil bacterial communities in Victoria Land macro-areas (Antarctica).

Ice-free areas of Victoria Land, in Antarctica, are characterized by different terrestrial ecosystems, that are dominated by microorganisms supporting highly adapted communities. Despite the unique conditions of these ecosystems, reports on their bacterial diversity are still fragmentary. From this perspective, 60 samples from 14 localities were analyzed. These localities were distributed in coastal sites with differently developed biological soil crusts, inner sites in the McMurdo Dry Valleys with soils lacking of plant coverage, and a site called Icarus Camp, with a crust developed on a thin locally weathered substrate of the underlying parent granitic-rock. Bacterial diversity was studied through 16S rRNA metabarcoding sequencing. Communities diversity, composition and the abundance and composition of different taxonomic groups were correlated to soil physicochemical characteristics. Firmicutes, Bacteroidetes, Cyanobacteria and Proteobacteria dominated these communities. Most phyla were mainly driven by soil granulometry, an often disregarded parameter and other abiotic parameters. Bacterial composition differed greatly among the three macrohabitats, each having a distinct bacterial profile. Communities within the two main habitats (coastal and inner ones) were well differentiated from each other as well, therefore depending on site-specific physicochemical characteristics. A core community of the whole samples was observed, mainly represented by Firmicutes and Bacteroidetes.

Rock weathering creates oases of life in a high Arctic desert.

During primary colonization of rock substrates by plants, mineral weathering is strongly accelerated under plant roots, but little is known on how it affects soil ecosystem development before plant establishment. Here we show that rock mineral weathering mediated by chemolithoautotrophic bacteria is associated to plant community formation in sites recently released by permanent glacier ice cover in the Midtre Lovénbreen glacier moraine (78 degrees 53'N), Svalbard. Increased soil fertility fosters growth of prokaryotes and plants at the boundary between sites of intense bacterial mediated chemolithotrophic iron-sulfur oxidation and pH decrease, and the common moraine substrate where carbon and nitrogen are fixed by cyanobacteria. Microbial iron oxidizing activity determines acidity and corresponding fertility gradients, where water retention, cation exchange capacity and nutrient availability are increased. This fertilization is enabled by abundant mineral nutrients and reduced forms of iron and sulfur in pyrite minerals within a conglomerate type of moraine rock. Such an interaction between microorganisms and moraine minerals determines a peculiar, not yet described model for soil genesis and plant ecosystem formation with potential past and present analogues in other harsh environments with similar geochemical settings.

Biodiversity of phototrophic biofilms dwelling on monumental fountains.

Among the stone monumental assets, artistic fountains are particularly affected by microbial colonization due to constant contact with water, giving rise to biodegradation processes related with physical-chemical and aesthetical alterations. In this paper, we make an overview of reported biodiversity of the phototrophic patina developed in various fountains of Italy and Spain. The microbial composition of four fountains (two from Florence, Italy and two from Granada, Spain) was investigated using traditional and/or molecular techniques. The results indicated many common similarities with regard the phototrophic biodiversity for all the investigated fountains. Automated ribosomal RNA intergenic spacer analysis (ARISA), a molecular fingerprint tool, was used to examine the eubacterial and cyanobacterial community for two of the investigated fountains. The principal component analysis of ARISA profiles strengthens the results obtained by traditional methods and revealed separate clusters, as a consequence of the differences of micro-environmental conditions for each fountain.

The stage of soil development modulates rhizosphere effect along a High Arctic desert chronosequence.

In mature soils, plant species and soil type determine the selection of root microbiota. Which of these two factors drives rhizosphere selection in barren substrates of developing desert soils has, however, not yet been established. Chronosequences of glacier forelands provide ideal natural environments to identify primary rhizosphere selection factors along the changing edaphic conditions of a developing soil. Here, we analyze changes in bacterial diversity in bulk soils and rhizospheres of a pioneer plant across a High Arctic glacier chronosequence. We show that the developmental stage of soil strongly modulates rhizosphere community assembly, even though plant-induced selection buffers the effect of changing edaphic factors. Bulk and rhizosphere soils host distinct bacterial communities that differentially vary along the chronosequence. Cation exchange capacity, exchangeable potassium, and metabolite concentration in the soil account for the rhizosphere bacterial diversity. Although the soil fraction (bulk soil and rhizosphere) explains up to 17.2% of the variation in bacterial microbiota, the soil developmental stage explains up to 47.7% of this variation. In addition, the operational taxonomic unit (OTU) co-occurrence network of the rhizosphere, whose complexity increases along the chronosequence, is loosely structured in barren compared with mature soils, corroborating our hypothesis that soil development tunes the rhizosphere effect.

The last 50 years of climate-induced melting of the Maliy Aktru glacier (Altai Mountains, Russia) revealed in a primary ecological succession.

In this article, we report and discuss the results obtained from a survey of plants, microorganisms (bacteria and fungi), and soil elements along a chronosequence in the first 600 m of the Maliy Aktru glacier's forefront (Altai Mountains, Russia). Many glaciers of the world show effects of climate change. Nonetheless, except for some local reports, the ecological effects of deglaciation have been poorly studied and have not been quantitatively assessed in the Altai Mountains. Here, we studied the ecological changes of plants, fungi, bacteria, and soil elements that take the form of a primary ecological succession and that took place over the deglaciated soil of the Maliy Aktru glacier during the last 50 year. According to our measurements, the glacier lost about 12 m per year during the last 50 years. Plant succession shows clear signs of changes along the incremental distance from the glacier forefront. The analysis of the plant α- and ß-diversity confirmed an expected increase of them with increasing distance from the glacier forefront. Moreover, the analysis of ß-diversity confirmed the hypothesis of the presence of three main stages of the plant succession: (a) initial (pioneer species) from 30 to 100 m; (b) intermediate (r-selected species) from 110 to 120-150 m; and (c) final (K-selected species) from 150 to 550. Our study also shows that saprotrophic communities of fungi are widely distributed in the glacier retreating area with higher relative abundances of saprotroph ascomycetes at early successional stages. The evolution of a primary succession is also evident for bacteria, soil elements, and CO 2 emission and respiration. The development of biological communities and the variation in geochemical parameters represent an irrefutable proof that climate change is altering soils that have been long covered by ice.

An Organizational Perspective to the Creation of the Research Field.

The aim of the paper is to contribute to the definition and analysis of the "access to the field" (Feldman et al. 2003) through an inter-organizational perspective. The paper discusses a case study on the access of a researcher to a hospital department where both organizations and actors are shown as actively constructing the research site. Both researcher and participants are described in terms of work organizations originally engaged in parallel systems of activity. Dynamics of negotiation "tied" the different actors' activities in a new activity system where researcher and participants concur to the effectiveness of both organizations (i.e., the research and the hospital ward). An Activity Theory perspective (Leont'ev 1978) is used with the aim of focusing the analysis on the activities in charge to the different actors. The approach adopted introduces the idea that, from the outset, research is made possible by a process of co-construction that works through the development of a completely new and shared work space arising around the encounter between researchers and participants. It is the balance between improvised actions and the co-creation of "boundary objects" (Star and Griesemer 1989), which makes interlacement possible between the two activity systems. The concept of "knotworking" (Engeström 2007a) is adopted to interpret specific actions by both organizations and actors intended to build a knot of activities whereby the new research system takes place.

Fungal Biodiversity in the Alpine Tarfala Valley.

Biological soil crusts (BSCs) are distributed worldwide in all semiarid and arid lands, where they play a determinant role in element cycling and soil development. Although much work has concentrated on BSC microbial communities, free-living fungi have been hitherto largely overlooked. The aim of this study was to examine the fungal biodiversity, by cultural-dependent and cultural-independent approaches, in thirteen samples of Arctic BSCs collected at different sites in the Alpine Tarfala Valley, located on the slopes of Kebnekaise, the highest mountain in northern Scandinavia. Isolated fungi were identified by both microscopic observation and molecular approaches. Data revealed that the fungal assemblage composition was homogeneous among the BSCs analyzed, with low biodiversity and the presence of a few dominant species; the majority of fungi isolated belonged to the Ascomycota, and Cryptococcus gilvescens and Pezoloma ericae were the most frequently-recorded species. Ecological considerations for the species involved and the implication of our findings for future fungal research in BSCs are put forward.