Judicial Opinion 129.

Opinion 129 addresses the status of Firmicutes corrig. Gibbons and Murray 1978 (Approved Lists 1980). The name has the category 'division' and was included in the Approved Lists of Bacterial Names, although that category had previously been removed from the International Code of Nomenclature of Bacteria (1975 revision onwards). When the category 'phylum' was introduced into the International Code of Nomenclature of Prokaryotes (ICNP) in 2021, equivalence between 'phylum' and 'division' was not stipulated. Since the definition of the taxonomic categories and their relative order is one of the principal tasks of every code of nomenclature, the inclusion of Firmicutes corrig. Gibbons and Murray 1978 in the Approved Lists was an error. The name is either not validly published or illegitimate because its category is not covered by the ICNP. If Firmicutes corrig. Gibbons and Murray 1978 (Approved Lists 1980) was a validly published phylum name, it would be illegitimate because it would contravene Rule 8, which does not permit any deviation from the requirement to derive a phylum name from the name of the type genus. Since Firmicutes corrig. Gibbons and Murray 1978 is also part of a 'misfitting megaclassification' recognized in Opinion 128, the name is rejected, without any pre-emption regarding a hypothetically validly published name Firmicutes at the rank of phylum. Gracilicutes Gibbons and Murray 1978 (Approved Lists 1980) and Anoxyphotobacteriae Gibbons and Murray 1978 (Approved Lists 1980) are also rejected. The validly published phylum names have a variety of advantages over their not validly published counterparts and cannot be replaced with ad hoc names suggested in the literature. To ease the transition, it is recommended to mention the not validly published phylum names which strongly deviate in spelling from their validly published counterparts along with the latter in publications during the next years.

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.

Rarity of Pseudomonas agarici on Edible Mushrooms Associated with Susceptibility to Biological Competition.

Taxonomically diverse Pseudomonas species induce bacterial blotch of edible mushrooms around the world. Pseudomonas tolaasii, [P. gingeri], and P. agarici are dominant mycopathogenic pseudomonads in mushroom production farms. In this study, among 216 mycopathogenic bacterial strains isolated from edible mushrooms in Iran, 96 strains were identified as Pseudomonas spp., while only three strains were preliminarily identified as P. agarici. Multilocus sequence analysis showed that only one strain (FH2) authentically belonged to P. agarici, while the other two strains either belonged to [P. gingeri] or represented a unique phylogenetic clade. The three strains also differed from each other in phenotypic characteristics, for example, production of fluorescent pigment and the reaction to tolaasin produced by P. tolaasii. Pathogenicity assays under a controlled environment showed that the symptoms induced by authentic P. agarici were far less severe than those caused by the predominant species P. tolaasii. Furthermore, coinoculation of P. agarici with three bacterial pathogens that are prevalent in Iran on mushroom caps, that is, P. tolaasii, Ewingella americana, and Mycetocola sp., resulted in the development of combined symptoms representing characteristics of both pathogens. The antibiosis assay showed that tolaasin-producing strains of P. tolaasii could inhibit the growth of P. agarici, while tolaasin-negative strains of the same species were unable to do so. This led us to the hypothesis that the inhibitory effect of P. tolaasii on P. agarici is driven by tolaasin production in the former species. This inhibitory effect is also associated with the rarity of P. agarici in natural conditions.

Multilocus sequence and phenotypic analysis of Pectobacterium and Dickeya type strains for identification of soft rot Pectobacteriaceae from symptomatic potato stems and tubers in Pennsylvania.

Outbreaks of potato blackleg and soft rot caused by Pectobacterium species and more recently Dickeya species across the U.S. mid-Atlantic region have caused yield loss due to poor emergence as well as losses from stem and tuber rot. To develop management strategies for soft rot diseases, we must first identify which members of the soft rot Pectobacteriaceae are present in regional potato plantings. However, the rapidly expanding number of soft rot Pectobacteriaceae species and the lack of readily available comparative data for type strains of Pectobacterium and Dickeya hinder quick identification. This manuscript provides a comparative analysis of soft rot Pectobacteriaceae and a comprehensive comparison of type strains from this group using rep-PCR, MLSA and 16S sequence analysis, as well as phenotypic and physiological analyses using Biolog GEN III plates. These data were used to identify isolates cultured from symptomatic potato stems collected between 2016 and 2018. The isolates were characterized for phenotypic traits and by sequence analysis to identify the bacteria from potatoes with blackleg and soft rot symptoms in Pennsylvania potato fields. In this survey, P. actinidiae, P. brasiliense, P. polonicum, P. polaris, P. punjabense, P. parmentieri, and P. versatile were identified from Pennsylvania for the first time. Importantly, the presence of P. actinidiae in Pennsylvania represents the first report of this organism in the U.S. As expected, P. carotorvorum and D. dianthicola were also isolated. In addition to a resource for future work studying the Dickeya and Pectobacterium associated with potato blackleg and soft rot, we provide recommendations for future surveys to monitor for quarantine or emerging soft rot Pectobacteriace regionally.