Renaming of 'Candidatus Methylocucumis oryzae' as Methylocucumis oryzae gen. nov., sp. nov., a novel Type I methanotroph isolated from India.

Abstract

Candidatus Methylocucumis (Mcu.) oryzae, strain Sn10-6, a Gram-negative, pale pink pigmented, motile, large Type I methanotroph (3-6 µm × 1.5-2 µm) was recently isolated from an Indian rice field. Due to the difficulties in preservation of the strain it could not be deposited and preserved in two recognised culture collections with public access located in two different countries. Hence, Sn10-6 was described as a member of a Candidatus genus and species, 'Ca. Mcu. oryzae'. Subsequent to the publication, the strain has been preserved in the Japan Collection of Microorganisms, Japan (JCM 32869T) in addition to its earlier preservation in the Korean collection for type cultures, KCTC, Korea and in National Centre for Microbial Resources, India. Addition of DMSO as a cryopreserving agent proved to be useful in the preservation of the strain. The deposition of the strain in two recognised culture collections in two different countries and additionally in the home country repository makes the strain eligible to be proposed as the type strain of the type species of a new genus and species with the name Methylocucumis oryzae strain Sn10-6T. In this paper we formally propose the name Mcu. oryzae, with Sn10-6T as the type strain, for the earlier described Ca. Mcu. oryzae. Other characteristics including the digital protologue of the culture (CA00040) remain the same as described earlier for Ca. Mcu. oryzae (Pandit et al. in Antonie Van Leeuwenhoek 111:2473-2484, 2018). Mcu. oryzae Sn10-6T (= MCC 3492 = KCTC 15683 = JCM 32869) represents a new genus and species within the family Methylococcaceae of the class Gammaproteobacteria.