Natrialbales
Natrialbales is an order of halophilic, chemoorganotrophic archaea within the class Haloarchaea. The type genus of this order is "Natrialba." The name "Natrialbales" is derived from the Latin term "Natriabla," referring to the type genus of the order and the suffix "-ales," an ending used to denote an order. Together, "Natrialbales" refers to an order whose nomenclatural type is the genus "Natrialba." Biochemical Characteristics and Molecular Signatures. Members are halophilic chemoorganotrophs and are mainly isolated from high-salt environments such as saline lakes, soda lakes and salted hides. Some members are motile. Morphology is variable, including rod, coccus or  pleomorphic shapes. Majority of the class are able to grow optimally in alkaline pH and do not possess gas vesicles. The DNA G+C content for this order ranges between 60-70 mol%. This order can be reliably distinguished from other orders within the phylum Euryarchaeota by the presence of eight conserved signature proteins (CSPs) and two conserved signature indels (CSIs) present in the ribosomal operon protein and small GTP-binding protein. Historical Systematics and Current Taxonomy. As of 2021, "Natrialbales" contains one family, "Natrialbaceae". Members of this order was demarcated from the class Halobacteria, previously a large phylogenetically unrelated group  of species with distinct biochemical characteristics and different ecological niches. 16S rRNA based phylogenetic trees and morphological/physiological characteristics were not sufficient to clarify the evolutionary relationship above the genus level within the class Halobacteria. In 2015, Gupta et al. proposed the division of the class Halobacteria into "Halobacteriales, Haloferacales and Natrialbales" based on comparative genomic analyses and the branching pattern of various phylogenetic trees constructed from several different datasets of conserved proteins and 16S rRNA sequences. Molecular markers, specifically conserved signature indels, specific to this order were also identified as evidence supporting the division independent of phylogenetic trees. Natrialbales