Bacillales: From Taxonomy to Biotechnological and Industrial Perspectives.

For a long time, the genus Bacillus has been known and considered among the most applicable genera in several fields. Recent taxonomical developments resulted in the identification of more species in Bacillus-related genera, particularly in the order Bacillales (earlier heterotypic synonym: Caryophanales), with potential application for biotechnological and industrial purposes such as biofuels, bioactive agents, biopolymers, and enzymes. Therefore, a thorough understanding of the taxonomy, growth requirements and physiology, genomics, and metabolic pathways in the highly diverse bacterial order, Bacillales, will facilitate a more robust designing and sustainable production of strain lines relevant to a circular economy. This paper is focused principally on less-known genera and their potential in the order Bacillales for promising applications in the industry and addresses the taxonomical complexities of this order. Moreover, it emphasizes the biotechnological usage of some engineered strains of the order Bacillales. The elucidation of novel taxa, their metabolic pathways, and growth conditions would make it possible to drive industrial processes toward an upgraded functionality based on the microbial nature.

When treated as heterotypic synonyms the names Caryophanaceae Peshkoff 1939 (Approved Lists 1980) and Caryophanales Peshkoff 1939 (Approved Lists 1980) have priority over the names Planococcaceae Krasil'nikov 1949 (Approved Lists 1980) and Bacillales Prévot 1953 (Approved Lists 1980), respectively.

The International Code of Nomenclature of Prokaryotes provides rules that govern the way names are to be selected based on priority of valid publication when two or more alternatives (synonyms) are available. However, these rules are not always followed. In the case of the name CaryophanaceaePeshkoff 1939 (Approved Lists 1980), when its nomenclatural type CaryophanonPeshkoff 1939 (Approved Lists 1980) is placed in the same taxon as PlanococcusMigula 1894 (Approved Lists 1980), the nomenclatural type of PlanococcaceaeKrasil'nikov 1949 (Approved Lists 1980), then the two are considered to be heterotypic synonyms and the name which has priority is CaryophanaceaePeshkoff 1939 (Approved Lists 1980). Similarly in the case of the name CaryophanalesPeshkoff 1939 (Approved Lists 1980) when its nomenclatural type CaryophanonPeshkoff 1939 (Approved Lists 1980) is placed in the same taxon as Bacillus Cohn 1872 (Approved Lists 1980), the nomenclatural type of BacillalesPrévot 1953 (Approved Lists 1980), then the two are considered to be heterotypic synonyms and the name which has priority is CaryophanalesPeshkoff 1939 (Approved Lists 1980) While the rules of the International Code of Nomenclature of Prokaryotes are unambiguous in determining the correct names despite the fact that the names CaryophanaceaePeshkoff 1939 (Approved Lists 1980) and CaryophanalesPeshkoff 1939 (Approved Lists 1980) are rarely used.