Bacillales: From Taxonomy to Biotechnological and Industrial Perspectives

Abstract

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.

Impacts of Groundwater Pumping on Subterranean Microbial Communities in a Deep Aquifer Associated with an Accretionary Prism

“…In addition, Rhodobacterales, Bacillales, and Bacteroidales belonging to the domain Bacteria were detected in the groundwater. These members of the bacterial groups possess the ability to grow by fermentation under anoxic environments [36][37][38]. The geothermal gradient around the deep well ranges from 25 • C to 30 • C km −1 [29].…”

“…Some species belonging to the order Natranaerobiales are able to use organic matter as an electron donor and thiosulfate as an electron acceptor [34,35]. In addition, Rhodobacterales, Bacillales, and Bacteroidales, which contain some species that can grow by fermentation in anoxic environments, were detected from groundwater sampled 0, 7, and 13 months after the initiation of groundwater pumping [36][37][38]. On the other hand, unclassified bacteria dominated in groundwater sampled 19 and 26 months after pumping initiation.…”

Bacillus megaterium: Evaluation of Chemical Nature of Metabolites and Their Antioxidant and Agronomics Properties

“…A total of 75 compounds were found to be present in BC extracts and not present in CS2 extracts, as illustrated in Table 3 for analysis without derivatization, and in Table 4 for analysis with derivatization. Some of these identified compounds were strictly found in BC extracts, suggesting a probable production by B. megaterium: 10 fatty acids derivatives (23 ′ , 32 ′ , 34 ′ , 39 ′ , 42 ′ , 44 ′ , 46 ′ , 47 ′ , 36, 44), 5 linear hydrocarbons (4,12,20,24,25), 5 cyclic hydrocarbons with 3 isomers (5,6,8,9,10,11,15,18), 6 amino acids (10 ′ , 12 ′ , 15 ′ , 18 ′ , 20 ′ , 22 ′ ), 2 dipeptides (29, 47), 2 cyclic dipeptides (46, 64), 6 aromatic hydrocarbons (1,16,26,27,31,33), 2 phthalates (59, 61), 2 sugar acids with 1 isomer (9 ′ , 24 ′ , 41 ′ ), 4 polyols with 1 isomer (2 ′ , 4 ′ , 5 ′ , 6 ′ , 21 ′ ), 2 cyclitols (29 ′ , 43 ′ ) and 17 others were identified (3,7,13,14,19,21,23,32,37,43,45,48,50,62, 63, 17 ′ , 38 ′ ). tr indicates integration inferior to 0.1 × 10 6 ; "ND": not detected.…”

“…In addition, the direct inoculation of responsible metabolites, like the antibiotics iturin A, surfactin and fengycin, instead of the entire organism has been shown to deliver positive results in several studies [17]. In addition, the production of metabolites from Bacillus is already used in industries other than agriculture: medical, chemical, or food industries [18].…”

“…In this regard, B. megaterium has already been commercialized for agricultural applications through its inoculation as a living organism [17]. But few B. megaterium metabolites have been described so far (phytohormones [20], antibiotic lipopeptides [21], vitamin B12 [22], siderophores [23], biopolymer [18], carotenoids [23], exopolysaccharides [24]) and valuated through their direct utilization for agriculture industry. In the present work, in order to identify its secondary metabolites related to plant growth promotion, a composition and activity analysis of B. megaterium filtrated supernatant was achieved through extraction, chemical family quantification, high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), antioxidant analysis and seed germination.…”