Description of Alicyclobacillus montanus sp. nov., a mixotrophic bacterium isolated from acidic hot springs

Abstract

Three morphologically similar thermo-acidophilic strains, USBA-GBX-501, USBA-GBX-502 and USBA-GBX-503, were isolated from acidic thermal springs at the National Natural Park Los Nevados (Colombia). All isolates were spore-forming, Gram-stain-positive and motile, growing aerobically at 25-55 °C (optimum ~45 °C) and at pH 1.5-4.5 (optimum pH ~3.0). Phylogenetic analysis of the 16S rRNA gene sequences of these isolates showed an almost identical sequence (99.0 % similarity) and they formed a robust cluster with the closest relative Alicyclobacillus tolerans DSM 16297 with a sequence similarity of 99.0 %. Average similarity to other species of the genus Alicyclobacillus was 93.0 % and average similarity to species of the genus Effusibacillus was 90 %. In addition, the level of DNA-DNA hybridization between strain USBA-GBX-503 and Alicyclobacillus tolerans DSM 16297 was 31.7 %. The genomic DNA G+C content of strain USBA-GBX-503 was 44.6 mol%. The only menaquinone was MK-7 (100.0 %). No ω-alicyclic fatty acids were detected in strain USBA-GBX-503, and the major cellular fatty acids were C18 : 1ω7c, anteiso-C17 : 0 and iso-C17 : 0. Based on phenotypic and chemotaxonomic characteristics, phylogenetic analysis and DNA-DNA relatedness values, along with low levels of identity at the whole genome level (ANIb and ANIm values of <67.0 and <91.0 %, respectively), it can be concluded that strain USBA-GBX-503 represents a novel species of the genus Alicyclobacillus, for which the name Alicyclobacillus montanus sp. nov. is proposed. The type strain is USBA-GBX-503 (=CMPUJ UGB U503=CBMAI1927).

Microbial communities in freshwater used for hydraulic fracturing are unable to withstand the high temperatures and pressures characteristic of fractured shales

“…1 ), we note that strains of this spore-forming genus have long been known as spoilage bacteria that evade conventional heat treatment preservation methods in the beverage industry [ 41 ]. Further, Alicyclobacillus montanus was isolated from acidic hot springs in Colombia with an optimal temperature of ~45 °C [ 42 ], in line with the temperatures used in our incubations. Taken together, our findings suggest that lineages conventionally associated with pathogenesis ( Chryseobacterium ) and beverage spoilage ( Alicyclobacillus ) are likely to be widespread in the environment, including the freshwater used in these experiments.…”

Salifodinibacter halophilus gen. nov., sp. nov., a halophilic gammaproteobacterium in the family Salinisphaeraceae isolated from a salt mine in the Colombian Andes

“…For all experimental assays, the growth of strains USBA 874 and USBA 960 T was evaluated in modified 142A medium (per litre of distilled water [9]): 19.5 % (w/v) NaCl, 1.0 g (NH 4 ) 2 SO 4 , 0.05 g K 2 HPO 4 , 1.5 g MgSO 4 ·7H 2 O, 0.42 g CaCl 2 ·2H 2 O, 0.05 NaHCO 3 and 0.64 g KCl and supplemented with 1 ml ml −1 of the oligoelement solution SL10, 2.0 g casamino acids and 1.0 g yeast extract. Unless otherwise indicated, the morphological observations and biochemical evaluations were performed in triplicate following protocols described previously [19].…”

Thermoacidophilic Alicyclobacillus Superoxide Dismutase: Good Candidate as Additives in Food and Medicine

“…Comparing with its thermostability, the acidic tolerance of SOD is far less addressed, since few species of SOD are enzymatically stable under extremely acidic conditions (Ken et al, 2005). Alicyclobacillus strains are heterotrophic organisms that mostly inhabit acidic geothermal environments such as hot springs and acid mine waters (Zhang et al, 2015;López et al, 2018). As an extraordinary resource for exploring unique enzymes with acidophilic and (or) thermophilic properties, the Alicyclobacillus isolates are of great interests in recent years because of their double physiological characteristics of acidophilic and thermotolerant (McKnight et al, 2010).…”