Alteribacter keqinensis sp. nov., a moderately halophilic bacterium isolated from a soda lake

Abstract

A Gram-stain-positive, aerobic, endospore-forming and rod-shaped bacterium (KQ-3T), which grew at 10–45 °C (optimum 35 °C), pH 8.0–10.5 (optimum pH 9.0) and in the presence of 0–16 % (w/v) NaCl (optimum 3.0 %), was isolated from a soda lake and identified as representing a novel species using a polyphasic taxonomic approach. Strain KQ-3T was catalase-positive, oxidase-negative and non-motile. Phylogenetic analysis based on 16S rRNA gene sequence affiliated KQ-3T to the genus Alteribacter and showed the highest similarities to Alteribacter natronophilus M30T (97.90 %), Alteribacter aurantiacus K1-5T (97.84 %) and Alteribacter populi FJAT-45347T (97.22 %). Digital DNA–DNA hybridization and average nucleotide identity analyses revealed that KQ-3T displayed 21.4 and 72.81% genomic DNA relatedness with the most closely related strain, A. natronophilus M30T, respectively. KQ-3T contained all of the conserved signature indels that are specific for members of the genus Alteribacter . The DNA G+C content was 45.03 mol%. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the polar lipids consisted of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and one unidentified phospholipid. The predominant menaquinone was MK-7 (100%) and the major fatty acids (>10 %) comprised anteiso-C15 : 0, iso-C15 : 0 and iso-C16 : 0. Based on the data from the current polyphasic studies, KQ-3T represents a novel species of the genus Alteribacter , for which the name Alteribacter keqinensis sp. nov. is proposed. The type strain is KQ-3T (=ACCC 61799T=KCTC 33933T).

Phylogenetic survey of the subtilase family and a data-mining-based search for new subtilisins from Bacillaceae

“…ALP-1 (S08.045) from Bacillus sp. NKS-21 ( Yamagata et al, 1995 ), WP_017729072.1 from Halalkalibacterium ligniniphilum ( Zhu et al, 2014 ; Joshi et al, 2021 ), WP_122896828.1 from Alteribacter keqinensis ( Liu et al, 2022 ), WP_047973137.1 from Bacillus sp. LL01 ( Vilo et al, 2015 ), and WP_022628745.1 from Alkalihalophilus marmarensis ( Denizci et al, 2010 ; Joshi et al, 2021 ) form a more separated clade, as they lack the four amino acid deletion around position 160, in contrast to the other high-alkaline proteases.…”

Salipaludibacillus daqingensis sp. nov., a moderately halophilic bacterium isolated from an oilfield

“…Endospores were examined according to the Schaeffer-Fulton staining method [31]. Growth at temperatures (10,15,20,25,30,37,40,45, 50 and 55 °C), NaCl concentration [0-30 % (w/v) in increments of 1 %] ranges and pH ranges (pH 5.5-11.5, with intervals of 0.5, with MES buffer for pH 5.5-6.5, HEPES buffer for pH 7.0-8.0, TAPS buffer for pH 8.0-9.0, CHES buffer for pH 9.0-10.0 and CAPS buffer for pH 10.0-11.5) for growth were tested described by Liu et al [32]. The following phenotypic characteristics were performed in media prepared with 8 % (w/v) NaCl and pH 9.0 adjusted using NaHCO 3 /Na 2 CO 3 buffer (100 mM) unless indicated.…”