Lysinibacillus endophyticus sp. nov., an indole-3-acetic acid producing endophytic bacterium isolated from corn root (Zea mays cv. Xinken-5)

A taxonomic note on the order Caryophanales: description of 12 novel families and emended description of 21 families

The order Caryophanales, belonging to class Bacilli, is globally distributed in various ecosystems. Currently, this order comprised 12 families that show vast phenotypic, ecological and genotypic variation. The classification of Caryophanales at the family level is currently mainly based on 16S rRNA gene sequencing analysis and the presence of shared phenotypic characteristics, resulting in noticeable anomalies. Our present study revises the taxonomy of Caryophanales based on 1080 available high-quality genome sequences of type strains. The evaluated parameters included the core-genome phylogeny, pairwise average aa identity, lineage-specific core genes, physiological criteria and ecological parameters. Based on the results of this polyphasic approach, we propose that the order Caryophanales be reclassified into 41 families, which include the existing 12 families, 17 families in a recent Validation List in the IJSEM (Validation List no. 215) and 12 novel families for which we propose the names Aureibacillaceae, Cytobacillaceae, Domibacillaceae, Falsibacillaceae, Heyndrickxiaceae, Lottiidibacillaceae, Oxalophagaceae, Pradoshiaceae, Rossellomoreaceae, Schinkiaceae, Sulfoacidibacillaceae and Sutcliffiellaceae. This work represents a genomic sequence-based and systematic framework for classifying the order Caryophanales at the family level, providing new insights into its evolution.

Endophytic microbes: biodiversity, plant growth-promoting mechanisms and potential applications for agricultural sustainability

Endophytic microbes are known to live asymptomatically inside their host throughout different stages of their life cycle and play crucial roles in the growth, development, fitness, and diversification of plants. The plant-endophyte association ranges from mutualism to pathogenicity. These microbes help the host to combat a diverse array of biotic and abiotic stressful conditions. Endophytic microbes play a major role in the growth promotion of their host by solubilizing of macronutrients such as phosphorous, potassium, and zinc; fixing of atmospheric nitrogen, synthesizing of phytohormones, siderophores, hydrogen cyanide, ammonia, and act as a biocontrol agent against wide array of phytopathogens. Endophytic microbes are beneficial to plants by directly promoting their growth or indirectly by inhibiting the growth of phytopathogens. Over a long period of co-evolution, endophytic microbes have attained the mechanism of synthesis of various hydrolytic enzymes such as pectinase, xylanases, cellulase, and proteinase which help in the penetration of endophytic microbes into tissues of plants. The effective usage of endophytic microbes in the form of bioinoculants reduce the usage of chemical fertilizers. Endophytic microbes belong to different phyla such as Actinobacteria, Acidobacteria, Bacteroidetes, Deinococcus-thermus, Firmicutes, Proteobacteria, and Verrucomicrobia. The most predominant and studied endophytic bacteria belonged to Proteobacteria followed by Firmicutes and then by Actinobacteria. The most dominant among reported genera in most of the leguminous and non-leguminous plants are Bacillus, Pseudomonas, Fusarium, Burkholderia, Rhizobium, and Klebsiella. In future, endophytic microbes have a wide range of potential for maintaining health of plant as well as environmental conditions for agricultural sustainability. The present review is focused on endophytic microbes, their diversity in leguminous as well as non-leguminous crops, biotechnological applications, and ability to promote the growth of plant for agro-environmental sustainability.

Lysinibacillus antri sp. nov., isolated from cave soil

A Gram-stain-positive, motile, rod-shaped and endospore-forming strain, SYSU K30002^T, was isolated from a soil sample collected from a karst cave in Xingyi county, Guizhou province, south-west China. SYSU K30002^T grew at 28-40 °C (optimum, 37 °C), at pH 5.0-8.0 (optimum, pH 7.0) and in the presence of 0-4 % (w/v) NaCl (optimum in the absence of NaCl). The cell-wall peptidoglycan type was A4α (Lys-Asp). The cell-wall sugars of SYSU K30002^T were ribose, galactose and mannose, and MK-7 was the menaquinone. The major fatty acids were iso-C_15 : 0, C_16 : 1 ω7c alcohol and iso-C_16 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and two unidentified phospholipids. The G+C content of the genomic DNA was 36.1 mol%. The average nucleotide identity values between SYSU K30002^T and its closest relatives were below the cut-off level (95-96 %) for species delineation. Based on phenotypic, chemotaxonomic and genome comparisons, strain SYSU K30002^T represents a novel species of the genus Lysinibacillus, for which the name Lysinibacillusantri sp. nov. is proposed. The type strain is SYSU K30002^T (=KCTC 33955^T=CGMCC 1.13504^T).

Complete Genome Sequence of Lysinibacillus sp. Strain SGAir0095, Isolated from Tropical Air Samples Collected in Singapore

Lysinibacillus sp. strain SGAir0095 was isolated from tropical air samples collected in Singapore, and its complete genome was sequenced with a hybrid strategy using single-molecule real-time sequencing and short reads. The genome consists of one chromosome of 4.14 Mbp and encompasses 3,885 protein-coding genes, 39 rRNAs, and 101 tRNAs.

Lysinibacillus sp. strain SGAir0095 was isolated from tropical air samples collected in Singapore, and its complete genome was sequenced with a hybrid strategy using single-molecule real-time sequencing and short reads. The genome consists of one chromosome of 4.14 Mbp and encompasses 3,885 protein-coding genes, 39 rRNAs, and 101 tRNAs.

Isolation and characterization of a novel piezotolerant bacterium Lysinibacillus yapensis sp. nov., from deep-sea sediment of the Yap Trench, Pacific Ocean

A Gram-positive, aerobic, rod-shaped, spore-forming bacterium, designated YLB-03^T, with peritrichous flagella was isolated from deep-sea sediment of the Yap Trench at a depth of 4435 m. The bacterium was found to be catalase-positive but oxidase-negative. Growth of this bacterium was observed at 15-50°C (optimum 37°C), pH 5-10.5 (optimum 7), 0-5% NaCl (optimum 1%, w/v) and 0.1-50 MPa (optimum 0.1 MPa). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YLB-03^T was a member of the genus Lysinibacillus. Strain YLB-03^T was closely related to Lysinibacillus sinduriensis BLB-1^T and Lysinibacillus chungkukjangi 2RL3-2^T (98.4%), Lysinibacillus halotolerans LAM-612^T (98.0%), Lysinibacillus telephonicus KT735049^T (97.5%), Lysinibacillus endophyticus C9^T (97.5%), Lysinibacillus composti NCCP-36^T and Lysinibacillus massiliensis 4400831^T (97.3%). The ANI and the GGDC DNA-DNA hybridization estimate values between strain YLB-03^T and closely related type strains were 73.7-76.3% and 34.7-38.7%, respectively. The principal fatty acids were anteiso-C_15:0 and iso-C_15:0. The G+C content of the chromosomal DNA was 39.6 mol%. The respiratory quinone was determined to be MK-7. The diagnostic amino acids in the cell wall peptidoglycan contained Lys-Asp (type A4α) and the cell-wall sugars were glucose and xylose. The polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and an unidentified phospholipid. The combined genotypic and phenotypic data showed that strain YLB-03^T represents a novel species within the genus Lysinibacillus, for which the name Lysinibacillus yapensis sp. nov. is proposed, with the type strain YLB-03^T (= MCCC 1A12698^T = JCM 32871^T).