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Objectives: This study aimed to screen, characterize, and annotate the genome along with the comparison of GABA synthesis genes presented in lactic acid bacteria (LAB). Results: Thirty-five LAB isolates from fermented foods were screened for GABA production using thin-layer chromatography (TLC). Fifteen isolates produced GABA ranging from 0.07 to 22.94 g/L. Based on their GTG5 profiles, phenotypic, and genotypic characteristics, isolates LSI1-1, LSI1-5, LSI2-1, LSI2-2, LSI2-3, LSI2-5, and LSM3-1-4 were identified as Lactobacillus plantarum subsp. plantarum; isolate LSM1-4 was Lactobacillus argentoratensis; isolates CAB1-2, CAB1-5, CAB1-7, and LSI1-4 were Lactobacillus pentosus; and CAB1-1, LSM3-1-1 and LSM3-2-3 were Lactobacillus fermentum. Strains LSI2-1 and CAB1-7 from pickled vegetables were selected for genome analysis. The gadA gene (1410 bp, 470aa) was encountered in GABA production of both strains and no other glutamate decarboxylase (GAD) genes were found in the genomes when compared with other LAB strains. The presence of gadA is evidence for GABA production. Strains LSI2-1 and CAB1-7 produced 22.94 g/L and 11.59 g/L of GABA in GYP broth supplemented with 3% (w/v) MSG at 30 °C for 72 h, respectively. Conclusions: Our report highlights the characterization of LAB and GABA production of L. plantarum LSI2-1 strain with its GABA synthesis gene. GABA production of strains LSI2-1 and CAB1-7 in GYP broth with 3% (w/v) MSG and comparative GAD genes [ABSTRACT FROM AUTHOR]

[Display omitted] • Three novel spore-forming bacteria, designated strains PP-18T, JC-4, and JC-7, isolated from soils in Thailand, were taxonomically characterized using polyphasic approach. • Weizmannia acidilactici sp. nov. is proposed for PP-18T, JC-4 and JC-7 based on 16S rRNA gene sequence similarity, ANI, and DNA-DNA hybridization (dDDH) values compared to those of W. coagulans LMG 6326T and W. acidiproducens KCTC 13078T. • Weizmannia strains PP-18T, JC-4 and JC-7 produced l -lactic acid from glucose in the range of 45.35–47.75 g/L with the yield of 0.63–0.76 g/g and productivity of 0.63–0.66 g/L·h. The strains designed PP-18T, JC-4 and JC-7 isolated from soils, were Gram-stain-positive rods, facultative anaerobe, endospore-forming bacteria. The strains produced l -lactic acid from glucose. They showed positive for catalase but negative for oxidase, nitrate reduction and arginine hydrolysis. Strains P-18T, JC-4 and JC-7 were closely related to Weizmannia coagulans LMG 6326T (97.27–97.64%) and W. acidiproducens KCTC 13078T (96.46–96.74%) based on 16S rRNA gene sequence similarity, respectively. They contained meso -diaminopimelic acid in cell wall peptidoglycan and had seven isoprene units (MK-7) as the predominant menaquinone. The major cellular fatty acids of strain PP-18T were iso -C 15:0 , anteiso-C 17:0 , iso-C 16:0 and anteiso-C 15:0. The ANIb and ANIm values among the genomes of strains PP-18T, JC-4 and JC-7 are above 99.4% while their ANIb and ANIm values among them and W. coagulans LMG 6326T and W. acidiproducens KCTC 13078T were ranged from 76.61 to 79.59%. These 3 strains showed the digital DNA-DNA hybridization (dDDH) values of 20.7–23.6% when compared with W. coagulans LMG 6326T and W. acidiproducens DSM 23148T. The DNA G + C contents of strains PP-18T, JC-4 and JC-7 were 45.82%, 45.86% and 45.86%, respectively. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphoglycolipids. The results of phenotypic and chemotaxonomic characteristics and whole-genome analysis indicated that the strains PP-18T, JC-4 and JC-7 should be represented as a novel species within the genus Weizmannia for which the name Weizmannia acidilactici sp. nov. is proposed. The type strain is PP-18T (=KCTC 33974T = NBRC 113028T = TISTR 2515T). [ABSTRACT FROM AUTHOR]

Two novel actinobacterial strains, MS1-9T and NGC1-4, were isolated from roots of Musa (ABB) cv. 'Kluai Namwa', collected from Chachoengsao province, and Musa (ABB) cv. 'Kluai Chang', from Suphan Buri province, Thailand, respectively. Comparative analysis of 16S rRNA gene (98.0 to 98.9% similarity), gyrase subunit B (gyrB) gene and whole-genome sequences emphasised that the strains MS1-9T and NGC1-4 showed closely related with Micromonospora peucetia DSM 43363T, M. krabiensis JCM 12869T and M. avicenniae DSM 45758T, respectively. Strains MS1-9T and NGC1-4 contained meso -diaminopimelic acid in cell-wall peptidoglycan. Whole-cell sugars were glucose, xylose, mannose, and ribose. The acyl type of peptidoglycan was glycolyl. MK-10(H 6), MK-9(H 6), and MK-10(H 8) were presented as the major menaquinones. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, and phosphatidylinositol were detected as predominant phospholipid profiles. The major cellular fatty acids consisted of iso -C 15:0 , anteiso -C 15:0 , anteiso -C 17:0 , iso -C 17:0 and C 17:0. The DNA G + C content of strains MS1-9T and NGC1-4 were 72.2 and 72.3 mol%, respectively. Draft genome sequences indicated by ANI values and digital DNA-DNA hybridisation analysis asserted that the strains MS1-9T and NGC1-4 should be represented as a novel species within the genus Micromonospora for which the name Micromonospora musae sp. nov. is proposed. The type strain is MS1-9T (=JCM 32149T = TISTR 2659T). [ABSTRACT FROM AUTHOR]

Histamine is a biogenic amine significantly formed in fish sauce leading to a major concern in consumers. This study aimed to identify a halophilic bacterium for histamine degradation in fish sauce, and understand its genomic insight to enhance histamine degradation activity. We discovered the novel halophilic bacterium, Bacillus piscicola FBU1786, degrading histamine and other biogenic amines. Its histamine breakdown was growth-associated in a wide range of NaCl concentrations, pH, and temperature from 4% to 18%, 6.0 to 9.0, and 30 to 45 °C, respectively. Genome sequencing revealed the presence of Cu2+-binding oxidase-encoding genes and their heterologous expression with Cu2+ supplementation triggered histamine degradation in E. coli. The degree of histamine breakdown in B. piscicola FBU1786 could be enhanced by Cu2+ addition. Histamine degradation of the culture was evaluated in raw fish sauce mixtures to partially mimic the condition during fish sauce fermentation. Histamine degradation was suppressed to the extent of raw fish sauce, but could be restored by Cu2+ supplementation. Together, this study disclosed B. piscicola FBU1786 with the potent histamine degradation activity, identified Cu2+-binding oxidases responsible for histamine breakdown, and enhanced histamine degradation of the culture using Cu2+ supplementation. • Bacillus piscicola FBU1786 is a halophilic bacterium degrading histamine. • Cu2+-binding oxidases are responsible for histamine degradation. • Cu2+ supplementation enhances the rate of histamine breakdown. • Histamine degradation is suppressed by the extent of fish sauce. • Inhibited histamine degradation is restored by Cu2+ supplementation. [ABSTRACT FROM AUTHOR]

An aerobic, Gram-stain-positive, endospore-forming, rod-shaped and moderately halophilic strain SKP4-6 T , was isolated from shrimp paste ( Ka-pi ) collected from Samut Sakhon Province, Thailand. Phylogenetic analysis revealed that strain SKP4-6 T belonged to the genus Halobacillus and was most closely related to Halobacillus salinus JCM 11546 T (98.6 %), Halobacillus locisalis KCTC 3788 T (98.6 %) and Halobacillus yeomjeoni KCTC 3957 T (98.6 %) based on 16S rRNA gene sequence similarity. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strain SKP4-6 T and its related species were 18.2-19.3 % and 69.84-84.51 %, respectively, which were lower than the threshold recommended for species delineation. The strain grew optimally at 30-40 °C, at pH 7.0 and with 10-15 % (w/v) NaCl. It contained l-Orn-d-Asp in the cell wall peptidoglycan. The DNA G+C content was 44.8 mol%. The major fatty acids were iso-C 15 : 0 , anteiso-C 15 : 0 and anteiso-C 17 : 0 . The predominant isoprenoid quinone was MK-7. Phosphatidylglycerol and diphosphatidylglycerol were present as major polar lipids. Based on this polyphasic approach, digital DNA-DNA relatedness and ANI values, strain SKP4-6 T represents a novel species of the genus Halobacillus , for which the name Halobacillus fulvus sp. nov. is proposed. The type strain is SKP4-6 T (=JCM 32624 T =TISTR 2595 T ).

Gamma-aminobutyric acid (GABA) plays a key role as an inhibitory neurotransmitter in the mammalian sympathetic nervous system and has other health benefits. Molecular characterization, genome analysis, and optimization were investigated to improve GABA production of a selected strain of lactic acid bacteria. Eleven isolates from plant materials were screened for GABA productivity and were identified based on phenotypic and genotypic characteristics. The most potent strain was chosen for genome analysis and GABA production optimization using the response surface methodology (RSM). Each of the two strains was closely related to Lactobacillus plantarum, Lactobacillus brevis, Weissella cibaria, Leuconostoc pseudomesenteroides while each strain was similar to Lactobacillus pentosus, Enterococcus lactis, and Leuconostoc mesenteroides. They produced GABA ranging from 0.036 ± 0.000 to 17.315 ± 0.171 g/L at 72 h-cultivation. Among them, the most potent strain, SL9-6, showed the highest GABA production (17.315 g/L) when cultivated with 10% (v/v) inoculum for 48 h. The draft genome sequence of strain SL9-6 exhibited 96.90% average nucleotide identity value and 74.50% digital DNA-DNA hybridization to Lactobacillus brevis NCTC 13768 T . This strain contained a glutamate decarboxylase gene system (gadA, gadB, and gadC). Optimal culture conditions were determined as 40.00 g/L glucose, 49.90 g/L monosodium glutamate, pH 5.94, and 31.10°C by RSM, giving maximum GABA production of 32.48 g/L. Results from RSM also indicated that monosodium glutamate concentration, pH, and temperature were significant variables. GABA production significantly improved here could promise further application of strain SL9-6.

A Gram-stain-positive, aerobic, spore-forming, moderately halophilic bacterium, SSKP1-9 T , was isolated from traditional salted shrimp paste ( Ka-pi ) produced in Samut Sakhon Province, Thailand. This strain grew optimally at 37-40 °C, pH 7.0 and in the presence of 8-16 % (w/v) NaCl. The 16S rRNA gene sequence similarity values between strain SSKP1-9 T and Lentibacillus juripiscarius TISTR 1535 T and Lentibacillus halophilus TISTR 1549 T were 98.7 and 97.2 %, respectively. Based on 16S rRNA gene sequence similarity, strain SSKP1-9 T represents a distinct novel species, as shown by phenotypic traits, DNA-DNA hybridization and average nucleotide identity values. In addition, the whole-cell protein profile confirmed the novelty of the taxon. The genomic DNA G + C content was 44.6 mol%. The major isoprenoid quinone was MK-7. The cell-wall peptidoglycan contained meso -diaminopimelic acid. Polar lipid analysis revealed the presence of phosphatidylglycerol, diphosphatidylglycerol, four unidentified lipids, an unidentified phospholipid and an unidentified glycolipid. The major cellular fatty acids were anteiso-C 15 : 0 , anteiso-C 17 : 0 and iso-C 16 : 0 . The results of phenotypic and chemotaxonomic characteristics and whole-genome analysis support that strain SSKP1-9 T represents a novel species of Lentibacillus , for which the name Lentibacilluslipolyticus sp. nov. is proposed. The type strain is SSKP1-9 T (=JCM 32625 T =TISTR 2597 T ).

A Gram-stain-positive and catalase negative coccus, designated strain Gos25-1 T , isolated from a cotton flower (Gossypium hirsutum L.) collected from Khao Wong district, Kalasin province, Thailand. The taxonomic position of this strain was systematically studied based upon polyphasic taxonomic methods. The strain was facultatively anaerobic and produced l-lactic acid from glucose. The predominant cellular fatty acids were the straight-chain fatty acids C18 : 1ω9c and C16 : 0. According to 16S rRNA and phenylalanyl-tRNA synthase alpha subunit (pheS) gene sequence similarity, this strain was closely related to Enterococcus pallens NBRC 100697 T , E. hermanniensis CIP 108559 T , E. avium NBRC 100477 T and E. raffinosus NBRC 100492 T with 98.9-99.1 % and 77.0-82.0 % sequence similarities, respectively. Phylogenetic analysis indicated that strain Gos25-1 T was clearly distinguished from closely related species of the genus Enterococcus. Draft genome of Gos25-1 T had a size of 3.99 Mb which was contained 3788 coding sequences with in silico G+C content of 42.4 mol%. The ANIb and a digital DNA-DNA hybridisation (dDDH) values between strain Gos25-1 T and the closest related species, E. pallens NBRC 100697 T were 73.65 and 21.10 %, respectively. According to polyphasic characterisation, this strain represents a novel species of the genus Enterococcus, for which the name Enterococcus florum sp. nov. is proposed. The type strain is Gos25-1 T (=CIP 110956 T =LMG 29007 T =NBRC 111461 T =TISTR 2382 T ).