Genus Brevibacterium Research Articles

Brevibacterium litoralis sp. nov., a cellulose-degrading strain isolated from marine surface sediment.

A Gram stain-positive, non-spore-forming, non-motile, short-rod actinomyces strain GXQ1321T was isolated from maritime surface sediments in Beihai (21° 41' 21.65″ N, 109° 05' 76.56″ E), Guangxi Zhuang Autonomous Region, and a number of categorization studies were performed. Following a period of 72h of incubation at a temperature of 30°C within a modified actinomycete culture medium, the colony was light-yellow, circular, smooth, central bulge, convex, opaque, with a 1.2-2.3mm diameter. Strain GXQ1321T had the ability to degrade cellulose. Chemotaxonomic studies revealed that the major methylnaphthoquinones in strain GXQ1321T was MK-8(H2). The most prevalent cellular fatty acids were anteiso-C19:0, anteiso-C15:0, anteiso-C17:0, and iso-C16:0. The whole-cell sugars of the strain GXQ1321T were identified rhamnose, xylose and glucose. Meso-diaminopimelic acid was found in the peptidoglycan hydrolysate, and the polar lipids were identified as diphosphatidylglycerol, three phosphoglycolipid, phosphatidylglycerol and two unknown glycolipid. This strain had 69.6% DNA G+C content. Strain GXQ1321T is classified as Brevibacterium based on its 16S rRNA gene sequence. It is closely related to Brevibacterium samyangense SST-8T (96.8%) and Brevibacterium rongguiense 5221T (96.3%). The average nucleotide identity (ANI) values of GXQ1321T and the above two type strains were 73.9-77.1%, and the digital DNA-DNA hybridisation (dDDH) values were 15.3-21.1%. Based on the phylogenetic, chemotaxonomic and physiological data, strain GXQ1321T was considered to be a novel species of the genus Brevibacterium, named Brevibacterium litoralis sp. nov, with the type strain GXQ1321T (= MCCC 1K08964T = KCTC 59167T).

Functional genomics and taxonomic insights into heavymetaltolerant novel bacterium Brevibacterium metallidurans sp. nov. NCCP-602T isolated from tannery effluent in Pakistan.

The strain designated NCCP-602T was isolated from tannery effluent, and displayed aerobic, gram-positive, rod-shaped cells that were characterized by oxidase negative, catalase positive, and non-motile features. The most favourable growth conditions were observed at a temperature of 30°C, pH 7.0, and NaCl concentration of 1% (w/v). It tolerated heavy metals at high concentrations of chromium (3600 ppm), copper (3300 ppm), cadmium (3000 ppm), arsenic (1200 ppm) and lead (1500 ppm). The results of phylogenetic analysis, derived from sequences of the 16S rRNA gene, indicated the position of strain NCCP-602T within genus Brevibacterium and showed that it was closely related to Brevibacterium ammoniilyticum JCM 17537T. Strain NCCP-602T formed a robust branch that was clearly separate from closely related taxa. A comparison of 16S rRNA gene sequence similarity and dDDH values between the closely related type strains and strain NCCP-602T provided additional evidence supporting the classification of strain NCCP-602T as a distinct novel genospecies. The polar lipid profile included diphosphatidylglycerol, glycolipid, phospholipids and amino lipids. MK-7 and MK-8 were found as the respiratory quinones, while anteiso-C15:0, iso-C15:0, iso-C16:0, iso-C17:0, and anteiso-C17:0 were identified as the predominant cellular fatty acids (> 10%). Considering the convergence of phylogenetic, phenotypic, chemotaxonomic, and genotypic traits, it is suggested that strain NCCP-602T be classified as a distinct species Brevibacterium metallidurans sp. nov. within genus Brevibacterium with type strain NCCP-602T (JCM 18882T = CGMCC1.62055T).

Phenotypic and genomic characteristics of Brevibacterium zhoupengii sp. nov., a novel halotolerant actinomycete isolated from bat feces.

Two strictly aerobic, Gram-staining-positive, non-spore-forming, regular rod-shaped (approximately 0.7 × 1.9 mm) bacteria (HY170T and HY001) were isolated from bat feces collected from Chongzuo city, Guangxi province (22°20′54″N, 106°49′20″E, July 2011) and Chuxiong Yi Autonomous Prefecture, Yunnan province (25°09′10″N, 102°04′39″E, October 2013) of South China, respectively. Optimal growth is obtained at 25–28°C (range, 4–32°C) on BHI-5% sheep blood plate with pH 7.5 (range, 5.0–10.0) in the presence of 0.5–1.0% NaCl (w/v) (range, 0–15% NaCl [w/v]). The phylogenetic and phylogenomic trees based respectively on the 16S rRNA gene and 845 core gene sequences revealed that the two strains formed a distinct lineage within the genus Brevibacterium, most closely related to B. aurantiacum NCDO 739T (16S rRNA similarity, both 98.5%; dDDH, 46.7–46.8%; ANI, 91.9–92.1%). Strain HY170T contained MK-8(H2), diphosphatidylglycerol (DPG) and phosphatidylglycerol (PG), galactose and ribose as the predominant menaquinone, major polar lipids, and main sugars in the cell wall teichoic acids, respectively. The meso-diaminopimelic acid (meso-DAP) was the diagnostic diamino acid of the peptidoglycan found in strain HY170T. Anteiso-C15:0 and anteiso-C17:0 were the major fatty acids (> 10%) of strains HY170T and HY001, with anteiso-C17:1A predominant in strain HY170T but absent in strain HY001. Mining the genomes revealed the presence of secondary metabolite biosynthesis gene clusters encoding for non-alpha poly-amino acids (NAPAA), ectoine, siderophore, and terpene. Based on results from the phylogenetic, chemotaxonomic and phenotypic analyses, the two strains could be classified as a novel species of the genus Brevibacterium, for which the name Brevibacterium zhoupengii sp. nov. is proposed (type strain HY170T = CGMCC 1.18600T = JCM 34230T).Supplemental material for this article may be found at 10.1007/s12275-022-2134-8.

Effect of Intramammary Dry Cow Antimicrobial Treatment on Fresh Cow's Milk Microbiota in California Commercial Dairies.

This study used 16S rRNA sequencing to evaluate the effects of dry cow antimicrobial therapy on the udder milk microbiota by comparing the microbial populations in milk at dry-off (DRY) (~60 days before calving) and post-partum (FRESH) (4–11 days after calving) from cows receiving an intramammary antibiotic infusion prior to dry-off (IMT) and cows that did not receive treatment (CTL). Milk was collected from 23 cows from the IMT group and 27 cows from the CTL group. IMT and DRY samples had a greater correlation with the genera Brevibacterium and Amaricoccus, and the family Micrococcaceae, when compared to IMT and FRESH samples. CTL group samples collected at DRY had a greater correlation with the genera Akkermansia and Syntrophus, when compared to FRESH samples; no bacterial taxa were observed to have a significant correlation with FRESH samples in the CTL group. DRY samples collected from the CTL group had a greater correlation with the genus Mogibacterium when compared to IMT and CTL samples. For DRY samples collected from the IMT group, a greater correlation with the genus Alkalibacterium when compared to DRY and CTL samples, was observed. The lack of a correlation for FRESH samples between the CTL and IMT treatment groups indicated that intramammary antimicrobial dry cow therapy had no significant effect on the udder milk microbiota post-partum.

Brevibacterium limosum sp. nov., Brevibacterium pigmenatum sp. nov., and Brevibacterium atlanticum sp. nov., three novel dye decolorizing actinobacteria isolated from ocean sediments.

During a study of the marine actinobacterial biodiversity, a large number of Brevibacterium strains were isolated. Of these, five that have relatively low 16S rRNA gene similarity (98.5-99.3%) with validly published Brevibacterium species, were chosen to determine taxonomic positions. On the basis of 16S rRNA gene sequence analysis and BOX-PCR fingerprinting, strains o2T, YB235T, and WO024T were selected as representative strains. Genomic analyses, including average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH), clearly differentiated the three strains from each other and from their closest relatives, with values ranging from 82.8% to 91.5% for ANI and from 26.7% to 46.5% for dDDH that below the threshold for species delineation. Strains YB235T, WO024T, and o2T all exhibited strong and efficient decolorization activity in congo red (CR) dyes, moderate decolorization activity in toluidine blue (TB) dyes and poor decolorization in reactive blue (RB) dyes. Genes coding for peroxidases and laccases were identified and accounted for these strains' ability to effectively oxidize a variety of dyes with different chemical structures. Mining of the whole genome for secondary metabolite biosynthesis gene clusters revealed the presence of gene clusters encoding for bacteriocin, ectoine, NRPS, siderophore, T3PKS, terpene, and thiopeptide. Based on the phylogenetic, genotypic and phenotypic data, strains o2T, YB235T and WO024T clearly represent three novel taxa within the genus Brevibacterium, for which the names Brevibacterium limosum sp. nov. (type strain o2T = JCM 33844T = MCCC 1A09961T), Brevibacterium pigmenatum sp. nov. (type strain YB235T = JCM 33843T = MCCC 1A09842T) and Brevibacterium atlanticum sp. nov. (type strain WO024T = JCM 33846T = MCCC 1A16743T) are proposed.

NGS-Based Metagenomic Study of Four Traditional Bulgarian Green Cheeses from Tcherni Vit

This is the first scientific study of the unique Bulgarian Cherni Vit green cheese based on 16S and ITS2 NGS metagenomics, accomplished on the Illumina HiSeq 2 × 250 bp paired end reads in order to obtain an overview of the microbial composition. The results revealed a rich microbiota, composed of on average of 120 eubacterial and 16 fungal species. Firmicutes were represented by the families Strepotococcaceae, Lactobacillaceae and Staphylococcaceae, while the Actinobacteria were represented mainly by the genera Brevibacterium and Corynebacterium. Low counts of Proteobacteria were also detected, mainly halophiles of the genera Cobetia and Psychrobacter. Almost all (99.99%) of the detected fungi belonged to Ascomycota, represented almost equally by the families Eurotiomycetes (exclusively by Penicillium roqueforti), Saccharomycetes (mainly by the genera Debaryomyces, Pichia, Candida and Kluyveromyces) and Sordariomycetes (mostly by Scopulariopsis flava). The performed diversity analyses revealed that despite some differences, which can be attributed to environmental factors, and the time of the ripening, all of the four batches displayed very rich but similar microbiota. We found a potentially beneficial microbiota with the potential to inhibit the growth of pathogenic bacterial species, as well as to neutralize possibly produced mycotoxins, as described in numerous research on raw milk dairy products.

Brevibacterium renqingii sp. nov., isolated from the Daqu of Baijiu.

Two bacterial strains, designated REN4T and REN4-1, were isolated from daqu sample collected from baijiu factory located in Shanxi, China. The two strains shared highly similar 16S rRNA gene sequences (99.67% identities) and formed a monophyletic clade within the Brevibacterium 16S rRNA gene tree, showing 97.56-97.85% 16S rRNA gene sequence identities with type strains Brevibacteriumpermense VKM Ac-2280T, Brevibacteriumsediminis FXJ8.269T, Brevibacterium oceani BBH7T and Brevibacterium epidermidis NCIMB 702286T. They contained MK-8(H2) as the most predominant menaquinone, antesio-C15:0, antesio-C17:0, Iso-C16:0 and Iso-C17:0 as the major cellular fatty acids, DPG (diphosphatidylglycerol), PG (phosphatidylglycerol), PGL (phosphatidylglycerollipids), and PL (phospholipids) as the main polar lipids. The genomic DNA G + C content of strains REN4 and REN4-1 were 64.35, 65.82mol%. Moreover, the low DNA-DNA relatedness values, physiological and biochemical characteristics, and taxonomic analysis allowed the differentiation of strains REN4T and REN4-1 from the other recognized species of the genus Brevibacterium. Therefore, strain REN4T represents a novel species of the genus Brevibacterium, for which the name Brevibacterium renqingii sp. nov. is proposed, with the type strain REN4T (= JCM 33953T = KCTC 49366T).

Comparative 16S rDNA metagenomics study of two samples of cassava peel heap from Nigeria and India.

The microbiology of many cassava products and the wastes generated during the processing have been reported; however, majority of these reports used culture-dependent methods. This has resulted in a dearth of information on the bacterial diversity of cassava peels and peel heaps. Large amounts of cassava peels generated during the processing of cassava root are usually discharged on land or water as wastes and are allowed to rot in the open, especially in some developing countries. Culture-independent methods such as PCR-based amplification and sequencing of 16S rRNA genes, among others have been used in recent times to study the diversity of microbes in different environmental samples. In this study, bacterial isolates were screened for cellulase and xylanase enzyme activities on minimal agar and genomic DNA was isolated from cassava peel samples; metagenomics was carried out using MiSeq2 × 300 with primers specific for V3-V4 bacterial region. Samples collected from Nigeria (AAG) had more species compared with samples from India (JHA) with 793 and 525 observed OTUs (operational taxonomic units), respectively. Five bacterial isolates from cassava peel-heap samples obtained from Ogbomoso, Nigeria showed no ability to produce cellulase enzyme, seven isolates from the Nigeria samples and three from Jorhat samples were positive for xylanase production; the highest amylase activity was shown by isolate AG18 (10,055U/mL), while the lowest was recorded for isolate JA2 (2333U/mL) with a significant difference observed in the amylase activities of isolates (p ≤ 0.05). Comparing the most abundant taxonomy for each of the samples at different taxonomic levels, the most abundant for sample AAG were phylum Firmicutes (42.11%), class Bacilli (41.27%), order Lactobacillales (33.11%), family Acetobacteraceae (31.30%), genus Acetobacter (30.02%) and unclassified species of Acetobacter (29.88%), while sample JHA had Actinobacteria (47.47%) as the highest phylum and class, order Actinomycetales (47.47%), family Brevibacteriaceae (46.97%), genus Brevibacterium (46.97%) and unclassified species of Brevibacterium (46.89%). This study provides an insight into the vast diversity of the bacteria associated with cassava peel heaps and the ability of some of the bacteria to produce selected extracellular enzymes.

Brevibacterium from Austrian hard cheese harbor a putative histamine catabolism pathway and a plasmid for adaptation to the cheese environment

The genus Brevibacterium harbors many members important for cheese ripening. We performed real-time quantitative PCR (qPCR) to determine the abundance of Brevibacterium on rinds of Vorarlberger Bergkäse, an Austrian artisanal washed-rind hard cheese, over 160 days of ripening. Our results show that Brevibacterium are abundant on Vorarlberger Bergkäse rinds throughout the ripening time. To elucidate the impact of Brevibacterium on cheese production, we analysed the genomes of three cheese rind isolates, L261, S111, and S22. L261 belongs to Brevibacterium aurantiacum, whereas S111 and S22 represent novel species within the genus Brevibacterium based on 16S rRNA gene similarity and average nucleotide identity. Our comparative genomic analysis showed that important cheese ripening enzymes are conserved among the genus Brevibacterium. Strain S22 harbors a 22 kb circular plasmid which encodes putative iron and hydroxymethylpyrimidine/thiamine transporters. Histamine formation in fermented foods can cause histamine intoxication. We revealed the presence of a putative metabolic pathway for histamine degradation. Growth experiments showed that the three Brevibacterium strains can utilize histamine as the sole carbon source. The capability to utilize histamine, possibly encoded by the putative histamine degradation pathway, highlights the importance of Brevibacterium as key cheese ripening cultures beyond their contribution to cheese flavor production.

Brevibacterium anseongense sp. nov., isolated from soil of ginseng field.

Gram-positive, aerobic, non-motile, pale-yellow, and rodshaped bacterium, designated as Gsoil 188T, was isolated from the soil of a ginseng field in Pocheon, South Korea. A phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that the strain formed a distinct lineage within the genus Brevibacterium and was most closely related to B. epidermidis NBRC 14811T (98.4%), B. sediminis FXJ8.269T (98.2%), B. avium NCFB 3055T (98.1%), and B. oceani BBH7T (98.1%), while it shared less than 98.1% identity with the other species of this genus. The DNA G + C content was 68.1 mol%. The predominant quinone was MK-8(H2). The major fatty acids were anteiso-C15:0 and anteiso-C17:0. The cell wall peptidoglycan of strain Gsoil 188T contained meso-diaminopimelic acid. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, and an unidentified aminolipid. The physiological and biochemical characteristics, low DNA-DNA relatedness values, and taxonomic analysis allowed the differentiation of strain Gsoil 188T from the other recognized species of the genus Brevibacterium. Therefore, strain Gsoil 188T represents a novel species of the genus Brevibacterium, for which the name Brevibacterium anseongense sp. nov. is proposed, with the type strain Gsoil 188T (= KACC 19439T = LMG 30331T).

Brevibacterium hankyongi sp. nov., isolated from compost.

A Gram-positive, strictly aerobic, non-motile, milky-white to creamy coloured and rod-shaped bacterium, designated BS05T, was isolated from compost. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that the strain formed a distinct lineage within the genus Brevibacterium and was most closely related to Brevibacterium avium NCFB 3055T (96.3 %), Brevibacterium oceani BBH7T (96.2 %) and Brevibacterium epidermidis NBRC 14811T (96.1 %). The DNA G+C content was 62.3 mol%. The predominant quinone was MK-8(H2). The major fatty acids were anteiso-C15 : 0, anteiso-C17 : 0, iso-C16 : 0 and iso-C15 : 0. The cell-wall peptidoglycan of strain BS05T contained meso-diaminopimelic acid. The major polar lipid was phosphatidylglycerol. Moreover, the low sequence similarity of the 16S rRNA gene sequencing, physiological, biochemical and chemotaxonomic analyses allowed the phenotypic and genotypic differentiation of strain BS05T from the recognized species of the genus Brevibacterium. Therefore, strain BS05T represents a novel species of the genus Brevibacterium, for which the name Brevibacteriumhankyongi sp. nov. is proposed, with the type strain BS05T (=KACC 18875T=LMG 29562T).

Halophilic-psychrotrophic bacteria of an Alaskan cryopeg—a model for astrobiology

Cryopegs, lenses of hypersaline unfrozen soil or water within permafrost, are a model for astrobiology, since free water can only be present on cryogenic bodies and planets in the form of brine. In this paper the diversity of aerobic halophilic-psychrotrophic microorganisms from an Alaskan cryopeg (Barrow Cape) were studied and described for the first time. This cryopeg is characterized by a constant subzero temperature (–7°C), high salinity (total mineralization is about 120 g/L) and isolation from external influences for a geologically significant period of time. Our study has revealed a large number of microorganisms capable of growth at low temperature (4°C) in a wide range of salinities from 5 to 250 g/L of NaCl, the latter being 3 times higher than the natural salt concentration of the Alaskan cryopeg. The microorganisms identified are comprised of four major phyla: Actinobacteria (genera Brevibacterium, Citricoccus, Microbacterium), Firmicutes (genus Paenibacillus), Bacteroidetes (genus Sphingobacterium), and Proteobacteria (genus Ochrobactrum).

Comparative analysis of Corynebacterium glutamicum genomes: a new perspective for the industrial production of amino acids

BackgroundCorynebacterium glutamicum is a non-pathogenic bacterium widely used in industrial amino acid production and metabolic engineering research. Although the genome sequences of some C. glutamicum strains are available, comprehensive comparative genome analyses of these species have not been done. Six wild type C. glutamicum strains were sequenced using next-generation sequencing technology in our study. Together with 20 previously reported strains, we present a comprehensive comparative analysis of C. glutamicum genomes.ResultsBy average nucleotide identity (ANI) analysis, we show that 10 strains, which were previously classified either in the genus Brevibacterium, or as some other species within the genus Corynebacterium, should be reclassified as members of the species C. glutamicum. C. glutamicum has an open pan-genome with 2359 core genes. An additional NAD+/NADP+ specific glutamate dehydrogenase (GDH) gene (gdh) was identified in the glutamate synthesis pathway of some C. glutamicum strains. For analyzing variations related to amino acid production, we have developed an efficient pipeline that includes three major steps: multi locus sequence typing (MLST), phylogenomic analysis based on single nucleotide polymorphisms (SNPs), and a thorough comparison of all genomic variation amongst ancestral or closely related wild type strains. This combined approach can provide new perspectives on the industrial use of C. glutamicum.ConclusionsThis is the first comprehensive comparative analysis of C. glutamicum genomes at the pan-genomic level. Whole genome comparison provides definitive evidence for classifying the members of this species. Identifying an aditional gdh gene in some C. glutamicum strains may accelerate further research on glutamate synthesis. Our proposed pipeline can provide a clear perspective, including the presumed ancestor, the strain breeding trajectory, and the genomic variations necessary to increase amino acid production in C. glutamicum.

Brevibacterium sediminis sp. nov., isolated from deep-sea sediments from the Carlsberg and Southwest Indian Ridges.

Three actinobacterial strains, FXJ8.128, FXJ8.269T and FXJ8.309, were isolated from deep-sea sediments collected from the Carlsberg Ridge and Southwest Indian Ridge at depths of 3690, 1800 and 2461 m, respectively. The three strains had highly similar 16S rRNA gene sequences (99.8-99.9 % identities) and formed a monophyletic clade within the Brevibacterium 16S rRNA gene tree, showing 98.2-98.9 % 16S rRNA gene sequence identities with type strains Brevibacterium epidermidis NCIMB 702286T, Brevibacterium iodinum DSM 20626T, Brevibacterium linens DSM 20425T, Brevibacterium oceani BBH7T and Brevibacterium permense VKM Ac-2280T. All three isolates showed activity towards the breakdown of pectin and fluoranthene. They contained MK-8(H2) as the most predominant menaquinone, diphosphatidylglycerol, phosphatidylglycerol and a glycolipd as the main polar lipids, and anteiso-C15 : 0 and anteiso-C17 : 0 as the major cellular fatty acids. Moreover, the three isolates were distinguished readily from the phylogenetically related type strains by DNA-DNA hybridization values, by random amplified polymorphic DNA fingerprint profiles and by a range of physiological and biochemical characteristics. On the basis of the above polyphasic taxonomic data, strains FXJ8.128, FXJ8.269T and FXJ8.309 represent a novel species of the genus Brevibacterium, for which the name Brevibacterium sediminis sp. nov. is proposed. The type strain is FXJ8.269T (=CGMCC 1.15472T=DSM 102229T).

Sediminivirga luteola gen. nov., sp. nov., a member of the family Brevibacteriaceae, isolated from marine sediment.

A Gram-stain-positive actinobacterial strain, designated F23T, was isolated from marine sediment collected from the western Pacific. Strain F23T showed less than 94.5 % 16S rRNA gene sequence similarity with type strains of species with validly published names. Phylogenetic analysis, based on 16S rRNA gene sequences, revealed that the novel isolate formed a distinct monophyletic clade within the family Brevibacteriaceae and clustered distantly with the genera Brevibacterium and Spelaeicoccus. Cells of strain F23T were non-motile, rod-shaped and aerobic to microaerophilic. Optimal growth occurred at 35-37 °C, at pH 8.0-9.0 and in the presence of 1 % NaCl (w/v). The isolate contained meso-diaminopimelic acid as the characteristic cell-wall diamino acid, MK-8(H2) and MK-7(H2) as the predominant menaquinones and anteiso-C15 : 0 and anteiso-C17 : 0 as the major fatty acids. The DNA G+C content of strain F23T was 69.0 mol%. On the basis of phylogenetic analysis, phenotypic and chemotaxonomic characteristics and 16S rRNA gene signature nucleotide patterns, strain F23T represents a novel species in a novel genus in the family Brevibacteriaceae, for which the name Sediminivirga luteola gen. nov., sp. nov. is proposed. The type strain is F23T ( = JCM 19771T = CGMCC 1.12785T = MCCC 1A09945T).

17.-ESTRADIOL DEGRADING BACTERIA IN SEQUENCING BATCH REACTORS FOR SWINE WASTEWATER TREATMENT

Two 17 -Estradiol (E2) degrading strains were isolated from the activated sludge of swine wastewater bio-treatment aerobic facility and affiliated to Bacillus subtilis based on 16S rRNA gene sequencing. The degradation rates were more than 90 95% at 37 C in 4 days when E2 was the sole carbon source. Steady and effective nutrients and estrogen removals were achieved in three parallel sequencing batch reactors (SBRs) treating real swine wastewater for 90 days, which contributed to the existence of the representatives from genera Brevibacterium, Bacillus, Nitrobacter and Methylophilus. However, the Bacillus subtilis-like strain was present in a greater abundance in Run A and Run B, as extra 10 mg/L and 1 mg/L E2 was added, to reveal its distribution contributed to process estrogen removal.

Teichoic, teichulosonic and teichuronic acids in the cell wall of Brevibacterium aurantiacum VKM Ac-2111Т

Two different teichoic acids, along with a teichulosonic and a teichuronic acids, were identified in the cell wall of Brevibacterium aurantiacum VKM Ac-2111Т. One teichoic acid is 1,3-poly(glycerol phosphate) with 2-acetamido-2-deoxy-α-d-galactopyranose and l-glutamic acid as non-stoichiometric substituents at O-2 of the glycerol residue. The second one is a poly(glycosylglycerol phosphate) with -4)-α-d-Galp-(1→2)-sn-Gro-(3-P- and/or -6)-α-d-Galp-(1→2)-sn-Gro-(3-P- units in the main chain. The structure of the first has not been reported so far, while the latter one is new for actinobacteria. The teichulosonic acid with α-3-deoxy-β-d-glycero-d-galacto-non-2-ulopyranosonic acid (Kdn) and β-d-glucopyranose residues in the backbone represents a novel polymer: →8)-α-Kdn-(2→6)-β-d-Glcp-(1→. The teichuronic acid has also hitherto unknown structure: →3)-β-d-Galf(2OAc)0.3-(1→3)-β-d-GlcpА-(1→ and is found in members of the genus Brevibacterium for the first time. The polymer structures were elucidated using 1D- and 2D-NMR spectroscopy: 1H,1H COSY, TOCSY, ROESY, 1H,13C HSQC, HSQC-TOCSY, and 1H,13C and 1H,31P HMBC.

Brevibacterium metallicus sp. nov., an endophytic bacterium isolated from roots of Prosopis laegivata grown at the edge of a mine tailing in Mexico.

A Gram-positive, aerobic, nonmotile strain, NM2E3(T) was identified as Brevibacterium based on the 16S rRNA gene sequence analysis and had the highest similarities to Brevibacterium jeotgali SJ5-8(T) (97.3 %). This novel bacterium was isolated from root tissue of Prosopis laegivata grown at the edge of a mine tailing in San Luis Potosí, Mexico. Its cells were non-spore-forming rods, showing catalase and oxidase activities and were able to grow in LB medium added with 40 mM Cu(2+), 72 mM As(5+) and various other toxic elements. Anteiso-C15:0 (41.6 %), anteiso-C17:0 (30 %) and iso-C15:0 (9.5 %) were the major fatty acids. MK-8(H2) (88.4 %) and MK-7(H2) (11.6 %) were the major menaquinones. The DNA G + C content of the strain NM2E3(T) was 70.8 mol % (Tm). DNA-DNA hybridization showed that the strain NM2E3(T) had 39.8, 21.7 and 20.3 % relatedness with B. yomogidense JCM 17779(T), B. jeotgali JCM 18571(T) and B. salitolerans TRM 45(T), respectively. Based on the phenotypic and genotypic analyses, the strain NM2E3(T) (=CCBAU 101093(T) = HAMBI 3627(T) = LMG 8673(T)) is reported as a novel species of the genus Brevibacterium, for which the name Brevibacterium metallicus sp. nov., is proposed.

Identification of Bacteriocin linocin M18 from Brevibacterium and Related Genera using PCR

Fifty bacterial isolates isolated from dairy product, skin and blood from cancer and kidney failure dialysis patients were identified to twenty two species and the following genera:- Brevibacterium, Corynebacterium, Arthrobacter, Actinomyces, Exiguobacterium, Kocuria, Micrococcus, Rothia, Rhodococcus using a set of phenetic characteristics. Twelve isolates of the different species from the genera Brevibacterium, Arthrobacter, Corynebacterium, Kocuria, Rhodococcus, Rothia were selected and probed for lin gene by polymerase chain reaction. One species Kocuria rhizophila which inhibited most of the tested organisms did not have lin gene in the chromosome, while, the species Corynebacterium glucuronolyticum, Arthrobacter comminsii, Arthrobacter oxydans have the lin gene. Our results found there wide distribution of the structural gene encoding this linocin M18 within coryneform bacteria and also in the genus Kocuria.

Bacterial contamination of dental unit waterlines

Safety of patients and dental personnel requires the appropriate microbiological water quality in dental units. During treatment, patients and dental workers are exposed both to direct contact with bacteria-contaminated water in the form of splatter and with contaminated water aerosol emitted during work by unit handpieces, including rotating and ultrasonic instruments. The aim of the study was to determine the qualitative and quantitative contamination of water in dental unit reservoirs with aerobic and facultative anaerobic bacteria. The study material included water sampled from 107 dental unit reservoirs located in dental surgeries of public health centres. Conventional microbiological methods were used to identify microorganisms. The study shows that the contamination of water in dental unit reservoirs with aerobic and facultative anaerobic bacteria is commonplace. The mean concentration of mesophile bacteria in dental unit reservoir water exceeded 1.1 × 105 cfu/ml. The prevailing species were Gram-negative bacteria of the families Burkholderiaceae, Pseudomonadaceae, Ralstoniaceae and Sphingomonadaceae. The most numerous bacteria were Ralstonia pickettii, constituting 49.33 % of all the identified aerobic and facultative anaerobic bacteria. Among Gram-positive rods, the most numerous were bacteria of the genus Brevibacterium (5.83 %), while the highest percentage shares (13.25 %) of all Gram-positive microorganisms were found for Actinomyces spp. The study confirms the necessity of regular monitoring of microbial contamination of dental unit waterlines (DUWL) and use of various water treatment procedures available to disinfect DWUL.