scholarly journals Expression of an alcohol dehydrogenase gene in a heterotrophic bacterium induces carbon dioxide-dependent high-yield growth under oligotrophic conditions

Microbiology ◽  
2020 ◽  
Vol 166 (6) ◽  
pp. 531-545
Author(s):  
Shinnosuke Inaba ◽  
Hironori Sakai ◽  
Hiromi Kato ◽  
Takayuki Horiuchi ◽  
Hirokazu Yano ◽  
...  

Sphingobium japonicum strain UT26, whose γ-hexachlorocyclohexane-degrading ability has been studied in detail, is a typical aerobic and heterotrophic bacterium that needs organic carbon sources for its growth, and cannot grow on a minimal salt agar medium prepared without adding any organic carbon sources. Here, we isolated a mutant of UT26 with the ability to grow to visible state on such an oligotrophic medium from a transposon-induced mutant library. This high-yield growth under oligotrophic conditions (HYGO) phenotype was CO2-dependent and accompanied with CO2 incorporation. In the HYGO mutant, a transposon was inserted just upstream of the putative Zn-dependent alcohol dehydrogenase (ADH) gene (adhX) so that the adhX gene was constitutively expressed, probably by the transposon-derived promoter. The adhX-deletion mutant (UT26DAX) harbouring a plasmid carrying the adhX gene under the control of a constitutive promoter exhibited the HYGO phenotype. Moreover, the HYGO mutants spontaneously emerged among the UT26-derived hypermutator strain cells, and adhX was highly expressed in these HYGO mutants, while no HYGO mutant appeared among UT26DAX-derived hypermutator strain cells, indicating the necessity of adhX for the HYGO phenotype. His-tagged AdhX that was expressed in Escherichia coli and purified to homogeneity showed ADH activity towards methanol and other alcohols. Mutagenesis analysis of the adhX gene indicated a correlation between the ADH activity and the HYGO phenotype. These results demonstrated that the constitutive expression of an adhX-encoding protein with ADH activity in UT26 leads to the CO2-dependent HYGO phenotype. Identical or nearly identical adhX orthologues were found in other sphingomonad strains, and most of them were located on plasmids, suggesting that the adhX-mediated HYGO phenotype may be an important adaptation strategy to oligotrophic environments among sphingomonads.

2013 ◽  
Vol 63 (Pt_4) ◽  
pp. 1317-1322 ◽  
Author(s):  
Yan-Zhou Zhang ◽  
Ming-Xu Fang ◽  
Wen-Wu Zhang ◽  
Tian-Tian Li ◽  
Min Wu ◽  
...  

A novel anaerobic, heterotrophic bacterium, designated strain Zn2T, was isolated from the wastewater of a paper mill in Zhejiang, China. Cells were Gram-type-positive rods, 0.5–0.8 µm wide and 2–4 µm long, and were motile by a lateral flagellum. The ranges of temperature and pH for growth were 10–50 °C and pH 6.0–9.5. Optimal growth occurred at 35 °C and pH 7.3–7.5. The strain did not require NaCl for growth, but its inclusion in the medium improved growth (optimum concentration 6 %). Substrates utilized as sole carbon sources were peptone, tryptone, Casamino acids, d-xylose, salicin, glycerol, formate, acetate and propionate. The main products of carbohydrate fermentation were acetate, formate, propionate and lactate. Elemental sulfur, thiosulfate and Fe(III) were used as electron acceptors, but sulfate, sulfite, nitrate, nitrite and Mn(IV) were not. Growth was inhibited by the addition of 10 µg ampicillin, penicillin, tetracycline or chloramphenicol ml−1. iso-C15 : 0, C14 : 0, C16 : 0, C16 : 1 cis9 and C18 : 1 cis9 were the major fatty acids. Strain Zn2T did not contain any detectable menaquinones or ubiquinones. The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylserine, two unknown phospholipids and four unknown glycolipids. The genomic DNA G+C content was 37 mol%, as determined by HPLC. 16S rRNA gene sequence analysis revealed that strain Zn2T was a member of family Clostridiaceae , and was most closely related to the type strains of Geosporobacter subterraneus , Thermotalea metallivorans and Caminicella sporogenes , showing 91.2, 90.3 and 91.1 % sequence similarity, respectively. On the basis of its phenotypic and genotypic properties, strain Zn2T is suggested to represent a novel species of a new genus, for which the name Salimesophilobacter vulgaris gen. nov., sp. nov. is proposed. The type strain of Salimesophilobacter vulgaris is Zn2T ( = DSM 24770T  = JCM 17796T).


2021 ◽  
Vol 7 (6) ◽  
Author(s):  
Paolo Emidio Costantini ◽  
Andrea Firrincieli ◽  
Stefano Fedi ◽  
Carola Parolin ◽  
Carlo Viti ◽  
...  

The vaginal microbiota, normally characterized by lactobacilli presence, is crucial for vaginal health. Members belonging to L. crispatus and L. gasseri species exert crucial protective functions against pathogens, although a total comprehension of factors that influence their dominance in healthy women is still lacking. Here we investigated the complete genome sequence and comprehensive phenotypic profile of L. crispatus strain BC5 and L. gasseri strain BC12, two vaginal strains featured by anti-bacterial and anti-viral activities. Phenotype microarray (PM) results revealed an improved capacity of BC5 to utilize different carbon sources as compared to BC12, although some specific carbon sources that can be associated to the human diet were only metabolized by BC12, i.e. uridine, amygdalin, tagatose. Additionally, the two strains were mostly distinct in the capacity to utilize the nitrogen sources under analysis. On the other hand, BC12 showed tolerance/resistance towards twice the number of stressors (i.e. antibiotics, toxic metals etc.) with respect to BC5. The divergent phenotypes observed in PM were supported by the identification in either BC5 or BC12 of specific genetic determinants that were found to be part of the core genome of each species. The PM results in combination with comparative genome data provide insights into the possible environmental factors and genetic traits supporting the predominance of either L. crispatus BC5 or L. gasseri BC12 in the vaginal niche, giving also indications for metabolic predictions at the species level.


Microbiology ◽  
2021 ◽  
Vol 167 (7) ◽  
Author(s):  
Poulami Ghosh ◽  
Anik Barman ◽  
Sujoy K. Das Gupta

In Mycobacterium smegmatis (renamed Mycolicibacterium smegmatis ), glucose 6-phosphate (G6P) level is exceptionally high as compared to other bacteria, E. coli for example. Earlier investigations have indicated that G6P protects M. smegmatis (Msm) against oxidative stress-inducing agents. G6P is a glycolytic intermediate formed either directly through the phosphorylation of glucose or indirectly via the gluconeogenic pathway. Its consumption is catalysed by several enzymes, one of which being the NADPH dependent G6P dehydrogenase (G6PDH) encoded by zwf (msmeg_0314). While investigating the extent to which the carbon sources glucose and glycerol influence Msm growth, we observed that intracellular concentration of G6P was lower in the former’s presence than the latter. We could correlate this difference with that in the growth rate, which was higher in glycerol than glucose. We also found that lowering of G6P content in glucose-grown cells was triggered by the induced expression of zwf and the resultant increase in G6PDH activity. When we silenced zwf using CRISPR-Cas9 technology, we observed a significant rise in the growth rate of Msm. Therefore, we have found that depletion of G6P in glucose-grown cells due to increased G6PDH activity is at least one reason why the growth rate of Msm in glucose is less than glycerol. However, we could not establish a similar link-up between slow growth in glucose and lowering of G6P level in the case of Mycobacterium tuberculosis (Mtb). Mycobacteria, therefore, may have evolved diverse mechanisms to ensure that they use glycerol preferentially over glucose for their growth.


2014 ◽  
Vol 64 (Pt_9) ◽  
pp. 3146-3152 ◽  
Author(s):  
Sylvain Brisse ◽  
Virginie Passet ◽  
Patrick A. D. Grimont

Strains previously classified as members of Klebsiella pneumoniae phylogroups KpI, KpII-A, KpII-B and KpIII were characterized by 16S rRNA (rrs) gene sequencing, multilocus sequence analysis based on rpoB, fusA, gapA, gyrA and leuS genes, average nucleotide identity and biochemical characteristics. Phylogenetic analysis demonstrated that KpI and KpIII corresponded to K. pneumoniae and Klebsiella variicola , respectively, whereas KpII-A and KpII-B formed two well-demarcated sequence clusters distinct from other members of the genus Klebsiella . Average nucleotide identity between KpII-A and KpII-B was 96.4 %, whereas values lower than 94 % were obtained for both groups when compared with K. pneumoniae and K. variicola . Biochemical properties differentiated KpII-A, KpII-B, K. pneumoniae and K. variicola , with acid production from adonitol and l-sorbose and ability to use 3-phenylproprionate, 5-keto-d-gluconate and tricarballylic acid as sole carbon sources being particularly useful. Based on their genetic and phenotypic characteristics, we propose the names Klebsiella quasipneumoniae subsp. quasipneumoniae subsp. nov. and K. quasipneumoniae subsp. similipneumoniae subsp. nov. for strains of KpII-A and KpII-B, respectively. The type strain of K. quasipneumoniae sp. nov. and of K. quasipneumoniae subsp. quasipneumoniae subsp. nov. is 01A030T ( = SB11T = CIP 110771T = DSM 28211T). The type strain of K. quasipneumoniae subsp. similipneumoniae subsp. nov. is 07A044T ( = SB30T = CIP 110770T = DSM 28212T). Both strains were isolated from human blood cultures. This work also showed that Klebsiella singaporensis is a junior heterotypic synonym of K. variicola .


2013 ◽  
Vol 63 (Pt_1) ◽  
pp. 219-223 ◽  
Author(s):  
P. Schumann ◽  
R. Pukall ◽  
C. Spröer ◽  
E. Stackebrandt

16S rRNA gene sequences deposited for the type strains of Paraoerskovia marina (CTT-37T; GenBank accession no. AB445007) and Koreibacter algae (DSW-2T; FM995611) show a similarity of 100 %. Consequently, the type strains were subjected to a polyphasic recharacterization under direct comparison in order to clarify their taxonomic position. PvuII RiboPrint patterns and quantitative ratios of cellular fatty acids revealed strain-specific differences between P. marina DSM 21750T ( = CTT-37T) and K. algae DSM 22126T ( = DSW-2T). The percentage of DNA–DNA binding of 94 % indicated that the two type strains belong to the same genomospecies. Agreement in the peptidoglycan structure and polar lipid pattern, highly similar fatty acid profiles and MALDI-TOF mass spectra, the ability to produce acid from the same carbon sources, corresponding enzymic activities and DNA G+C contents of 70.8±0.3 mol%, in addition to the consistent characteristics reported in the original descriptions, support the view that the two strains should be affiliated to the same species. According to Rules 38 and 42 of the Bacteriological Code, Koreibacter algae should be reclassified as later heterotypic synonym of Paraoerskovia marina , and the descriptions of the genus Paraoerskovia Khan et al. 2009 and of Paraoerskovia marina Khan et al. 2009 are emended accordingly.


2020 ◽  
Vol 70 (9) ◽  
pp. 4960-4965 ◽  
Author(s):  
Jianyang Li ◽  
Mingming Qi ◽  
Qiliang Lai ◽  
Xianhua Liu ◽  
Zongze Shao

A Gram-stain-negative, motile, aerobic and heterotrophic bacterium, designated as GYS_M3HT, was isolated from marine coastal sediment sampled at Xiamen Island. Cells were rod-shaped with one polar flagellum and weakly positive for oxidase and catalase. Growth of the strain occurred at pH 6–9 (optimum, pH 7–8), at 15–37 °C (optimum, 28 °C) and with NaCl concentrations of 1.0–6.0 % (optimum, 2.0 %). It had highest 16S rRNA similarity (97.7 %) to Ketobacter alkanivorans GI5T, followed by the members of the genus Alcanivorax (lower than 91.2 %). The results of phylogenetic analysis indicated that it belonged to the genus Ketobacter within the family Alcanivoracaceae . In addition, the average nucleotide identity and digital DNA–DNA hybridization values between strain GYS_M3HT and K. alkanivorans GI5T were 71.4 and 19.7 %, respectively, indicating that strain GYS_M3HT belonged to a novel species. Its genome consisted of 5 318 758 bp, with a genomic DNA G+C content of 50.0 mol%. The respiratory quinone was Q-8 and the dominant fatty acids were identified as iso-C15 : 0 (25.4 %), C16 : 1  ω6c/C16 : 1  ω7c (14.4 %) and iso-C13 : 0 (7.2 %). The main polar lipids were phosphatidylethanolamine and phosphatidylglycerol. Therefore, based on phenotypic, chemotaxonomic and phylogenetic results, strain GYS_M3HT represents a novel species within the genus Ketobacter , for which the name Ketobacter nezhaii sp. nov. is proposed, with the type strain GYS_M3HT (=MCCC 1A13808T=KCTC 72247T).


Author(s):  
Ling-Fei Lu ◽  
Yang Yang ◽  
Li-Juan Chai ◽  
Zhen-Ming Lu ◽  
Li-Qiang Zhang ◽  
...  

A novel Gram-positive, non-motile, non-flagellated, strictly anaerobic, non-spore-forming and dumbbell-shaped, coccoid- or chain-shaped bacterium, designated strain LZLJ-3T, was isolated from a mud fermentation cellar which has been used for the production of Chinese strong-flavour liquor for over 100 years. Strain LZLJ-3T grew at 20–40 °C (optimum, 37 °C), at pH 6.0–8.0 (optimum, pH 8.0) and with NaCl concentrations up to 1 % (w/v; optimum, 0 %). Phylogenetic trees established based on 16S rRNA gene sequences showed that strain LZLJ-3T belonged to the genus Blautia of the family Lachnospiraceae, with the highest sequence similarity to Blautia stercoris GAM6-1T (91.7 %) and Blautia faecicola KGMB01111T (91.7 %). Comparative genome analysis showed that the orthologous average nucleotide identity (OrthoANI) and genome-to-genome distance (GGD) values between strain LZLJ-3T and B. stercoris GAM6-1T were respectively 69.1 and 22.9 %; the OrthoANI and GGD values between strain LZLJ-3T and B. faecicola KGMB01111T were respectively 70.86 and 36 % . The DNA G+C content of strain LZLJ-3T genome was 42.1 mol%. The predominant celluar fatty acids (>10 %) of strain LZLJ-3T were C16 : 0 FAME (27.9 %), C14 : 0 FAME (17.6 %) and C16 : 0 DMA (13.0 %). Arabinose, glucose and maltose could be utilized by strain LZLJ-3T as sole carbon sources for growth, with weak utilization of raffinose and l-fucose. API ZYM analysis gave positive reactions with α-galactosidase, β-galactosidase, α-glucosidase and β-glucosidase. The major end product of glucose fermentation was acetic acid. Based on the results of phenotypic, genotypic and phylogenetic analyses, strain LZLJ-3T is considered to represent a novel species of Blautia , for which the name Blautia liquoris sp. nov. is proposed. The type strain is LZLJ-3T (=KCTC 25163T=CGMCC 1.5299T=JCM 34225T).


Author(s):  
Da Min Jung ◽  
Yeong Seok Kim ◽  
Jeong Hwan Bang ◽  
Seung Bum Kim

This paper presents a polyphasic taxonomic study of a Gram-stain-negative bacterium designated GA093T, a soil isolate capable of benzo(α)pyrene degradation. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain GA093T is a member of the genus Flavobacterium , and formed an independent phylogenetic line while clustering with the type strains of Flavobacterium hibernum , Flavobacterium branchiarum and Flavobacterium hydatis . Strain GA093T was facultatively anaerobic, and could grow at 4–33 °C (optimum, 30 °C), at pH 6–11 (optimum, pH 7) and in the presence of 0–2 % (w/v) NaCl (optimum, 0 %). Strain GA093T was capable of producing acid from various carbon sources, which was comparable to other related species of Flavobacterium . The strain contained MK-6 as the only isoprenoid quinone, iso-C15 : 0 as the major cellular fatty acid, phosphatidylethanolamine and phosphatidylinositol as diagnostic polar lipids, and sym-homospermidine as the major polyamine. The chemotaxonomic properties of strain GA093T were consistent with the general properties of Flavobacterium except the presence of phosphatidylinositol, which distinguished it from other related species. The total stretch of the obtained genome of GA093T was 5.05 Mbp, and the DNA G+C content was 34.79 mol%. The genome contained genes potentially related to the degradation of aromatic hydrocarbons. On the basis of the present polyphasic analysis, strain GA093T was found to have properties that distunguished it as representing a novel species of the genus Flavobacterium , for which the name Flavobacterium hydrocarbonoxydans sp. nov. is proposed. The type strain is GA093T (=KCTC 72594T=LMG 31760T).


2013 ◽  
Vol 63 (Pt_9) ◽  
pp. 3197-3203 ◽  
Author(s):  
Felizitas Bajerski ◽  
Lars Ganzert ◽  
Kai Mangelsdorf ◽  
André Lipski ◽  
Hans-Jürgen Busse ◽  
...  

A novel psychrotolerant, Gram-negative, shiny white, curved-rod-shaped, facultatively anaerobic bacterium PB1T was isolated from a soil sample collected from a glacier forefield of the Larsemann Hills, East Antarctica. Isolate PB1T has catalase and low urease activity and hydrolyses gelatin and starch. Strain PB1T is able to grow between −5 °C and 30 °C with optimum growth at 14–20 °C. Glycerol, dl-arabinose, d-xylose, d-galactose, d-fructose, d-lyxose, d-fucose and potassium gluconate are used as sole carbon sources. The major quinone is ubiquinone Q-8. The major fatty acids (>10 %) for PB1T are C16 : 0 (19.1 %), C16 : 1ω7cis (44.6 %) and C18 : 1ω7cis (16.2 %). The major polyamines are putrescine [54.9 µmol (g dry weight)−1] and 2-hydroxy putrescine [18.5 µmol (g dry weight)−1]. DNA G+C content is 62.5 mol%. Strain PB1T is phylogenetically related to species of the genus Herbaspirillum , with highest 16S rRNA gene sequence similarities to Herbaspirillum canariense (97.3 %), Herbaspirillum aurantiacum (97.2 %), Herbaspirillum soli (97.2 %) and Herbaspirillum frisingense (97.0 %). The DNA–DNA relatedness values were below 30 % between PB1T and the type strains of Herbaspirillum canariense , Herbaspirillum aurantiacum and Herbaspirillum soli . The different geographical origin of strain PB1T from its closest phylogenetic relatives resulted in different phenotypic and genotypic specifications, whereby strain PBT represents a novel species of the genus Herbaspirillum , for which the name Herbaspirillum psychrotolerans is proposed. The type strain is PB1T (DSM 26001T = LMG 27282T).


2014 ◽  
Vol 64 (Pt_4) ◽  
pp. 1134-1141 ◽  
Author(s):  
Freek Spitaels ◽  
Anneleen Wieme ◽  
Tom Balzarini ◽  
Ilse Cleenwerck ◽  
Anita Van Landschoot ◽  
...  

Three strains, LMG 27748T, LMG 27749 and LMG 27882 with identical MALDI-TOF mass spectra were isolated from samples taken from the brewery environment. Analysis of the 16S rRNA gene sequence of strain LMG 27748T revealed that the taxon it represents was closely related to type strains of the species Gluconobacter albidus (100 % sequence similarity), Gluconobacter kondonii (99.9 %), Gluconobacter sphaericus (99.9 %) and Gluconobacter kanchanaburiensis (99.5 %). DNA–DNA hybridization experiments on the type strains of these species revealed moderate DNA relatedness values (39–65 %). The three strains used d-fructose, d-sorbitol, meso-erythritol, glycerol, l-sorbose, ethanol (weakly), sucrose and raffinose as a sole carbon source for growth (weak growth on the latter two carbon sources was obtained for strains LMG 27748T and LMG 27882). The strains were unable to grow on glucose-yeast extract medium at 37 °C. They produced acid from meso-erythritol and sucrose, but not from raffinose. d-Gluconic acid, 2-keto-d-gluconic acid and 5-keto-d-gluconic acid were produced from d-glucose, but not 2,5-diketo-d-gluconic acid. These genotypic and phenotypic characteristics distinguish strains LMG 27748T, LMG 27749 and LMG 27882 from species of the genus Gluconobacter with validly published names and, therefore, we propose classifying them formally as representatives of a novel species, Gluconobacter cerevisiae sp. nov., with LMG 27748T ( = DSM 27644T) as the type strain.


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