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1.
Sheng Wu Gong Cheng Xue Bao ; 38(4): 1527-1536, 2022 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-35470624

RESUMO

Halomonas can grow on diverse carbon sources. As it can be used for unsterile fermentation under high-salt conditions, it has been applied as a chassis for next-generation industrial biotechnology. Short-chain volatile fatty acids, including acetate, propionate, and butyrate, can be prepared from biomass and are expected to be novel carbon sources for microbial fermentation. Halomonas sp. TD01 and TD08 were subjected to shaking culture with 10-50 g/L butyrate, and they were found to effectively synthesize poly-3-hydroxybutyrate with butyrate as the carbon source. The highest yield of poly-3-hydroxybutyrate was achieved at butyrate concentration of 20 g/L (9.12 g/L and 7.37 g/L, respectively). Butyrate at the concentration > 20 g/L inhibited cell growth, and the yield of poly-3-hydroxybutyrate decreased to < 4 g/L when butyrate concentration was 50 g/L. Moreover, Halomonas sp. TD08 can accumulate the copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate by using propionate and butyrate as carbon sources. However, propionate was toxic to cells. To be specific, when 2 g/L propionate and 20 g/L butyrate were simultaneously provided, cell dry weight and polymer titer were 0.83 g/L and 0.15 g/L, respectively. The addition of glycerol significantly improved cell growth and boosted the copolymer titer to 3.95 g/L, with 3-hydroxyvalerate monomer content of 8.76 mol%. Short-chain volatile fatty acids would be promising carbon sources for the production of polyhydroxyalkanoates by Halomonas.


Assuntos
Halomonas , Poli-Hidroxialcanoatos , Butiratos , Carbono , Ácidos Graxos Voláteis , Propionatos
2.
Bioresour Technol ; 351: 126919, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35240276

RESUMO

The alkali-halophilic Halomonas alkalicola M2 was isolated and developed for an open unsterile polyhydroxyalkanoate (PHA) fermentation from lignocellulose at pH 10.0 and NaCl 70 g/L. The alkaline pretreatment liquid (APL) was converted into PHA by the strain, which was significantly affected by the cultural conditions, including pH, NaCl concentration, nitrogen source, and APL concentration. The extracted PHA was composed of three monomers and similar in physicochemical properties to conventional short chain-length PHA. A record yield of 2.1 and 5.9 g of PHA was accumulated from 100 g dry bamboo powder (BP) by using APL and APL combined with hydrolysate during a 48-h open unsterile fermentation process, respectively. In summary, the alkali-halophilic H. alkalicola M2 achieved the open unsterile fermentation for lignocellulose efficient bioconversion into PHA under high alkalinity and salinity conditions and would be an ideal producer in the field.


Assuntos
Halomonas , Poli-Hidroxialcanoatos , Álcalis , Lignina , Cloreto de Sódio
3.
Bioresour Technol ; 351: 126925, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35272037

RESUMO

Studies toward biotreating hypersaline wastewater containing different salts and halotolerant mechanism of robust strains are important but still rare. Here an isolated bacterium Halomonas salifodinae can perform simultaneous nitrification and denitrification (SND) at 15% salinity, showing high nitrogen removal efficiencies of over 98% via response surface methodology optimization. Besides NaCl, this robust strain had high resistance to other salts (KCl, Na2SO4, and K2SO4) and can efficiently remove nitrogen in saline wastewater containing heavy metals such as Fe(II), Mn(II), Zn(II), Cr(VI), Ni(II), and Cu(II). After repeated-batch culturing at different salinities, the treated strains with different halotolerant capabilities were used as single strain model to study halotolerant mechanism via metabolic analysis. The halotolerant bacterium can convert D-proline and glutamic acid to glutamine as well as lactulose to trehalose. The accumulated intracellular compatible solutes can resist high osmotic pressure and bound water molecule in hypersaline wastewater to accomplish high-efficiency SND processes.


Assuntos
Desnitrificação , Águas Residuárias , Aerobiose , Bactérias/metabolismo , Halomonas , Processos Heterotróficos , Nitrificação , Nitritos , Nitrogênio/metabolismo , Sais
4.
Mar Genomics ; 62: 100890, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35246302

RESUMO

H. boliviensis strain kknpp38 is a dense exopolysaccharide (EPS) producing bacterium, isolated from the early-stage (72-h-old) of marine biofilm. Laboratory experiments demonstrated that this isolate forms a potent biofilm on various artificial substrata viz. polystyrene, stainless steel as well as titanium and possesses high tolerance to chlorine disinfection. To determine the genes and biosynthetic pathways involved in the EPS production, whole-genome sequencing was performed using high-throughput Illumina tag sequencing. The high-quality reads were first de novo assembled using Unicycler genome assembler (version 0.4.9b) and then annotated using Prokka (version 1.13). The complete genome comes from one circular chromosome containing 4.96 Mbp DNA with G + C content of 55%, and encompasses genes encoding 4476 proteins, 2 rRNAs, and 57 tRNAs. Intriguingly, genomic analysis revealed the existence of genes involved in ATP-binding cassette (ABC) transporter-dependent EPS biosynthesis pathways (ugd, ugd2, galU). In addition, we identified genes involved in ectoine (ectA, ectB, ectC, ectD) and polyhydroxyalkanoates (PHAs; fabA, fabB, fabD, fabF, fabH, fabV, fabZ, phaC, phaD, phaG, phaR, phaZ1) production, which are known to involve in bacterial adaptation in saline environment. The outcomes of this study expand scientific understanding on the genes and pathways involved in EPS biosynthesis by marine bacteria.


Assuntos
Cloro , Halomonas , Biofilmes , Cloro/metabolismo , Genes Bacterianos , Genoma Bacteriano , Halomonas/genética
5.
Extremophiles ; 26(1): 14, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35229247

RESUMO

Halophilic bacteria such as the genus Halomonas are promising candidates in diverse industrial, agricultural and biomedical applications. Here, we successfully isolated a halophilic Halomonas alkaliphila strain XH26 from Xiaochaidan Salt Lake, and studied its osmoadaptation strategies using transcriptome and ectoine analysis. Divergent mechanisms were involved in osmoadaptation at different salinities in H. alkaliphila XH26. At moderate salinity (6% NaCl), increased transcriptions of ABC transporters related to iron (III), phosphate, phosphonate, monosaccharide and oligosaccharide import were observed. At high salinity (15% NaCl), transcriptions of flagellum assembly and cell motility were significantly inhibited. The transcriptional levels of ABC transporter genes related to iron (III) and iron3+-hydroxamate import, glycine betaine and putrescine uptake, and cytochrome biogenesis and assembly were significantly up-regulated. Ectoine synthesis and accumulation was significantly increased under salt stress, and the increased transcriptional expressions of ectoine synthesis genes ectB and ectC may play a key role in high salinity induced osmoadaptation. At extreme high salinity (18% NaCl), 5-hydroxyectoine and ectoine worked together to maintain cell survival. Together these results give valuable insights into the osmoadaptation mechanisms of H. alkaliphila XH26, and provide useful information for further engineering this specific strain for increased ectoine synthesis and related applications.


Assuntos
Diamino Aminoácidos , Halomonas , Diamino Aminoácidos/metabolismo , Halomonas/genética , Halomonas/metabolismo , Estresse Salino , Transcriptoma
6.
Microbes Environ ; 37(1)2022.
Artigo em Inglês | MEDLINE | ID: mdl-35296582

RESUMO

Halomonas species, which are aerobic, alkaliphilic, and moderately halophilic bacteria, produce diverse biochemicals. To identify food-related Halomonas strains for bioremediation and the industrial production of biochemicals, 20 strains were isolated from edible seashells, shrimp, and umeboshi (pickled Japanese plum) factory effluents. All isolates were phylogenetically classified into a large clade of Halomonas species. Most isolates, which grew in wide pH (6-13) and salt concentration (0-14%) ranges, exhibited the intracellular accumulation of poly(3-hydroxybutyrate) granules. The characteristics of these isolates varied. A020 isolated from umeboshi factory effluents exhibited enhanced stress tolerance and proliferation and comprised two plasmids. IMZ03 and A020 grew to more than 200 OD600, while IMZ03 produced 3.5% 3-hydroxybutyrate in inorganic medium supplemented with 10% sucrose. The mucus of TK1-1 cultured on agar medium comprised approximately 64| |mM of ectoine. Whole-genome sequencing of A020 was performed to elucidate its origin and genomic characteristics. The genome ana-lysis revealed a region exhibiting synteny with a large virus genome isolated from the ocean, but did not identify any predictable pathogenic genes. Therefore, saline foods and related materials may be suitable resources for isolating Halomonas strains exhibiting unique, useful, and innocuous features.


Assuntos
Halomonas , Biodegradação Ambiental , Alimentos , Halomonas/genética , Filogenia , Cloreto de Sódio
7.
Artigo em Inglês | MEDLINE | ID: mdl-35238736

RESUMO

A Gram-negative, moderately halophilic bacterium, designated as strain Y3S6T, was isolated from a surface seawater sample collected from Dongangyoeng cave, Udo-myeon, Jeju-si, Jeju-do, Repulic of Korea. Cells of strain Y3S6T were aerobic, rod-shaped, non-sporulated, yellow, catalase- negative, oxidase-negative and motile with one polar flagellum. Growth of strain Y3S6T occurred at 15-40 °C (optimum: 25-30 °C), at pH 6.0-9.0 (optimum: pH 7.0) and in the presence of 0-13% NaCl (optimum: 1-6 %, w/v). The novel strain was able to produce carotenoids. Its chemotaxonomic and morphological characteristics were consistent with those of members of the genus Halomonas. Phylogenetic analysis of the 16S rRNA gene sequence revealed that strain Y3S6T formed a clade with Halomonas pellis L5T (98.97 %) and Halomonas saliphila LCB169T(98.90%). The average nucleotide identity and digital DNA-DNA hybridization values of strain Y3S6T with the most closely related strains for which whole genomes are publicly available were 82.3-85.2% and 62.8-66.1 %, respectively. The major fatty acids in strain Y3S6T were C16 : 0, C19 : 0 cyclo ω8c and summed feature 8 (composed of C18 : 1 ω7c and/or C18 : 1 ω6c), and the predominant quinone was Q-9. Its polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unidentified phosphoglycolipid, one unidentified phosphoaminoglycolipid and one unidentified phospholipid. The genomic DNA G+C content based on the draft genome sequence was 64.2 mol%. The results of physiological and biochemical tests and 16S rRNA sequence analysis clearly revealed that strain Y3S6T represents a novel species in the genus Halomonas, for which the name Halomonas antri sp. nov. has been proposed. The type strain is Y3S6T (=KACC 21536T=NBRC 114315=TBRC 15164T).


Assuntos
Halomonas , Técnicas de Tipagem Bacteriana , Composição de Bases , Carotenoides , DNA Bacteriano/genética , Ácidos Graxos/química , Filogenia , RNA Ribossômico 16S/genética , Água do Mar/microbiologia , Análise de Sequência de DNA
8.
Antonie Van Leeuwenhoek ; 115(4): 545-559, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35243586

RESUMO

Here, we report the whole genome of a novel halophilic Halomonas species strain XH36 with high ectoine production potential. The genome was 3,818,310 bp in size with a GC content of 51.97%, and contained 3533 genes, 61 tRNAs and 18 rRNAs. The phylogenetic analysis using the 16s rRNA genes, the UBCGs and the TYGS database indicated that XH36 belongs to a novel Halomonas species, which we named as Halomonas qaidamensis. Osmoadaptation related genes including Na(+) and K(+) transport and compatible solute accumulation were both present in the XH36 genome, the latter of which mainly contained ectoine, 5-hydroxyectoine and betaine. HPLC validation studies showed that H. qaidamensis XH36 accumulated ectoine to cope with salt stress, and the content of ectoine could be as high as 315 mg/g CDW under 3 mol/l NaCl. Our results show that XH36 is a new promising industrial strain for ectoine production, and the genomic analysis will guide us to better understand its salt-induced osmoadaptation mechanisms, and provide theoretical references for future application research of ectoine.


Assuntos
Diamino Aminoácidos , Halomonas , Halomonas/genética , Filogenia , RNA Ribossômico 16S/genética , Sequenciamento Completo do Genoma
9.
Bioresour Technol ; 349: 126865, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35183730

RESUMO

Cadaverine, a derivative of l-lysine, has been used as a monomer for the synthesis of bio-based nylon-5,6. This study engineered Halomonas bluephagenesis TD1.0 by blocking the feedback inhibition, overexpressing the key l-lysine synthesis genes, strengthening the l-lysine export system and increasing the supply of oxaloacetate for production of l-lysine in the supernatant and PHB in the cells. Subsequently, cadaverine biosynthetic pathway was constructed in H. campaniensis LC-9 to improve the efficiency of de novo cadaverine biosynthesis which combines l-lysine producing H. bluephagenesis TDL8-68-259 and cadaverine producing H. campaniensis LC-9-ldcC-lysP. When H. campaniensis LC-9-ldcC-lysP was used as a whole cell catalysis for cadaverine production, the conversion efficiency of l-lysine to cadaverine reached 100% in the presence of 0.05% Triton X-100 for cell membrane permeability enhancement, resulting in 118 g L-1 cadaverine formed in the fermentor. Thus, Halomonas spp. have been successfully constructed for l-lysine and cadaverine production.


Assuntos
Halomonas , Vias Biossintéticas , Cadaverina/metabolismo , Halomonas/genética , Halomonas/metabolismo , Lisina/metabolismo
10.
Microb Biotechnol ; 15(5): 1586-1597, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34978757

RESUMO

Bacterial outer membrane (OM) is a self-protective and permeable barrier, while having many non-negligible negative effects in industrial biotechnology. Our previous studies revealed enhanced properties of Halomonas bluephagenesis based on positive cellular properties by OM defects. This study further expands the OM defect on membrane compactness by completely deleting two secondary acyltransferases for lipid A modification in H. bluephagenesis, LpxL and LpxM, and found more significant advantages than that of the previous lpxL mutant. Deletions on LpxL and LpxM accelerated poly(3-hydroxybutyrate) (PHB) production by H. bluephagenesis WZY229, leading to a 37% increase in PHB accumulation and 84-folds reduced endotoxin production. Enhanced membrane permeability accelerates the diffusion of γ-butyrolactone, allowing H. bluephagenesis WZY254 derived from H. bluephagenesis WZY229 to produce 82wt% poly(3-hydroxybutyrate-co-23mol%4-hydroxybutyrate) (P(3HB-co-23mol%4HB)) in shake flasks, showing increases of 102% and 307% in P(3HB-co-4HB) production and 4HB accumulation, respectively. The 4HB molar fraction in copolymer can be elevated to 32 mol% in the presence of more γ-butyrolactone. In a 7-l bioreactor fed-batch fermentation, H. bluephagenesis WZY254 supported a 84 g l-1 dry cell mass with 81wt% P(3HB-co-26mol%4HB), increasing 136% in 4HB molar fraction. This study further demonstrated that OM defects generate a hyperproduction strain for high 4HB containing copolymers.


Assuntos
Halomonas , 4-Butirolactona , Reatores Biológicos/microbiologia , Halomonas/genética , Hidroxibutiratos , Poliésteres
11.
J Biol Inorg Chem ; 27(2): 221-227, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35094116

RESUMO

Orthovanadate was shown to serve as a substrate for nucleoside phosphorylases from Escherichia coli, Shewanella oneidensis, Geobacillus stearothermophilus, and Halomonas chromatireducens AGD 8-3. An exception is thymidine phosphorylase from the extremophilic haloalkaliphilic bacterium Halomonas chromatireducens AGD 8-3, which cannot catalyze the vanadolysis of nucleosides. The kinetic parameters of nucleoside vanadolysis were evaluated.


Assuntos
Nucleosídeos , Vanadatos , Escherichia coli/metabolismo , Halomonas , Pentosiltransferases/química , Pentosiltransferases/metabolismo , Especificidade por Substrato
12.
Artigo em Inglês | MEDLINE | ID: mdl-35100102

RESUMO

Two novel Gram-stain-negative, facultative anaerobic, non-flagellated, rod-shaped bacterial strains, designated MT13T and MT32, were isolated from sediment samples collected from the Mariana Trench at a depth of 8300 m. The two strains grew at -2-30 °C (optimum, 25 °C), at pH 5.5-10.0 (optimum, pH 7.5-8.0) and with 0-15 % (w/v) NaCl (optimum, 3-6 %). They did not reduce nitrate to nitrite nor hydrolyse Tweens 40 and 80, aesculin, casein, starch and DNA. The genomic G+C contents of draft genomes of strain MT13T and MT32 were 52.2 and 54.1 m ol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains MT13T and MT32 were affiliated with the genus Halomonas, with the highest similarity to the type strain of Halomonas olivaria. The values of average nucleotide identity and in silico DNA-DNA hybridization between strain MT13T and MT32, and between strain MT13T and five closely related type strains of Halomonas species indicated that strains MT13T and MT32 belonged to the same species, but represented a novel species in the genus of Halomonas. The major cellular fatty acids of strains MT13T and MT32 were C16 : 0, summed feature 3(C16 : 1 ω7c/ω6c) and summed feature 8 (C18 : 1 ω7c/ω6c). Major polar lipids of strains MT13T and MT32 included phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol. Ubiquinone-9 was the predominant respiratory quinone. Based on data from the present polyphasic study, strains MT13T and MT32 represent a novel species of the genus Halomonas, for which the name Halomonas profundi sp. nov. is proposed. The type strain is MT13T (=MCCC 1K06389T=KCTC 82923T).


Assuntos
Sedimentos Geológicos/microbiologia , Halomonas , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Halomonas/classificação , Halomonas/isolamento & purificação , Hibridização de Ácido Nucleico , Oceano Pacífico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química
13.
Mar Genomics ; 61: 100911, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35058038

RESUMO

Halomonas sp. MT13, a moderately psychrotolerant, piezotolerant and exopolysaccharide-producing bacterium, was isolated from deep-sea sediment of the Mariana Trench at the depth of 8300 m. Here, we report the complete genome sequence of strain MT13 and its genomic characteristics related to deep-sea environmental adaptation by comparing with its three closely related Halomonas species. The genome of strain MT13 contains one circular chromosome of 3,643,760 bp without any plasmid. Gene annotation, Cluster of Orthologous Groups (COG) and KEGG analysis showed that strain MT13 possesses a serial of genes involved in deep-sea environmental adaptation, including ectoine biosynthesis, osmolyte transport, and cold-shock response. Compared with type strains of three closely related Halomonas species, strain MT13 has higher proportions of genes assigned to translation, ribosomal structure and biogenesis, and coenzyme, lipid and inorganic ion transport and metabolism, but lacks genes involved in flagellar assembly. The genome of strain MT13 would deepen our knowledge on the adaptation strategies of microorganisms dwelling in deep-sea environment.


Assuntos
Halomonas , Aclimatação/genética , Sequência de Bases , Genômica , Halomonas/genética , Filogenia
14.
Environ Sci Pollut Res Int ; 29(15): 22043-22055, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34773587

RESUMO

Large quantities of waste biomass are generated annually worldwide by many industries and are vastly underutilized. However, these wastes contain sugars and other dissolved organic matter and therefore can be exploited to produce microbial biopolymers. In this study, four selected Halomonas strains, namely, Halomonas caseinilytica K1, Halomonas elongata K4, Halomonas smyrnensis S3, and Halomonas halophila S4, were investigated for the production of exopolysaccharides (EPS) using low-cost agro-industrial wastes as the sole carbon source: cheese whey, grape pomace, and glycerol. Interestingly, both yield and monosaccharide composition of EPS were affected by the carbon source. Glucose, mannose, galactose, and rhamnose were the predominant monomers, but their relative molar ratio was different. Similarly, the average molecular weight of the synthesized EPS was affected, ranging from 54.5 to 4480 kDa. The highest EPS concentration (446 mg/L) was obtained for H. caseinilytica K1 grown on cheese whey that produced an EPS composed mostly of galactose, rhamnose, glucose, and mannose, with lower contents of galacturonic acid, ribose, and arabinose and with a molecular weight of 54.5 kDa. Henceforth, the ability of Halomonas strains to use cost-effective substrates, especially cheese whey, is a promising approach for the production of EPS with distinct physicochemical properties suitable for various applications.


Assuntos
Halomonas , Resíduos Industriais , Peso Molecular , Monossacarídeos , Polissacarídeos Bacterianos/química
15.
J Basic Microbiol ; 62(2): 124-134, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34796543

RESUMO

A strain was isolated from an activated sludge system and identified as Halomonas piezotolerans HN2 in this study, which is the first strain in H. piezotolerans with the capability of heterotrophic nitrification and aerobic denitrification. Strain HN2 showed the maximum nitrogen removal rate of 9.10 mg/L/h by utilizing ammonium at the salinity of 3.0%. Under saline environment, HN2 could remove nitrogen efficiently in neutral and slightly alkaline environments, with the carbon sources of sodium succinate and sodium citrate and the C/N ratio of 15-20, and the maximum removal efficiencies of ammonium, nitrite, and nitrate were 100%, 96.35%, and 99.7%, respectively. The genomic information revealed the presence of amoA, napA, and nosZ genes in strain HN2, and the target bands of nirS were obtained via a polymerase chain reaction. Therefore, we inferred that ammonium was mainly utilized for the growth of strain HN2 through assimilation, and another part of the initial ammonium was converted into nitrate through nitrification, and then into gaseous nitrogen through denitrification. This report indicated the potential application of strain HN2 and other nitrifying and denitrifying Halomonas strains in the removal of nitrogen pollution in marine-related environments and also implies the important role of Halomonas in the nitrogen cycle process of the ocean.


Assuntos
Compostos de Amônio , Halomonas , Aerobiose , Desnitrificação , Halomonas/genética , Processos Heterotróficos , Nitrificação , Nitritos , Nitrogênio
16.
Arch Microbiol ; 204(1): 86, 2021 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-34961889

RESUMO

Three yellow-pigmented, Gram-stain-negative, aerobic, motile by flagella and rod-shaped strains, designated as MCT, PC and RC, were isolated from stems of Populus euphratica. Growth of those three strains occurs at 4-40 °C, pH 6.0-10.0 and with 0.5-18.0% (w/v) NaCl. Respiratory quinones contained ubiquinone-9 and ubiquione-8 as major and minor components, respectively. Major fatty acids (> 10%) were summed feature 8 (C18:1ω6c and/or C18:1ω7c), summed feature 3 (C16:1ω6c and/or C16:1ω7c) and C16:0. Polar lipids included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two unidentified phospholipids, one unidentified aminolipid, one unidentified glycolipid and four unidentified lipids. Strains MCT, PC and RC shared pairwise 16S rRNA gene sequence similarities of 99.9-100.0%, and showed higher similarities of 98.4-98.5% with Halomonas songnenensis NEAU-ST10-39T and 98.3-98.4% with Halomonas nanhaiensis YIM M 13059T than to other Halomonas type strains. Genomic comparisons revealed that those three strains had the pan-genome consisting of 4446 orthologous clusters, among which 676 orthologous clusters were absent in other Halomonas type strains. Phylogenomic tree indicated that strains MCT, PC and RC formed an independently stable clade with Halomonas nanhaiensis YIM M 13059T and Halomonas songnenensis NEAU-ST10-39T. The average nucleotide identity and digital DNA-DNA hybridization values between those three strains and other Halomonas type strains were < 89.9% and < 39.3%, respectively. Based upon phenotypic, chemotaxonomic, phylogenetic and genomic results, strains MCT, PC and RC represent a novel species in the genus Halomonas, for which the name Halomonas populi sp. nov. is proposed. The type strain is MCT (= JCM 33545T = MCCC 1K03942T).


Assuntos
Halomonas , Populus , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/análise , Halomonas/genética , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
17.
Arch Microbiol ; 203(10): 6033-6039, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34731274

RESUMO

Strain WRN001T, a Gram-staining-negative, strictly aerobic, non-motile bacterium was isolated from the natural saline-alkali wetland soil of Binhai new district, Tianjin, China (38°46' N, 117°13' E). Cells of strain WRN001T were 0.3-0.5 µm in width and 1.5-2.5 µm in length, and the growth occurred optimally at 33-37 °C, pH 7.5-8.0, and in the presence of 8-10% (w/v) NaCl. Based on 16S rRNA gene sequence analysis, the isolate could be affiliated to the genus Halomonas, and the highest 16S rRNA gene sequence similarity of strain WRN001T to its closest relative Halomonas qiaohouensis DSM 26770 T was 97.5%. The size of the genome as presented here was 5,475,884 bp with a G + C content of 63.8 mol %. The major respiratory quinone of strainWRN001T was Q-9, and the dominant fatty acids were summed feature 8, summed feature 3, C10:0, C12:0, C12:0 3-OH, C16:0, and C17:0 cyclo. The major polar lipids were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phophatidylcholine (PC), two phospholipids (PL), aminolipid (AL), and three unidentified lipids (L). These data combined with the low digital DDH values between strain WRN001T and the close relative, Halomonas alkalitolerans CGMCC 1.9129 T (42.2%) and based on comparisons with currently available genomes, the highest average nucleotide identity (ANIm) value was 91.4% to Halomonas alkalitolerans CGMCC 1.9129 T (GenBank accession No. GCA_001971685.1). Therefore, we propose a novel species in the genus Halomonas to accommodate this novel isolate: Halomonas salipaludis sp. nov. (type strain WRN001T = KCTC 52853 T = ACCC 19974 T).


Assuntos
Halomonas , Álcalis , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Ácidos Graxos/análise , Halomonas/genética , Hibridização de Ácido Nucleico , Fosfolipídeos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Solo , Áreas Alagadas
18.
ACS Synth Biol ; 10(11): 3017-3027, 2021 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-34704752

RESUMO

Itaconic acid (IA), an important five-carbon unsaturated dicarboxylic acid, is one of the top 12 renewable chemicals with an urgent need to reduce industrial production costs. Halomonas bluephagenesis, which possesses the potential for cost-effective bioproduction of chemicals and organic acids due to its ability to grow under open nonsterile conditions and high tolerance to organic acid salts, was genetically engineered and used to produce IA from citrate by a cell catalytic strategy. Here, two essential genes (cis-aconitate decarboxylase encoding gene cadA and aconitase (ACN) encoding gene acn) were introduced into H. bluephagenesis to construct an IA biosynthesis pathway. Further engineering modifications including coexpression of molecular chaperones GroESL, increasing the copy number of the gene encoding rate-limiting enzyme ACN, and weakening the competing pathway were implemented. Under the optimized condition for the cell catalytic system, the engineered strain TAZI-08 produced 451.45 mM (58.73 g/L) IA from 500 mM citrate, with 93.24% conversion in 36 h and a productivity of 1.63 g/(L h). An intermittent feeding strategy further increased the IA titer to 488.86 mM (63.60 g/L). The IA titer and citrate conversion in H. bluephagenesis are the highest among heterologous hosts reported so far, demonstrating that this strain is a suitable chassis for hyperproduction of IA.


Assuntos
Ácido Cítrico/metabolismo , Halomonas/metabolismo , Succinatos/metabolismo , Vias Biossintéticas/fisiologia , Catálise , Hidroxibutiratos/metabolismo , Engenharia Metabólica/métodos , Poliésteres/metabolismo , Poli-Hidroxialcanoatos/metabolismo
19.
Soft Matter ; 17(37): 8474-8482, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34586147

RESUMO

We identify factors leading to aggregation of bacteria in the presence of a surfactant using absorbance and microscopy. Two marine bacteria, Marinobacter hydrocarbonoclasticus SP17 and Halomonas titanicae Bead 10BA, formed aggregates of a broad size distribution in synthetic sea water in the presence of an anionic surfactant, dioctyl sodium sulfosuccinate (DOSS). Both DOSS at high concentrations and calcium ions were necessary for aggregate formation, but DOSS micelles were not required for aggregation. Addition of proteinase K but not DNase1 eliminated aggregate formation over two hours. Finally, swimming motility also enhanced aggregate formation.


Assuntos
Cálcio , Tensoativos , Bactérias , Halomonas , Íons , Marinobacter
20.
Bioresour Technol ; 341: 125818, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34455251

RESUMO

Biotreatment of hypersaline wastewater requires robust strains with high resistance to activity inhibition and even bacterium death, which remains a worldwide challenge. Here Halomonas salifodinae, a simultaneous nitrification and denitrification (SND) bacterium, was isolated by performing repeated-batch acclimation, showing efficient nitrogen removal at 0-15% salinity and low activity inhibition prominently superior to that of other strains such as Pseudomonas sp. and Acinetobacter sp. Community analysis as well as comparison of microbial activity at different salinities revealed an increased relative abundance of halotolerant populations by stimulating their salt tolerance during the repeated-batch process. For single or mixed nitrogen sources at 15% salinity, the SND efficiencies of the isolated strain reached above 95%. The high activities were attributed to the key enzymes AMO and HAO for nitrification as well as NAP and NIR for denitrification. The findings provide a promising acclimation pathway to obtain robust bacteria for biotreatment of hypersaline wastewater.


Assuntos
Nitrificação , Águas Residuárias , Aclimatação , Aerobiose , Bactérias , Desnitrificação , Halomonas , Processos Heterotróficos , Nitrogênio
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