Ginsenoside Rb1, Compound K and 20(S)-Protopanaxadiol Attenuate High-Fat Diet-Induced Hyperlipidemia in Rats via Modulation of Gut Microbiota and Bile Acid Metabolism.

Hyperlipidemia, characterized by elevated serum lipid concentrations resulting from lipid metabolism dysfunction, represents a prevalent global health concern. Ginsenoside Rb1, compound K (CK), and 20(S)-protopanaxadiol (PPD), bioactive constituents derived from Panax ginseng, have shown promise in mitigating lipid metabolism disorders. However, the comparative efficacy and underlying mechanisms of these compounds in hyperlipidemia prevention remain inadequately explored. This study investigates the impact of ginsenoside Rb1, CK, and PPD supplementation on hyperlipidemia in rats induced by a high-fat diet. Our findings demonstrate that ginsenoside Rb1 significantly decreased body weight and body weight gain, ameliorated hepatic steatosis, and improved dyslipidemia in HFD-fed rats, outperforming CK and PPD. Moreover, ginsenoside Rb1, CK, and PPD distinctly modified gut microbiota composition and function. Ginsenoside Rb1 increased the relative abundance of Blautia and Eubacterium, while PPD elevated Akkermansia levels. Both CK and PPD increased Prevotella and Bacteroides, whereas Clostridium-sensu-stricto and Lactobacillus were reduced following treatment with all three compounds. Notably, only ginsenoside Rb1 enhanced lipid metabolism by modulating the PPARγ/ACC/FAS signaling pathway and promoting fatty acid ß-oxidation. Additionally, all three ginsenosides markedly improved bile acid enterohepatic circulation via the FXR/CYP7A1 pathway, reducing hepatic and serum total bile acids and modulating bile acid pool composition by decreasing primary/unconjugated bile acids (CA, CDCA, and ß-MCA) and increasing conjugated bile acids (TCDCA, GCDCA, GDCA, and TUDCA), correlated with gut microbiota changes. In conclusion, our results suggest that ginsenoside Rb1, CK, and PPD supplementation offer promising prebiotic interventions for managing HFD-induced hyperlipidemia in rats, with ginsenoside Rb1 demonstrating superior efficacy.

Mucilaginibacter Phenanthrenivorans sp. nov., a Novel Phenanthrene Degradation Bacterium Isolated from Wetland Soil.

BJC16-A38T, a Gram-negative, aerobic and non-motile rod-shaped strain was isolated from a permafrost wetland soil sample. BJC16-A38T was oxidase- and catalase-positive, and produced pale yellow colonies on modified R2A agar plates. The 16S rRNA gene sequence of BJC16-A38T shared the highest sequence similarity with those of Mucilaginibacter xinganensis BJC16-A31T (97.44%), Mucilaginibacter gotjawali SA3-7T (96.79%) and Mucilaginibacter frigoritolerans FT22T (96.14%). Phylogenetic analysis revealed that BJC16-A38T formed a separate lineage together with strain M. xinganensis BJC16-A31T in the genus Mucilaginibacter. BJC16-A38T contained menaquinone-7 (MK-7) as the predominant isoprenoid quinine. Major fatty acids in cells were iso-C15:0, summed feature 3 (16:1ω7c/16:1ω6c) and iso-C17:03-OH. BJC16-A38T contained phosphatidylethanolamine, two unknown polar lipids, six unidentified phospholipids and an unidentified aminolipid. The Genome of BJC16-A38T was sequenced using the Genome Analyzer IIx sequence platform and 38 contigs were produced in total with an average G + C percentage of 44.00%. The average nucleotide identity (ANI) of BJC16-A38T with respect to those of M. xinganensis BJC16-A31T, M. gotjawali SA3-7T and M. frigoritolerans FT22T were 79.60%, 77.24% and 77.58%, respectively. Digital DNA-DNA hybridization (DDH) values between BJC16-A38T and the tree reference strains were 21.30%, 19.60% and 19.70%, respectively. BJC16-A38T exhibited phenanthrene biodegradation activity that can degrade 88.02% phenanthrene in the MM medium after 7 days cultivation. Phenotypic, chemotaxonomic, phylogenetic and genomic characteristics concluded that strain BJC16-A38T represents a novel species of the genus Mucilaginibacter. Hence, the name Mucilaginibacter phenanthrenivorans sp. nov. is proposed. The type strain is BJC16-A38T (= CGMCC 1.12693T = NBRC 110383T).

Mucilaginibacter xinganensis sp. nov., a phenanthrene-degrading bacterium isolated from wetland soil.

An aerobic, Gram-stain negative, rod-shaped and non-motile strain, BJC16-A31T, was isolated from the wetland soil sample taken from Daxing'anling, Heilongjiang, People's Republic of China. Strain BJC16-A31T was found to be oxidase- and catalase-positive, and produced light orange colonies on modified R2A agar. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BJC16-A31T is closely related to Mucilaginibacter gotjawali SA3-7T with 96.54% sequence similarity and it formed a separate lineage in the genus Mucilaginibacter. Strain BJC16-A31T contained menaquinone-7 (MK-7) as the predominant isoprenoid quinine. Anteiso-C15:0, C16:0 and anteiso-C15:0 were the major fatty acids. The major polar lipids were phosphatidylethanolamine, six unidentified polar lipid, two unidentified aminophospholipids and one unidentified aminolipid. The genome is composed of a circular 5,301,339 bp chromosome with average G + C percentage of 42.25%. The Average Nucleotide Identity (ANI) between strain BJC16-A31T and M. gotjawali SA3-7T was 77.51%. Combined phenotypic, chemotaxonomic, phylogenetic and genomic characteristics support the conclusion that strain BJC16-A31T represents a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter xinganensis sp. nov. is proposed. The type strain is BJC16-A31T (= CGMCC 1.12728T = NBRC 110384T).

Chryseobacterium zhengzhouense sp. nov., isolated from groundwater of the well in a vegetable field, and emended description of the genus Chryseobacterium.

A Gram-negative, strictly aerobic, non-motile, asporogenous rod-shaped bacterium, designated M05W1-39A1(T), was isolated from a Chinese cabbage farmland located in Zhengzhou. China, and subjected to a taxonomic study. Strain M05W1-39A1(T) was found to grow optimally at 25-30 °C, at pH 6.0-7.0 and in the presence of 0.5-2.0 % (w/v) NaCl. According to phylogenetic analysis using 16S rRNA gene sequences, strain M05W1-39A1(T) belongs to the genus Chryseobacterium and is closely related to Chryseobacterium arachidis LMG 27813(T) (98.8 %) and Chryseobacterium geocarposphaera LMG 27811(T) (98.1 %). The DNA G + C content was determined to be 35.3 mol%. The respiratory quinone was identified as MK-6 and the predominant cellular fatty acids as iso-C15:0, Summed feature 3 (C16:1 ω7c/C16:1 ω6c), iso-C17:0 3-OH and Summed feature 9 (iso-C17:1 ω9c). Based on the genotypic, chemotaxonomic and phenotypic data, strain M05W1-39A1(T) is concluded to represent a novel species of the genus Chryseobacterium, for which the name Chryseobacterium zhengzhouense sp. nov. is proposed. The type strain is M05W1-39A1(T) (=HNMC11208(T) = CGMCC 1.15067(T) = JCM 30863(T)).

Construction and application of an expression vector from the new plasmid pLAtc1 of Acidithiobacillus caldus.

In this study, a recently sequenced 9.8-kb plasmid, pLAtc1, from Acidithiobacillus caldus strain SM-1 was characterized and developed into an expression vector. The pLAtc1 backbone carried an oriV, three rep genes, five mob genes, a Nic site, and an addiction system. Multilocus sequence analysis indicated that pLAtc1 was phylogenetically more related to the IncQ-like broad host range plasmids than to other IncQ plasmids. pLAtc1 was able to replicate and reside in Gram-negative Escherichia coli, Comamonas testosteroni, but not in Gram-positive Corynebacterium glutamicum. pLAtc1 was mobilized via conjugation into E. coli BL21 and A. caldus SM-1 from E. coli S17-1. Quantitative PCR revealed seven and four copies of plasmid in A. caldus and E. coli cells, respectively. The expression vector pLAtcE was constructed from pLAtc1 by introducing a regulatable promoter (P tetH ), a transcriptional terminator, a multiple cloning site, a kanamycin resistance gene, and a streptomycin resistance gene. The functionality of pLAtcE was demonstrated by expressing a gene encoding enhanced green fluorescence protein in E. coli and in A. caldus. pLAtcE was used to express α-ketoglutarate dehydrogenase (sucAB) and succinate dehydrogenase (sdhA) genes in A. caldus. The newly engineered strain that harbored sucAB and sdhA on a plasmid pLAtcE-sucA-sucB-sdhA grew better than the parent strain SM-1/pLAtcE in tetrathionate and glucose-supplemented medium and produced more acidity and resulted in a more oxidative environment. This study created a useful molecular tool for genetic manipulation of the thermoacidophilic and autotrophic A. caldus.

Nutritional, Textural, and Sensory Attributes of Protein Bars Formulated with Mycoproteins.

Research accumulated over the past decades has shown that mycoprotein could serve as a healthy and safe alternative protein source, offering a viable substitute for animal- and plant-derived proteins. This study evaluated the impact of substituting whey protein with fungal-derived mycoprotein at different levels (10%, 20%, and 30%) on the quality of high-protein nutrition bars (HPNBs). It focused on nutritional content, textural changes over storage, and sensory properties. Initially, all bars displayed similar hardness, but storage time significantly affected textural properties. In the early storage period (0-5 days), hardness increased at a modest rate of 0.206 N/day to 0.403 N/day. This rate dramatically escalated from 1.13 N/day to 1.36 N/day after 5 days, indicating a substantial textural deterioration over time. Bars with lower mycoprotein levels (10%) exhibited slower hardening rates compared with those with higher substitution levels (20% and 30%), pointing to a correlation between mycoprotein content and increased bar hardness during storage. Protein digestibility was assessed through in vitro gastric and intestinal phases. Bars with no or low-to-medium levels of mycoprotein substitution (PB00, PB10, and PB20) showed significantly higher digestibility (40.3~43.8%) compared with those with the highest mycoprotein content (PB30, 32.9%). However, digestibility rates for all mycoprotein-enriched bars were lower than those observed for whey-protein-only bars (PB00, 84.5%), especially by the end of the intestinal digestion phase. The introduction of mycoprotein enriched the bars' dietary fiber content and improved their odor, attributing a fresh mushroom-like smell. These findings suggest that modest levels of mycoprotein can enhance nutritional value and maintain sensory quality, although higher substitution levels adversely affect texture and protein digestibility. This study underscores the potential of mycoprotein as a functional ingredient in HPNBs, balancing nutritional enhancement with sensory acceptability, while also highlighting the challenges of textural deterioration and reduced protein digestibility at higher substitution levels.

Complete genome sequence of Metallosphaera cuprina, a metal sulfide-oxidizing archaeon from a hot spring.

The genome of the metal sulfide-oxidizing, thermoacidophilic strain Metallosphaera cuprina Ar-4 has been completely sequenced and annotated. Originally isolated from a sulfuric hot spring, strain Ar-4 grows optimally at 65°C and a pH of 3.5. The M. cuprina genome has a 1,840,348-bp circular chromosome (2,029 open reading frames [ORFs]) and is 16% smaller than the previously sequenced Metallosphaera sedula genome. Compared to the M. sedula genome, there are no counterpart genes in the M. cuprina genome for about 480 ORFs in the M. sedula genome, of which 243 ORFs are annotated as hypothetical protein genes. Still, there are 233 ORFs uniquely occurring in M. cuprina. Genome annotation supports that M. cuprina lives a facultative life on CO(2) and organics and obtains energy from oxidation of sulfidic ores and reduced inorganic sulfuric compounds.

Metallosphaera cuprina sp. nov., an acidothermophilic, metal-mobilizing archaeon.

A novel acidothermophilic archaeon, strain Ar-4(T), was isolated from a sulfuric hot spring in Tengchong, Yunnan, China. Cells of strain Ar-4(T) were Gram-staining-negative, irregular cocci and motile by means of flagella. Strain Ar-4(T) grew over a temperature range of 55-75 °C (optimum, 65 °C), a pH range of 2.5-5.5 (optimum, pH 3.5) and a NaCl concentration range of 0-1 % (w/v). The novel strain was aerobic and facultatively chemolithoautotrophic. The strain could extract metal ions from sulfidic ore. It was also able to oxidize reduced sulfur compounds. In addition, it was able to use heterogeneous organic materials for organotrophic growth. The main cellular lipids were calditoglycerocaldarchaeol (CGTE) and caldarchaeol (DGTE). The DNA G+C content of the strain was 40.2 mol%. Analysis of 16S rRNA gene sequences showed that strain Ar-4(T) was phylogenetically related to members of the genus Metallosphaera and had sequence similarities of 97.7 %, 97.0 % and 96.8 % with Metallosphaera hakonensis DSM 7519(T), Metallosphaera sedula DSM 5348(T) and Metallosphaera prunae DSM 10039(T), respectively. Strain Ar-4(T) showed DNA-DNA relatedness values of 47.5 %, 30.8 % and 29.1 % with M. hakonensis DSM 7519(T), M. sedula DSM 5348(T) and M. prunae DSM 10039(T), respectively. The differences in cell motility, the temperature and pH ranges for growth, the ability to utilize carbon sources, the DNA G+C content, and the low DNA-DNA relatedness values distinguished strain Ar-4(T) from recognized species of the genus Metallosphaera. On the basis of these results, it was concluded that strain Ar-4(T) represents a novel species of the genus Metallosphaera, for which the name Metallosphaera cuprina is proposed. The type strain is Ar-4(T) ( = JCM 15769(T) = CGMCC 1.7082(T)).

Genomic analysis of Acidianus hospitalis W1 a host for studying crenarchaeal virus and plasmid life cycles.

The Acidianus hospitalis W1 genome consists of a minimally sized chromosome of about 2.13 Mb and a conjugative plasmid pAH1 and it is a host for the model filamentous lipothrixvirus AFV1. The chromosome carries three putative replication origins in conserved genomic regions and two large regions where non-essential genes are clustered. Within these variable regions, a few orphan orfB and other elements of the IS200/607/605 family are concentrated with a novel class of MITE-like repeat elements. There are also 26 highly diverse vapBC antitoxin-toxin gene pairs proposed to facilitate maintenance of local chromosomal regions and to minimise the impact of environmental stress. Complex and partially defective CRISPR/Cas/Cmr immune systems are present and interspersed with five vapBC gene pairs. Remnants of integrated viral genomes and plasmids are located at five intron-less tRNA genes and several non-coding RNA genes are predicted that are conserved in other Sulfolobus genomes. The putative metabolic pathways for sulphur metabolism show some significant differences from those proposed for other Acidianus and Sulfolobus species. The small and relatively stable genome of A. hospitalis W1 renders it a promising candidate for developing the first Acidianus genetic systems.

Activated hippo signal pathway inhibits cell proliferation and promotes apoptosis in NK/T cell lymphoma cells.

BACKGROUND: Natural Killer T-Cell Lymphoma (NKTCL) is a subtype of Non-Hodgkin's Lymphoma, and its morbidity is ranked the first of T-Cell Lymphoma. Hippo signaling pathway is involved in the pathogenesis of tumors. However, the role of Hippo signaling pathway in the oncogenesis of NKTCL still remains unclear. METHODS: The expressions of mammalian sterile 20-like kinase 1 (MST1) and Yes-associated protein (YAP) were investigated by RT-PCR and Western blotting. Cell viability was detected by MTT assays. Cell cycle and cell apoptosis were determined by flow cytometry. Cell proliferative capacity was detected by colony formation assay. Nude mice xenograft models were established and the tumor sections were analyzed by immunohistochemistry (IHC) staining. RESULTS: The expression of MST1 was significantly down-regulated in NKTCL tissues (n = 30) and cell lines, while the expression of YAP was significantly up-regulated, and the phosphorylation of YAP was inhibited. Overexpression of MST1, knockdown of YAP, or verteporfin (VP) treatment could inhibit cell proliferation, and promote cell cycle arrest and apoptosis in NKTCL cells, while knockdown of MST1 and overexpression of YAP promoted cell proliferation. Additionally, Bcl-2/Bax ratio and downstream effectors of Hippo signaling pathway (c-myc, survivin, cyclinD1, CTGF, and TEAD) were significantly decreased when MST1 was overexpressed and YAP was knocked down or after VP treatment. Furthermore, our mice model demonstrated that activation of Hippo signal pathway suppressed the tumorigenesis of NKTCL. CONCLUSION: The activation of Hippo signal pathway via overexpressing MST1 or down-regulating YAP can inhibit the tumorigenesis of NKTCL.

[Study on SNP of the H-FABP gene and its association with slaughter performance in chicken].

Abstract: In this experiment, Caoke chicken was used to analyze H-FABP gene polymorphism by PCR-SSCP. Results indicated that there were eight mutation sites in Caoke chicken: 332G-->A, 534G-->A, 835C-->T, 1131-->A, 1294C-->A, 2329C-->T, 2372C-->T, 2636C-->T. In seven pairs of primers that generated polymorphisms, only the first pair resulted in genotypes that showed a significant difference in body weight, carcass weight, breast weight, leg weight and half-eviscerated weight (P < 0.05). It implied that H-FABP could have a major effect on slaughter performance or could be linked to gene(s) that significantly affect slaughter performance in chicken.

The Relationship between MC1R Mutation and Plumage Color Variation in Pigeons.

The polymorphisms of MC1R gene play a crucial role in coat color variation in mammals; however, the relationship is still unclear in pigeons. In this study, we sequenced 741 bp fragment of the MC1R for 39 individuals with five plumage color patterns (gray plumage, n = 12; black plumage, n = 9; white plumage, n = 3; spotted plumage, n = 12; red plumage, n = 3). A total of three single nucleotide polymorphisms (SNPs) were detected, including G199A, G225A, and A466G, which subsequently determined four haplotypes (H1-H4). Among them, H1 is the predominant haplotype. Association analysis revealed that H1 and H3 were significantly associated with the black plumage trait (P < 0.05), while the H4 was significantly associated with gray plumage trait (P < 0.05). Furthermore, only diplotype H1H1 was significantly associated with black and gray traits of pigeons. Collectively, our study suggested an association between genetic variation of MC1R and plumage color in pigeon.

Complete genome sequence of the molybdenum-resistant bacterium Bacillus subtilis strain LM 4-2.

Bacillus subtilis LM 4-2, a Gram-positive bacterium was isolated from a molybdenum mine in Luoyang city. Due to its strong resistance to molybdate and potential utilization in bioremediation of molybdate-polluted area, we describe the features of this organism, as well as its complete genome sequence and annotation. The genome was composed of a circular 4,069,266 bp chromosome with average GC content of 43.83 %, which included 4149 predicted ORFs and 116 RNA genes. Additionally, 687 transporter-coding and 116 redox protein-coding genes were identified in the strain LM 4-2 genome.

Resolution of carbon metabolism and sulfur-oxidation pathways of Metallosphaera cuprina Ar-4 via comparative proteomics.

Metallosphaera cuprina is able to grow either heterotrophically on organics or autotrophically on CO2 with reduced sulfur compounds as electron donor. These traits endowed the species desirable for application in biomining. In order to obtain a global overview of physiological adaptations on the proteome level, proteomes of cytoplasmic and membrane fractions from cells grown autotrophically on CO2 plus sulfur or heterotrophically on yeast extract were compared. 169 proteins were found to change their abundance depending on growth condition. The proteins with increased abundance under autotrophic growth displayed candidate enzymes/proteins of M. cuprina for fixing CO2 through the previously identified 3-hydroxypropionate/4-hydroxybutyrate cycle and for oxidizing elemental sulfur as energy source. The main enzymes/proteins involved in semi- and non-phosphorylating Entner-Doudoroff (ED) pathway and TCA cycle were less abundant under autotrophic growth. Also some transporter proteins and proteins of amino acid metabolism changed their abundances, suggesting pivotal roles for growth under the respective conditions. BIOLOGICAL SIGNIFICANCE: The described work is of great significance: For general microbiology: How do extremophile organisms use their unique metabolic capabilities in adapting to autotrophic and hetetrotrophic growth conditions? Which are important enzymes involved in the metabolic adaptation and which enzyme candidate should be investigated in more detail with microbiological/biochemical approaches? For applied microbiology: Which are the key enzymes and reaction pathways for sulfur oxidation and autotrophic growth? This knowledge should accelerate future design of improved bioleaching processes in biomining industries or bioremediation.

Unraveling the Acidithiobacillus caldus complete genome and its central metabolisms for carbon assimilation.

Acidithiobacillus caldus is one of the dominant sulfur-oxidizing bacteria in bioleaching reactors. It plays the essential role in maintaining the high acidity and oxidation of reduced inorganic sulfur compounds during bioleaching process. In this report, the complete genome sequence of A. caldus SM-1 is presented. The genome is composed of one chromosome (2,932,225 bp) and four plasmids (pLAtc1, pLAtc2, pLAtc3, pLAtcm) and it is rich in repetitive sequences (accounting for 11% of the total genome), which are often associated with transposable genetic elements. In particular, twelve copies of ISAtfe and thirty-seven copies of ISAtc1 have been identified, suggesting that they are active transposons in the genome. A. caldus SM-1 encodes all enzymes for the central metabolism and the assimilation of carbon compounds, among which 29 proteins/enzymes were identifiable with proteomic tools. The SM-1 fixes CO(2)via the classical Calvin-Bassham-Benson (CBB) cycle, and can operate complete Embden-Meyerhof pathway (EMP), pentose phosphate pathway (PPP), and gluconeogenesis. It has an incomplete tricarboxylic acid cycle (TCA). Four putative transporters involved in carbohydrate uptake were identified. Taken together, the results suggested that SM-1 was able to assimilate carbohydrates and this was subsequently confirmed experimentally because addition of 1% glucose or sucrose in basic salt medium significantly increased the growth of SM-1. It was concluded that the complete genome of SM-1 provided fundamental data for further investigation of its physiology and genetics, in addition to the carbon metabolism revealed in this study.

Alicyclobacillus aeris sp. nov., a novel ferrous- and sulfur-oxidizing bacterium isolated from a copper mine.

A novel mesophilic, acidophilic, endospore-forming bacterium, designated strain ZJ-6(T), was isolated from Zi-Jin copper mine in Inner Mongolia, China. Cells of strain ZJ-6(T) were rod-shaped, stained Gram-positive or were Gram-variable, and grew aerobically at 25-35 degrees C (optimum, 30 degrees C) and pH 2.0-6.0 (optimum, pH 3.5). 16S rRNA gene sequence analysis showed that strain ZJ-6(T) was related phylogenetically to members of the genus Alicyclobacillus, with 16S rRNA gene sequence similarities of 89.5-94.2 %. Cells contained MK-7 as the major quinone and the DNA G+C content was 51.2 mol%. Strain ZJ-6(T) possessed a number of phenotypic characteristics that differentiated it from recognized Alicyclobacillus species, including its growth temperature, assimilation of various carbon sources, production of acids from a range of compounds, and the ability to grow chemoautotrophically using ferrous iron, elemental sulfur and tetrathionate as electron donors. The predominant cellular fatty acids of strain ZJ-6(T) were anteiso-C(15 : 0) (67.1 %), iso-C(16 : 0) (7.7 %) and anteiso-C(17 : 0) (7.4 %); omega-alicyclic fatty acids were not found. On the basis of these results, it is concluded that strain ZJ-6(T) represents a novel species within the genus Alicyclobacillus, for which the name Alicyclobacillus aeris sp. nov. is proposed; the type strain is ZJ-6(T) (=CGMCC 1.7072(T)=NBRC 104953(T)).

[Degradation of soil phenolic acids by Phanerochaete chrysosporium under continuous cropping of cucumber].

With inoculation of Phanerochaete chrysosporium in shaking flask, this paper studied the degradation of soil p-hydroxybenzoic acid, vanillic acid and ferulic acid under continuous cropping of cucumber, and evaluated the effect of this inoculation in overcoming the continuous cropping obstacle of cucumber. The results showed that after 8 days of inoculation, more than 99% of soil phenolic acids were decomposed by P. chrysosporium. Compared with the control, the contents of soil phenolic acids under 7 years continuous cropping of cucumber declined, with a degradation rate of 54.46%. After inoculating P. chrysosporium, soil fungal population and the plant height, stem width, and fresh and dry mass of cucumber had less change, but the occurrence of cucumber root diseases reduced greatly, with the relative disease index of wilt and root knot nematode declined by 10.2% and 14.6%, respectively. It was suggested that inoculation of P. chrysosporium had definite effect in overcoming the continuous cropping obstacle of cucumber.

Alicyclobacillus ferrooxydans sp. nov., a ferrous-oxidizing bacterium from solfataric soil.

A novel mesophilic and acidophilic Gram-positive bacterium, designated strain TC-34(T), was isolated from solfataric soil. Strain TC-34(T) grew aerobically at 17-40 degrees C and pH 2.0-6.0, and optimally at 28 degrees C and pH 3.0. Analysis based on 16S rRNA gene sequences showed that strain TC-34(T) was phylogenetically related to members of the genus Alicyclobacillus, with the highest similarity (94.8 %) to Alicyclobacillus pomorum. Strain TC-34(T) showed a range of phenotypic characteristics that differentiated it from recognized Alicyclobacillus species, including growth temperature, assimilation of carbon sources and production of acids from a range of compounds. Strain TC-34(T) was able to oxidize ferrous iron and its growth was correlated with the oxidation of Fe(2+) in culture medium. omega-Alicyclic fatty acids were not detected. On the basis of these results, it was concluded that strain TC-34(T) represents a novel species of the genus Alicyclobacillus, for which the name Alicyclobacillus ferrooxydans (type strain TC-34(T)=JCM 15090(T)=CGMCC 1.6357(T)) is proposed.