Improving Flavonoid Accumulation of Bioreactor-Cultured Adventitious Roots in Oplopanax elatus Using Yeast Extract.

Oplopanax elatus is an endangered medicinal plant, and adventitious root (AR) culture is an effective way to obtain its raw materials. Yeast extract (YE) is a lower-price elicitor and can efficiently promote metabolite synthesis. In this study, the bioreactor-cultured O. elatus ARs were treated with YE in a suspension culture system to investigate the elicitation effect of YE on flavonoid accumulation, serving for further industrial production. Among YE concentrations (25-250 mg/L), 100 mg/L YE was the most suitable for increasing the flavonoid accumulation. The ARs with various ages (35-, 40-, and 45-day-old) responded differently to YE stimulation, where the highest flavonoid accumulation was found when 35-day-old ARs were treated with 100 mg/L YE. After YE treatment, the flavonoid content increased, peaked at 4 days, and then decreased. By comparison, the flavonoid content and antioxidant activities in the YE group were obviously higher than those in the control. Subsequently, the flavonoids of ARs were extracted by flash extraction, where the optimized extraction process was: 63% ethanol, 69 s of extraction time, and a 57 mL/g liquid-material ratio. The findings provide a reference for the further industrial production of flavonoid-enriched O. elatus ARs, and the cultured ARs have potential application for the future production of products.

Adventitious root cultures of Oplopanax elatus inhibit LPS-induced inflammation via suppressing MAPK and NF-κB signaling pathways.

Bioreactor-cultured adventitious roots (ARs) of the endangered medicinal plant Oplopanax elatus Nakai is a novel alternative plant material. To utilize ARs in the product production, the present study investigated the anti-inflammatory effect of O. elatus ARs. In the in vivo experiment, lipopolysaccharide (LPS)-induced acute lung injury disease model was established and several inflammatory indexes were determined. For the LPS-stimulated mice, after pretreatment of AR crude extract (200 mg/kg), cell infiltration in lungs was decreased, the production of proinflammatory mediators, including nitric oxide (NO), tumor necrosis factor (TNF)-α, and interleukin (IL)-6, and 1ß in the bronchoalveolar lavage fluid was evidently reduced, which indicated that O. elatus ARs had an anti-inflammatory effect. In the in vitro experiment, ethyl acetate (EtOAc) fractions (12.5, 25, and 50 µg/mL) were used to treat LPS-induced peritoneal macrophages (PMs) of mice. The production of NO, prostaglandin E2, TNF-α, IL-6, and IL-1ß in LPS-stimulated PMs was obviously inhibited (p < 0.05) after pretreatment with EtOAc fractions, and the expression of the inducible nitric oxide synthase and cyclooxygenase were also suppressed. To clarify the anti-inflammatory mechanism, effects of EtOAc fraction on changes of proteins related to the pathways of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-κB) were investigated. The phosphorylation of extracellular regulated protein kinases, c-jun n-terminal kinase, and p38 MAPK in LPS-induced PMs was inhibited after pretreatment of EtOAc fractions. In addition, EtOAc fractions enhanced inhibitor of nuclear factor-kappa B-α expression and decreased nuclear translocation of p65 NF-κB. Thus, EtOAc from O. elatus ARs is involved in regulating MAKP and NF-κB signaling pathways to inhibit LPS-induced inflammation.

Microbial conversion of major ginsenosides in ginseng total saponins by Platycodon grandiflorum endophytes.

BACKGROUND: In this study, we screened and identified an endophyte JG09 having strong biocatalytic activity for ginsenosides from Platycodon grandiflorum, converted ginseng total saponins and ginsenoside monomers, determined the source of minor ginsenosides and the transformation pathways, and calculated the maximum production of minor ginsenosides for the conversion of ginsenoside Rb1 to assess the transformation activity of endophyte JG09. METHODS: The transformation of ginseng total saponins and ginsenoside monomers Rb1, Rb2, Rc, Rd, Rg1 into minor ginsenosides F2, C-K and Rh1 using endophyte JG09 isolated by an organizational separation method and Esculin-R2A agar assay, as well as the identification of transformed products via TLC and HPLC, were evaluated. Endophyte JG09 was identified through DNA sequencing and phylogenetic analysis. RESULTS: A total of 32 ß-glucosidase-producing endophytes were screened out among the isolated 69 endophytes from P. grandiflorum. An endophyte bacteria JG09 identified as Luteibacter sp. effectively converted protopanaxadiol-type ginsenosides Rb1, Rb2, Rc, Rd into minor ginsenosides F2 and C-K, and converted protopanaxatriol-type ginsenoside Rg1 into minor ginsenoside Rh1. The transformation pathways of major ginsenosides by endophyte JG09 were as follows: Rb1→Rd→F2→C-K; Rb2→C-O→C-Y→C-K; Rc→C-Mc1→C-Mc→C-K; Rg1→Rh1. The maximum production rate of ginsenosides F2 and C-K reached 94.53% and 66.34%, respectively. CONCLUSION: This is the first report about conversion of major ginsenosides into minor ginsenosides by fermentation with P. grandiflorum endophytes. The results of the study indicate endophyte JG09 would be a potential microbial source for obtaining minor ginsenosides.

Mucilaginibacter daejeonensis sp. nov., isolated from dried rice straw.

A novel strain, designated Jip 10(T), isolated from dried rice straw, was characterized by a polyphasic approach to clarify its taxonomic position. The isolate was Gram-negative, facultatively aerobic, heterotrophic, non-motile, non-spore-forming and rod-shaped. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate clustered with the genus Mucilaginibacter in the phylum Bacteroidetes. 16S rRNA gene sequence similarities between strain Jip 10(T) and the type strains of Mucilaginibacter gracilis and Mucilaginibacter paludis were 93.7 and 93.6 %, respectively. The G+C content of the genomic DNA was 48.1 mol%. Chemotaxonomic data [major menaquinone MK-7 and major fatty acids iso-C(15 : 0), iso-C(17 : 0) 3-OH and summed feature 3 (iso-C(15 : 0) 2-OH and/or C(16 : 1)omega7c)] supported the affiliation of strain Jip 10(T) to the genus Mucilaginibacter. However, the results of physiological and biochemical tests allowed phenotypic differentiation of strain Jip 10(T) from other Mucilaginibacter species with validly published names. Therefore, strain Jip 10(T) (=KCTC 12639(T) =LMG 23488(T)) was classified in the genus Mucilaginibacter as the type strain of a novel species, for which the name Mucilaginibacter daejeonensis sp. nov. is proposed.

Aeromicrobium panaciterrae sp. nov., isolated from soil of a ginseng field in South Korea.

A Gram-positive, rod-shaped, non-spore-forming and strictly aerobic bacterium (Gsoil 161(T)) was isolated from soil of a ginseng field in Pocheon Province, South Korea. The novel isolate was characterized using a polyphasic approach in order to determine its taxonomic position. On the basis of 16S rRNA gene sequence similarity, strain Gsoil 161(T) was shown to belong to the family Nocardioidaceae and was related to Aeromicrobium marinum (98.0 % similarity to the type strain), Aeromicrobium alkaliterrae (97.6 %), Aeromicrobium fastidiosum (97.0 %) and Aeromicrobium erythreum (96.7 %); the sequence similarity with other species within the family was less than 94.4 %. It was characterized chemotaxonomically as having ll-2,6-diaminopimelic acid in the cell-wall peptidoglycan, MK-9(H(4)) as the predominant menaquinone and C(16 : 0), 10-methyl C(18 : 0) (tuberculostearic acid), C(16 : 0) 2-OH, 10-methyl C(17 : 0) and 10-methyl-C(16 : 0) as the major fatty acids. The G+C content of the genomic DNA was 65.5 mol%. These chemotaxonomic properties and phenotypic characteristics support the affiliation of strain Gsoil 161(T) to the genus Aeromicrobium. Results of physiological and biochemical tests enabled strain Gsoil 161(T) to be differentiated genotypically and phenotypically from currently known Aeromicrobium species. Therefore, strain Gsoil 161(T) represents a novel species, for which the name Aeromicrobium panaciterrae sp. nov. is proposed. The type strain is strain Gsoil 161(T) (=KCTC 19131(T)=DSM 17939(T)=CCUG 52476(T)).

Microlunatus ginsengisoli sp. nov., isolated from soil of a ginseng field.

A Gram-positive, aerobic, coccus-shaped, non-endospore-forming bacterium (Gsoil 633(T)) was isolated from soil from a ginseng field in Pocheon province in South Korea. The novel isolate was characterized in order to determine its taxonomic position. On the basis of 16S rRNA gene sequence similarities, strain Gsoil 633(T) was shown to belong to the family Propionibacteriaceae. The closest phylogenetic relative was Microlunatus phosphovorus DSM 19555(T), with 96.1 % sequence similarity; the sequence similarity to other members of the family was less than 95.4 %. The isolate was characterized chemotaxonomically as having ll-2,6-diaminopimelic acid in the cell-wall peptidoglycan, MK-9(H(4)) as the predominant menaquinone and anteiso-C(15 : 0), iso-C(15 : 0) and iso-C(16 : 0) as the major fatty acids. The G+C content of the genomic DNA was 69.8 mol%. The morphological and chemotaxonomic properties of the isolate were consistent with those of M. phosphovorus, but the results of physiological and biochemical tests allowed the phenotypic differentiation of strain Gsoil 633(T) from this species. Therefore, strain Gsoil 633(T) represents a novel species, for which the name Microlunatus ginsengisoli sp. nov. is proposed. The type strain is Gsoil 633(T) (=KCTC 13940(T)=DSM 17942(T)).

Hydrolyzed molasses as an external carbon source in biological nitrogen removal.

Hydrolyzed molasses was evaluated as an alternative carbon source in a biological nitrogen removal process. To increase biodegradability, molasses was acidified before thermohydrolyzation. The denitrification rate was 2.9-3.6 mg N/g VSSh with hydrolyzed molasses, in which the percentage of readily biodegradable substrate was 47.5%. To consider the hydrolysate as a carbon source, a sequencing batch reactor (SBR) was chosen to treat artificial municipal wastewater. During the 14 days (28 cycles) of operation, the SBR using hydrolyzed molasses as a carbon source showed 91.6 +/- 1.6% nitrogen removal, which was higher than that using methanol (85.3 +/- 2.0%). The results show that hydrolyzed molasses can be an economical and effective external carbon source for the nitrogen removal process.

Odorous swine wastewater treatment by purple non-sulfur bacteria, Rhodopseudomonas palustris, isolated from eutrophicated ponds.

Three strains of phototrophic, purple, non-sulfur bacteria, isolated from eutrophic ponds, were used to treat odorous swine wastewater. One isolate, Rhodopseudomonas palustris, when cultured in swine wastewater without supplementation for 7 d, removed odorous organic acids (170 mg l(-1)), COD (10,000 mg l(-1)) and phosphate (180 mg l(-1)).

Isolation and characterization of bacteria capable of degrading phenol and reducing nitrate under low-oxygen conditions.

Nitrate-reducing bacteria capable of degrading phenol were isolated from natural and contaminated environments under low-oxygen conditions with nitrate-containing media, using phenol as a sole carbon and energy source. A total of 27 bacteria able to degrade phenol and reduce nitrate under low-oxygen conditions were isolated from all of the inoculum samples, regardless of previous phenol contamination. For all of these bacteria, oxygen was an essential requirement for phenol degradation. Nitrate reduction by 19 of the strains was insensitive to 10 mM sodium azide, and these strains were placed into the alpha- and beta-subclasses of Proteobacteria and two were Gram-positive bacteria. To date, the order of Rhizobiales has hardly been reported to have an ability to degrade aromatic compounds. Interestingly, our study showed that all isolates that were placed into the alpha-subclass of Proteobacteria are in the order of Rhizobiales. Furthermore, the genus Agrobacterium was isolated from most inoculum samples and one genus of Gram-positive bacteria, Staphylococcus, was also isolated. In the case of the remaining eight strains, nitrate reduction was inhibited by 10 mM sodium azide. Of these strains, seven were placed into the gamma-subclass of Proteobacteria.