Jinmeng Li

Effects of cold stress on nitric oxide in duodenum of chicks

Animals may suffer from a variety of environmental stressors every day, among which is cold stress, which commonly exists in cold regions. The aim of this study was to investigate changes in antioxidative function and inducible nitric oxide synthase-nitric oxide (iNOS-NO) system activity in the duodenum of chicks as a reaction to cold stress. A total of 84 male chicks (15 d old) were randomly allocated to 12 groups (7 chickens/group). There were 1 control group and 5 treatment groups for acute cold stress and 3 control groups and 3 treatment groups for chronic cold stress. Antioxidative function was examined by superoxide dismutase (SOD), and oxidative damage was examined by malondialdehyde (MDA) detection. The iNOS-NO system activity was identified by NO content and NOS activity assay, and the transcription of iNOS mRNA was tested by fluorescence quantitative PCR. The results showed that under acute cold stress MDA level increased, the activity of NO in the duodenum fluctuated, and the activity of SOD and iNOS in the duodenum first increased and then decreased, whereas the expression of iNOS mRNA decreased. Under chronic cold stress the activity of SOD, NO, and NOS first decreased and then increased, whereas the MDA level and the expression of iNOS mRNA increased. The results indicated that both acute and chronic cold stress could cause duodenum oxidative stress and change in iNOS, which was related to the intestinal damage process.

Effects of cold stress on the messenger ribonucleic acid levels of peroxisome proliferator-activated receptor-γ in spleen, thymus, and bursa of Fabricius of chickens

This study was to investigate the expression trait of the peroxisome proliferator-activated receptor-gamma (PPAR-gamma) gene and the effect of cold stress on the mRNA levels of PPAR-gamma in spleen, thymus, and bursa of Fabricius of chickens. Eighty-four 1-d-old male chickens were randomly allocated to 12 groups (7 chickens per group). There was 1 control group and 5 treatment groups for acute cold stress and 3 control groups and 3 treatment groups for chronic cold stress. Chickens were maintained in our animal facility, kept under a 16L:8D cycle and temperature (30 +/- 2 degrees C), and given free access to standard chow and water. The cold stress was initiated when the birds were 15 d of age, with the duration of the acute cold stress being 1, 3, 6, 12, and 24 h, and the chronic cold stress was 5, 10, and 20 d, respectively. Cold stress temperature was 12 +/- 1 degrees C. Spleen, thymus, and bursa of Fabricius were collected for the assessment of the mRNA levels by real-time PCR after stress termination. The results showed that the PPAR-gamma gene is expressed in spleen, thymus, and bursa of Fabricius, and its expression level is different in different tissues and at different ages. Acute cold stress significantly decreased (P < 0.05) the mRNA levels of the PPAR-gamma gene of spleen and thymus in all treatment groups and significantly increased (P < 0.05) the mRNA levels of the PPAR-gamma gene of bursa of Fabricius in all treatment groups. Compared with the corresponding control groups, chronic cold stress resulted in a significant increase (P < 0.05) of the mRNA levels of the PPAR-gamma gene in spleen and a significant decrease (P < 0.05) of the mRNA levels of the PPAR-gamma gene in thymus and bursa of Fabricius. The results indicate that the PPAR-gamma gene is expressed in all 3 immune organs and has different expression traits. The magnitude and direction of change in PPAR-gamma gene expression differs with the type of cold stress applied and also varies by tissue.

Plantactinosporasoyae sp. nov., an endophytic actinomycete isolated from soybean root [Glycine max (L.) Merr]

A novel actinomycete, designated strain NEAU-gxj3T, was isolated from soybean root [Glycine max (L.) Merr.] collected from Harbin, Heilongjiang Province, China, and characterized using a polyphasic approach. The 16S rRNA gene sequence of strain NEAU-gxj3T showed highest similarity to those of Micromonospora equina Y22T (98.2 %) and Plantactinospora endophytica YIM 68255T (98.0 %). Phylogenetic analysis based on the 16S rRNA gene and gyrB gene demonstrated that the isolate clustered with the members of the genus Plantactinospora. The chemotaxonomic properties of strain NEAU-gxj3Twere also consistent with those of members of the genus Plantactinospora. The cell wall contained meso-diaminopimelic acid and whole-cell sugars were xylose, glucose and galactose. The predominant menaquinones were MK-10(H6), MK-9(H8), MK-10(H2) and MK-10(H4). The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The major fatty acids were identified as anteiso-C17 : 0, iso-C16 : 0, iso-C15 : 0 and C15 : 0. A combination of DNA-DNA hybridization result and some phenotypic characteristics indicated that strain NEAU-gxj3Tcould be differentiated clearly from its closest phylogenetic relatives. Therefore, the strain is concluded to represent a novel species of the genus Plantactinospora, for which the name Plantactinospora soyae sp. nov. is proposed. The type strain is NEAU-gxj3T (=CGMCC 4.7221T=DSM 46832T).

Two new lankacidin-related metabolites from Streptomyces sp. HS-NF-1178

Two new lankacidin-related metabolites, 2,18-seco-lankacidinol A (1), 2,18-seco-lankacidinol B (2) and a known compound, lankacidinol (3), were isolated from the fermentation broth of Streptomyces sp. HS-NF-1178. Their structures were determined on the basis of spectroscopic analysis, including 1D and 2D NMR techniques as well as ESI-MS and comparison with data from the literature. These two new compounds, especially compound 1, exhibited potent antitumor activity.

New aliphatic acid amides from Streptomyces maoxianensis sp. nov.

Unsaturated fatty acid amides, which formed from an unsaturated fatty acid and an amine, have diverse biological potency including the modulatory effect on isolated gastrointestinal tract, the effect on transactivational activity of peroxisome proliferator-activated receptors (PPARs) and the cholesterol acyltransferase inhibitory activity.1–3 At present, more than 20 unsaturated fatty acid amides have been isolated from Zanthoxylum piperitum, such as α-sanshool, β-sanshool, hydroxyl-γ-sanshool and ZP-amide A–F, which possessed unsaturated aliphatic acids conjugated with isobutylamine or its derivatives.2–6 To our knowledge, natural compounds possessing a 12-carbon polyketide conjugated with L-isoleucine (or derivatives), for example, curvularides A–E and coronatine, have been obtained from microbial resources.7,8 In the course of hunting for new biologically active compounds from microbial sources, two new unsaturated fatty acid amides, maoxianamides A (1) and B (2), were isolated from Streptomyces maoxianensis sp. nov. Herein, we report details of the isolation, structure elucidation and biological activity of the two new compounds. The producing strain S. maoxianensis sp. nov. was isolated from a soil sample collected from a pine forest in Songpinggou, Maoxian, southwest China, which has been reported in the previous paper.9 The GenBank/EMBL/DDBJ database accession number of the 16S ribosomal RNA sequence of strain is KF887908 and it was deposited in the China General Microbiological Culture Collection Center (CGMCC) with accession CGMCC No. 4.7139. This strain was grown and maintained on the medium containing 4 g yeast extract, 4 g glucose, 10 g malt extract and 20 g agar in 1.0 l tap water, pH 7.0–7.2 and incubated for 6–7 days at 28 °C. The strain of stock culture was transferred into 1 l Erlenmeyer flasks containing 25% volume of the seed medium and incubated at 28 °C for 24 h, shaken at 150 r.p.m. Then, 1 l of the culture was transferred into a 50 l fermentor containing 30 l of producing medium consisting of 10 g glucose, 40 g soluble amylum, 5 g yeast extract, 25 g soybean powder, 5 g peptone, 2 g CaCO3, 8 g MgSO4·7H2O, 6 g FeSO4·7H2O, 2 g ZnSO4·7H2O, 2 g MnSO4·H2O, 0.5 g CoCl2·6H2O, 2 g Na2MoO4·2H2O, pH 7.0–7.2. The fermentation was carried out at 28 °C for 6 days and stirred at 100 r.p.m. with an aeration rate of 900 l of air per hour. The fermentation broth (30 l) was centrifuged to separate mycelial cake and supernatant. The mycelial cake was extracted with MeOH (5 l) and the supernatant was subjected to a Diaion HP-20 resin (Mitsubushi Chemical, Tokyo, Japan) column eluting with 95% EtOH (5 l). The MeOH extract and the EtOH eluents were evaporated under reduced pressure to yield a mixture (33 g) at 50 °C. The mixture was chromatographed on a silica gel column (Qingdao Haiyang Chemical Group, Qingdao, China; 100–200 mesh), and successively eluted with a stepwise gradient of CHCl3/MeOH (100:0–50:50, v/v) to obtain three fractions (Fr.1–Fr.3) based on the TLC profiles. The Fr.2 was subjected to another silica gel column eluted with CHCl3/MeOH (95:5–60:40, v/v) to give one fraction (Fr.2–1). Fr.2–1 was further isolated by preparative HPLC (Shimadzu LC-8 A, Shimadzu-C18, 5 μm, 250× 20 mm inner diameter; 20 ml min 1; 220 /254 nm; Shimadzu, Kyoto, Japan) eluting with a stepwise gradient MeOH/H2O (10–70%, v/v 30 min) to obtain five subfractions (Fr.2–1–1 to Fr.2–1–5) based on the retention time. Then, Fr.2–1–2 (tR 12.1 min) was purified by semi-preparative HPLC (Agilent 1100, Zorbax SB-C18, 5 μm, 250× 9.4 mm inner diameter; 1.5 ml min 1; 220 nm; Agilent, Palo Alto, CA, USA) eluting with CH3CN/H2O (12:88, v/v) to obtain maoxianamide A (1) (tR 29.0 min, 31 mg). Fr.2–1–3 (tR 10.3 min) was also isolated by semi-preparative HPLC eluting with CH3CN/H2O (17:83, v/v) to obtain maoxianamide B (2) (tR 18.6 min, 6.3 mg). 1H and 13C NMR spectra were measured with a Bruker DRX-400 (400 MHz for 1H and 100 MHz for 13C) spectrometer (Rheinstetten, Germany). The ESIMS and HRESIMS spectra were taken on a Q-TOF Micro LC-MS-MS mass spectrometer (Milford, MA, USA). Maoxianamide A (1) was obtained as colorless oil with UV (EtOH) λmax nm (log ε): 202 nm (4.32) and [α] 25 D +44 (c 0.25, EtOH).

A new tetrahydrobenzofuranone metabolite from Streptomyces sp. HS-NF-853

Abstract A new tetrahydrobenzofuranone derivative, strefuranone A (1), was isolated from Streptomyces sp. HS-NF-853. The structure of the compound was elucidated on the basis of MS and extensive NMR analysis.

Streptomyces lasiicapitis sp. nov., a novel actinomycete that produces kanchanamycin isolated from the head of an ant (Lasius fuliginosus L.).

During a screening for novel and biotechnologically useful actinobacteria in insects, a kanchanamycin-producing actinomycete with antifungal activity, designated strain 3H-HV17(2)T, was isolated from the head of an ant (Lasius fuliginosus L.) and characterized using a polyphasic approach. 16S rRNA gene sequence similarity studies showed that strain 3H-HV17(2)T belongs to the genus Streptomyces with the highest sequence similarities to Streptomyces spectabilis NBRC 13424T (98.90 %, with which it phylogenetically clustered, Streptomyces alboflavus NRRL B-2373T (98.65 %) and Streptomyces flavofungini NBRC 13371T (98.36 %). Phylogenetic analysis based on the gyrB gene also supported the close relationship of these strains. The morphological and chemotaxonomic properties of the strain are also consistent with those members of the genus Streptomyces. A combination of DNA-DNA hybridization experiments and phenotypic tests were carried out between strain 3H-HV17(2)T and its phylogenetically closely related strains, which further clarified their relatedness and demonstrated that strain 3H-HV17(2)T could be distinguished from these strains. Therefore, strain 3H-HV17(2)T is concluded to represent a novel species of the genus Streptomyces, for which the name Streptomyces lasiicapitis sp. nov. is proposed. The type strain is 3H-HV17(2)T (=CGMCC 4.7349T=DSM 103124T).

Baia soyae gen. nov., sp. nov., a mesophilic representative of the family Thermoactinomycetaceae, isolated from soybean root [Glycine max (L.) Merr].

A mesophilic, endophytic, filamentous bacterium, designated strain NEAU-gxj18T, was isolated from soybean root [Glycine max (L.) Merr.] collected from Harbin, Heilongjiang Province, China and characterized using a polyphasic approach. Growth was observed at 20–40 °C (optimum 37 °C). Aerial mycelium was absent on all the media tested. Substrate mycelia were well-developed and formed abundant single endospores with smooth surfaces. The only menaquinone was MK-7.The diagnostic diamino acid was meso-diaminopimelic acid. The whole-cell sugars were ribose, glucose and galactose. The major fatty acids were iso-C15 : 0, C13 : 0 and iso-C17 : 0. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminophospholipid and one undientified phospholipid. The DNA G+C content was 49.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NEAU-gxj18T was phylogenetically related to members of the family Thermoactinomycetaceae, with the highest sequence similarity to Geothermomicrobium terrae YIM 77562T (93.35 %). On the basis of morphological and chemotaxonomic characteristics, phylogenetic analysis and characteristic patterns of 16S rRNA gene signature nucleotides, strain NEAU-gxj18T represents a novel species of a new genus within the family Thermoactinomycetaceae, for which the name Baia soyae gen. nov., sp. nov. is proposed. The type strain of the type species is NEAU-gxj18T ( = CGMCC 4.7223T = DSM 46831T).