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An alpha-proteobacterial strain JXJ CY 53 T was isolated from the cyanosphere of Microcystis sp. FACHB-905 (MF-905) collected from Lake Dianchi, China. JXJ CY 53 T was observed to be an aerobic, Gram-stain-negative, oval shaped, and mucus-secreting bacterium. It had C18:1ω7c and C16:0 as the major cellular fatty acids, Q-10 as the predominant ubiquinone, and sphingoglycolipid, diphosphatidylglycerol, phosphatidylcholine, and phosphatidylmethylethanolamine as the polar lipids. The G + C content of DNA was 65.85%. The bacterium had 16S rRNA gene sequence identities of 98.9% and 98.7% with Sphingomonas panni DSM 15761 T and Sphingomonas hankookensis KCTC 22579 T, respectively, while less than 97.4% identities with other members of the genus. Further taxonomic analysis indicated that JXJ CY 53 T represented a new member of Sphingomonas, and the species epithet was proposed as Sphingomonas lacusdianchii sp. nov. (type strain JXJ CY 53 T = KCTC 72813 T = CGMCC 1.17657 T). JXJ CY 53 T promoted the growth of MF-905 by providing bio-available phosphorus and nitrogen, plant hormones, vitamins, and carotenoids. It could modulate the relative abundances of nonculturable bacteria associated with MF-905 and influence the interactions of MF-905 and other bacteria isolated from the cyanobacterium, in addition to microcystin production characteristics. Meanwhile, MF-905 could provide JXJ CY 53 T dissolved organic carbon for growth, and control the growth of JXJ CY 53 T by secreting specific chemicals other than microcystins. Overall, these results suggest that the interactions between Microcystis and its attached bacteria are complex and dynamic, and may influence the growth characteristics of the cyanobacterium. This study provided new ideas to understand the interactions between Microcystis and its attached bacteria. Key points: • A novel bacterium (JXJCY 53T) was isolated from the cyanosphere of Microcystis sp. FACHB-905 (MF-905) • JXJCY 53Tmodulated the growth and microcystin production of MF-905 • MF-905 could control the attached bacteria by specific chemicals other than microcystins (MCs) [ABSTRACT FROM AUTHOR]

A novel alphaproteobacterial strain JXJ CY 41T was isolated from a culture mass of Microcystis, collected from Lake Dianchi, south-west, China. Strain JXJ CY 41T was gram-strain-negative, aerobic, motile, with rod-shaped cells (0.4–1.0 × 1.7–3.5 μm). It was positive for catalase and starch hydrolysis, negative for oxidase and hydrolysis of Tweens (20, 40, and 80). Growth occurred at 10–44 °C, pH 5.0–10.0, and 0–5.0% (w/v) NaCl. Major fatty acids included C16:0 (28.1%), 11-methyl C18:1 ω7c (36.7%) and C18:1 ω7c (20.8%). Q10 was the sole ubiquinone. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, glycolipid, and an unidentified lipid. The DNA G + C content was 63.1%. Its 16S rRNA gene sequence showed high similarities with Devosia oryziradicis G19T (99.5%; not validly published), D. yakushimensis Yak96BT (98.3%) and D. ginsengisoli Gsoil 520T (98.1%), and less than 98.1% similarities with other members of the genus Devosia. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strain JXJ CY 41T and its 5 closest similar strains were 19.9–24.1% and 75.7–80.5%, respectively. Based on the data above, strain JXJ CY 41T was identified as a novel species of the genus Devosia, for which the epithet Devosia lacusdianchii sp. nov. was proposed. The type strain is JXJ CY 41T (= KCTC 72812T = CGMCC 1.17502T). Strain JXJ CY 41T exhibited different interactions with Microcystis aeruginosa FACHB-905 (Maf) under different conditions, and Maf could control the bacterial cellular density by secreting unknown specific chemical compounds according to its nutritional requirements. [ABSTRACT FROM AUTHOR]

Attached bacteria of Microcystis play important roles in the occurence, outbreak and decline of Microcystis water blooms. In this study, a novel actinobacterium, designated strain JXJ CY 38 T, was isolated from the culture mass of Microcystis aeruginosa FACHB-905 (MAF), collected from Lake Dianchi, south-west, China. The strain was found to be a Gram-stain positive, short rod, catalase positive and oxidase negative. The isolate was found to be able to grow at 5.0–38.0 °C (optimum, 28.0 °C), pH 4.0–11.0 (optimum, 7.0–8.0) and 0–3.0% (w/v, optimum, 0%) NaCl. Based on 16S rRNA gene sequences, strain JXJ CY 38 T shows high similarities to Nocardioides furvisabuli JCM 13813 T (99.0%) and Nocardioides alpinus JCM 18960 T (98.7%), and less than 98.2% similarities to other members of the genus. The major cellular fatty acids (> 10.0%) were identified as iso-C16:0 (23.6%), C18:1ω9c (18.2%) and C17:1ω8c (16.4%), while the predominant menaquinone was found to be MK-8 (H4). The diagnostic diamino acids in the cell wall peptidoglycan were identified as aspartic acid, glutamic acid, glycine and alanine, with mannose, ribose and arabinose as whole cell sugars. The polar lipids were found to be diphosphatidylglycerol, phosphatidylglycerol, a phospholipid, phosphatidylcholine and an unidentified lipid. The DNA G + C content was determined to be 71.3%. The digital DNA-DNA hybridization and average nucleotide identity values between strain JXJ CY 38 T and the type strains N. furvisabuli JCM 13813 T and N. alpinus JCM 18960 T were 49.4% and 37.7%, and 92.0% and 83.4%, respectively. On the basis of the above taxonomic data and differences in physiological characteristics from the closely related type strains, strain JXJ CY 38 T was determined to represent a novel species of genus Nocardioides, for which the name Nocardioides lacusdianchii sp. nov. is proposed. The type strain is JXJ CY 38 T (= KCTC 49381 T = CGMCC 4.7665 T). Strain JXJ CY 38 T apparently exhibits complex effects on the interactions between MAF and other attached bacteria, including the promotion or inhibition of the growth of MAF and bacteria, and the synthesis and release of microcystins by MAF. [ABSTRACT FROM AUTHOR]

A novel actinobacterium, designated strain JXJ CY 21, was isolated from the culture mass of Microcystis sp. FACHB-905 collected from Lake Dianchi, South-west China. Polyphasic taxonomic study revealed that the isolate should be a member of the genus Citricoccus. Comparison of the 16S rRNA gene sequence of strain JXJ CY 21 with the available sequences in the GenBank database showed that the strain is closely related to Citricoccus zhacaiensis FS24 (97.8 % similarity), Citricoccus parietis 02-Je-010 (97.7 %), Citricoccus terreus V3M1 (97.6 %), Citricoccus nitrophenolicus PNP1 (97.2 %), Citricoccus alkalitolerans YIM 70010 (97.2 %) and Citricoccus muralis 4-0 (97.0 %). The DNA-DNA hybridization values between strain JXJ CY 21 and the related type strains C. zhacaiensis FS24 and C. parietis 02-Je-010 were 16.0 ± 2.6 and 5.4 ± 1.7 %, respectively. The peptidoglycan in the cell wall was A4α type containing lysine-glutamic acid-glycine. The major respiratory menaquinone was found to be MK-8 (H) (98.5 %), while the major cellular fatty acids (>10 %) were anteiso-C, iso-C, iso-C and iso-C. The polar lipids detected were diphosphatidylglycerol, phosphatidylinositol, phosphatidylglycerol, an unidentified phospholipid and an unidentified glycolipid. The DNA G + C content was determined to be 62.7 mol%. Strain JXJ CY 21 can solubilize both insoluble inorganic and organic phosphates up to 24.7 and 1.7 mg/l respectively. This property of the novel actinobacterium acts as a modulator for enhancement of growth of Microcystis sp. FACHB-905 in the lake ecosystem where the amount of soluble phosphate is limited. On the basis of the above taxonomic data, strain JXJ CY 21 represents a novel species of the genus Citricoccus, for which the name Citricoccus lacusdiani sp. nov. is proposed. The type strain is JXJ CY 21 (=KCTC 29653 = DSM 29160). [ABSTRACT FROM AUTHOR]

An antialgal compound was isolated from the cultured broth of Streptomyces jiujiangensis JXJ 0074 by using bioassay methods. Based on the data of H-NMR, C-NMR, ESI-MS, and thin layer chromatography, the active compound was identified as L-valine, which showed antialgal activity mainly against Microcystis. L-valine exhibited greater antialgal activities than both L-lysine and copper sulfate (CuSO) did on Microcystis aeruginosa lawn. However, M. aeruginosa recovered growth earlier with higher growth rate in L-valine treatment than in L-lysine treatment. L-valine dissipated completely within 2 days, much quicker than L-lysine (6 days), which resulted in the lysing of more than 80 % M. aeruginosa cells and the release of amount of intracellular microcystin-LR (MC-LR) within 2 days. As a resultant, the extracellular MC-LR content was more than twice of the control from day 1 to 5. Exposure to L-valine significantly promoted the synthesis of MC-LR. L-lysine also promoted the release and synthesis of MC-LR with much lesser efficiency than L-valine. L-valine could damage Microcystis severely, causing perforation and collapse of M. aeruginosa cells and decrease of the chlorophyll. The superoxide dismutase (SOD) activity in L-valine-treated cells of M. aeruginosa initially increased with 32.94 ± 3.37 % higher than the control after 36 h and then decreased quickly. However, the increase rate of superoxide anion radical (O) was much higher than that of SOD, which resulted in serious lipid peroxidation and accumulation of malondialdehyde (MDA). To our knowledge, this is the first report showing L-valine active against cyanobacteria. [ABSTRACT FROM AUTHOR]

Previous investigations suggested that Streptomyces jiujiangensis JXJ 0074 can secrete antialgal compounds. In this study, an antialgal compound was isolated from the cultured broth of S. jiujiangensis JXJ 0074 by using bioassay methods. Based on spectroscopic data, the active compound was identified as 2′ -deoxyadenosine, which exhibited a greater antialgal activity against cyanobacteria than its analogues such as adenosine, guanosine, and 2′-deoxyguanosine. The antialgal activity of 2′ -deoxyadenosine increased with the content and time. 2′-Deoxyadenosine severely damaged the vegetative cells of cyanobacteria, causing crumpling, collapse, expanding, perforation, breakage of filamentous cyanobacteria, and decrease of the chlorophyll. However, 2′-deoxyadenosine seemed to have less impact on the morphology of heterocysts of filamentous cyanobacteria. The superoxide dismutase (SOD) activity in the treated cells of M. aeruginosa FACHB-905 initially increased with 31.14 ± 2.00 % higher than that of the control after 36 h and then decreased quickly. On the same time, there were rapid increases in superoxide anion radical (O) and malondialdehyde (MDA) contents with 315.53 ± 12.81 and 84.72 ± 6.15 % higher than these of the controls at 60 h, respectively. The intracellular microcystin-LR (MC-LR) content in the treated cells of M. aeruginosa FACHB-905 increased by 36.34 ± 7.35 % 1 day later, followed by a rapid decrease with a rate of 90.50 ± 1.08 % 8 days later, while the extracellular MC-LR content showed no significant difference with the control. Five days after adding 15 μg/ml of 2′ -deoxyadenosine to the culture of M. aeruginosa FACHB-905, there was no 2′ -deoxyadenosine detected by HPLC, suggesting that 2′ -deoxyadenosine completely degraded. This study provides a new clue to screen natural-based antialgal compounds from nucleoside analogues. [ABSTRACT FROM AUTHOR]

An actinomycete capable of lysing cyanobacteria, strain JXJ 0074, was isolated from a soil sample collected from Jiangxi province, south China, and characterized by using polyphasic taxonomy. The new isolate showed morphological and chemotaxonomic properties typical of members of the genus Streptomyces. Phylogenetic analysis of the near-complete 16S rRNA gene sequence indicated that strain JXJ 0074 should be affiliated to the genus Streptomyces and exhibited highest similarities to Streptomyces shenzhenensis DSM 42034 (98.99 %) and Streptomyces lucensis NBRC 13056 (98.60 %), while the similarities to other members of the genus are lower than 98.22 % similarity. However, the DNA-DNA hybridization values between strain JXJ 0074 and S. shenzhenensis DSM 42034 or S. lucensis NBRC 13056 were 46.2 ± 2.6 and 32.6 ± 3.1 %, respectively. Thus, on the basis of the polyphasic data, strain JXJ 0074 represents a novel species of the genus Streptomyces, for which the name Streptomyces jiujiangensis sp. nov. is proposed. The type strain is JXJ 0074 (= BCRC 16953 = KCTC 29262). [ABSTRACT FROM AUTHOR]

A novel filamentous bacterium, designated YIM 77831, was isolated from a geothermal soil sample collected at Rehai National Park, Tengchong, Yunnan province, south-west China. Growth occurred from 28 to 65 °C (optimum 50 °C), pH 6.0-8.0 (optimum pH 7.0). The strain formed branched substrate mycelia, endospores were produced on the substrate mycelium and aerial mycelium was not produced on any of the growth media tested. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain YIM 77831 was affiliated with the family Thermoactinomycetaceae. The stain YIM 77831 contained meso-diaminopimelic acid in the cell wall. Whole-cell hydrolysates contained glucose, galactose, mannose, ribose and rhamnose. The polar lipids were phosphatidylmethylethanolamine, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminophospholipid and four unknown phospholipids. The only menaquinone was MK-7. Major fatty acids were iso-C, anteiso-C and anteiso-C. The G+C content was 55.6 mol%. On the basis of the morphological and chemotaxonomic characteristics as well as genotypic data, strain YIM 77831 represents a novel genus and species, Lihuaxuella thermophila gen. nov., sp. nov., in the family Thermoactinomycetaceae. The type strain is YIM 77831 (CCTCC AA 2011024 = JCM 18059). [ABSTRACT FROM AUTHOR]