Showing papers by "Min Wu published in 2016"

Isolation and Complete Genome Sequence of Algibacter alginolytica sp. nov., a Novel Seaweed-Degrading Bacteroidetes Bacterium with Diverse Putative Polysaccharide Utilization Loci

Abstract: The members of the phylum Bacteroidetes are recognized as some of the most important specialists for the degradation of polysaccharides. However, in contrast to research on Bacteroidetes in the human gut, research on polysaccharide degradation by marine Bacteroidetes is still rare. The genus Algibacter belongs to the Flavobacteriaceae family of the Bacteroidetes, and most species in this genus are isolated from or near the habitat of algae, indicating a preference for the complex polysaccharides of algae. In this work, a novel brown-seaweed-degrading strain designated HZ22 was isolated from the surface of a brown seaweed (Laminaria japonica). On the basis of its physiological, chemotaxonomic, and genotypic characteristics, it is proposed that strain HZ22 represents a novel species in the genus Algibacter with the proposed name Algibacter alginolytica sp. nov. The genome of strain HZ22, the type strain of this species, harbors 3,371 coding sequences (CDSs) and 255 carbohydrate-active enzymes (CAZymes), including 104 glycoside hydrolases (GHs) and 18 polysaccharide lyases (PLs); this appears to be the highest proportion of CAZymes (∼7.5%) among the reported strains in the class Flavobacteria Seventeen polysaccharide utilization loci (PUL) are predicted to be specific for marine polysaccharides, especially algal polysaccharides from red, green, and brown seaweeds. In particular, PUL N is predicted to be specific for alginate. Taking these findings together with the results of assays of crude alginate lyases, we prove that strain HZ22(T) can completely degrade alginate. This work reveals that strain HZ22(T) has good potential for the degradation of algal polysaccharides and that the structure and related mechanism of PUL in strain HZ22(T) are worth further research.

Parvularcula flava sp. nov., an alphaproteobacterium isolated from surface seawater of the South China Sea.

Abstract: An aerobic, coccoid to short rod, yellow-pigmented, non-sporulating and Gram-staining-negative bacterium, designated NH6-79T, was isolated from surface seawater of the South China Sea. The isolate was motile with a polar flagellum. Growth was observed at 4–42 °C (optimum 37 °C), at pH 6.0–8.5 (optimum pH 7.0), and with 0.5–11 % (w/v) NaCl (optimum 4.5 %) and 1.5–17 % (w/v) sea salt (optimum 3.5–5 %). Strain NH6-79T could decompose peptone to produce H2S, but could not hydrolyse skimmed milk. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NH6-79T had the closest affinity to the genus Parvularcula , sharing the highest 16S rRNA gene sequence similarity with ‘ Parvularcula oceanus ’ JLT2013 (94.1 %), Parvularcula lutaonensis CC-MMS-1T (93.4 %), Parvularcula dongshanensis SH25T (92.9 %) and Parvularcula bermudensis HTCC2503T (92.7 %), and lower sequence similarities (<90 %) with all other genera. The dominant fatty acids were C18 : 1 ω7c and C16 : 0. The polar lipid profile was mainly composed of three unidentified glycolipids. The predominant isoprenoid quinone was ubiquinone-10. The DNA G+C content was 60.7 mol%. Based on the polyphasic taxonomic characterization, strain NH6-79T is considered to represent a novel species of the genus Parvularcula , for which the name Parvularcula flava sp. nov. is proposed. The type strain is NH6-79T (=CGMCC 1.14984T=JCM 30557T=MCCC 1K00277T).

Pseudohongiellanitratireducens sp. nov., isolated from seawater, and emended description of the genus Pseudohongiella.

Abstract: Two Gram-stain-negative, aerobic, motile by a single polar flagellum and rod-shaped strains, designated SCS-49T and SCS-111, were isolated from seawater of the South China Sea. The two strains grew at 4–35 °C, with 0.5–7.5 % (w/v) NaCl and at pH 6.5–9.0 and were able to reduce nitrate. Q-8 was the sole ubiquinone. The major fatty acids of the two strains were C16 : 0, C18 : 1 ω7c and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c). The polar lipids included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phospoglycolipid, three unidentified glycolipids, five unidentified phospholipids and two to three unidentified lipids. The isolates formed a stable clade with Pseudohongiella acticola and Pseudohongiella spirulinae based on phylogenetic analysis of 16S rRNA gene sequences. Strains SCS-49T and SCS-111 exhibited 16S rRNA gene sequence similarity values of 97.2 and 96.0 % with respect to the type strains of P. acticola and P. spirulinae , respectively. The average nucleotide diversity and in silico DNA–DNA hybridization values between strain SCS-49T and P. acticola KCTC 42131T were 71.4 and 25.1 %, respectively and the values between strain SCS-49T and SCS-111 were 99.9 and 99.2 %, respectively. Based upon the phenotypic, chemotaxonomic and genetic data, strains SCS-49T and SCS-111 represent a novel species in the genus Pseudohongiella , for which the name Pseudohongiella nitratireducens sp. nov. is proposed. The type strain is SCS-49T (=CGMCC 1.15425T=KCTC 52155T=MCCC 1K03186T).

Thalassobaculum fulvum sp. nov., isolated from deep seawater.

Abstract: A novel Gram-stain-negative, rod-shaped (1.0-1.2×2.0-8.0 µm), non-motile without flagella strain, designated HSF7T, was isolated from deep seawater. Strain HSF7T was able to grow at 20-40 °C (optimum 35 °C), pH 5.5-9.0 (optimum pH 6.5) and 0-10 % (w/v) NaCl (optimum 2 %). The G+C content of the genomic DNA was 69 mol%. Bacteriochlorophyll a and poly-β-hydroxybutyrate (PHB) granules were not found. The major fatty acids were C18 : 1ω7c (69.3 %), C16 : 0 (9.1 %) and C19 : 0 cyclo ω8c (6.6 %). The polar lipids were phosphatidylglycerol, three unknown aminophospholipids, an unknown phospholipid, an unknown aminolipid and two unknown lipids. The only isoprenoid quinone was Q-10. 16S rRNA gene sequence analysis revealed that strain HSF7T was most closely related toThalassobaculum salexigens DSM 19539T, Thalassobaculum litoreum DSM 18839T, Nisaeadenitrificans DSM 18348T and Oceanibaculum indicum MCCC 1A02083Twith pairwise sequence similarities of 95.56 %, 95.21 %, 93.64 % and 92.65 %, respectively. On the basis of genotypic, phenotypic, phylogenetic and chemotaxonomic characteristics, strain HSF7T represents a novel species of the genus Thalassobaculum, or which the name Thalassobaculum fulvum sp. nov. is proposed. The type strain is HSF7T(=KCTC 42651T=MCCC 1K01158T).

Chemical Oxygen Demand Removal in Na2SO4 Saturated Wastewater by Cultivable Halotolerant Bacterial Community

Abstract: Industrial wastewater with a high Na2SO4 concentration is characterized by high osmotic pressure and salinity, and requires pretreatment before discharging into central treatment facilities. To date, few studies have addressed the chemical oxygen demand (COD) removal in biotreatment of Na2SO4 wastewater. Here, a novel aerobic system for treating Na2SO4 wastewater was developed based on screening halotolerant bacterial strains. The system maintained a stable COD removal at >90% in saturated concentration (varying from 5 to 40% depending on the temperature) of Na2SO4 for 5 years. Activated sludge was initially constructed by cultured strains of Hyphomicrobium sp. CB03, Dietzia sp. XM15, Staphylococcus sp. T211, Flavobacterium sp. AXY1, Ochrobactrum sp. BY4, Bacillus sp. BYXT, Sphingobacterium sp.YY1, Rhodococcus sp. NH7-4, Stappia sp. HM4, Microbacterium sp. PY3-1, and Pseudomonas sp. MN3-2. Uncultured phylum TM7 was detected in the sludge after acclimatization. The present aerobic cultivable halotolerant bacterial community was successfully applied to large scale removal of organic pollutants in saline wastewater.