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1.
Zhong Li Ruo-Wei Chen Heng-Yi Lei Zhong Shan Tao Bai Qiang Yu Hua-Liang Li 《World journal of microbiology & biotechnology》2009,25(5):745-752
We studied a novel bioflocculant, PX, that is produced from Bacillus Bacillus circulans X3, and has excellent flocculating activity with regard to its characterization and flocculating properties. The bioflocculant
was purified from supernatant by ethanol precipitation, dialysis and gel permeation chromatography (GPC). The major component
of PX was an acid polysaccharide including uronic (19.8%), pyruvic (6.5%) and acetic acids (0.7%). It consisted of galactose,
mannose, xylitol, rhamnose and galacturonic acid in an approximate molar ration of 5:4.1:3:2:1.2. The molecular weight of
PX was about 4.85 × 104 Da as determined by GPC. The infrared spectrum of the bioflocculant indicated the presence of carboxyl, hydroxyl, amino and
methoxyl groups. Studies of the flocculating properties revealed that it was stable at 60–100°C and pH 4–10. Moreover, it
could flocculate a kaolin suspension over a wide range of pH and temperature in the presence of CaCl2. 相似文献
2.
Lanyan Peng Chunping Yang Guangming Zeng Lu Wang Chuanhua Dai Zhiyong Long Hongyu Liu Yuanyuan Zhong 《Applied microbiology and biotechnology》2014,98(15):6847-6858
A new bioflocculant was produced by culturing Rhodococcus erythropolis in a cheap medium. When culture pH was 7.0, inoculum size was 2 % (v/v), Na2HPO4 concentration was 0.5 g L?1, and the ratio of sludge/livestock wastewater was 7:1 (v/v), a maximum flocculating rate of 87.6 % could be achieved. Among 13 different kinds of pretreatments for sludge, the optimal one was the thermal-alkaline pretreatment. Different from a bioflocculant produced in a standard medium, this bioflocculant was effective over a wide pH range from 2 to 12 with flocculating rates higher than 98 %. Approximately, 1.6 g L?1 of crude bioflocculant could be harvested using cold ethanol for extraction. This bioflocculant showed color removal rates up to 80 % when applied to direct and disperse dye solutions, but only 23.0 % for reactive dye solutions. Infrared spectrum showed that the bioflocculant contained functional groups such as –OH, –NH2, and –CONH2. Components in the bioflocculant consisted of 91.2 % of polysaccharides, 7.6 % of proteins, and 1.2 % of DNA. When the bioflocculant and copper sulfate (CuSO4) were used together for decolorization in actual dye wastewater, the optimum decolorization conditions were specified by the response surface methodology as pH 11, bioflocculant dosage of 40 mg/L, and CuSO4 80 mg/L, under which a decolorization rate of 93.9 % could be reached. 相似文献
3.
Aims
Bioflocculant production potential of an actinobacteria isolated from a freshwater environment was evaluated and the bioflocculant characterized.Methods and Results
16S rDNA nucleotide sequence and BLAST analysis was used to identify the actinobacteria and fermentation conditions, and nutritional requirements were evaluated for optimal bioflocculant production. Chemical analyses, FTIR, 1H NMR spectrometry and SEM imaging of the purified bioflocculant were carried out. The 16S rDNA nucleotide sequences showed 93% similarities to three Cellulomonas species (strain 794, Cellulomonas flavigena DSM 20109 and Cellulomonas flavigena NCIMB 8073), and the sequences was deposited in GenBank as Cellulomonas sp. Okoh (accession number HQ537132 ). Bioflocculant was optimally produced at an initial pH 7, incubation temperature 30°C, agitation speed of 160 rpm and an inoculum size of 2% (vol/vol) of cell density 1·5 × 108 cfu ml?1. Glucose (88·09% flocculating activity; yield: 4·04 ± 0·33 g l?1), (NH4)2NO3 (82·74% flocculating activity; yield: 4·47 ± 0·55 g l?1) and MgCl2 (90·40% flocculating activity; yield: 4·41 g l?1) were the preferred nutritional source. Bioflocculant chemical analyses showed carbohydrate, protein and uronic acids in the proportion of 28·9, 19·3 and 18·7% in CPB and 31·4, 18·7 and 32·1% in PPB, respectively. FTIR and 1H NMR indicated the presence of carboxyl, hydroxyl and amino groups amongst others typical of glycosaminoglycan. SEM imaging revealed horizontal pleats of membranous sheets closely packed.Conclusion
Cellulomonas sp. produces bioflocculant predominantly composed of glycosaminoglycan polysaccharides with high flocculation activity.Significance and Impact of the Study
High flocculation activity suggests suitability for industrial applications; hence, it may serve to replace the hazardous flocculant used in water treatment. 相似文献4.
Production of a novel bioflocculant by a fed-batch culture of Citrobacter sp. TKF04 was investigated using acetic acid as a sole carbon source. Synthesis of the bioflocculant was favored by dissolved O2 tension at 20% of air saturation and C/N ratio (mol acetic acid/mol ammonium) of 10:1 in the feed solution. Under optimal conditions, 4.6 g crude bioflocculant per liter broth was produced, whose flocculating activity was 22 300 units. This activity was 9 times higher than that of the control (only acetic acid was supplied). 相似文献
5.
Nie M Yin X Jia J Wang Y Liu S Shen Q Li P Wang Z 《Journal of applied microbiology》2011,111(3):547-558
Aims: To isolate and characterize the novel bioflocculant‐producing bacteria, to optimize the bioflocculant production and to evaluate its potential applications. Methods and Results: Klebsiella pneumoniae strain NY1, a bacterium that produces a novel bioflocculant (MNXY1), was selected on the chemically defined media. It was classified according to the 16S rRNA gene sequence, morphological and microscopic characteristics. MNXY1 was characterized to contain 26% protein and 66% total sugar. The constituent sugar monomers of MNXY1, revealed by NMR analysis, are glucose, galactose and quinovose. Favourable culture conditions for MNXY1 production were determined. Strain NY1 produces a high level (14.9 g l?1) of MNXY1. MNXY1 is thermostable and tolerant to the extreme pH. It precipitated 54% of cyanobacteria from laboratory culture and 72% of the total suspended solids from raw wastewater. Conclusions: Strain NY1 was identified to produce a novel bioflocculant MNXY1. The outstanding performance of MNXY1 in practical applications and its availability in copious amounts make it attractive for further investigation and development for industrial scale applications. Significance and Impact of the Study: This is first report for the identification of a quinovose‐containing bioflocculant and application of a protein–polysaccharide complex bioflocculant in precipitation of cyanobacteria. These findings suggest that MNXY1 holds great potential for use in management of harmful algae and city wastewater treatment. 相似文献
6.
《Bioscience, biotechnology, and biochemistry》2013,77(4):734-736
Setosol, a biologically active natural product, was extracted from Pleiochaeta setosa, an organism isolated from volcanic rock in the Canaries. With molecular formula C15H16O5 and a melting point of 139°C, this pale yellow and amorphous compound inhibited the growth of Pyricularia oryzae, Drechslera oryzae, and Gerlachia oryzae. Isolation of the new compound was performed by repeated centrifugal TLC on silica gel, and its structure was established as 2,8-dimethyl-4-methoxy-6,10,11-trihydroxy-benzooxaonin by detailed spectral studies, including COSY, 2D 1H-13C direct chemical shift correlation (XHCORR), 2D 1H-13C correlation via long-range coupling (COLOC), heteronuclear-gated decoupling (GATEDEC), and single-frequency heteronuclear-gated decoupling (SFDEC) NMR techniques, as well as UV, IR, and MS. 相似文献
7.
Screening of flocculant-producing microorganisms and some characteristics of flocculants 总被引:5,自引:0,他引:5
Summary 27 strains of microorganisms including moulds, bacteria, actinomyces and yeasts, which produced substances that flocculated a kaolin clay, were screened. One strain, identified as Arthrobacter sp., secreted bioflocculant during growth. The flocculant (MF-6) was purified to electrophoretic homogeneity by precipitation with ethanol and gel chromatography. Its molecular weight was higher than 106 Da. It could efficiently flocculate all suspended solids tested in aqueous solution and colored water like dye solution, and its flocculating ability was significantly enhanced by adding Ca2+, Mn2+, Mg2+, etc. 相似文献
8.
Hyejoo Kim Hyuk-Sung Kwon Jungoh Ahn Chang-Ha Lee 《Biocatalysis and Biotransformation》2013,31(4):246-253
Magnetic particles of size 10 nm have been coated with silica to a mean diameter of 40 nm and charged with Cu2+ ions via a multidentate ligand, iminodiacetic acid (IDA), for the immobilization of His-tagged Bacillus stearothermopilus L1 lipase. Microporous (average pore diameter of 60 Å) silica gel with a mean particle diameter of 115 µm has been used as a comparative support material. The molar ratio of Cu2+ to IDA was found to be 1:1.14 and 1:1.99 in the silica gel and the silica-coated magnetic nanoparticles (SiMNs), respectively. The specific activity of the immobilized enzyme was found to conform to the following order: Cu2+-charged SiMN>SiMN>Cu2+-charged silica gel>silica gel. When it was immobilized on the Cu2+-charged SiMNs, over 70% of the initial activity of the lipase remained after it had been reused five times. However, only 20% of the initial activity remained after the enzyme immobilized on the Cu2+-charged silica gel had been reused five times. For the enzyme immobilized on supports without Cu2+ cations, all activity was lost after threefold reuse. The differences in the specific activities and the efficiencies of reuse of the enzymes immobilized on the various support materials are discussed in terms of immobilization mechanisms (physical adsorption vs. coordination bonding), mass transfer of a substrate and a product of the enzyme reaction, and the status of the Cu (Cu bound to the IDA on the silica layer vs. Cu directly adsorbed on the silica layer). 相似文献
9.
N. A. Shakil Manish K. Singh M. Sathiyendiran J. Kumar 《Archives Of Phytopathology And Plant Protection》2013,46(20):1958-1965
Microwave irradiation of 2-hydroxy chalcones under solvent-free conditions resulted in a “green-chemistry” procedure for the preparation of flavanones in good yields, using an unmodified household microwave oven and silica as solid support. By irradiation of 2-hydroxy chalcones with trifluoroacetic acid over silica gel, 11 known flavanones were prepared in high yields. The synthesised compounds were characterised using spectroscopic techniques, namely, 1H NMR, 13C NMR and IR, and screened for their antifungal activity in vitro against Sclerotium rolfsii and Rhizoctonia solani by poisoned food technique. The compounds tested were found to be more active against R. solani, whereas against S. rolfsii, moderate activity was observed, as evident from LC50 values. The most potent compound 2-(4-fluorophenyl)-2,3-dihydrochromen-4-one (4a) had LC50 value of 12.0 mg L?1 followed by 11, 11a, 3a, 9a, 8a, 10a and 10 having LC50 values 18.21, 18.3, 32.9, 50.7, 88.8, 118.8 and 119.7 mg L?1, respectively. 相似文献
10.
为了获得具有药用价值的活性天然产物,采用4种大孔吸附树脂对柴达木沙漠链霉菌(Streptomyces qaidemensis)S10T发酵液进行静态吸附和解吸实验,优化分离工艺。结果显示,AB-8型树脂具有良好的吸附和解吸性能,该树脂对柴达木沙漠链霉菌S10T发酵液中的活性天然产物吸附工艺为发酵液pH值9,吸附时间4 h,洗脱液70%甲醇溶液。经正向硅胶、反相硅胶和葡聚糖凝胶Sephadex LH-20分离得到了一个化合物,1H-NMR和13C-NMR结合高分辨质谱(LC-HR-MS)鉴定该化合物为阿糖腺苷(vidarabine),是一种具有抗病毒活性的核苷类抗生素,并简单探究了其在柴达木沙漠链霉菌中的生物合成过程。 相似文献
11.
K. Okaiyeto U. U. Nwodo L. V. Mabinya A. I. Okoh 《Applied Biochemistry and Microbiology》2014,50(6):601-608
Bioflocculants are safe, biodegradable and environmentally friendly biopolymeric materials. These merits portend it as preferred alternative to inorganic and organic synthetic polymeric flocculants. The culture conditions optimal for the production of bioflocculant by Micrococcus sp. Leo with subsequent evaluation of the properties of the produced compound were investigated. Optimum culture conditions for bioflocculant production included 2% (vol/vol) inoculum size, incubation temperature of 28°C, agitation speed of 160 rpm and initial pH of 4.0. Glucose and (NH4)2SO4 and Al3+ were the best as sole carbon, nitrogen and cation sources, respectively. The purified bioflocculant flocculated kaolin suspension optimally at a dosage of 0.2 mg/mL following jar test, and flocculating activity of about 70% was retained after heat treatment of 100°C. Chemical analysis showed that the bioflocculant was composed of 28.4% polysaccharide, 2.6% protein and 9.7%. uronic acid. Thermogravimetric analysis demonstrated that the bioflocculant could not decompose completely at 400°C. FTIR spectra revealed the presence of hydroxyl, carboxyl and amino groups as the main functional groups. The bioflocculant produced by Micrococcus sp. Leo appears to hold promise as an alternative to conventional flocculants commonly used in water/wastewater treatment. 相似文献
12.
He Jin Zou Juan Shao Zongze Zhang Jibin Liu Ziduo Yu Ziniu 《World journal of microbiology & biotechnology》2010,26(6):1135-1141
A novel bioflocculant HBF-3 produced by deep-sea bacterium mutant Halomonas sp. V3a’ was investigated with regard to its flocculating characteristics and mechanism. 4.0 m g l−1 HBF-3 showed the maximum flocculating activity of 96.9% in 5.0 g l−1 Kaolin suspension containing 11.25 mM CaCl2, and that its flocculating activity was more than 90% within 5–40°C and over 80% in a wide pH range (3.0–11.0). Chemical
analyses indicated that the biopolymer HBF-3 was mainly a polysaccharide, including neutral sugar residues (20.6%), uronic
acid residues (7.6%), amino sugar residues (1.6%) and sulfate groups (5.3%). Fourier transform infrared (FTIR) spectrum showed
the presence of carboxyl and hydroxyl groups in HBF-3 molecular. The average molecular mass of HBF-3, as determined by gel
filtration chromatography (GFC), was approximately 590 kDa. Flocculation of Kaolin suspension with HBF-3 acted as a model
to explore the flocculating mechanism in which bridging mediated by Ca2+ was proposed as the primary action based upon the experimental observations. 相似文献
13.
Ondeyka JG Dombrowski AW Polishook JP Felcetto T Shoop WL Guan Z Singh SB 《Journal of industrial microbiology & biotechnology》2003,30(4):220-224
Mellamide, a novel indole amide, was isolated from a fermentation of Aspergillus melleus using silica gel and high-performance liquid chromatographic methods. This allowed its separation from three known antiparasitic
compounds (ochratoxin A, viomellin and xanthomegnin) also present in the potent extract. The structure was elucidated by 1H, 13C, COSY, DEPT, HMQC and HMBC NMR experiments. HR-FTMS aided in the molecular weight and formula determination. Mellamide showed
in vitro insecticidal activity in bioassays against larvae of Lucilia sericata and Aedes egypti with LD90 of 1,000 and 50 μg/ml, respectively.
Electronic Publication 相似文献
14.
Nobuo Ohno Keimei Fujimoto Yoshitoshi Okuno Toshio Mizutani Masachika Hirano Nobushige Itaya 《Bioscience, biotechnology, and biochemistry》2013,77(4):881-883
A new nucleoside antibiotic, mildiomycin D, was isolated from the culture broth of Streptoverticillium rimofaciens B-98891 as a minor component. The molecular formula of the antibiotic purified by silica gel and ion exchange resin column chromatographies was determined to be C19H30N8O8 ? (2H2O) from its physicochemical data. The ultraviolet and infrared spectra were very similar to those of mildiomycin, a major component. On the basis of 1H and 13C-NMR spectra and acidic hydrolysates of the compound, the chemical structure of the antibiotic was determined as a deoxy compound at the C8′ position in mildiomycin. Mildiomycin D showed weak activities against Gram-positive and negative bacteria, phytopathogenic fungi and some yeasts, and its activity against Rhodotorula rubura was about 40% that of mildiomycin. 相似文献
15.
The optimized production of MBF-HG6, which is a novel salt-tolerant alkaliphilic bioflocculant produced by Oceanobacillus polygoni with its application in tannery wastewater treatment was investigated in this study. It was found the optimal carbon source, nitrogen source, cation, and initial pH of the medium for bioflocculant production were starch, urea, Fe2+, and pH 9.0, respectively. The best stability in the temperature range was from 0 to 80°C and the purified MBF-HG6 contained polysaccharides of 81.53% and proteins of 9.98%. The carboxyl, hydroxyl, and amino groups were determined in bioflocculants, while the optimized bioflocculating activity was observed as 90.25% for the dosages of 6.96mL MBF-HG6, 4.77mL CaCl2 (1%, m/v), and 19.24g/L NaCl using response surface methodology. In addition, SS and turbidity removal rates of the tannery wastewater (4g/L MBF-HG6) could, respectively, reach 46.49% and 91.08%, indicating that the great potential was emerged in enhancement of tannery wastewater treatment by MBF-HG6. 相似文献
16.
Inheritance of gel consistency in rice was studied in crossés involving highamylose, low-gelatinizalion temperature parents
with hard, medium, and soft gel consistency. The results of single-grain analysis of parents, F1, F2, B1F1, B2F2, and their reciprocal crosses from a single-season harvest showed that the differences between hard and soft, hard and medium,
and medium and soft gel consistency are under monogenic control and that modifiers affect the expression of the trait. Multiple
alleles at the same locus, hereby designated asgec
a for medium gel consistency andgec
b for soft gel consistency, were recessive to the wild type allele for hard gel consistency andgec
a was dominant overgec
b. The results indicate that selection for desired gel consistency can effectively be done in early segregating generations. 相似文献
17.
John P. Dirlam Annette M. Belton Jon Bordner Walter P. Cullen Liang H. Huang Yasuhiro Kojima Hiroshi Maeda Satoshi Nishiyama John R. Oscarson Anthony P. Ricketts Tatsuo Sakakibara Junsuke Tone Mamoru Yamada 《Journal of industrial microbiology & biotechnology》1990,6(2):135-142
Summary A new polyether antibiotic CP-82,996 (C50H86O16) was isolated by solvent extraction from the fermentation broth ofActinomadura sp. (ATCC 63764). Following purification by silica gel column chromatography and crystallization, the structure of CP-82,996 was determined by a single crystal X-ray analysis. The structure is closely related to monensin, but is unique in that it contains two sugar groups, whereas monensin has none. The1H and13C NMR chemical shifts and assignments for CP-82, 996 were elucidated, and they were compared with those determined previously for monensin. CP-82,996 is active against certain Gram-positive bacteria, and is a very potent anticoccidial agent. It effectively controlled chicken coccidiosis caused by severalEimeria species at 5–10 ppm in feed, and is 10–20 times more potent than monensin. 相似文献
18.
Harvesting of Chlorella vulgaris using a bioflocculant from Paenibacillus sp. AM49 总被引:12,自引:0,他引:12
Hee-Mock Oh Seog June Lee Myung-Hwan Park Hee-Sik Kim Hyoung-Chin Kim Jung-Hoon Yoon Gi-Seok Kwon Byung-Dae Yoon 《Biotechnology letters》2001,23(15):1229-1234
Microbial flocculants for harvesting mass cultured Chlorella vulgaris were screened and that from Paenibacillussp. AM49 was identified as the best. The flocculation efficiency of this bioflocculant increased with the pH within a range of pH 5–11 and was 83%, which was higher than the 72% and 78% produced by aluminum sulfate and polyacrylamide, respectively. The highest flocculation efficiency was with 6.8 mm CaCl2 as co-flocculant. The bioflocculant from Paenibacillussp. AM49 can be used effectively to harvest C. vulgaris from large-scale cultures. 相似文献
19.
Isolation and characterization of dihydromonacolin-MV from <Emphasis Type="Italic">Monascus purpureus</Emphasis> for antioxidant properties 总被引:4,自引:0,他引:4
Dhale MA Divakar S Kumar SU Vijayalakshmi G 《Applied microbiology and biotechnology》2007,73(5):1197-1202
The methanolic extract of Monascus purpureus cultivated by solid-state fermentation on rice showed strong 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity
and better yield as compared to other polarity based extracted fractions. It was selected for further purification of the
antioxidant. The activity-guided repeated fractionation of methanolic extract on a silica gel column chromatography yielded
a compound that exhibited strong antioxidant activity. Based on the spectroscopic analysis by UV, IR, 1H NMR, 13C NMR, 2D-HSQCT NMR, and MS, the antioxidant isolated was elucidated as a derivative of dihydromonacolin-K, where the ester
group is 2-methyl propionate, designated as dihydromonacolin-MV. The DPPH radical was significantly scavenged by the dihydromonacolin-MV
(IC50 20±1 μg ml−1). The dihydromonacolin-MV showed strong inhibition of lipid peroxidation in a liposome model with an IC50 value of 5.71±0.38 μg ml−1 and superoxide radical scavenging activity with an IC50 value of 163.97±2.68 μg ml−1. 相似文献
20.
Microbial flocculant from Arcuadendron sp. TS-49 总被引:9,自引:0,他引:9
Summary A flocculant was purified from the culture broth of Archuadendron sp. TS-49 by a series of precipitations with acetone, 60% ammonium sulfate-butanol, salting-out by dialysis, and cetylpyridinium chloride. The flocculating activity was observed most highly at pH 3.0 and markedly enhanced by the addition of salts, especially in the case of FeCl3 or FeSO4. This bioflocculant efficiently flocculated all tested solids, including various microorganisms and organic/ inorganic materials. Qualitative analyses of the bioflocculant showed that it might contain hexosamine, uronic acid, neutral sugar, and protein. 相似文献