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1.
A bioflocculant with high flocculating activity, LC13-SF, produced by strain LC13T which was in a viable but nonculturable (VBNC) state, and which was woken up by Rpf (resuscitation promoting factor), was
systematically investigated with regard to its fermentation conditions and flocculating activity. The key parameters influencing
the bioflocculant LC13-SF were investigated through measuring the optical density at 660 (OD660) of the fermentation liquid and the optical density at 550 (OD550) of the centrifugal supernatant. The flocculating efficiency and the Zeta potentials were chosen as the response variables
for the study of the flocculating activity. The results showed that the optimal conditions for bioflocculant LC13-SF production
were a fermentation time of 72 h, an initial pH of 7.0, a fermentation temperature of 30°C and a shaking speed of 150 r/min.
The optimized flocculating process was as follows: a final volume percentage of bioflocculant LC13-SF and 0.5% (w/w) CaCl2 were 1.5 and 5%, respectively in a 4 g/L Kaolin suspension, and the system pH was adjusted to 8.0. Under these conditions,
the flocculating efficiency and the absolute value of the Zeta potential reached 94.83% and 4.37, respectively. 相似文献
2.
Xia S Zhang Z Wang X Yang A Chen L Zhao J Leonard D Jaffrezic-Renault N 《Bioresource technology》2008,99(14):6520-6527
A bioflocculant TJ-F1 with high flocculating activity, produced by strain TJ-1 from a mixed activated sludge, was investigated with regard to its production and characterization. By 16S rDNA sequence and biochemical and physiological characteristics, strain TJ-1 was identified as Proteus mirabilis. The most preferred carbon source, nitrogen source and C/N ratio (w/w) for strain TJ-1 to produce the bioflocculant were found to be glucose, peptone and 10, respectively. TJ-F1 production could be greatly stimulated by cations Ca(2+), Mg(2+) and Fe(3+). The optimal conditions for TJ-F1 production were inoculum size 2 per thousand (v/v), initial pH 7.0, culture temperature 25 degrees C, and shaking speed 130r/min, under which the flocculating activity of the bioflocculant reached 93.13%. About 1.33 g of the purified bioflocculant, whose molecular weight (MW) was 1.2 x 10(5) Da, could be recovered from 1.0 l of fermentation broth. Chemical analysis of bioflocculant TJ-F1 indicated that it contained protein (30.9%, w/w) and acid polysaccharide (63.1%, w/w), including neutral sugar, glucuronic acid and amino sugar as the principal constituents in the relative weight proportions of 8.2:5.3:1. Scanning electron microscopy (SEM) image of the purified solid-state TJ-F1 showed that it had a crystal-linear structure. Spectroscopic analysis of the bioflocculant by Fourier-transform infrared (FTIR) spectrometry indicated the presence of carboxyl, hydroxyl and amino groups preferred for the flocculation process. 相似文献
3.
Chi Zhu Chuanhong Chen Liangyuan Zhao Yihui Zhang Jiaoyan Yang Lirong Song Shao Yang 《Journal of applied phycology》2012,24(5):1245-1251
Bioflocculants of Chlamydomonas reinhardtii were investigated under axenic conditions. C. reinhardtii was found to produce significant amounts of bioflocculants. Flocculating activity by C. reinhardtii began in the linear phase of growth and continued until the end of the stationary phase. The highest flocculating efficiency of the culture broth was 97.06%. The purified C. reinhardtii bioflocculant was composed of 42.1% (w/w) proteins, 48.3% carbohydrates, 8.7% lipids, and 0.01% nucleic acid. The optimum condition for bioflocculant production of C. reinhardtii was as follows: under temperature of 15°C to 25°C, pH 6–10 and illumination of 40–60 μmol photons m?2 s?1. The bioflocculants produced by C. reinhardtii showed maximum activity in pH ranges from 2 to 10. The flocculating activity was significantly enhanced by the addition of CaCl2 as a co-flocculant at an optimal concentration of 4.5 mM. 相似文献
4.
WeiJie Liu Kai Wang BaoZhen Li HongLi Yuan JinShui Yang 《Bioresource technology》2010,101(3):1044-1048
A novel intracellular bioflocculant (named MBF-W6) produced by Chryseobacterium daeguense W6 cultured in low nutrition medium was investigated in this study. The effects of carbon source, nitrogen source, C/N ratio, initial pH, inoculum size, culture temperature and shaking speed on MBF-W6 production were studied. Chemical analysis showed that the purified MBF-W6 was mainly composed of 32.4% protein, 13.1% polysaccharide and 6.8% nucleic acid. Fourier-transform infrared (FTIR) spectroscopy indicated the presence of carboxyl, hydroxyl, and methoxyl groups. The elemental analysis of purified MBF-W6 revealed that the mass proportion of C, H, O, N and S was 40.92:6.53:44.01:8.53:1.01 (w/w) correspondingly. MBF-W6 had good flocculating rate in Kaolin suspension without any cation addition. The highest flocculating rate of 96.9% was achieved under the optimal conditions (bioflocculant dosage 1.2 mg l−1, pH 5.6 and temperature 15 °C). 相似文献
5.
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
6.
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
7.
Zhong Li Shan Zhong Heng-yi Lei Ruo-wei Chen Qiang Yu Hua-Liang Li 《Bioresource technology》2009,100(14):3650-3656
A novel bioflocculant ZS-7 produced by Bacillus licheniformis X14 was investigated with regard to its synthesis and application to low temperature drinking water treatment. The effects of culture conditions including pH, carbon source, nitrogen source, temperature, inoculum size and shaking speed on ZS-7 production were studied. The purified bioflocculant was identified as a glycoprotein consisting of polysaccharide (91.5%, w/w) and protein (8.4%, w/w), with an approximate molecular weight of 6.89 × 104 Da. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) indicated the presence of amino, amide, carboxyl, methoxyl and hydroxyl groups. This bioflocculant showed good flocculating performance and industrial potential for treatment of low temperature drinking water, and the maximum removal efficiencies of CODMn and turbidity were 61.2% and 95.6%, respectively, which were better than conventional chemical flocculants. Charge neutralization and bridging were proposed as the reasons for the enhanced performance based upon the experimental observations. 相似文献
8.
Summary The characteristics of bioflocculant MBF3-3 produced by Bacillus sp. BF3-3 were investigated here. MBF3-3 showed excellent flocculating activity on real and synthetic wastewaters, and consumed
a much lower dosage than that of the widely used polyaluminum chloride (PAC) when flocculating brewery wastewater. Except
Fe3+, metal ions, including Al3+, Mg2+, Ca2+, K+ and Na+, can stimulate the flocculating activity of MBF3-3 obviously, and the stimulating effects increased in the order: monovalent < bivalent < trivalent.
MBF3-3 was mainly composed of acidic polysaccharide (66.1%) and protein (29.3%), in which acidic polysaccharide was the main
effective flocculating component. OH and COO– groups may play a vital role in the flocculation of suspended particles. 相似文献
9.
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10.
A bioflocculant-producing bacterium isolated from soil was identified as Bacillus sp. and the bioflocculant produced was named MBFF19. Effects of physico-chemical conditions including pH, carbon sources and nitrogen sources on MBFF19 production were studied. Chemical analyses of the purified bioflocculant MBFF19 indicated that it was a sugar-protein derivative, composed of neutral sugar (3.6%, w/w), uronic acid (37.0%, w/w), amino sugars (0.5%, w/w) and protein (16.4%, w/w). The two neutral sugar components were mannose and glucose and the molar ratio was 1.2:1. Infrared spectrophotometry analysis revealed that MBFF19 contained carboxyl, hydroxyl and methoxyl groups in its structural. Flocculating properties of bioflocculant MBFF19 was examined using kaolin, activated carbon and fly coal suspension. Cation supplement had no positive effects on the flocculating activity whereas the presence of Fe3+ inhibited flocculation. Influences of pH and bioflocculant dosage on the flocculation were also examined. 相似文献
11.
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
12.
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
13.
Lignocelluloses have been used as carbon sources for bioflocculant production. However, the low bioconversion efficiency of lignocellulose to bioflocculants is a major challenge. In this study, a lignocellulolytic strain of Alcaligenes faecalis-X3 was cultivated in ramie bio-degumming wastewater. Optimal production of ligninase, cellulase and bioflocculants (MBF-X3) was evaluated. The highest activity of MBF-X3 under the optimal conditions of pH 6.0 at 48 h of fermentation was 95.44%, with the maximum production of ligninase and cellulase (0.27 and 0.12 U/mL, respectively). The crude ligninase and cellulase had optimum activities at pH 5.0 and 40 °C and pH 6.0 and 50 °C, respectively. The cellulase activity was increased by Mn2+, Ca2+, Zn2+, and Mg2+ at 1 mM. The ligninase activity was significantly enhanced in the presence of Zn2+ at 10 mM. The flocculating activity of MBF-X3 was not changed by the addition of any metal cation. The results demonstrated that A. faecalis possesses an excellent enzyme system for the efficient bioconversion of lignocellulose into MBF-X3. Additionally, MBF-X3 has a high flocculating efficiency of Disperse Blue-2BLN (85.7%) at a dose of 1.0 g/L. 相似文献
14.
Lili Wang Fang Ma Yuanyuan Qu Dezhi Sun Ang Li Jingbo Guo Bing Yu 《World journal of microbiology & biotechnology》2011,27(11):2559-2565
A compound bioflocculant CBF-F26, produced by mixed culture of Rhizobium radiobacter F2 and Bacillus sphaeicus F6, was investigated with regard to its physicochemical and flocculating properties. It was identified as a polysaccharide
bioflocculant composed of rhamnose, mannose, glucose, and galactose, respectively, in a 1.3: 2.1: 10.0: 1.0 molar ratio. The
average molecular weight was determined as 4.79 × 105 Da by gel-permeation chromatography. Infrared spectrum and X-ray photoelectron spectroscopy revealed the presence of carboxyl,
hydroxyl and amino groups in its structure. Thermostability test suggested that CBF-F26 was thermostable and high flocculating
activity was maintained. Thermogravimetric property, intrinsic viscosity and surface morphology of CBF-F26 were also studied.
CBF-F26 was effective under neutral and weak alkaline conditions (pH 7.0–9.0), and flocculating activities of higher than
90% were obtained in the concentration range of 8–24 mg l−1 at pH 8.0. The flocculation could be stimulated by cations Ca2+, Zn2+, Fe2+, Al3+, and Fe3+. In addition, the probable flocculation mechanisms were proposed. 相似文献
15.
In this study, the feasibility of bioflocculant extraction from backwashing sludge to reduce its production costs was investigated. Results showed that ultrasound and base treatment could significantly enhance bioflocculant extraction efficiency, however, flocculating activity was affected. It was observed that bioflocculants extracted from sludge of pH 11.0 had no flocculating activity. In contrast, bioflocculants extracted from sludge of pH 5.0, named as M-1, had good flocculating activity. To further study the flocculating activity of M-1, factors such as bioflocculant dosage, temperature and pH of the reaction solution were tested. The optimal conditions were 6.0 mg/l bioflocculant dosage and pH 5.0, at a temperature of 10 °C. Under these conditions, the flocculating rate of kaolin clay was 92.67%. The effectiveness of such bioflocculants in the decolorization of synthetically dyed wastewater was then examined. In flocculating methylene blue and fast blue in aqueous solutions, decolorization efficiency levels were 82.9% and 77.8%, respectively. 相似文献
16.
《Biocatalysis and Biotransformation》2013,31(4):244-250
AbstractApplication of wastes from the food processing industry as carbon sources in enzyme production processes reduces the cost of production, and also helps in solving problems of their disposal. In this work, we demonstrated that sweet cheese whey, in combination with passion fruit rind flour, can be successfully used for the production of protease by Bacillus sp. SMIA-2, opening perspectives for the use of these agricultural byproducts as novel and cost-effective culture media for the production of protease. The maximum production of the enzyme was observed in a sweet cheese whey-based culture medium preparation (0.5%, w/v) containing 0.25% (w/v) passion fruit rind flour and supplemented with different metal salts at an initial pH of 7.5–8.0, incubated at 50°C for 48 h. Studies on enzymatic characterization revealed that crude protease showed maximum activity at pH 9.0 and 70°C. These characteristics presented by the protease produced by Bacillus sp. SMIA-2 could be very useful when thinking about biotechnological applications. 相似文献
17.
Yi-Guang Chen Di-Fei Hao Qi-Hui Chen Yu-Qin Zhang Jian-Ben Liu Jian-Wu He Shu-Kun Tang Wen-Jun Li 《Antonie van Leeuwenhoek》2011,99(3):481-488
A novel Gram-stain-positive, slightly halophilic, catalase- and oxidase-positive, endospore-forming, motile, aerobic, rod-shaped bacterium, designated strain JSM 081003T, was isolated from non-saline forest soil in Hunan Province, China. Growth occurred with 0.5?C15% (w/v) NaCl (optimum 2?C4%) at pH 6.5?C10.5 (optimum pH 7.5?C8.5) and at 5?C40°C (optimum 30°C). meso-Diaminopimelic acid was present in the cell-wall peptidoglycan. The major cellular fatty acids were iso-C15:0, anteiso-C15:0 and iso-C14:0. Strain JSM 081003T contained MK-7 as the predominant respiratory quinone, and diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol as the major polar lipids. The genomic DNA G + C content of strain JSM 081003T was 40.9 mol%. A phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain JSM 081003T should be assigned to the genus Bacillus, and was related most closely to the type strains of Bacillus lehensis (sequence similarity 99.6%), Bacillus oshimensis (99.4%) and Bacillus patagoniensis (96.6%); lower than 96.0% sequence similarity was observed with other Bacillus species. The combination of phylogenetic analysis, DNA?CDNA relatedness values, phenotypic characteristics and chemotaxonomic data supports the view that strain JSM 081003T represents a new species of the genus Bacillus, for which the name Bacillus hunanensis sp. nov. is proposed. The type strain is JSM 081003T (= DSM 23008T = KCTC 13711T). 相似文献
18.
Haijun Wu Qingbiao Li Rui Lu Yuanpeng Wang Xiaoling Zhuang Ning He 《Journal of industrial microbiology & biotechnology》2010,37(11):1203-1209
The constant-rate fed-batch production of the polygalacturonic acid bioflocculant REA-11 was studied. A controlled sucrose-feeding
strategy resulted in a slight improvement in biomass and a 7% reduction in flocculating activity compared with the batch process.
When fed with a 3 g l−1 urea solution, the flocculating activity was enhanced to 720 U ml−1 in 36 h. High cell density (2.12 g l−1) and flocculating activity (820 U ml−1) were obtained in a 10-l fermentor by feeding with a sucrose-urea solution, with values of nearly two times and 50% higher
than those of the batch process, respectively. Moreover, the residual sucrose declined to 2.4 g l−1, and residual urea decreased to 0.03 g l−1. Even higher flocculating activity of 920 U ml−1 and biomass of 3.26 g l−1 were obtained by feeding with a sucrose-urea solution in a pilot scale fermentation process, indicating the potential industrial
utility of this constant-rate feeding strategy in bioflocculant production by Corynebacterium glutamicum. 相似文献
19.
利用多孔聚酯泡沫为载体,进行微生物絮凝剂产生菌的固定化及连续生产絮凝剂的研究。研究发现,利用多孔聚酯泡沫可吸附固定XN1菌丝细胞,且能较长时间保持高的活性。固定化XN1菌在三相流化床反应器中连续发酵运行13d无发现菌膜脱落现象,且发酵液絮凝活性均维持在90%以上,说明利用多孔聚酯泡沫颗粒作为固定化载体,连续生产絮凝剂的方法是可行的。另外,研究还发现,该菌所产生絮凝剂具有较高的热稳定性,在反应器中室温下保存数日仍可维持较高的絮凝活性。 相似文献
20.
A preliminary study was carried out to optimize the culture medium conditions for producing a novel microbial flocculant from the marine bacterial species Cobetia marina. The optimal glucose, yeast extract, and glutamate contents were 30, 10, and 2 g/l, respectively, while the optimal initial pH of the culture medium was determined to be 8. Following response surface optimization, the maximum bioflocculant production level of 1.36 g/l was achieved, which was 43.40% higher than the original culture medium. Within 5 min, a 20.0% (v/v) dosage of the yielded bioflocculant applied to algal cultures resulted in the highest flocculating efficiency of 93.9% with Spirulina platensis. The bioflocculant from C. marina MCCC1113 may have promising application potential for highly productive microalgae collection, according to the findings of this study. Open in a separate window 相似文献