Thermostable exo-inulinase production by semicontinuous cultivation of membrane-immobilized Bacillus sp. 11 cells

Uzunova, Kristina; Vassileva, Anna; Иванова, В.; Spasova, D; Tonkova, Alexandra

doi:10.1016/s0032-9592(01)00283-7

Cited by 29 publications

(11 citation statements)

References 11 publications

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“…These results suggest that the high mannanase yield and operational stability of the immobilized B. subtilis WY34 cells were due to good cell immobilization, which was confirmed by SEM. Similar phenomena for bacterial cells immobilized on the surfaces of membranes have also been observed by other researchers (Dobreva et al 1998;Uzunova et al 2002).…”

Section: Scanning Electron Microscopy (Sem)supporting

confidence: 88%

“…PS-immobilized Bacillus sp. 11 cells retained 60-90% of their initial exo-inulinase activities at the end of the fifth cycle of repeated batch cultivation (Uzunova et al 2002). In this study, the B. subtilis WY34 cells immobilized on PES and nylon-6 membranes could be reused efficiently for mannanase production six cycles with 1.3-and 1.1-fold increase of enzyme yield at the end of the sixth batch cultivation, respectively.…”

Section: Operational Stability Of Immobilized Cellsmentioning

confidence: 72%

“…Cell immobilization was carried out on various types of polymer membranes according to the method described by Uzunova et al (2002). Activation and sterilization of various membranes were performed by treating with 10% (v/v) formaldehyde at 45°C.…”

Section: Cell Immobilization and Growth Conditionsmentioning

confidence: 99%

“…Extracellular enzyme production by Bacillus strains may be enhanced by using immobilized cells. Previous investigations on different methods for cell immobilization (by gel entrapment and on various membrane carriers) have indicated that polysulphone membranes (PS) are the most suitable supports for immobilization of Bacillus cells (Tonkova et al 1994;Kapoor et al 2008;Dobreva et al 1998;Uzunova et al 2002). High levels of a-amylase and exo-inulinase production and operational stability of biocatalysts were obtained from Bacillus cells immobilized on PS (Dobreva et al 1998;Uzunova et al 2002).…”

Section: Introductionmentioning

confidence: 99%

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Enhanced production of a thermostable mannanase by immobilized cells of Bacillus subtilis on various membranes

Yan

Jiang

et al. 2009

World J Microbiol Biotechnol

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Cells of the thermophilic Bacillus subtilis WY34 were immobilized on various formaldehyde-activated polymer membranes and the immobilized cells were used for the production of thermostable mannanase in flasks. The results showed that polyethersulfone membranes (PES) and nylon-6 membranes were the most suitable supports for cell immobilization to produce the mannanase. Moreover, PES and nylon-6 membranes immobilized cells provided 1.78-and 1.74-fold higher mannanase activity compared to the control after 4 days of cultivation, respectively. The immobilized cells on PES and nylon-6 membranes had good stability and retained 131.5 and 114.3% of ability of enzyme production even after six cycles of repeated batch fermentation, respectively. Active cell growth was observed by scanning electron microscopy (SEM) after 16 days (four cycles) repeated batch cultivation. Therefore, the membrane-immobilized cells of B. subtilis WY34 can be proposed as an effective biocatalyst for repeated usage for production of the thermostable mannanase.

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Section: Scanning Electron Microscopy (Sem)supporting

confidence: 88%

Section: Operational Stability Of Immobilized Cellsmentioning

confidence: 72%

Section: Cell Immobilization and Growth Conditionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Enhanced production of a thermostable mannanase by immobilized cells of Bacillus subtilis on various membranes

Yan

Jiang

et al. 2009

World J Microbiol Biotechnol

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“…The immobilized cells have advantages over the native cells due to the possibility for multiple applications for a extended period of time. Different carriers have been used for microbial cell immobilization, but there aren't many reports for cell immobilization on polymer membranes (Uzunova et al 2002;Marrot et al 2006;Hua et al 2005;Godjevargova et al 2006). Synthetic polymers constitute the largest group of supports in use.…”

Section: Introductionmentioning

confidence: 99%

Biodegradation of phenol by immobilized Aspergillus awamori NRRL 3112 on modified polyacrylonitrile membrane

et al. 2009

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Covalent immobilization of Aspergillus awamori NRRL 3112 was conducted onto modified polyacrylonitrile membrane with glutaraldehyde as a coupling agent. The polymer carrier was preliminarily modified in an aqueous solution of NaOH and 1,2-diaminoethane. The content of amino groups was determined to be 0.58 mgeq g(-1). Two ways of immobilization were used-in the presence of 0.2 g l(-1) phenol and without phenol. The capability of two immobilized system to degrade phenol (concentration-0.5 g l(-1)) as a sole carbon and energy source was investigated in batch experiments. Seven cycles of phenol biodegradation were conducted. Better results were obtained with the immobilized system prepared in the presence of phenol, regarding degradation time and phenol biodegradation rate. Scanning electron micrographs of the polyacrylonitrile membrane/immobilized Aspergillus awamori NRRL at the beginning of repeated batch cultivation and after the 7th cycle were compared. After the 7th cycle of cultivation the observations showed large groups of cells. The results from the batch experiments with immobilized system were compared to the results produced by the free strain. Phenol biodegradation experiments were carried out also in a bioreactor with spirally wound membrane with bound Aspergillus awamori NRRL 3112 in a regime of recirculation. 10 cycles of 0.5 g l(-1) phenol biodegradation were run consecutively to determine the degradation time and rate for each cycle. The design of the bioreactor appeared to be quite effective, providing large membrane surface to bind the strain.

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Inulinases

Sandhya¹,

Pandey²

2006

Enzyme Technology

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Thermostable exo-inulinase production by semicontinuous cultivation of membrane-immobilized Bacillus sp. 11 cells

Cited by 29 publications

References 11 publications

Enhanced production of a thermostable mannanase by immobilized cells of Bacillus subtilis on various membranes

Enhanced production of a thermostable mannanase by immobilized cells of Bacillus subtilis on various membranes

Biodegradation of phenol by immobilized Aspergillus awamori NRRL 3112 on modified polyacrylonitrile membrane

Inulinases

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