Investigation of the bacitracin biosynthesis in an airlift bioreactor

Roman, R. V.

doi:10.1002/abio.370130215

Cited by 13 publications

(3 citation statements)

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“…Average results of the runs performed in an EAL during the Bacitracin biosynthesis, carried out at 1.0 wm, are analyzed below. The values of the cell mass content (as DNA arbitrary unitsfl [22]) compared to those obtained in an STRl are plotted in Fig. 13 a. The rates of biomass production were different during biosyntheses in the --01 I * two systems (EAL and STRl), but the final values were between 0.165-0.200 DNA arbitrary unitsh (Fig.…”

Section: Biosynthesis Resultsmentioning

confidence: 97%

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Performance of airlift bioreactors in the cultivation of some antibiotic producing microorganisms

Roman

1998

Acta Biotechnologica

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The specific aspects of airlift reactors emphasizing their function relevance to particular application as bioreactors are presentedThe two main groups of airlift reactors -external-loop and concentric-tube reactors -were investigated on a pilot-plant scale with regard to their performance during the cultivation of unicellular and filamentous microorganisms which produce Baciwcin, Cephalosporin C and Nystatin. Some results were compared to those obtained in conventional stirred tank bioreactors. The comparison was carried out based on physical properties (oxygen transfer rate (OTR), volumetric mass transfer coefficient ( h a ) and efficiency of oxygen transfer (EQ)), cell mass, productivity and substrate consump tion, secondary metabolite production, and efficiency of the product formation with regard to the specific power input.It was shown that B. lichenifomis, C. acremonium and S. noursei fermentations occurred similarly to those performed in stirred vessels, proving that the capacity of the airlift bioreactors surpassed the problems which arise from the morphology and rheology of the broths. From the chemical engineering point of view, it was obvious that the primary tasks of a bioreactor (uniform distribution of microorganisms and nutrients over the entire fernenter volume, appropriate supply of biomass with nutrients and oxygen) were fulfilled by the airlift bioreactors tested. In addition, the efficiency of oxygen transfer (OTR referred to power input) in the airlift fermenters proved to be about 38% higher than in the stirred tank bioreactors (expressed as average values). while the sorption efficiency ( O R referred to antibiotic production) was found to be 22% greater in the airlift system than in an STR. Therefore, the biosyntheses were performed with about a 3040% increase in energy efficiency and energy savings compared to the conventional system. Moreover, the lack of mechanical devices in the airlift system provides greater safety and a gentler environment for the cultivation of microorganisms.

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Section: Biosynthesis Resultsmentioning

confidence: 97%

“…The biosynthesis liquids are characterized by time-dependent non-Newtonian behaviour. All of them are pseudoplastic with tixothropy [22][23][24]29, 331 (Fig. 4).…”

Section: Analysis Of the Fermentation Processes Biof Uid Characteristmentioning

confidence: 99%

Performance of airlift bioreactors in the cultivation of some antibiotic producing microorganisms

Roman

1998

Acta Biotechnologica

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“…Bacitracin is mainly produced by Bacillus licheniformis (13, 30). We used locally isolated strain of Bacillus licheniformis to obtain mutants that can produce high titers of bacitracin.…”

Section: Discussionmentioning

confidence: 99%

Systematic mutagenesis method for enhanced production of bacitracin by Bacillus licheniformis mutant strain UV-MN-HN-6

Aftab¹,

Haq²,

Baig³

2012

Braz. J. Microbiol.

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The purpose of the current study was intended to obtain the enhanced production of bacitracin by Bacillus licheniformis through random mutagenesis and optimization of various parameters. Several isolates of Bacillus licheniformis were isolated from local habitat and isolate designated as GP-35 produced maximum bacitracin production (14±0.72 IU ml-1). Bacitracin production of Bacillus licheniformis GP-35 was increased to 23±0.69 IU ml-1 after treatment with ultraviolet (UV) radiations. Similarly, treatment of vegetative cells of GP-35 with chemicals like N-methyl N’-nitro N-nitroso guanidine (MNNG) and Nitrous acid (HNO2) increased the bacitracin production to a level of 31±1.35 IU ml-1 and 27±0.89 IU ml-1respectively. Treatment of isolate GP-35 with combined effect of UV and chemical treatment yield significantly higher titers of bacitracin with maximum bacitracin production of 41.6±0.92 IU ml-1. Production of bacitracin was further enhanced (59.1±1.35 IU ml-1) by optimization of different parameters like phosphate sources, organic acids as well as temperature and pH. An increase of 4.22 fold in the production of bacitracin after mutagenesis and optimization of various parameters was achieved in comparison to wild type. Mutant strain was highly stable and produced consistent yield of bacitracin even after 15 generations. On the basis of kinetic variables, notably Yp/s (IU/g substrate), Yp/x (IU/g cells), Yx/s(g/g), Yp/s, mutant strain B. licheniformis UV-MN-HN-6 was found to be a hyperproducer of bacitracin.

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Bioreactors, Airlift

Takayama¹

2000

Encyclopedia of Cell Technology

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Investigation of the bacitracin biosynthesis in an airlift bioreactor

Cited by 13 publications

References 20 publications

Performance of airlift bioreactors in the cultivation of some antibiotic producing microorganisms

Performance of airlift bioreactors in the cultivation of some antibiotic producing microorganisms

Systematic mutagenesis method for enhanced production of bacitracin by Bacillus licheniformis mutant strain UV-MN-HN-6

Bioreactors, Airlift

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