Enhanced production of thrombinase by Streptomyces venezuelae: Kinetic studies on growth and enzyme production of mutant strain

Naveena, Balakrishnan; Gopinath, Kannapan Panchamoorthy; Sakthiselvan, Punniavan; Partha, Nagarajan

doi:10.1016/j.biortech.2012.02.056

Cited by 27 publications

(22 citation statements)

References 26 publications

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“…In their study, mutation frequency arose steadily with exposure time, with no evidence of failure rate of increase at high doses (29). It is reported that a decrease in the survival rate of S. venezuelae from 100% to 8% occurred as a result of UV mutagenesis when the time of UV exposure was increased from 0 to25 minutes (21). In another study, survival rates of 8% and 5% were observed at UV exposure of 100 and 120 seconds, respectively, showing a gradual reduction in the survival rate with increasing UV exposure on S. fradiae NRRL-2702.…”

Section: Discussionmentioning

confidence: 99%

“…At lower concentrations of EB (10 and 20 µL/mL), the obtained mutants showed almost similar activities (17 mg/L B1b) as was shown by parent strains. In a study conducted by Naveena et al it was mentioned that by increasing the concentration of chemical mutagens, the survival capacity of the mutants get adversely affected (21). In the present study, it is also observed that at a higher EB concentration (40 µL/mL), obtained mutants did not show any production and it resulted in the loss of activity.…”

Section: Discussionmentioning

confidence: 99%

“…A suitable selection of exposure times is therefore mandatory to accomplish a good and fruitful chemical mutagenesis (21). In one of the studies conducted previously, MMS was used as a mutagen for the enhanced production of avermectin from S. avermitilis .…”

Section: Discussionmentioning

confidence: 99%

“…The plates were incubated at 28°C for 24 hours. Thereafter, the percentage of survival rate in each plate was calculated using the equation mentioned below, and mutants with the lowest survival rates were selected from the plates (21). …”

Section: Methodsmentioning

confidence: 99%

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Production and Screening of High Yield Avermectin B1b Mutant of Streptomyces avermitilis 41445 Through Mutagenesis

Siddique

Syed

Adnan

et al. 2014

Jundishapur J Microbiol

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Background:Secondary metabolite production from wild strains is very low for economical purpose therefore certain strain improvement strategies are required to achieve hundred times greater yield of metabolites. Most important strain improvement techniques include physical and chemical mutagenesis. Broad spectrum mutagenesis through UV irradiation is the most important and convenient physical method.Objectives:The present study was conducted for enhanced production of avermectin B1b from Streptomyces avermitilis 41445 by mutagenesis using ultraviolet (UV) radiation, ethidium bromide (EB), and ethyl methanesulfonate (EMS) as mutagens.Materials and Methods:S. avermitilis DSM 41445 maintained on yeast extract malt extract glucose medium (YMG) was used as inoculum for SM2 fermentation medium. Spores of S. avermitilis DSM 41445 were exposed to UV radiation for physical broad spectrum mutagenesis and to EMS and EB for chemical mutagenesis. For each mutagen, the lethality rate and mutation rate were calculated along with positive mutation rate.Results:Avermectin B1b-hyper-producing mutant, produced using these three different methods, was selected according to the HPLC results. The mutant obtained after 45 minutes of UV radiation to the spores of S. avermitilis 41445, was found to be the best mutant for the enhanced production of avermectin B1b component (254.14 mg/L). Other avermectin B1b-hyper-producing mutants, were obtained from EMS (1 µL/mL) and EB (30 µL/mL) treatments, and yielded 202.63 mg/L and 199.30 mg/L of B1b, respectively.Conclusions:The hereditary stability analysis of the UV mentioning 45 minutes revealed the UV exposure time for mutants and 3 represented the colony taken from the plate irradiated for 45 minutes mutant showed that the production of avermectin B1b remained constant and no reverse mutation occurred after 15 generations.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Production and Screening of High Yield Avermectin B1b Mutant of Streptomyces avermitilis 41445 Through Mutagenesis

Siddique

Syed

Adnan

et al. 2014

Jundishapur J Microbiol

View full text Add to dashboard Cite

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“…However, industrial applications of laccases are usually hindered by long fermentation period, low laccase yield, as well as poor enzyme stability [15]. In addition to enzyme source viz., microorganism and substrate, other factors should be considered to develop efficient enzymatic bioprocesses and to satisfy commercial needs.…”

Section: Introductionmentioning

confidence: 99%