A bacterial strain YS24 produced high Tuyen Quang.. Based on the colony observation, level of extracellular protease was isolated from cell soil sample collected at Yen Son - morphology
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ĐẠI HỌC QUỐC GIA HÀ NỘI
VIETNAM NATIONAL UNIVERSITY, HANOI
ISSN 0866 - 8612
@ JOURNAL
KHOA HOC TU NHE
NATURAL SCIENCE
Volume 27, No 2S, 2011 :
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VNU Journal of Science, Natural Sciences and Technology 27, No 2S (2011) 226-238
optimization of culture conditions for protease production
Dao Thi Luong’*, Vi Dai Lam’, Tran Thi Le Quyen!, Ha Thi Hang’,
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Pham Duc Ngoc’, Duong Van Hop'
1YNU Institute of Microbiology and Biotechnology, 144 Xuan Thuy, Hanoi, Vietnam
2 Faculty of Biology, VNU University of Science, 334 Nguyen Trai,
Received 09 September 2011
Abstract A bacterial strain YS24 produced high Tuyen Quang Based on the colony observation, level of extracellular protease was isolated from cell soil sample collected at Yen Son -
morphology and the analysis of 16S rDNA nucleotide
The highest levels of extracellular protease production and bacterial growth were
9 (g/l): Glucose-5; peptone-7.5; MgSO4.7H;O-5; K,HPO,-5;
Bacillus subtilis
obtained by using medium V FeSO,.7H,0-0.1 Enzyme production corresponded with bacterial
the bacterium was cultured on the condition: at speed of 200 rpm, inoculum size of 7% , temperature of 40-45°C, medium pH of 7.0
- 8.0 and incubation time in 48 hours The best carbon at extract Protease activity reached the highest source was either glucose or galactose The level at pH
level of 1,390 U/ml when
best nitrogen source was peptone or me
of 8.0 and temperature of 50 °C The enzyme retained 93, 86 and 76% of its initial
treatment at 60 °C, 70 °C and 80 °C for 10 min,
after exposing to temperature above 90°C
Keywords: Bacillus subtilis, protease, taxonomic, culture conditions, enzyme properties
1 Introduction
Proteases are the most important enzymes accounting for about 60% of the total industries
of enzyme market They have diverse applications in a wide variety of industries,
such as in detergent, food, leather tanning and processing, fiber, pharmaceuticals, garments
and for recovery of silver from used x-ray films
[1]
* Corresponding author Tel.: 84-4-37547695
E-mail: luongdt@vnu.edu.vn
Hanoi, Vietnam |
sequence, the strain YS24 was identified as growth and reached a maximal
orbital shaker under following
activity after respectively Enzyme activity was completely lost BAR
Many bacteria belonging to the genus Bacillus excrete large amounts of the enzymes
into the culture medium [2] Microbial
proteases dominate the world wide enzyme market, eg accounting for a two - third share of the detergent industry [3]
Although protease production is an inherent
property of all living organisms, only microorganisms that produce a substantial
amount of extracellular protease have been exploited commercially [3]
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