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Protease-, pectinase-and amylase-producing bacteria from a Kenyan soda lake

Oluoch, Kevin Raymond LU ; Okanya, Patrick Wafula; Hatti-Kaul, Rajni LU ; Mattiasson, Bo LU and Mulaa, Francis Jakim (2018) In Open Biotechnology Journal 12. p.33-45
Abstract

Background: Alkaline enzymes are stable biocatalysts with potential applications in industrial technologies that offer high quality products. Objective: The growing demand for alkaline enzymes in industry has enhanced the search for microorganisms that produce these enzymes. Methods: Eighteen bacterial isolates from Lake Bogoria, Kenya, were screened for alkaline proteases, pectinases and amylases; characterized and subjected to quantitative analysis of the enzymes they produced. Results: The screening analysis ranked 14, 16 and 18 of the bacterial isolates as potent producers of alkaline proteases, pectinases and amylases, respectively. The isolates were classified into two groups: Group 1 (16 isolates) were facultatively alkaliphilic... (More)

Background: Alkaline enzymes are stable biocatalysts with potential applications in industrial technologies that offer high quality products. Objective: The growing demand for alkaline enzymes in industry has enhanced the search for microorganisms that produce these enzymes. Methods: Eighteen bacterial isolates from Lake Bogoria, Kenya, were screened for alkaline proteases, pectinases and amylases; characterized and subjected to quantitative analysis of the enzymes they produced. Results: The screening analysis ranked 14, 16 and 18 of the bacterial isolates as potent producers of alkaline proteases, pectinases and amylases, respectively. The isolates were classified into two groups: Group 1 (16 isolates) were facultatively alkaliphilic B. halodurans while group 2 (2 isolates) were obligately alkaliphilic B. pseudofirmus. Further analysis revealed that group 1 isolates were divided into two sub-groups, with sub-group I (4 isolates) being a phenotypic variant sub-population of sub-group II (12 isolates). Variation between the two populations was also observed in their enzymatic production profiles e.g. sub-group I isolates did not produce alkaline proteolytic enzymes while those in sub-group II did so (0.01-0.36 U/ml). Furthermore, they produced higher levels of the alkaline pectinolytic enzyme polygalacturonase (0.12-0.46 U/ml) compared to sub-group II isolates (0.05-0.10 U/ml), which also produced another pectinolytic enzyme-pectate lyase (0.01 U/ml). No clear distinction was however, observed in the production profiles of alkaline amylolytic enzymes by the isolates in the two sub-populations [0.20-0.40 U/ml (amylases), 0.24-0.68 U/ml (pullulanases) and 0.01-0.03 U/ml (cyclodextrin glycosyl transferases)]. On the other hand, group 2 isolates were phenotypically identical to one another and also produced similar amounts of proteolytic (0.38, 0.40 U/ml) and amylolytic [amylases (0.06, 0.1 U/ml), pullulanases (0.06, 0.09 U/ml) and cyclodextrin glycosyl transferases (0.01, 0.02 U/ml)] enzymes. Conclusion: The facultatively alkaliphilic B. halodurans and obligately alkaliphilic B. pseudofirmus isolates are attractive biotechnological sources of industrially important alkaline enzymes.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Alkaliphiles, Amylases, Bacillus halodurans, Bacillus pseudofirmus, Pectinases, Proteases, Soda lake
in
Open Biotechnology Journal
volume
12
pages
13 pages
publisher
Bentham Science Publishers
external identifiers
  • scopus:85049116834
ISSN
1874-0707
DOI
10.2174/1874070701812010033
language
English
LU publication?
yes
id
2acb666f-5df9-434c-a710-ef5c491feafc
date added to LUP
2018-07-09 13:44:30
date last changed
2018-11-21 21:40:43
@article{2acb666f-5df9-434c-a710-ef5c491feafc,
  abstract     = {<p>Background: Alkaline enzymes are stable biocatalysts with potential applications in industrial technologies that offer high quality products. Objective: The growing demand for alkaline enzymes in industry has enhanced the search for microorganisms that produce these enzymes. Methods: Eighteen bacterial isolates from Lake Bogoria, Kenya, were screened for alkaline proteases, pectinases and amylases; characterized and subjected to quantitative analysis of the enzymes they produced. Results: The screening analysis ranked 14, 16 and 18 of the bacterial isolates as potent producers of alkaline proteases, pectinases and amylases, respectively. The isolates were classified into two groups: Group 1 (16 isolates) were facultatively alkaliphilic B. halodurans while group 2 (2 isolates) were obligately alkaliphilic B. pseudofirmus. Further analysis revealed that group 1 isolates were divided into two sub-groups, with sub-group I (4 isolates) being a phenotypic variant sub-population of sub-group II (12 isolates). Variation between the two populations was also observed in their enzymatic production profiles e.g. sub-group I isolates did not produce alkaline proteolytic enzymes while those in sub-group II did so (0.01-0.36 U/ml). Furthermore, they produced higher levels of the alkaline pectinolytic enzyme polygalacturonase (0.12-0.46 U/ml) compared to sub-group II isolates (0.05-0.10 U/ml), which also produced another pectinolytic enzyme-pectate lyase (0.01 U/ml). No clear distinction was however, observed in the production profiles of alkaline amylolytic enzymes by the isolates in the two sub-populations [0.20-0.40 U/ml (amylases), 0.24-0.68 U/ml (pullulanases) and 0.01-0.03 U/ml (cyclodextrin glycosyl transferases)]. On the other hand, group 2 isolates were phenotypically identical to one another and also produced similar amounts of proteolytic (0.38, 0.40 U/ml) and amylolytic [amylases (0.06, 0.1 U/ml), pullulanases (0.06, 0.09 U/ml) and cyclodextrin glycosyl transferases (0.01, 0.02 U/ml)] enzymes. Conclusion: The facultatively alkaliphilic B. halodurans and obligately alkaliphilic B. pseudofirmus isolates are attractive biotechnological sources of industrially important alkaline enzymes.</p>},
  author       = {Oluoch, Kevin Raymond and Okanya, Patrick Wafula and Hatti-Kaul, Rajni and Mattiasson, Bo and Mulaa, Francis Jakim},
  issn         = {1874-0707},
  keyword      = {Alkaliphiles,Amylases,Bacillus halodurans,Bacillus pseudofirmus,Pectinases,Proteases,Soda lake},
  language     = {eng},
  month        = {01},
  pages        = {33--45},
  publisher    = {Bentham Science Publishers},
  series       = {Open Biotechnology Journal},
  title        = {Protease-, pectinase-and amylase-producing bacteria from a Kenyan soda lake},
  url          = {http://dx.doi.org/10.2174/1874070701812010033},
  volume       = {12},
  year         = {2018},
}