Starch-hydrolyzing bacteria from Ethiopian soda lakes

Martins, Rita; Davids, Wagied; Al‐Soud, Waleed Abu; Levander, Fredrik; Rådström, Peter; Hatti‐Kaul, Rajni

doi:10.1007/s007920100183

Cited by 66 publications

(33 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Few moderate alkaliphilic strains especially represents the genus Bacillus, are able to produce extracellular lipase, amylase and proteases that are even active at alkaline pH 11,12 .…”

Section: Resultsmentioning

confidence: 99%

Untitled

2017

IJPSR

View full text Add to dashboard Cite

Microbial enzymes such as amylase, lipase and protease are commercially significant and have widespread applications in many industries like pharmaceutical, leather, detergent, textile and other industries. Many haloalkaliphilic Bacillus species in hyper saline environment produces various types of commercially important enzymes such as lipase. A total of twelve Bacillus strains were isolated from Lonar crater and screened for lipase production on egg yolk agar medium. A Bacillus species (DHT 25) was found to be a prominent lipase producer which was later on identified by various morphological, cultural, biochemical and 16s rRNA sequencing as Bacillus flexus. Alkaline lipase production and activity recorded optimum at pH 9; at temperature 60°C, and enzyme concentration at 7mL and substrate concentration at 3mL. Lipase from this bacterial strain was active at higher temperature and pH and may find potential applications in food, pharmaceutical and detergent industries.

show abstract

“…Few moderate alkaliphilic strains especially represents the genus Bacillus, are able to produce extracellular lipase, amylase and proteases that are even active at alkaline pH 11,12 .…”

Section: Resultsmentioning

confidence: 99%

Untitled

2017

IJPSR

View full text Add to dashboard Cite

show abstract

“…The soda lake from which A. gottschalkii was originally isolated (Lake Bogoria, Kenya) is severely depleted of Ca 2ϩ (4), which makes a dependence of extracellular enzymes on loosely bound Ca 2ϩ seem inappropriate. It has even been reported for two Bacillus-related strains isolated from soda lakes in Ethiopia that amylase activity in the culture supernatant was stimulated by EDTA and decreased by Ca 2ϩ ions, possibly due to adaptation to the Ca 2ϩ -deficient environment (16). Thermoalkaliphilic organisms are thus a promising source for chelating-reagent-resistant glycoside hydrolases, which are active at alkaline pH values and tolerant of elevated temperatures.…”

Section: Discussionmentioning

confidence: 99%

AmyA, an α-Amylase with β-Cyclodextrin-Forming Activity, and AmyB from the Thermoalkaliphilic OrganismAnaerobranca gottschalkii: Two α-Amylases Adapted to Their Different Cellular Localizations

Ballschmiter

Armbrecht

Ivanova

et al. 2005

Appl Environ Microbiol

View full text Add to dashboard Cite

Two ␣-amylase genes from the thermophilic alkaliphile Anaerobranca gottschalkii were cloned, and the corresponding enzymes, AmyA and AmyB, were investigated after purification of the recombinant proteins. Based on their amino acid sequences, AmyA is proposed to be a lipoprotein with extracellular localization and thus is exposed to the alkaline milieu, while AmyB apparently represents a cytoplasmic enzyme. The amino acid sequences of both enzymes bear high similarity to those of GHF13 proteins. The different cellular localizations of AmyA and AmyB are reflected in their physicochemical properties. The alkaline pH optimum (pH 8), as well as the broad pH range, of AmyA activity (more than 50% activity between pH 6 and pH 9.5) mirrors the conditions that are encountered by an extracellular enzyme exposed to the medium of A. gottschalkii, which grows between pH 6 and pH 10.5. AmyB, on the other hand, has a narrow pH range with a slightly acidic pH optimum at 6 to 6.5, which is presumably close to the pH in the cytoplasm. Also, the intracellular AmyB is less tolerant of high temperatures than the extracellular AmyA. While AmyA has a half-life of 48 h at 70°C, AmyB has a half-life of only about 10 min at that temperature, perhaps due to the lack of stabilizing constituents of the cytoplasm. AmyA and AmyB were very similar with respect to their substrate specificity profiles, clearly preferring amylose over amylopectin, pullulan, and glycogen. Both enzymes also hydrolyzed ␣-, ␤-, and ␥-cyclodextrin. Very interestingly, AmyA, but not AmyB, displayed high transglycosylation activity on maltooligosaccharides and also had significant ␤-cyclodextrin glycosyltransferase (CGTase) activity. CGTase activity has not been reported for typical ␣-amylases before. The mechanism of cyclodextrin formation by AmyA is unknown.

show abstract

“…CDs have numerous applications in the pharmaceutical, cosmetics, textile, food, as well as bioremediation and separation processes. Industrial production of CGTase became attractive when alkalophilic Bacillus species were introduced as producer organisms because of their high level of activity in wide pH and high temperature ranges (Atanasova et al, 2008;Martins et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Production of a novel Cyclodextrin glycosyltransferase from Bacillus sp. SK13.002

Sun¹,

Letsididi²,

Pan³

2013

Afr. J. Microbiol. Res.

View full text Add to dashboard Cite

A β-cyclodextrin glycosyltransferase (β-CGTase) from a new alkalitolerant Bacillus sp. SK 13.002 strain which can significantly hydrolyze starch into short linear saccharides, in addition to production of cyclodextrins (CDs) was produced. The hydrolytic activity of this CGTase as a side reaction is thought to be due to partial retention of ancestral enzyme function from evolution over time. This CGTase is therefore another example of an enzyme at an intermediary stage in between ''true'' α-amylases and ''true'' CGTases. The strain also produced two CGTase isozymes which were purified to homogeneity using DEAE-Sepharose anion exchange chromatography and Superdex 75 gel filtration chromatography to show Molecular masses of 67.5 and 46.8 kDa on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) respectively, which were confirmed by liquid chromatography/mass spectrometry (LC/MS) analysis to be 67.6 and 47.3 kDa, respectively. Both CGTase isozymes formed CDs from soluble starch. Most of the reported CGTases were composed of one single enzyme with only a few strains having CGTase isozymes showing different isoelectric points. Therefore, Bacillus sp. SK 13.002 strain is another Bacillus capable of producing CGTase isozymes which were individually purified to homogeneity.

show abstract

Starch-hydrolyzing bacteria from Ethiopian soda lakes

Cited by 66 publications

References 28 publications

Untitled

Untitled

AmyA, an α-Amylase with β-Cyclodextrin-Forming Activity, and AmyB from the Thermoalkaliphilic OrganismAnaerobranca gottschalkii: Two α-Amylases Adapted to Their Different Cellular Localizations

Production of a novel Cyclodextrin glycosyltransferase from Bacillus sp. SK13.002

Contact Info

Product

Resources

About