Extracellular β-agarase LSL-1 producing neoagarobiose from a newly isolated agar-liquefying soil bacterium, Acinetobacter sp., AG LSL-1

Abstract

An agar-liquefying Acinetobacter species capable of utilizing agar as sole source of carbon and energy was isolated from soil samples and the culture conditions were standardized for the maximal production of extracellular agarase. The bacterium was capable of liquefying an agar-plate within 3 days of incubation and produced extracellular agarase within a short period of time (16-18 h) when grown in defined mineral salts medium. Bacterium grew in the pH range 4.0-9.0, optimal at pH 7.0; temperature 25-40°C and optimal at 37°C. The agarase secreted by the Acinetobacter strain was inducible by agar and not repressed by other simple sugars when supplemented along with agar in the medium. The bacterium did not require NaCl for growth or production of agarase. The bacterium did not utilize other polysaccharides like j-carrageenan, alginate, cellulose, and CMC. The activity staining of partially purified agarase preparations after native-PAGE and SDS PAGE revealed the presence of a single zone of clearance corresponding to the molecular weight 100 kDa, suggesting that it is a monomer. Neoagarobiose was the end product of agarose hydrolysis by this enzyme. The agarase was an endo-type glycosidase and belongs to Group-III b-agarase family.

Optimization of Agrase Production by Alkaline <i>Pseudomonas aeruginosa</i> ZSL-2 Using Taguchi Experimental Design

“…The Alteromonas strain 2-40 is reported to grow at pH range between 5.0 and 9.2 and optimally at pH 7.5 [23], The Pseudomonas aeruginosa AG LSL-11 is reported to grow in the pH range 5.0-11.0 and optimally at pH 8.0 [10]. Acinetobacter sp., AG LSL-1 grew at pH range from pH 4.0 to 9.0, and optimally at pH 7.0 [24]. However, it was reported P. agarivorans as a slightly alkali tolerant with pH growth range of 6 to 9 and with an optimum pH of 8 to 9 [22].…”

Optimization of Anion-exchange Chromatography for the Separation of Agarase from Culture Broth of Pseudoalteromonas sp.

“…아가레이즈는 아가로오스를 가수분해하는 효소 로 그 분해 특성에 따라 두 그룹으로 나뉜다 [1][2][3]. β-아가레이즈는 α-1,3 결합을 끊어 agarooligosaccharide를 생성하는 반면 [4][5][6], β-아 가레이즈는 β-1,4 결합을 끊어 neooligosaccharide를 생성한다 [7][8][9][10].…”

An agar degrading diazotrophic actinobacteria from hyperalkaline meteoric lonar crater lake - a primary study

“…Agarases are enzymes that hydrolyse the polymer agarose and have potential applications in the food, cosmetic and medical industries for breaking down agar components. 2 Agar is attacked by relatively few species of microorganisms, including bacteria and actinomycetes. Most of the previously reported agar degrading bacteria such as Alteromonas species, Bacillus cereus, Cytophaga, Pseudoalteromonas, Pseudomonas, Vibrio sp.…”

“…have quite been isolated from marine environment. [2][3][4][5][6][7][8][9][10][11][12][13][14] Since agar is a polysaccharide produced by marine red algae, it is natural that most agar degrading bacteria are inhabitants of marine habitats. However, there are very few reports of nitrogen fixing bacteria degrading agar except for an agar degrading marine nitrogen fixing bacterium placed in the family Vibrionaceae 15 There are also no reports of any actinobacteria other than Streptomyces coelicolor reported by Stanier.…”