Optimization of Culture Conditions for the Production of Extracellular Agarases from Newly Isolated Pseudomonas Aeruginosa AG LSL-11

Abstract

An agar-degrading bacterium capable of utilizing agar as sole source of carbon and energy was isolated from sea water by enrichment culture technique. The bacterium was identified as Pseudomonas aeruginosa and the culture conditions were standardized for the maximal production of extracellular agarases. The bacterium grew in the pH range 5.0-11.0, optimal between pH 7.0 and 8.0; temperature between 25°C and 37°C, optimal at 30°C and sodium chloride concentration 0-8% and optimal at 2% respectively. The agarases secreted by Pseudomonas aeruginosa AG LSL-11 were inducible by agar and not by any other simple sugars tested. Maximal agarase production was observed at pH 8.0, and temperature 30°C. The bacterium had no requirement for NaCl for both growth and production of agarases. The bacterium did not utilize other polysaccharides like j-carrageenan, alginate, cellulose and CMC. The activity staining of partially purified agarase preparation after native-PAGE revealed the presence of three different agarases, agarase LSL-11a, LSL-11b and LSL-11c, whose molecular weights were estimated to be 76, 64 and 46 kDa respectively.

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

“…17at 1 % NaCl concentration and unlike other agarolytic marine Pseudomonads, Pseudomonas aeruginosa ZSL-2 do not demand for sodium chloride as a specific requirement, moreover, even in absence of which, the bacterium grows well and produces extracellular agarases. Similar observations are reported for P. aeruginosa AG LSL 11 [10].…”

“…The agarase producing bacteria are also isolated from nonmarine environments, like the ones from low-land river [6], soil [7,8] and plant root [9]. There are limited number of studies which have investigated the optimization of culture conditions for agarase-producing microbes [10][11][12][13][14][15][16]. Optimal culture conditions for agarase-producing Pseudomonas sp.…”

“…In order to check the effect of fermentation period the flasks were incubated on a rotary shaker at 170 rpm and 37 °C for 60 h. The effect of incubation period was analysed by withdrawing 2 ml of culture medium aseptically at different intervals. To study the effect of initial pH, the culture inoculated media flasks were individually incubated at different pH (pH [5][6][7][8][9][10][11]. To check the effect of temperature, the flasks were incubated at different temperature such as 20, 25, 30, 37 and 40 °C.…”

“…HZ105 is reported to grew at the broad pH range of 6.0-11.0, and optimally at about pH 8.0 [13]. 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].…”

Media Optimization for Depolymerization of Alginate by <i>Pseudomonas aeruginosa</i> AG LSL-11

“…Previously it was utilizing agar as sole carbon source [Lakshmikanth 2006, Basawaraj et al 2012and 2013, later bacterium was acclimatized to alginate for the production of alginase. A typical growth curve of bacterium reveals that the bacterial growth was observed after 12h of incubation in the medium, also the alginase production in extracellular medium was observed at the same incubation time, both cell growth and the alginase production reached maximum at 48h of incubation.…”