Isolation and characterization of alginate-degrading bacteria for disposal of seaweed wastes

Abstract

Aims: Isolation of novel alginate degrading bacteria for the disposal of seaweed waste in composting process. Methods and Results: Decomposition of alginate polymers was checked by the 3,5‐dinitrosalicylic acid (DNS) method for reducing sugar, and absorbance at 235 nm for unsaturated sugar. A bacterium A7 was isolated from wakame compost and confirmed to belong to the genus Gracilibacillus by partial 16S rDNA analysis. The optimum condition for the growth of A7 in a medium containing 5 g l−1 of sodium alginate is as follows: pH, 8·5–9·5; NaCl, 0·5 mol l−1; temperature, 30°C and polypeptone as nutrient content, 2–5 g l−1. In a laboratory‐scale composting experiment, the alginate content in wakame compost decreased to 14·3% after 72 h of composting from an initial value of 36%, indicating the effectiveness of alginate decomposition of A7 in wakame composting. Conclusions: The bacterium A7 was found to be alginate lyase‐producing in genus Gracilibacillus and effective in degrading alginate to oligosaccharides in wakame during composting process. Significance and Impact of the Study: Development of new methods for the disposal of marine wastes and production of functional products.

Optimization of saccharification and ethanol production by simultaneous saccharification and fermentation (SSF) from seaweed, Saccharina japonica

“…Brown seaweed has a high content of easily degradable carbohydrates, making it a potential substrate for the production of liquid fuels [9]. The carbohydrates of brown seaweed are composed of alginate, laminaran and mannitol, with alginate being the main component at almost 50% of the total carbohydrates [10,11]. Alginate is composed of D-mannuronate and its C5-epimer, L-guluronate, which are linked by b-(1,4) glycosidic linkages, and it is a major structural component of the cell wall and intracellular matrix of brown seaweeds.…”

Avances tecnológicos en la producción de alginatos en México

“…Cada día se descubren más usos para estos compuestos en diferentes industrias y la mayoría de los estudios recientes sobre el tema de los alginatos se ha concentrado en nuevas aplicaciones como: acarreadores de proteínas (Coppi et al, 2001); intercambiadores de metales (Davis et al, 2004;De Stefano et al, 2005); incorporación en textiles (Gorenšek y Bukošek, 2006); inmovilización de levaduras (Pajic et al, 2007); micro encapsulados (Schuldt y Hunkeler, 2007;Mørc, 2008); absorción de radiación ultravioleta (Tavares, 2007); control de la colitis ulcerativa (Alireza et al, 2008), promotor del crecimiento de las raíces de las plantas terrestres (Iwasaki y Matsubara, 2000). Entre los usos indirectos, se encuentra que los residuos del proceso de extracción de alginatos, pueden ser utilizados como fertilizante, ya que la bacteria Gracilibacilus (A7) degrada el alginato a oligosacáridos durante el proceso de composta (Tang et al, 2009). Estudios recientes describen el potencial económico de la producción de bioetanol a partir de algas, basados en el hecho de que la materia prima puede derivarse de los residuos producidos por la industria de alginato, que está altamente enriquecida en azúcares como manitol y laminaran, de tal modo que los costos iniciales se reducen drásticamente (Moen et al, 1997;Horn et al, 2000).…”

Alginate Lyase from Indonesian Bacillus megaterium S245 Shows Activities Toward Polymannuronate and Polyguluronate

“…The reducing sugar produced by enzyme substrate reaction was detected using the 3,5-dinitrosalicylic acid (DNS) method following Tang et al (2009) with slight modification. 1 ml of sample mixture at (0,8 ml sodium phosphate buffer + 0.1 mg alginate + 0.1 ml enzyme) was mixed with 1 ml of DNS solution and boiled for 5 min.…”

“…Alginate lyase has been used in many applications such as in producing poly (M) and poly (MG) blocks (Wong, Preston & Shiller, 2000), to degrade alginate in wakame composting process (Tang, Taniguchi, Chu, Zhou & Nagata, 2009), to produce bioactive oligosaccharide Guo et al, 2011;Iwamoto, Araki, Iriyama, Oda, Fukuda & Hayashida, 2005) and to analyze alginate fine structure (Kim, Lee & Lee, 2011). Since many bioactive molecule can be produced using alginate lyase, the future application of this enzyme will continue to increase (Wong, Preston & Shiller, 2000).…”