Protoplast isolation and regeneration from Gracilaria changii (Gracilariales, Rhodophyta)

Abstract

The tropical agarophyte Gracilaria changii has been much researched and documented by the Algae Research Laboratory, University of Malaya, especially with regards to its potential as a seaweed bioreactor for valuable compounds. Protoplast regeneration of this seaweed was developed following the optimization of protoplast isolation protocol. Effect of the concentration and combination of isolating enzymes, incubation period, temperature, enzyme solution pH, tissue source on the protoplast yields were used to optimize the isolation protocol. The enzyme mixture with 4% w/v cellulase Onozuka R-10, 2% w/v macerozyme R-10 and 1 unit mL -1 agarase was found to produce the highest yield of protoplast at 28°C and 3 h incubation period. Thallus tips gave higher yields of protoplasts than middle segments. Freshly isolated G. changii protoplasts were cultured in MES medium. Regeneration of protoplast cell walls after 24 h was confirmed by calcofluor white M2R staining under UV fluorescence microscopy. The protoplasts with regenerated cell walls then underwent a series of cell division to produce calluslike cell masses in MES medium. Following this, juvenile plants of G. changii were obtained.

Effects of temperature, salinity and irradiance on carposporeling development of Hidropuntia caudata (Gracilariales, Rhodophyta)

“…The germination pattern of Hydropuntia caudata carpospores observed in the present study was similar to that described by Yokoya (1993), Polifrone et al (2006), Yeong et al (2008), and Mantri et al (2009) and corresponds to the Dumontia-type according to Guiry (1990). A very common characteristic observed was the coalescence of basal discs, which gave rise to three or more erect axis.…”

Reproductive Processes in Red Algal Genus Gracilaria and Impact of Climate Change

“…The establishment of the apical cell takes place at the summit, while the initiation of the rhizoids takes place in the lower half of the sporeling from the outermost cells that are in direct contact of the substratum (Oza, 1975). Similar pattern of spore germination and development as disc, holdfast stage, and apical dome formation has also been reported in G. changii (Yeong et al, 2008).…”

Biochemical Characterization and Substrate Degradation Mode of a Novel Exotype β-Agarase from Agarivorans gilvus WH0801

“…Agarases, which catalyze the hydrolysis of agarose, can cleave the α-1,3 linkages of agarose to produce agaro-oligosaccharides (AOS) (α-agarase; EC 3.2.1.158), or they can hydrolyze the β-1,4 linkages to neoagaro-oligosaccharides (NAOS) (β-agarase; EC 3.2.1.81). , Agarases have been successfully used in biotechnology applications such as protoplast preparation from seaweed and DNA gel recovery. , Until now, most of the reported agarases have been isolated from marine microbes . Only two α-agarases classified as glycoside hydrolase (GH) 96 have been characterized according to the CAZy database () and literature, , while the other enzymes are β-agarases that were isolated from marine bacteria such as Agarivorans , , Catenovulum , Flammeovirga , Streptomyces , and Vibrio . , On the basis of their amino acid sequence similarities, β-agarases are usually distributed into four GH families: GH16, GH50, GH86, and GH118.…”