Comparison of three gracilarioids: growth rate, agar content and quality

Abstract

Three gracilarioid species, Gracilariopsis bailiniae and Gracilaria tenuistipitata from Vietnam and Gracilaria gracilis from Russia, were studied in order to determine whether Gracilaria gracilis might be a superior species for cultivation in brackish-water ponds for agar production compared with the Vietnamese species. The effects of different salinity levels on the growth rate and agar production as well as agar properties of three gracilarioid species were compared in controlled laboratory experiments. Gracilaria tenuistipitata and G. gracilis were tolerant to low salinity (∼10‰), whereas Gp. bailiniae died under these conditions. G. tenuistipitata showed superior growth among the three species examined. Gracilaria gracilis had the highest agar content [36.8-46.6% dry weight (dw)]. Agar yield from Vietnamese gracilarioids did not exceed 30% dw. Gel strength of native agar from Gracilaria gracilis was two-fold higher that from Vietnamese species (278 g cm −2 vs 130 g cm −2 ). Alkali pretreatment increased gel strength significantly for Gracilaria gracilis (1.4-fold), and G. tenuistipitata and Gp. bailiniae (2.3-fold) compared with native agar. The results suggest that Gracilaria gracilis may be a suitable species for production of reasonably good quality agar.

Characterization of agar from Gracilaria tikvahiae cultivated for nutrient bioextraction in open water farms

“…without re-extraction steps (e.g. Arvizu-Higuera et al, 2008;Lewis & Hanisak, 1996;Skriptsova & Nabivailo, 2009;Villanueva et al, 2010). Nevertheless, extraction yields below 10% were reported for G. tikvahiae (Lopezbautista & Kapraun, 1995), making the yields achieved in this work significant.…”

“…Gelling temperatures were slightly higher than the typical gelling temperatures of commercial agars, which are generally below 40°C, but common in agar from Gracilaria sp., particularly if highly methylated. Despite the good gelling ability, the gel temperatures above 32-36°C made these agars unsuitable for direct use in bacteriological grade applications (Skriptsova & Nabivailo, 2009).…”

The Effects of Different Ph and Salinities on Growth Rate and Carrageenan Yield of Gracilaria Manilaensis

“…to abiotic factors such as light intensity, pH, salinity, temperature [22,23]. This showed that environmental parameters play essential role in the growth and carrageenan contain.…”

Analysis of expressed sequence tags from the agarophyte Gracilaria tenuistipitata (Rhodophyta)

“…These characteristics together with a high growth rate and high agar yield make this strain suitable for cultivation, and it has been extensively cultivated in ponds in Southern China and Taiwan (Chiang 1981). G. tenuistipitata has also been increasingly used as a model species in studies on red algal physiology (Carnicas et al 1999;Collén et al 2003;Falcão et al 2008Falcão et al , 2010García-Sánchez et al 1994;Pedersén 1992, 1993;Haglund et al 1996;Hu et al 1996;Lopes et al 1997Lopes et al , 2002Mercado et al 2001;Nyvall et al 1999;Nyvall Collén et al 2004;Skriptsova and Nabivailo 2009;Xu et al 2009;Yokoya et al 2004;Yu and Pedersén 1993). Another example of the growing interest in this alga is the sequencing of its chloroplast (Hagopian et al 2004) and mitochondrial (Takahashi 2010) genomes as well as completion of its life history in the laboratory (Barufi et al 2010).…”