Produksi pelengkap nutrisi dari mikroalga laut Spirulina platensis dan Botyrococcus braunii

Production of nutritional supplements from Spirulina platensis and Botyrococcus Braunii marine microalgae.The low level of health of pregnant women is one of the results from the deficiency of omega-3 and omega-6 fatty acids in Indonesia. Giving supplement containing DHA, EPA, and AA, can solve the problem. Usually, these nutritional supplements are produced from marine fish oil. However, this source has several deficiencies that influence the quality of the fatty acid produced. Therefore, alternative sources of oil need to be found that can replace fish oil to produce DHA, EPA, and AA. One of the very potential sources is heterotrophic cultivated microalgae. In this study, microalgae from species Spirulina platensis and Botyrococcus braunii collected from Research Center for Marine and Fisheries Product Processing and Biotechnology in Jakarta, were cultivated. Once microalgae is cultivated autotrophically, the culture were transformed to heterotrophic condition by adding 0.5 g/L glucose solution. Results showed that lipid yield from S.platensis and B. braunii were 5.297 and 0.173 (%-w dry biomass), respectively. Composition of DHA, EPA and AA from S.platensis and B.braunii oils were 0.006, 0.002, and 0.001 (%-w of lipid), respectively.Keywords: Spirulina platensis, Botryococcus braunii, heterotroph, microwave, microalgae AbstrakSalah satu dampak kekurangan asam-asam lemak omega-3 dan omega-6 di Indonesia adalah rendahnya tingkat kesehatan ibu hamil. Pemberian pelengkap nutrisi yang mengandung DHA, EPA dan AA dapat menjadi solusi permasalahan tersebut. Pada umumnya suplemen tersebut diperoleh dari minyak ikan laut, namun sumber ini memiliki beberapa kekurangan yang mempengaruhi kualitas asam lemak yang dihasilkan, sehingga diperlukan pengganti minyak ikan laut sebagai sumber utama DHA, EPA dan AA. Salah satu sumber pelengkap nutrisi yang sangat potensial adalah mikroalga yang dikultivasi secara heterotrof. Pada penelitian ini dilakukan kultivasi mikroalga spesies Spirulina platensis dan Botyrococcus braunii yang dikoleksi oleh Balai Besar Bioteknologi dan Perikanan di Jakarta. Kultivasi masing-masing mikroalga tersebut mula-mula dilakukan secara normal (autotrof), kemudian dikondisikan menjadi heterotrof dengan pemberian glukosa 0,5 g/L. Hasil ekstraksi dengan gelombang mikro menunjukkan bahwa S. platensis dan B. braunii yang dikultivasi secara heterotrof memiliki kandungan minyak berturut-turut sebesar 5,297 dan 0,173 %-b (berdasarkan biomassa kering). Kandungan DHA, EPA, dan AA dalam minyak dari kedua mikroalga tersebut adalah berturut-turut sebesar 0,006, 0,002, dan 0,001 %-massa relatif terhadap minyak.Kata kunci: Spirulina platensis, Botryococcus braunii, heterotrof, gelombang mikro, mikroalga

Fossil species in Boehmerieae (Urticaceae) in Dominican and Mexican amber: a new genus (Ekrixanthera) and two new species with anemophilous pollination by explosive pollen release, and possible lepidopteran herbivory

The first fossil flowers of Neotropical Urticaceae (Boehmerieae) are described from the Dominican Republic and Mexico as belonging to a new genus, Ekrixanthera. Ekrixanthera hispaniolae sp. nov. from Dominican amber has pentamerous staminate flowers on short pedicels with a pilose pistillode and heteromorphic pilose tepals: two are clavate and three linear. Ekrixanthera ehecatli sp. nov. has pentamerous staminate flowers lacking pedicels, a pistillode with greatly reduced pilosity, glabrous and heteromorphic tepals with two linear and three wedge-shaped with truncate tips. The presence or absence of a pedicel, heterotrophic condition of the tepals, and the presence or absence of pilosity of the pistillode and tepals separate the two species. Those characters, together with the pentamerous flowers separate both fossil species from extant genera. The floral structures indicate explosive pollen release and pollination by wind (anemophily). Pistillate flowers have not been found for this usually dioecious tribe. Lepidopteran herbivory is suggested by a damaged stipule in one specimen and a nymphalid butterfly (Vanessa-like) caterpillar that may have used Ekrixanthera as a food plant is illustrated. The fossils establish an early lineage of Boehmerieae with characteristic explosive pollen release and perhaps associated herbivorous insects in the West Indies and North America during the mid-Tertiary.

The Influence of Glucose on Growth and Lipid Production under Heterotrophic and Mixotrophic Conditions for Monoraphidium sp. FXY-10

The impact of glucose on the growth under heterotrophic and mixotrophic conditions for Monoraphidium sp. FXY-10 as well as its lipid content was investigated through the Andrew equation. The results demonstrated that the subsaturation constant of Monoraphidium sp. FXY-10 under heterotrophic condition to glucose was smaller than that of Monoraphidium sp. FXY-10 under mixotrophic condition, indicating that Monoraphidium sp. FXY-10 is more sensitive to glucose under heterotrophic condition. Furthermore, the biomass productivity, lipid productivity and lipid content of Monoraphidium sp. FXY-10 all reached the peak at 10 g L-1 of glucose concentration under both heterotrophic and mixotrophic conditions. Compared with other Chlorella sp., the Monoraphidium sp. FXY-10 represented higher lipid productivity (131.79 mg L-1 d-1).

The Influence of Various pH Values on Monoraphidium sp. FXY-10 Growth and Lipid Parameters in Autotrophic and Heterotrophic Conditions

The influence of pH on Monoraphidium sp. FXY-10 growth, lipid content, lipid yield, biomass yield, and fatty acid composition is studied in autotrophic and heterotrophic conditions. The results reveal that Monoraphidium sp. FXY-10 can grow better in an acidic environment. Under autotrophic and heterotrophic conditions, the culture time is 37 and 9 day, respectively. And the maximum biomass of algal cells is 32 and 367mg/l/d with the lipid content in autotrophic and heterotrophic conditions reached to 49% and 39%, respectively, with high biomass yield, lipid yield, the saturated fatty acid and monounsaturated fatty acid under heterotrophic condition, proving that the algal cells are a viable material for the production of biodiesel.