Pertumbuhan Bakteri Anaerobic Ammonia Oxidation (Anammox) Pada Salinitas 2 dan 9 Persen

When ammonia in waste water is lost inappropriately, it  will raise an adverse environmental effect for the aquatic cycle. Anammox, anaerobic ammonia oxidation, is a novel process in which nitrite is used as an electron acceptor in the conversion of ammonium to nitrogen gas. The anammox process removes ammonium in the autrotrophic system by leaving little biomass. This study aims to analyze the effect of salinity on the growth of anammox bacteria. The samples used were from the brackish water sediments of the East Flood Canal River of Semarang. The isolation was done by gram staining and the bacteria were inoculated on media with different salinity concentration and the growth was measured using spectrophotometer. The results showed that anammox bacteria had a higher growth rate of 3% (control) when it was grown on a medium with a concentration of 9%. Anammox bacteria grown on anammox selective media showed that the bacteria were able to adapt to environments with different salinity concentrations of 2% and 9%. Key words: anammox, ammonium, nitrogen, anammox bacteria

Produksi Pigmen Karotenoid oleh Khamir Phaffia rhodozyma yang Diperlakukan dengan Radiasi Sinar UV

Carotenoid pigment is an essential element in aquaculture, since it gives characteristic of color on shrimp and fish. Carotenoid pigments can be produced microbiologically using Paffia rhodozyma. Genetic improvement of the yeast, one of which can be accomplished by radiation mutation, will increase the production of carotenoid pigments. The aims of this study were to mutate P. rhodozyma using UV irradiation and to figure out pigment production by the mutant strains resulting from 30 minute-irradiation. Irradiated culture was incubated in dark condition and plated onto YMA media. Grown mutant colonies were collected in order to test for their pigment production. Pigment production was measured on the basis of extinction coefficient of 1%. The results showed that mutant strain encoded with MUV-1 produced the highest pigment at 179.96 mg/g dry weight cell, higher than the wild type (63.20 mg/g dry weight cell)