Abstract. Nannochloropsissp. has been identified as a promising feed stock for biodiesel production in recent years. Nannochloropsis sp. have high lipid content between 31-68 % of dry biomass weight. Mutagenesis induced by Gamma 60 Co irradiation can be utilized to alter Nannochloropsis sp. characteristic to get microalgae mutant strain that can produce a higher lipid content than the wild strain. The aim of this research was to know the effect of gamma 60 Co irradiation to the biomass, lipid content and fatty acid compotition of Nannochloropsis sp. microalgae. In this research, irradiation was done in different doses there were 0, 2, 4, 6 and 10 Gray (Gy). Measuring microalgae biomass and lipid content were done in late exponential phase at the end of each treatment. Research design used is random complete with 95 % confident level for quantitative analysis based on biomass and lipid content. Fatty acid compotition was analyzed by gas chromatography-mass spectrometry (GC-MS). Results showed that gamma irradiated gave an effect on lipid content and fatty acid profile of Nannochloropsis sp. Tukey test showed total lipid content of control micoalgae (0 Gy) was significat different with 10 Gy irradiated microalgae, but no significant different with 2,4 and 6 Gy irradiated microalgae. The highest lipid content were found in 10 Gy irradiated microalgae equal to 62.65 %. Fatty acid profile of 10 Gy irradiated Nannochloropsis sp. had 9 fatty acids while control Nannochloropsis sp. had 6 fatty acids.

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Abstract. Ramadhan R, Phuwapraisirisan P, Amirta R, Darmawan MFB, Ul-Haq K, Kusuma IW, Suwito H, Abdulgani N, Mukhdlor A, Saparwadi. 2022. The potency of selected ethnomedicinal plants from East Kalimantan, Indonesia as antidiabetic agents and free-radical scavengers. Biodiversitas 23: 2225-2231. Ten ethnomedicinal plant extracts from East Kalimantan flora, traditionally used to treat blood sugar levels and other diabetes-related diseases, were examined in vitro for their antidiabetic and free radical scavenging activities by inhibiting rat alpha-glucosidase and several free radicals such as DPPH, ABTS, and Nitric oxide respectively. Out of the ten plant species investigated for their antidiabetic activity against maltase and sucrase rat alpha-glucosidase, three exhibited the strongest ?-glucosidaseinhibitory activity with maltose as a substrate, namely extracts of Garcinia nervosa, Syzygium caudatilimbum, and Shorea balangeran with IC50 values of 0.046; 0.037; 0.045 mg/mL. Meanwhile, quercetin as a positive control appeared to have a comparable IC50value. Furthermore, among the ten extracts, Syzygium caudatilimbum, Shorea balangeran, and Ixora javanica showed good inhibition against sucrase rat alpha-glucosidase. Moreover, the antioxidant test showed that the ten methanol extracts of plants from East Kalimantan have an antioxidant activity indicated by IC50values. The present study confirms that the ethnopharmacological use of selected plants from East Kalimantan might have potential as an antidiabetic and natural antioxidant.

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The snakehead fish (SHF) has commercial value due to its health benefit. Steaming extraction method using distilled water within temperature below 60°C is the one of extraction methods to obtaining the SHF extract with high yield of valuable soluble protein albumin, as well as relatively simple to applied at home industries. Recently, the recommended storage for these conventional steamed SHF extract (SSHFE) product is in freeze temperature (-20°C), not in room temperature. Evaluation to find scientific reason related to the SSHFE storage stability is necessary required. The series of storage stability and microbiological test toward SSHFE had investigated included total plate count (TPC); most probable number (MPN) of coliform and Eschericia coli test using Gram staining and Indol, Methyl Red, Voges Praskauer, Citrate (IMVIC) at different storage stability treatments. This research found that SHF extract during storage of 0 week after out from freezer were negatively contaminated (TPC <= 102 CFU/ml). While, TPC at storage of 1; 4; 8 weeks after out from freezer showed contamination in level of 1.722x103 CFU/ml; 1.327x104. CFU/ml and 6.839x104 CFU/ml, respectively which still below threshold that stipulated by Indonesian Food Standardization (5x105 CFU/ml). While MPN index were exceed the standard, i.e. 24/g (1 week), 350/g (4 weeks), and < 1600/g (8 weeks). Moreover, the gram stain and IMVIC test indicated that they were positively contaminated by Eschericia coli. Accordingly, SSHFE is recommended to store at freeze temperature and immediately consumed after melt in room temperature. Further research of sterilizing methods for SSHFE processing is suggested.

Abstract. Hidayati D, Darmanto Y, Nurhidayati T, Abdulgani N. 2016. Short Communication: Larvicidal and antifeedant activities of Kalanchoe daigremontiana against Plutella xylostella larvae. Nusantara Bioscience 8: 312-315. Larvicidal and antifeedant activities of Kalanchoe daigremontiana polar extract were tested on fourth instar of Plutella xylostella larva using choice test, leaf dipping method and antifeedant capacity test (no choice test). K. daigremontiana polar extract in level of 0.25, 0.5, 0.75, 1, 1.25, and 1.5% were used on choice test to determined the larvae behavior tendencies of an attractant or to be an antifeedant, while on toxicity test were used extract in level of 0.25% and 0.5%, whereas on antifeedant capacity test were in level of 0.75, 1, 1.25, and 1.5%. The Probit analysis resulted that 50% of lethal concentration (LC 50) was found at 72 hours exposure of 0,5% polar extract. Effective concentration for antifeedant at 1.25%, while antifeedant capacity percentage was in level of 84.85%.