Using sialyl-methylumbelliferyl -glycoside as substrate, sialidase in horse liver was detected as a membrane-bound enzyme. A yield of about 50% of sialidase activity was found in supernatant when solubilized in 0.1 M sodium-phosphate buffer pH 5.5, containing 0.15 M NaCl, 0.25 M sucrose, and 0.5% Triton X-100. Sialidase in the solubilisate could be activated by incubating in acidic pH at 37 oC. Incubation of this solubilized enzyme at 37 oC for 1.5 h at pH 5.0 led to 10% increase of activity and to the precipitation of about 50% of contaminating protein. Using cation-exchange chromatography on S-Sepharose FF and affinity chromatography on p-aminophenyl oxamic acid-agarose following solubilization and activation, about 6% of total sialidase activity was recovered with the purification factor of about 500. The pH and temperature optimum were measured at pH 4.3 and between 37-45 oC, respectively. Neu5Ac2en was a strong inhibitor, while p-aminophenyl oxamic acid had only a weak inhibitory effect.

Oilly seeds, such as those of sunflower (Helianthus annuus L.), have short storability (3-4 months in room condition) due to oxidative stress during storage. The objective of this research was to determine whether prestorage seed invigoration by antioxidants, could improve storability of sunflower seeds. The research was performed using fresh harvested seeds. Prestorage seed invigorations were conducted by matriconditioning with water or antioxidants solution i.e. 4.17% curcumin or 100 and 150 ppm ascorbic acid. The seeds were stored for four months at room condition (28-29 °C and 62-79% relative humidity). Observations were conducted monthly. Experiment was arranged in split plot design. The result showed that all prestorage seed invigoration treatments were not effective to enhance storability of sunflower seeds compared to control. Inefficiency exogenous antioxidants was probably due to highly endogenous antioxidants activity during storage. This was indicated by the slow deterioration rate of control seeds, or due to high concentration of curcumin which was actually potential to enhance storability of sunflower seeds. It is suggested that presowing treatment and midstorage treatment will enhance storability of sunflower seeds.

A coral-associated bacterium was successfully screened for secondary metabolites production based on PCR amplification of the nonribosomal peptide synthetase gene and was identified as closely related to Pseudoalteromonas luteoviolacea based on its 16S rDNA. The bacterium was found to inhibit the growth of shrimp pathogenic bacterium tested, Vibrio harveyi. To characterize the inhibiting metabolite, a 279 bp long DNA fragment was obtained and the deduced amino acid sequence showed conserved signature regions for peptide synthetases and revealed a high similarity to NosD (40% identity), a multifunctional peptide synthetase from Nostoc sp. GSV224, and NdaB (44% identity), a peptide synthetase module of Nodularia spumigena

Dextranase of Arthrobacter sp. strain B7 (B7DEX enzyme) was characterized in this study. This enzyme hydrolyzed sucrose and dextran, but not other glucans (starch, nigeran, cellulose, β-soluble glucan). It also hydrolyzed glucan from dental plaque with the activity of 7.38 ± 0.66 U/ml, where the activity toward dextran was 31.88 ± 1.24 U/ml. The enzyme exhibited the pH optimum of 7 and the temperature optimum of 50 °C. Its optimum stability was at pH 7 and 50 °C. The enzyme was inhibited by Fe3+, Cu2+, Zn2+, and Ag+, but not by the anionic detergent (SDS) and the nonionic detergent (Triton-X). The enzyme was activated by Ca2+, Na+, Mg2+, and saliva.

A study on the diversity of moths was conducted from July to Augustus 2004 at the peat swamp forest Setya Alam research station, Sebangau, Central Kalimantan. The result showed that diversity of moths at this area was lower (100 species of 12 families; H’ = 6.643, E = 0.794) than that in secondary rain forest Busang River (278 species of 19 families; H’ = 8.139, E = 0.831). The result also showed that the similarity index (Cj) of the two areas was very low (0.05). Geometridae, Noctuidae, and Pyralidae were dominant in both areas. There might be more species that have not been found during eight night sampling as indicated by the species numbers in both areas has not reach a plateau.

Photosynthetic gas exchange in response to increased carbon dioxide concentration ([CO2]) and drought stress of two C3 (wheat and kale) and two C4 species (Echinochloa crusgallii and Amaranthus caudatus) were analysed. Plants were grown in controlled growth chambers with ambient (350 μmol mol−1) and doubled ambient [CO2]. Drought was given by withholding water until the plants severely wilted, whereas the control plants were watered daily. Even though stomatal conductance (Gs) of C4 species either under ambient or double [CO2] was lower than those in C3, doubled [CO2] decreased Gs of all species under well watered conditions. As a result, the plants grown under doubled [CO2] transpired less water than those grown under ambient [CO2]. Photosynthesis (Pn) of the C4 species was sustained during moderate drought when those of the C3 species decreased significantly. Doubled [CO2] increased photosynthesis of C3 but not of C4 species. Increased [CO2] was only able to delay Pn reduction of all species due to the drought, but not remove it completely. The positive effects of increased [CO2] during moderate drought and the disappearance of it under severe drought suggesting that metabolic effect may limit photosynthesis under severe drought.

Photosynthetic gas exchange in response to increased carbon dioxide concentration ([CO2]) and drought stress of two C3 (wheat and kale) and two C4 species (Echinochloa crusgallii and Amaranthus caudatus) were analysed. Plants were grown in controlled growth chambers with ambient (350 mol mol-1) and doubled ambient [CO2]. Drought was given by withholding water until the plants severely wilted, whereas the control plants were watered daily. Even though stomatal conductance (Gs) of C4 species either under ambient or double [CO2] was lower than those in C3, doubled [CO2] decreased Gs of all species under well watered conditions. As a result, the plants grown under doubled [CO2] transpired less water than those grown under ambient [CO2]. Photosynthesis (Pn) of the C4 species was sustained during moderate drought when those of the C3 species decreased significantly. Doubled [CO2] increased photosynthesis of C3 but not of C4 species. Increased [CO2] was only able to delay Pn reduction of all species due to the drought, but not remove it completely. The positive effects of increased [CO2] during moderate drought and the disappearance of it under severe drought suggesting that metabolic effect may limit photosynthesis under severe drought.

An estimate of genetic parameters was made to study the types of gene action in rice. A half diallel analysis was performed among seven rice genotypes with different genetical backgrounds, i.e. Situgintung, Jatiluhur, Gajah Mungkur, B8503E-TB-9-0-3, Krowal, CT6510-24-1-3, IR 64, and its 21 progenies. This experimental material was arranged in a complete block design with four replications. All observed characters had highly significant genotypic differences. The genetic parameters were estimated following Hayman method. The simple model of additive-dominance was sufficiently detected through the absence of nonalellic interaction. Productive tillers exhibited partial dominance. Heritability in a narrow sense was high. There was a positive correlation between grain yield and the number of productive tillers.

The cholesterol lowering effect of seaweed (Eucheuma cottonii) powder as a source of dietary fiber was evaluated in hypercholesterolemic rats. Four groups of five male Sprague Dawley hypercholesterolemic rats were fed a 0% cholesterol-0% seaweed powder (negative control); 1% cholesterol-5% seaweed powder; 1% cholesterol-10% seaweed powder; and 1% cholesterol-0% seaweed powder (positive control) for 35 days. Seaweed powder contained feed did not affect the growth of rats but significantly lowered the serum total cholesterol, LDL cholesterol, triglyceride, and atherogenic index. The lowest serum cholesterol was found in the hypercholesterolemic rats fed with 1% cholesterol-10% seaweed powder. The values of total-cholesterol, LDL-cholesterol, and triglyceride were 67.7, 33.0, and 47.3 mg/dl, respectively.