Callipogon relictus, a natural monument, is an insect whose life cycle was assumed to take more than 5 years in nature. Winter is a very harsh season, but it is known to be a crucial condition for many insects’ growth. However, no information is known about the overwintering condition and its effects on C. relictus. To understand the overwintering effects on the growth of C. relictus, we investigated the growth patterns of its larvae in indoor conditions after chilling treatment. The larvae were induced to dormancy at low temperature (4°C) for two months, and put them into 10°C for two weeks to break dormancy. After awakening, the temperature was increased 15°C, 20°C to 25°C at a time, and the larvae were kept for two weeks at each temperature. The larvae were divided into 3 groups (3rd to 5th instar, 6th to 8th instar, 9th to last instar). Lastly, head width and weight of the larvae were measured every 30 days under 25°C condition, and mortality and deformity were counted as well. The mortality and deformity rates were the highest in the first group, and the rates decreased toward the last group. On the other hands, growth rate appeared opposite to mortality and deformity rate of each larval group.

NRPS (non-ribosomal pepetide synthetase) plays an important role in the biosynthesis of secondary metabolites, which includes economically important compounds such as antibiotics, antitumor agents, immune-suppressants, siderophores, toxins, etc. In most cases, however, their functions and biosynthesizing pathways have been still remained riddles because of their cryptic expression and recalcitrant genetics. In our previous genome analyses of Cordyceps bassiana C101, we predicted the sequences of secondary metabolite biosynthesizing gene clusters, which contain non-ribosomal pepetide synthetases whose functions are already known such as beauvericin, bassianolide, bassiatin, tenellin, beauverolides, and oosporein. The authors focused on nrps6 that has not been functionally studied. The single-gene deletion and overexpression mutants were established via Agrobacterium-mediated transformations. PCR, quantitative real-time PCR, and southern blot analyses were carried out to confirm the correct single-gene integrated homologous recombination. In further study, comparative metabolic profiling between wild-type and mutant strains will be followed by their detailed chemical structure analysis through NMR spectroscopy.

A membrane module including grid was designed and introduced to MBR (membrane bio-reactor) for the purpose of better control of membrane fouling. It could be anticipated that the grid enhances the shear force of fluid-air mixture into the membrane surface by even-distributing the fluid-air to the membrane module. As MLSS concentration, packing density which is expressed in the ratio of the housing and the cross-sectional area of membrane fibers (Am/At) and air-flow rate were changed, membrane foulings were checked by monitoring fouling resistances. The total fouling resistance (Rc+Rf) without grid installation (i.e., control) was 2.13×1012 m-1 , whereas it was reduced to 1.69×1012 m-1 after the grid was installed. Regardless of the grid installation, the Rc+Rf increased as the packing density increased from 0.09 to 0.28, however, the increment of resistance for the grid installation was less than that of the control. Increase in the air flow rate did not always guarantee the reduction of fouling resistance, indicating that the higher air flow rate can partially de-flocculate the activated sludge flocs, which led to severer membrane fouling. Consequently, installation of grids inside the housing have brought a beneficial effect on membrane fouling and optimum air flow rate is important to keep the membrane lowering fouling.

For last couple of years many apartments, roads and bridges are constructed along the Kok-kyo stream which is penetrating Asan city, Chung-Nam Province. The effect of construction on stream environment was investigated in this study. Various kinds of water qualities of the Kok-kyo stream were monitored for 5 months. As it passed through the construction sites, CODcr concentration increased abruptly whereas the increment of the BOD5 was not so great, indicating that non-biodegradable organics were flowed from the construction sites to the stream. Particularly, 0.2 mg/L of N-hexane was measured, which is believed to be mainly responsible for the organic pollution from construction sites. In spite of short periods of water quality monitoring, it could be concluded that there was a good correlation between construction sites and stream pollution. Therefore, legislative activity or enforced management by local government to the construction sites are needed for keeping the small stream environment better.