해양생태 독성시험법의 중요성이 인식되면서 새로운 시험법의 개발과 더불어 유용수산생물을 이용하고자 하는 연구가 활발하게 진행되고 있으나, 대부분의 시험법은 유해물질에 대한 급성독성을 평가하고 있다. 해양생태계 내에서 오랫동안 아치사 농도로써 생물에게 영향을 미치는 유해물질을 평가하기 위한, 만성독성 평가기법은 그 수가 대단히 한정되어 있다. 유용수산생물 자원인 미역(U ndar ia pinnatifida )은 생산자로서 해양생태계 내에서 중요한 위 치를 차지하고 있을 뿐만 아니라, 유주자 방출, 발아, 수정 및 아포체 성장의 초기생활사 동안 실내배양이 가능하다. 실내 배양기간 동안 아포체 성장을 이용한 만성적 독성영향을 파악할 수 있어, 향후 해양생태 독성시험과 환경변화 등에 의해 발생하는 갯녹음 원인 구명에도 적절하게 이용될 수 있을 것으로 판단된다. 성숙한 U . pinnatifida의 포자 엽으로부터 방출된 유주자를 6개 중금속(Cd, Cu, Zn, Pb, Cr, As)에 노출시켜 21일간 배양한 후에 아포체 성장률을 측정하였고, 이들 결과를 바탕으로 무영향농도(NOEC), 최소영향농도(LOEC)를 나타내는 독성평가를 실시하였다. 중 금속에 노출된 U . pinnatifida의 아포체 성장률은 중금속 농도가 증가할수록 급격히 감소하는 농도 의존성을 나타냈 다. 중금속이 아포체 성장에 미치는 영향의 정도를 살펴보면, 대부분이 0.1ppb 미만의 낮은 농도에서 NOEC가 관찰 되었고 LOEC의 경우도 Cd, Cu 및 Pb는 0.1ppb에서, Zn, Cr 및 As는 1ppb 정도의 매우 낮은 농도를 나타내는 것을 알 수 있었다.

This study was carried out to determine the effect of dietary crude fucoidans extracted from brown algae and brown seaweed powder supplementation on performance and bacterial count on feed additives of early broiler chicks. A total 180 broiler chicks were assigned to 4 treatments. Each treatment had 15 chicks with 3 replications. The supplementation levels of fucoidan and brown seaweed powder in the experimental diets were 0.5% (fucoidan), 3.0% (brown seaweed). The results obtained summarized as follows: The body weight gain and weight of chicks fed fucoidan (0.5%) was heavy compared with control. Feed efficiency of chicks fed fucoidan (0.5%) slightly improved compare with control. But also not significantly different among treatments. Gizzard weight, length of small intestine and weight of small intestine were not significantly different among treatments. The villi height of chicks fed fucoidan (0.5%) was long compared with control. According to these data, this trial proves the fucoidan could be successfully used as the dietary supplement.

We studied a extraction and degradation of alginate from seaweed-stems using microorganism DS-02. DS-02 has a maximum growth rate at 30℃ and the enzyme has a maximum activity of alginate extraction at 35℃. The yield of alginate extraction using DS-02 is about 16.0% for 3.0 hour and molecular weight of the alginate decreased to about 1/8 of initial value after 24 hour extraction. Alginate extraction method by DS-02, compared with general alkali-extraction method, has an advantage of decreasing the molecular weight of alginate during extraction.

We studied a storage of waste-brown seaweed at room temperature and degradation of alginate in seaweed by microorganism DS-02. The seaweeds, mixed with 5.0 wt% DS-02 and sealed in vinyl package without any other treatment, could be stored longer than 1 year without spoilage at room temperature. During the storage process, the alginate of seaweed was decomposed by enzyme of DS-02 and the molecular weight of alginate decreased to about 1/10 of initial quantity. DS-02 growed as fast as it had maximum weight after 24 hour culture and it's enzyme had a maximum activity of alginate degradation at 40℃. The seaweed sample became particles in DS-02 culture solution and the M.W of alginate decreased to about 1/10 of initial value after 24 hour decomposition. The effect of alginate degradation with DS-02 was similar to that of degradation with 3.0 M HCl solution for 24 hour.

Effective alginate extraction from waste-brown seaweeds was studied. The waste-brown seaweeds almost consist of stems of seaweeds. Alginate could be obtained from the stems as well as leaves of seaweed. Ultrasonic vibration(47kHz) facilitated filtering step in the alginate extraction process. Among various alkalies for alginate extraction, NaHCO3 was most appropriate concerning use of dealginates. The yield of alginate extraction using NaHCO3 2wt% solution was 19.3% at 60℃. The dealginates from NaHCO3-extraction process have been found most suitable food for red-worms.

The biosorption abilities of different parts of waste brown seaweeds and their derivatives to remove heavy metals(Cd, Zn, Pb, Cu, Fe, Ni, Mn) from waste water were evaluated. The two parts of waste brown seaweeds (Undaria pinnatifida) were stems and sporophyls, and the brown seaweed derivatives were alginic fibers, active carbon added alginate(AC-alginate) and dealginate. The abilities of the sporophyls to adsorb the heavy metal ions were higher than those of stems, and those of alginates were slightly higher than those of dealginate in single ion solution. With decreasing the size of biosorbents, the velocity and the amount of adsorption increased. The abilities of alginate to remove the heavy metal ions increased in multi-ion solutions by adding active carbon to alginate. The selectivity of these biosorbents(alginate, AC-alginate) to lead ion was highest and to manganese ion was lowest.