• Mycobiology
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• v.28 no.4
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• pp.193-196
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• 2000

Thirty-eight species in addition to 2 varieties (3 unidentified) of zoosporic organisms belonging to 14 genera of Oomycetes and 3 genera of Chytridiomycetes were recovered from 50 soil samples randomly collected from different localities in the western region of Saudi Arabia. Allomyces and Dictyuchus have the highest frequency of occurrence while Achlya, Aqualinderella, Saproleginia and Phytophthora were of moderate occurrence, The remaining genera were less frequent. Seven species and two varieties were new records to Saudi Arabia, which are Achlya oblongata, Allomyces javancius var. allomorphus, Aphanomyces stellatus, Blastoccladia gracile, Dictyuchus magnusii, Olpidiopsis Saproleginia var. levis, Olpidium species, Phytophthora megasperma, and Saproleginia turfosa. Water and organic matter contents of soil samples are considered as major factors influencing the prevalence and occurrence of zoosporic organisms.

• CELLMED
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• v.6 no.4
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• pp.22.1-22.19
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• 2016

The biologically active compounds derived from different natural organisms such as animals, plants, and microorganisms like algae, fungi, bacteria and merine organisms. These natural compounds possess diverse biological activities like anthelmintic, antibacterial, antifungal, antimalarial, antiprotozoal, antituberculosis, and antiviral activities. These biological active compounds were acted by variety of molecular targets and thus may potentially contribute to several pharmacological classes. The synthesis of natural products and their analogues provides effect of structural modifications on the parent compounds which may be useful in the discovery of potential new drug molecules with different biological activities. Natural organisms have developed complex chemical defense systems by repelling or killing predators, such as insects, microorganisms, animals etc. These defense systems have the ability to produce large numbers of diverse compounds which can be used as new drugs. Thus, research on natural products for novel therapeutic agents with broad spectrum activities and will continue to provide important new drug molecules.

• Ocean and Polar Research
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• v.23 no.4
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• pp.433-440
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• 2001

Marine organisms in Antarctica live in an environment which exhibits variability in physical processes over a wide range of temporal scales, from seconds to millennia. This time scale tends to be correlated with the spatial scale over which a given process operates, though this relationship is influenced by biology. The way organisms respond to variability in the physical environment depends on the time-scale of that variability in relation to life-span. Short-term variations are perceived largely as noise and probably have little direct impact on ecology. Of much greater importance to organisms in Antarctica are seasonal and decadal variations. Although seasonality has long been recognised as a key feature of polar environments, the realization that decadal scale variability is important is relatively recent. Long-term change has always been a feature of polar environments and may be a key factor in the evolution of the communities we see today.

• YAKHAK HOEJI
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• v.37 no.5
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• pp.527-531
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• 1993

As a part of chemical study on the bioactive metabolites from marine organisms, we have investigated cytotoxicity using brine shrimp bioassay for each solvent fractions of the marine algae(12 species), marine sponges(3 species), coelenterates(2 species), echinoderms(4 species), marine molluscs(17 species), and ascidians(2 species), respectively. As the results, chloroform extract of Stichopus japonicus (LC$_{50}$ : 274 $\mu\textrm{g}$/ml), ethyl acetate extract of Anthocidaris crassispina(LC$_{50}$ : 121 $\mu\textrm{g}$/ml), n-butanol extract of Unda), ia Pinnatifida (LC$_{50}$ : 178 $\mu\textrm{g}$/ml), and water extract of Thais clavigera (LC$_{50}$ : 61 $\mu\textrm{g}$/ml) displayed the most significant cytotoxic activity against brine shrimp. Among the marine organisms tested, echinoderms and marine molluscs were thought to be the most active Phylums on screening of new bioactive compounds.

• Toxicological Research
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• v.24 no.4
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• pp.235-243
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• 2008

While in some instances, loss of diversity results from acute toxicity (e.g. major pollution incidents), in most cases it results from long-term sub-lethal effects that alter the relative competitive ability and fitness of certain organisms. In such cases the sub-lethal effects will cause a physiological response in the organism that ultimately leads to community level changes. Very sensitive tools are now available to study sub-lethal responses at the molecular level. However, relating such laboratory measurements to ecological effects represents a substantial challenge that can only be met by investigation at all scales (molecular, individual organism and community level) with an appropriate group of organisms. Among the various in vertebrates which can be used as model organisms in such a way, the soil nematode, Caenorhabditis elegans appear to be a promising biological model to diagnose environmental quality. This paper reviews the current status of multilevel biomarkers in environmental toxicology, and C. elegans as promising organisms for this approach.

• Proceedings of the Korean Aquaculture Society Conference
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• 2002.08a
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• pp.225-226
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• 2002

To investigate the food organisms of the Tridentiger trigonocephalus during the juveniles stage, the stomach contents of fish, captured in the intertidal zone of Chungchongnam-do Sochon-gun Su-myon Dodun-ri getween on early June from end of May 1999, were observed. Total length of the juveniles of T. trigonocephalus was 5.5mm∼9.0mm size, and the participation rate of feeding was 68.5%. Main food organisms were such as copepods, shrimp larvae, polychaete larvae, and these occupied more than dry weight 2%. Copepods among them dominated the most quantitys by average 67.5%, and next, food organismsms appeared much by order of polychaete larvae and shrimp larvae etc.. Therefore, most important food organisms of juvenile stage of T. trigonocephalus were copepods, polychaete larvae, shrimp larvae etc.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.3
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• pp.247-252
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• 1995

To investigate the food organisms of the Japanese anchovy (Engraulis japonicus) during the first feeding stage, the gut contents of anchovy, captured in Kwangyang Bay at June 1990, were observed. Anchovies started to eat from 3.0mm (NL) after finishing to absorb the yolk. The food organisms were composed of copepod eggs and nauplii tintinnids, and etc. The major food organisms of the anchovy larvae of 3.0-3.8mm (NL) were copepod eggs and nauplii, whereas those of larvae longer than 3.8mm(NL) were only copepod nauplii.

• Journal of environmental and Sanitary engineering
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• v.2 no.2 s.2
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• pp.61-67
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• 1987

The genus Vibrio contains some of the most important intestinal pathogens of humans, including Vibrio cholerae, the cause of epidemic Asiatic cholera. A group of organisms which have been reffered to as the non-agglutinating vibrio (NAG) do not agglutinate in the Vibrio cholerae 0 group 1 antisera, but are indistinguishable from the 0-1 group both chemically and genetically. Non-O-l Vibrio cholerae can cause isolated as well as focal outbreaks of diarrhea, but the volume of fluid loss does not approach that of classic cholera, and the disease is usually self-limiting. These free-living organisms are found world-widely distributed in the environment including sewage, contaminated water, estuaries, seafood and animals. These strains involved in several cases were isolated from the environment and some patients of diarrhea, and a few epidemiologic reports indicated the wide distribution of the strains throughout the country, giving an attention to the role the organisms may play in an outbreak of diarrhea in Korea. More research on the epidemiology, serologic typing and virulence of the group of organisms, should be, therefore, done to obtain a complete understanding of their role in human disease.

• Korean Journal of Veterinary Research
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• v.13 no.1
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• pp.31-34
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• 1973

Investigations of the prevalence of SalmoneIla organisms in chicken of Suwon area and the effect of selenite broth on the growth of Sal. pullorum were made. The results obtained were summarized as foIlowings. 1. Salmonella organisms was not isolated from fecal samples of 357 chicken from 6 poultry farms of Suwon area. 2. In selenite broth, the growth of Sal. pullorum was completely inhibited may due to the toxic effect of the medium when the inoculum contained less than $5{\times}10^3$ organisms. However, enrichment was attained overcoming the inhibitory action of the medium when $5{\times}10^3$ or more organisms were inoculated.

• Journal of Fisheries and Marine Sciences Education
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• v.24 no.6
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• pp.781-792
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• 2012

Seasonal variation of species composition in marine organisms around Oryukdo of Busan was investigated using a gill net between 2009 and 2011. A total of 82 species, 52 families, and 6 taxa were collected during the sampling periods. Species were included two species in Cnidaria, one in Urochordata, 12 in Mollusca, 12 in Crustacea, seven in Echinodermata, and 48 in Pisces. The dominant species were Crepidula onyx, Asterina pectinifera, Ceratostoma burnetti, Asterias amurensis, Anthocidaris crassispina, and Trachurus japonicus. These six species accounted for 48.4% in the total number. Diversity indices were highest in spring 2009 (2.77) and lowest in spring 2011 (1.66). Seasonal variation of species composition and abundance in marine organisms corresponded with the water temperature.