Development of Growth Media from Agricultural By-Products for Cultivation of PUFA-Producing Sicyoidochytrium minutum.

The demand for novel sources of marine oils, which contain polyunsaturated fatty acids (PUFAs), has increased due to the realization of the importance of PUFAs, e.g., docosahexaenoic acid (DHA), in the human diet. However, the natural supply is limited. By-product peptones (BYPP) intended as a growth medium for the PUFA-producing strain Sicyoidochytrium minutum of family Thraustochytriaceae were produced after several experiments on the pancreatic digestion of bovine lungs and spleens. S. minutum was able to grow in a medium containing BYPP made from the pancreatic digestion of lung and spleen with glycerol, resulting in 1.14 ± 0.03 g cell dry weight (CDW)/L and 1.44 ± 0.24 g CDW/L, respectively, after 5 days of incubation at 25 °C, compared to 1.92 ± 0.25 g CDW/L in Basal Medium (BM) containing tryptone, peptone, and glycerol. The lipid content, obtained after growth in lung BYPP media with glycerol as a carbon source, was significantly higher (28.17% ± 1.33 of dry weight) than in the control basal medium (BM) (21.72% ± 2.45); however, DHA as a percentage of total fatty acids was lower in BYPP than in the control BM (25.24% ± 1.56 and 33.02% ± 2.37, respectively). It is concluded that low-value by-products from abattoirs can be used as ingredients for the cultivation of oligogenic Thraustochytriaceae.

Isolation, Characterization and Biotechnological Potentials of Thraustochytrids from Icelandic Waters.

The following study reports on the first thraustochytrid isolates identified from Iceland. They were collected from three different locations off the northern coast of the country (Location A, Skagaströnd; Location B, Hveravík; and Location C, Eyjafjörður). Using 18S rDNA sequence analysis, isolates from Locations A and B were identified within the Thraustochytrium kinnei species while other isolates within the Sicyoidochytrium minutum species when compared to other known strains. Cells isolated from Locations A ( 2 . 10 ± 0 . 70 g/L) and B ( 1 . 54 ± 0 . 17 g/L) produced more biomass than the ones isolated from Location C ( 0 . 43 ± 0 . 02 g/L). This study offers the first-time examination of the utility of byproducts from fisheries as a nitrogen source in media formulation for thraustochytrids. Experiments showed that isolates produced more biomass (per unit of substrate) when cultured on nitrogen of marine ( 2 . 55 ± 0 . 74 g/L) as compared to of commercial origin (  1 . 06 ± 0 . 57 g/L). Glycerol ( 2 . 43 ± 0 . 56 g/L) was a better carbon source than glucose ( 1 . 84 ± 0 . 57 g/L) in growth studies. Fatty acid (FA) profiles showed that the isolates from Location C (S. minutum) had low ratios of monounsaturated ( 4 . 21 ± 2 . 96 % ) and omega-6 ( 0 . 68 ± 0 . 59 % ) FAs. However, the isolates also had high ratios of docosahexaenoic acid (DHA; 35 . 65 ± 1 . 73 % ) and total omega-3 FAs ( 40 . 39 ± 2 . 39 % ), indicating that they could serve as a source of marine oils for human consumption and in aquaculture feeds. The T. kinnei isolates from Location A could be used in biodiesel production due to their high ratios of monounsaturated ( 18 . 38 ± 6 . 27 % ) long chain ( 57 . 43 ± 8 . 27 % ) FAs.

[Bacterial meningitis in one month-16 year old children at three Pediatric departments in Iceland during the period 1973-2000.].

OBJECTIVE: Bacterial meningitis is a serious disease most common in children. We report the epidemiology and outcome of bacterial meningitis in children between the age of one month to 16 years admitted to three Pediatric Departments in Iceland in 1973-2000 (28 years). MATERIAL AND METHODS: Information was collected retrospectively from the medical records of admitted children diagnosed with bacterial meningitis. RESULTS: 454 children were diagnosed; 255 boys and 199 girls; 77% were less than five years of age. Before 1989 the age specific incidence was 29/100.000/year and 12/100.000/year thereafter. The cerebral spinal fluid was culture positive in 74% but no organism was identified in 17%. The most common pathogens were N. meningitidis (44%), Hib (30%), and S. pneumoniae (7%). The incidence varied according to age. No child was diagnosed with Hib after launching of Hib vaccination in 1989. The mean age of the children increased significantly from less than two years prior to 1989 to less than three years thereafter and of children infected with N. meningitidis from around two year to three years. The mortality rate was 4,5%, none due to Hib. Fourteen percent suffered sensory-neural hearing impairment and no protective effects were seen of steroid therapy. CONCLUSIONS: The age specific incidence of bacterial meningitis of children in Iceland has decreased during the last decade, especially due to Hib vaccination. Further reduction can be expected by implementing general vaccination to N. meningitidis C and S. pneumoniae. Additionally, recognizing the symptoms of bacterial meningitis and starting proper therapy as soon as possible is crucial in order to minimize ominous outcome.