No abstract

SUMMARYCryotolerant eukaryotic microalgae were isolated from meltwater streams on Ardley Island and King George Island in Antarctica, and their morphological, molecular, and physiological characteristics were investigated. Owing to their simple morphology, distinctive characters were not observed with neither light microscopy nor transmission electron microscopy. However, molecular phylogenetic inferences drawn from the concatenated small subunit rRNA and internal transcribed spacer sequence data indicated that these microalgal strains belonged to the genus Micractinium. All the Micractinium strains showed cryotolerant properties, while their optimum growth temperature was around 20°C. Similar to other cryotolerant organisms, these Antarctic microalgae also contained a higher ratio of polyunsaturated fatty acids to saturated fatty acids. In this study, new Antarctic Micractinium spp. were discovered and added to the culture collection. These cryotolerant strains may serve as a promising source of nutritionally important linoleic (C18:2 ω6) and α-linolenic (C18:3 ω3) acids.

BackgroundGinseng contains many small metabolites such as amino acids, fatty acids, carbohydrates, and ginsenosides. However, little is known about the relationships between microorganisms and metabolites during the entire ginseng fermentation process. We investigated metabolic changes during ginseng fermentation according to the inoculation of food-compatible microorganisms.MethodsGas chromatography mass spectrometry (GC-MS) datasets coupled with the multivariate statistical method for the purpose of latent-information extraction and sample classification were used for the evaluation of ginseng fermentation. Four different starter cultures (Saccharomyces bayanus, Bacillus subtilis, Lactobacillus plantarum, and Leuconostoc mesenteroide) were used for the ginseng extract fermentation.ResultsThe principal component analysis score plot and heat map showed a clear separation between ginseng extracts fermented with S. bayanus and other strains. The highest levels of fructose, maltose, and galactose in the ginseng extracts were found in ginseng extracts fermented with B. subtilis. The levels of succinic acid and malic acid in the ginseng extract fermented with S. bayanus as well as the levels of lactic acid, malonic acid, and hydroxypruvic acid in the ginseng extract fermented with lactic acid bacteria (L. plantarum and L. mesenteroide) were the highest. In the results of taste features analysis using an electronic tongue, the ginseng extracts fermented with lactic acid bacteria were significantly distinguished from other groups by a high index of sour taste probably due to high lactic acid contents.ConclusionThese results suggest that a metabolomics approach based on GC-MS can be a useful tool to understand ginseng fermentation and evaluate the fermentative characteristics of starter cultures.

A freshwater cyanobacterium, Phormidium autumnale KNUA026, was isolated from puddles of icy water in Gyeongsan City, South Korea and its potential as a biofuel feedstock was investigated. Maximal growth was obtained when the culture was incubated at 25°C and around pH 9.0. The total lipid content of the isolate was approximately 14.0% of dry weight and it was found that strain KNUA026 was able to autotrophically synthesize heptadecane (C 17 H 36 ) which can be directly used as fuel without requiring a transesterification step. As this benthic cyanobacterium was capable of forming thick mats, it could be easily harvested by gravitational settling and this property may reduce the cost of production in commercial applications. Hence, P. autumnale KNUA026 appears to be a promising resource for use in the production of microalgae-based biofuels.Key Words: algae-based fuel; alkane; cyanobacterium; heptadecane; Phormidium autumnale INTRODUCTIONIn recognition of the current energy crisis, alternative energy sources are currently being explored and developed at an increasing pace; biofuels in particular have received a considerable amount of attention over the past few years. Conventional biofuels, such as bioethanol and biodiesel, are produced primarily from cereal crops and oil seeds. However, the mass production of crop-based biofuels has resulted in serious side effects, such as increases in food prices, deforestation, and carbon emissions (Sims et al. 2010). Thus, algae-based biofuels have been recognized as an attractive option, as they use minimal land resources (Chisti 2007) and do not compete with food production (Huang et al. 2010). Additionally, algaebased biofuels have several other advantages, including rapid growth rates (Schenk et al. 2008), higher lipid contents (Hu et al. 2008), and higher CO 2 uptake rates (Jorquera et al. 2010) relative to other energy crops. Considering these advantages, microalgae biofuels have been recognized as the only current renewable source of liquid transportation fuel which is compatible with the existing engines and distribution systems (Schenk et al. 2008). Microalgae, including cyanobacteria, have been reported to generate a variety of lipids, hydrocarbons, fatty alcohols, and other complex oils ( ), until growth was apparent. An aliquot of the brown-colored biomass was taken by pipetting, and was sonicated for approximately 3-5 s using an ultrasonic cell disruptor (Model 550; Fisher Scientific, Pittsburgh, PA, USA). The filaments were then transferred onto BG-11 agar plates containing 100 µg mL -1 of meropenem (Yuhan Pharmaceuticals, Ochang, Korea) and were incubated in the dark for 24 h to eliminate contaminating bacteria (Choi et al. 2008). The culture was then inoculated onto fresh BG-11 agar plates and incubated for 14 days under a light : dark cycle (16 : 8 h) at 15°C. Morphological and molecular identificationThe isolate was grown in BG-11(+) medium for 21 days. Live cells were harvested by centrifugation at 3,000 ×g for 5 min, washed with sterile distilled water, ...

: Prostaglandin (PG) E 2 is an important mediator of skin wound healing without excessive scarring and gastric ulcer healing. However, PGE 2 has a short lifetime in vivo because it is metabolized rapidly by 15-hydroxyprostaglandin dehydrogenase (15-PGDH). Ethanol extract of Eriobotryae folium (EFEE) elevated intracellular and extracellular PGE 2 levels in HaCaT cells and inhibited 15-PGDH (ED 50 : 168.4 ㎍/mL) with relatively low cytotoxicity (IC 50 : 250.0 ㎍/mL). Real-time PCR analysis showed that mRNA expression of cyclooxygenase (COX)-1 and COX-2 enzymes were increased and prostaglandin transporter (PGT) was decreased in HaCaT cells by EFEE. Moreover, wound healing effect of EFEE (168.4 ㎍/mL) was comparable to that of TGF-β1 (300 pg/mL) as a positive control. These results demonstrate that EFEE may be valuable therapeutic materials for the treatment of PGE 2 level dependent diseases.