• Microbiology and Biotechnology Letters
• /
• v.17 no.6
• /
• pp.568-573
• /
• 1989

As a way to determine the optimal culture conditions for the production of ${\gamma}$-linolenic acid by Mucor sp. KCTC 8405P, the influence of different carbon and nitrogen sources, initial pH, and C/N ratio of medium was investigated. Glucose was found to be the best carbon source in terms of lipid content and ${\gamma}$-linolenic acid yield. Ammonium sulfate and organic nitrogen sources such as urea and peptone resulted in relatively increased lipid and ${\gamma}$-linolenic acid production. The highest accumulation of lipid was obtained at a C/N ratio of 56.6 using glucose and (NH$_4$)$_2$SO$_4$ as carbon and nitrogen source, respectively. It was found that the lipid content increased significantly with increasing initial pH of medium up to pH 9.0. The influence of mixed carbon source on the ${\gamma}$-linolenic acid yield was also investigated. High accumulation of lipids, 315 mg/100 ml medium, and 13-14% of ${\gamma}$-linolenic acid content in the cellular lipid were obtained in a shaking culture containing 3% of glucose and 2% sodium acetate as carbon source and 0.1% of (NH$_4$)$_2$SO$_4$ as nitrogen source at pH 8.0.

• Ocean and Polar Research
• /
• v.36 no.1
• /
• pp.25-37
• /
• 2014

To understand the degradation processes of organic matter related to sulfate reduction by Sulfate Reduction Bacteria (SRB) in the tidal flat sediments of Hwang-do and Sogeun-ri, Tae-an Peninsula in Chungnam-do, biogeochemical characteristics were analyzed and highlighted using specific microbial biomarkers. The organic geochemical parameters (TOC, ${\delta}^{13}C_{org}$, C/N ratio, long-chain-n-alkane) indicate that most of the organic matter has been derived from marine phytoplankton and bacteria in the fine-grained sediment of Sogeun-ri, although terrestrial plant components have occasionally been incorporated to a significant degree in the coarse-grained sediment of Hwang-do. The concentration of sulfate in pore water is a constant tendency with regard to depth profile, while methane concentration appears to be slightly different with regard to depth profile at the two sites. Especially, the sum of bacteria fatty acid (a-C15:0 + i-C15:0 + C16:1w5) confirms that the these concentrations in Sogeun-ri are related to the degradation of Benzene, Toluene, Ethylbenzene and Xylene (BTEX) compounds from the crude oil retained in the sediments as a result of the Hebei Spirit oil-spill accident in 2007. The methane-related microbial communities as shown by lipid biomarkers (crocetane, PMI) are larger in some sedimentary sections of Hwang-do than in the Sogeunri tidal flat. These findings suggest that methane production by microbiological processes is clearly governed by SRB activity along the vertical succession in organic-enriched tidal flats.

• Polymer(Korea)
• /
• v.37 no.2
• /
• pp.141-147
• /
• 2013

Poly(lactide-co-glycolic acid) (PLGA) has been widely used in the drug delivery and tissue engineering applications because of its good mechanical strength and biodegradation profile. However, cell attachment to the scaffold is low compared with that on fibrin although cells can be attached to the polymer surface. In this study, PLGA scaffolds were soaked in cells-fibrin suspension and polymerized with dropping fibrinogen-thrombin solution. Cellular proliferation activity was observed in PLGA/fibrin-seeded costal cartilage cells (CC) on 1, 3, and 7 days using the MTT assay and SEM. The effects of fibrin on the extracellular matrix (ECM) formation were evaluated using CC cell-seeded PLGA/fibrin scaffolds. The PLGA/fibrin scaffolds elicited more production of glycosaminoglycan (GAG) and collagen than the PLGA scaffold. In this study, fibrin incorporated PLGA scaffolds were prepared to evaluate the effects of fibrin on the cell attachment and proliferation in vitro and in vivo. In this result, we confirmed that proliferation of cells in PLGA/fibrin scaffolds were better than in PLGA scaffolds. The PLGA/fibrin scaffolds provide suitable environment for growth and proliferation of costal cartilage cells.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.11
• /
• pp.1583-1591
• /
• 2003

The influence of varying levels of urea and additives on nitrogen (N) retention and chemical composition of wheat straw was studied. The wheat straw was treated with 4, 6 and 8% urea and ensiled with 1.5, 2 and 2.5% of acetic or formic acid and 2, 4 and 6% of corn steep liquor (CSL) or acidified molasses for 15 days. The N content of wheat straw was significantly different across all treatments. The N content of urea treated wheat straw was increased with the increasing level of urea. The N content was higher in urea treated wheat straw ensiled with acetic or formic acid as compared to urea treated wheat straw ensiled without these organic acids. The N content of urea treated wheat straw was further enhanced when it was ensiled with CSL or acidified molasses. This effect was significant across all levels of urea used to treat the wheat straw. Nitrogen retention in urea treated wheat straw was decreased linearly as the urea level was increased to treat the wheat straw. The N content was increased linearly when higher levels of CSL or acidified molasses were used to ensile the urea treated wheat straw. Most of the N in urea treated wheat straw was held as neutral detergent insoluble N (NDIN). The NDIN content was increased linearly with the increasing levels of urea and additives. The neutral detergent fiber (NDF) contents were higher in urea treated wheat straw ensiled with acetic or formic acid as compared to urea treated wheat straw ensiled without additive. The NDF content further increased in urea treated wheat straw ensiled with CSL and acidified molasses. The entire increase in NDF content was because of fiber bound N. The hemicellulose content of urea treated wheat straw ensiled with CSL or acidified molasses was higher as compared to urea treated wheat straw ensiled with acetic or formic acid. The acid detergent fiber content of urea treated wheat straw ensiled with or without additives remained statistically non-significant. The cellulose contents of wheat straw was linearly reduced when urea level was increased from 4 to 6 and 8% to treat the wheat straw. This effect was further enhanced when urea treated wheat straw was ensiled with different additives. The results of the present study indicated that fermentable carbohydrates might improve the Nitrogen retention and bring the favorable changes in physiochemical nature of wheat straw. However, biological evaluation of urea treated wheat straw ensiled with fermentable carbohydrates is required.

• Korean Journal of Weed Science
• /
• v.15 no.2
• /
• pp.154-159
• /
• 1995

Water extracts from Polygonum aviculare and Salix koreansis markedly inhibited the germination of lettuce and rice seeds, indicating the presence of biologically active substances. The biochemical substances such as salicylic and+vanillic acid, tannic acid + gallic acid, p-coumaric acid, p-cressol, sinapic acid and catechol etc. belonging to phenolic compounds were detected in the cultured cells, suggesting that the secondary metabolites can be synthesized in plant cell and tissue culture. In addition, fatty acid like linolenic acid and organic acid such as oxalic acid were presented in the highest amount, 3.7 mg/g and 14.288 mg/g, respectively, which seem to be related to exhibiting phytotoxicity of P. aviculare. Petroleum ether extract exhibited another potential relating to inhibitory effect which needs further investigation. Calli from two plant sources were easily introduced by uses of 1.0 mg/l of 2.4-D and 0.1 to 0.2 mg/l of BAP in MS basal medium which can be implemented for a large scale production through cell culture.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.9
• /
• pp.1281-1287
• /
• 2015

This study was performed to determine the effect of field pea silages which were the organic acid (OA) alternative of oregano and cinnamon essential oils on fermentation quality and aerobic stability. Whole crop pea was harvested at full pod stage and wilted in the laboratory at the 48 h. The chopped pea was mixed and divided into equal portions allocated to five groups: CON (non-treated), distilled water, denoted as control group; OA group, a mixture of 60% formic acid, 20% sodium formate and 20% water applied at a rate of 5 g/kg fresh forage (Silofarm Liquid, Farmavet); origanum (ORE) group, Origanum onites essential oil at 400 mg/kg fresh forage; cinnamon (CIN) group, cinnamon essential oil at 400 mg/kg fresh forage; origanum+cinnamon (ORECIN) group, a mixture of ORE and CIN applied at an equal rate of 400 mg/kg fresh forage. Cinnamon decreased acetic acid (AA), ammonia nitrogen ($NH_3-N$) and weight loss (WL) at the end of 60 days silage. Crude protein (CP) and dry matter (DM) increased by cinnamon essential oil. Yeasts were not detected in any treatments, including the control, after 7 days of air exposure. The $CO_2$ amount decreased and the formation mold was inhibited in the aerobic period by the addition of cinnamon oil. Oregano did not show a similar effect, but when it was used with cinnamon, it showed synergic effect on AA and during aerobic period, it showed antagonistic effect on mold formation and DM losses. It was found in this study that cinnamon can be an alternative to organic acids.

• Korean Journal of Organic Agriculture
• /
• v.10 no.4
• /
• pp.47-60
• /
• 2002

'Probiotics' as a live microbial feed supplementation which beneficially affects the host animal by improving its microbial balance and it is known to as a substitue for antibiotics in livestock feed industry. Lactic acid bacteria as a Lactobacillus sp. is formed acid and decrease pH in gastro-intestine that is result in suppress harmful microorganism. Lactobacillus sp. also produces vitamin and a variety amino acids. Yeast as a saccharomyces sp. secretes digestive enzymes, decreases ammonia emission and increases feed palatability by alcohol and glutamic acid. The effects of dietary probiotics in monogastric animals that improve weight gain and feed efficiency ratio and decrease diarrhea accurence frequency in pigs. Also, probiotics increase egg production ratio and beneficial microorganisms in laying hens. In broiler, they have more gain weight and lower blood cholesterol concentrations by probiotics. However, the other study reported probiotics supplementation in animal diets has no effect on ADG, G/F or performance. Thus, future study in these area will allow for more efficient use of the probiotics, selection of more superior microorganism and development of more efficient environment-friendly probiotics like a photosynthetic bacteria.

• Journal of Applied Biological Chemistry
• /
• v.52 no.4
• /
• pp.205-211
• /
• 2009

This study was carried out to acquire basic data for industrial production of Korean traditional kanjang (soy sauce). Five types of meju, $23{\times}11{\times}12$ ($L{\times}W{\times}H$, cm), $23{\times}11{\times}7$, $15{\times}11{\times}7$, $11{\times}11{\times}6$, $11{\times}11{\times}6$ (made a hole $\varphi$ 1.5 cm) were prepared. The temperature and humidity of meju preparation were $15{\sim}20^{\circ}C$ and 40~50% respectively. The smaller size of meju, the lower free amino acid and non-volatile organic acid content of that. And, two types of meju, conventional method (CM-meju, the temperature and humidity were prepared at $15{\sim}20^{\circ}C$ and 40~50% of relative humidity) and improved method(IM-meju, the temperature and humidity were prepared at $25{\sim}30^{\circ}C$ and 80~90% of relative humidity) for kanjang production were prepared. There was no difference of total nitrogen content and soluble nitrogen content in the size of meju. In total free amino acid content and total free sugar content, IM-meju was the higher than CM-meju. So, the quality of IM-meju was better than that of CM-meju.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.7
• /
• pp.935-940
• /
• 2000

The objective of this study was to evaluate the nutritive value of selected fruits (pods and seeds) and leaves of acacia tree species namely; Acacia nubica (nubica), Acacia tortilis (tortilis) and Acacia brevispica (brevispica), Acacia reficiens (reficiens) and Acacia senegal (senegal). A wide variability in chemical composition, polyphenolics and gas production was recorded. The crude protein (CP) ranged from 131 to 238 g/kg DM. Neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin (ADL) were higher in senegal and significantly different (p<0.05) from other species. The nitrogen bound to fiber tended to be higher in leaves than the fruits, ranging from 2.6 to 11.3 g/kg NDF and 1.6 to 3.2 g/kg ADF. The leaves of reficiens and senegal had higher concentrations of total extractable phenolics (TEPH), total extractable tannins (TET) and total condensed tannins (TCT), but lower in NDF, ADF and ADL than the fruits of nubica, tortilis and brevispica. Mineral concentrations varied among species; all were relatively poor in phosphorus, moderate in calcium and magnesium, and rich in microelements. A significant (p<0.05) variation in gas production after 12, 24, 48, 72 and 96 h was recorded between species. Nubica had the highest (p<0.05) rate of gas production (0.0925) while the highest potential gas production was recorded in tortilis. A strong negative correlation between TEPH and TET with gas production after 24, 48, 72 and 96 was established (r=-0.72 to -0.82). Crude protein and TCT correlated negatively but also weakly with gas production characteristics. Organic matter digestibility calculated from gas production after 48 h (OMD48) ranged between 465 g/kg DM in reficiens and 611 g/kg DM in tortilis. The results of this study indicate that acacia species have the potential to be used as feed supplements.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.1
• /
• pp.51-61
• /
• 2016

In order to provide recommendations on the most useful forage species to smallholder farmers, eleven grass and eleven legume forages grown in Abomey-Calavi in Republic of Benin were investigated for nutritive value (i.e. chemical composition and energy content) and fermentation characteristics (i.e. gas and volatile fatty acid production, organic matter degradability). The in vitro gas production technique was used, incubating the forages for 120 h under anaerobic condition with buffalo rumen fluid. Compared to legume, tropical grass forages showed lower energy (8.07 vs 10.57 MJ/kg dry matter [DM]) and crude protein level (16.10% vs 19.91% DM) and higher cell wall content (neutral detergent fiber: 63.8% vs 40.45% DM), respectively. In grass forages, the chemical composition showed a quite high crude protein content; the in vitro degradability was slightly lower than the range of tropical pasture. The woody legumes were richer in protein and energy and lower in structural carbohydrates than herbaceous plants, however, their in vitro results are influenced by the presence of complex compounds (i.e. tannins). Significant correlations were found between chemical composition and in vitro fermentation characteristics. The in vitro gas production method appears to be a suitable technique for the evaluation of the nutritive value of forages in developing countries.