• Journal of Microbiology and Biotechnology
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• v.17 no.10
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• pp.1638-1644
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• 2007

The effect of carbon sources on tacrolimus production by a mutant strain of Streptomyces clavuligerus CKD 1119, an isolate from soil, was examined. Among the carbohydrates and oils tested in this work, a mixed carbon source of soluble starch and com oil was the best. An analysis of the culture kinetics also showed that, in contrast to the carbohydrates, the com oil was consumed later in the antibiotic production phase, implying that the oil substrate was the principal carbon source for the biosynthesis of tacrolimus, and this was directly proven by experiments using $^{14}C$-glucose and $^{14}C$-oleate substrates. Furthermore, com oil induced the formation of lipase by the mutant strain, whereas the addition of glucose significantly repressed lipase activity. The lipase activity exhibited by the FK-506-overproducing mutants was also observed to be directly proportional to their tacrolimus yield, indicating that a high lipase activity is itself a crucial factor for tacrolimus production. A feasibility study with a 200-1 pilot-scale fermentor and the best strain (Tc-XII-15322) identified in this work revealed a high volumetric and specific productivity of about 495 mg/l and 0.34 mg/mg dry mycelium, respectively.

• Journal of Microbiology and Biotechnology
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• v.31 no.10
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• pp.1438-1445
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• 2021

A bifunctional glycoside hydrolase GH78 from the ascomycete Xylaria polymorpha (XpoGH78) possesses catalytic versatility towards both glycosides and esters, which may be advantageous for the efficient degradation of the plant cell-wall complex that contains both diverse sugar residues and esterified structures. The contribution of XpoGH78 to the conversion of lignocellulosic materials without any chemical pretreatment to release the water-soluble aromatic fragments, carbohydrates, and methanol was studied. The disintegrating effect of enzymatic lignocellulose treatment can be significantly improved by using different kinds of hydrolases and phenoloxidases. The considerable changes in low (3 kDa), medium (30 kDa), and high (> 200 kDa) aromatic fragments were observed after the treatment with XpoGH78 alone or with this potent cocktail. Synergistic conversion of rape straw also resulted in a release of 17.3 mg of total carbohydrates (e.g., arabinose, galactose, glucose, mannose, xylose) per gram of substrate after incubating for 72 h. Moreover, the treatment of rape straw with XpoGH78 led to a marginal methanol release of approximately 17 ㎍/g and improved to 270 ㎍/g by cooperation with the above accessory enzymes. In the case of beech wood conversion, the combined catalysis by XpoGH78 and laccase caused an effect comparable with that of fungal strain X. polymorpha in woody cultures concerning the liberation of aromatic lignocellulose fragments.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.2
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• pp.81-88
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• 2001

To investigate C and N metabolisms in response to potassium-deficient stress during regrowth of Italian ryegrass(Lolium multiflorum L.), C and N metabolites were analyzed at day 0 (cutting date), 6, 12 and 24 days after defoliation. K-sufficient (control, +K) and K-absent (-K) nutrition solutions were applied from 7 days before defoliation, and continued for one cycle of 24 days-regrowth period. During 24 days of regrowth dry matter of regrowing shoots and remaining tissues were not significantly different between +K and -K treatment. In remaining stubble, all C compounds in both +K and -K treatment largely decreased (69% to 84% of the initial level) during the first 6 days of regrowth, and then rapidly recovered. The decline of soluble sugars and fructan in roots for the first 6 days much less in the -K medium. Amino acids, soluble and insoluble proteins in stubble also feel down during the first 6 days, thereafter actively replenished in both +K and -K treatment. The decline of nitrate in stubble prolonged to 12 days of regrowth. Initial amounts of all N compounds in roots were significantly lower in the -K medium. Higher accumulation of amino acids and soluble protein in roots in the -K medium was observed after 12 days of regrowth. In regrowing shoots, 3 all carbohydrates increased with a very similar pattern for both treatments. Nitrate was not significantly different between two treatments. Depress of soluble protein accumulation in -K medium was noteworthy after 12 days of regrowth. These results indicated that an active utilization of organic reserves occurred to support regrowth even under K deficient condition with a similar extent with K sufficient condition.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.291-296
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• 2017

This study was conducted to evaluate the influence of early defoliation on photosynthesis and carbohydrate reserves when the source leaves of 'Fuji'/M9 apple (Malus domestica Borkh.) trees were removed during the growing period. Bud regrowth rates of 80%, 50% defoliation and non-defoliation treatments were significantly different 82.7%, 45.9% and 2.1% respectively at 30 days after treatment. In all treatments, sucrose and starch concentrations in remaining leaves decreased non-significantly during the 14-day period. No significant changes were observed for total soluble carbohydrates in non-defoliation and 50% defoliation. However, in 80% defoliated treatments, concentrations of sorbitol and total soluble carbohydrates in remaining leaves declined steadily during the 14-day period. It is thought that high sink strength increases the requirements of carbohydrate from remaining leaves more than non-defoliated. The concentrations of starch in the roots tend to decrease non-significantly as percentage of defoliation increased. Photosynthesis of remaining leaves was monitored during the 14-day period after partial defoliation treatments. Net photosynthetic rates (Pn) and stomatal conductance were significantly enhanced in the 80% defoliation. The observed photosynthetic enhancement following partial defoliation may have been due to the enhancement of osmotic potential in leaves. These results were estimated that increasing of photosynthetic rate in the partial defoliation is due to the sink carbohydrate requirements for the current year's secondary growth of buds.

• Journal of Environmental Health Sciences
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• v.25 no.3
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• pp.29-35
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• 1999

Quantity and composition of biogas from semi-continuous anaerobic digestion of straw were obtained experimentally in laboratory scale digesters fed with 1 liter of 5% straw-water mixture and maintained at 35$^{\circ}C$. Experiments were carried out for hydraulic retention time(HRT) of 8, 10 and 15days, respectively. The amount and composition of biogas produced were measured until steady-state was achieved for each run. The amount of biogas and methane percent go through a maximum and decrease continuously towards the steady-state after three times operation of hydraulic retention time(HRT). Methane gas production rates at steady-state increase with the increasing of HRT. Biogas production of 0.45 liter/day with 25% methane, 0.42 liter/day with 33.7% methane and 0.492 liter/day with 31.7% methane were obtained for 8, 10 and 15days of HRT, respectively. The high proportion of soluble carbohydrates present in straw makes the volatile fatty acids to build up within the digester causing a drop in pH that inhibits digestion. Regular control of pH is therefore necessary by adding alkalinity. Reductions in COD increase with increase in HRT. The stratification of plant material within the digester is different from that of manure, and modifications in design and operation of digesters may be necessary if they are fed with plant matter.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1611-1611
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• 2001

The main selection parameters used by forage grass (rye and Italian rye grass) breeders are dry-matter yield, seasonal growth, persistency, disease resistance, heading date, and heading. These characteristics can all be identified usually in the segregating F2 population, however characteristics such as soluble carbohydrate level, protein, lipid and digestibility cannot be identified. The emphasis of this work is to introduce a quantitative selection process for characterization of herbage quality e.g. protein, water-soluble carbohydrates, fiber fractions, dry matter digestibility. NIRS calibrations are currently being developed for identifying grass genotypes to assist the selection process, thereby allowing the opportunity to actively breed improved herbage quality. The changes in fibre fractions, associated components and digestibility of a number of grass clones at different growth stages are being assessed changes taking place during a growing season. This will provide a database of the major changes taking place during a growing season. Attempts to classify quality differences between genotypes will be carried out using multivariate analysis of the spectral data. I addition changes associated with maturity of grass will be considered in order to develop robust calibrations.

• Korean Journal of Soil Science and Fertilizer
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• v.2 no.1
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• pp.49-51
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• 1969

Manuring has been classified into five stages to study the absorbtive and metabolic process of potassium in the period of growth of soybeans. The contents in harvest time have not shown much difference regardless of earlier or later manuring. But in the testing period of comparatively earlier manuring, supply of potassium has precipitated the synthesizing of carbohydrates, and in the testing period of comparatively later manuring, decrease of not only soluble sugar, but also soluble nitrogen and protein-nitrogen has been discoverd thus resulting in the existence of connection between supply of potassium and nitrogen metabolism.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.2
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• pp.123-128
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• 1989

An experiment was conducted to study the effect of frequency of defoliation on the ensiling characteristics and nutritive value of Guineaecotype 'A' (Panicum maximum Jacq) grass. Guinea grass harvested at 2, 3, 4, 5, 6, 7, 8, 9, 10 and 12-week cutting intervals was chopped (2 cm) and ensiled alone or with the addition of coconut (Cocos nucifera L.) meal (w/w-fresh weight basis), for periods of 6, 7 or 8 weeks in 2-litre laboratory silos. Dry matter, water soluble carbohydrates, lactic acid, pH, ash, nitrogen and digestibility in vitro were measured in representative samples of preensiled and ensiled material. Dry matter content of silages prepared from herbage harvested at 2 and 3 weeks intervals was lower (P<0.05) compared to longer defoliation intervals. The pH of silage prepared from herbage over 8 weeks old were higher (P<0.05) than those harvested below 8 weeks. The water soluble carbohydrate content of silage prepared from 3-weekly defoliated herbage was higher (P<0.05) than those prepared from longer periods. Lengthened growth period decreased (P<0.001) the crude protein content of the ensiled material, whereas the addition of coconut meal resulted in marginal increases. In vitro organic matter digestibility of the silages decreased (P<0.05) with the increase in forage maturity.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.51-54
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• 1992

Silages were prepared with different ratios of oat and wheat straw 100:0, 80:20, 60:40, 40:60, 20:80, and 0:100 with or without urea supplementation and were ensiled for 60 days in air tight polyethylene bags and kept at room temperature. Results showed that dry matter loss was maximum in 100% oat silage and it decreased as the ratio of wheat straw increased. There was a significant difference in crude protein value of the silages prepared by different ratios of oat and wheat straw. Addition of urea significantly increased the crude protein and decreased the crude fibre value. Silage made with urea supplementation were well fermented as indicated by higher value of volatile fatty acids (VFA) and lower value of residual carbohydrates. Maximum VFA concentrations were observed in 60:40 oat-wheat straw silages. The value of enzyme soluble organic matter (ESOM) was high in all the urea supplemented silages as compared to without urea and maximum value was found in 60:40 oat-wheat straw combination.

• Food Science and Preservation
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• v.3 no.1
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• pp.15-21
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• 1996

Physicochemical properties and the conditions of cold storage of kiyomi clangor(Citrus unshiu x sinensis) produced in Cheju were investigated. Firmness, edible part ratio, soluble solids, and acid content were decreased gradually with incurasing fruit size. Carbohydrates in juice were consisted of 65.12% sucrose, 19.65% fructose, and 15.23% glucose The main organic acrid In juice was 57.4% of citric acid, and others were lactic acid, malic acid, oxalic acid and fumaric acid, respectively. Weight loss were occured very. slowly to about 6% till late of May, but decayed fruits were occurred very slowly to about 6% till late of May, but decayed fruits were arisen to about 8% at 3$^{\circ}C$, and about 13% at 5$^{\circ}C$ of storage temperature. The changes of peel moisture content, soluble solids, total sugar, vitaamin C, and density of fruits were slightly occured during cold storage. Cold storage at 3$^{\circ}C$ and 87% relative humidity kept freshness of citrus fruits for a long-term without damage of cold injury.