• KSBB Journal
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• v.15 no.1
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• pp.100-105
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• 2000

Optimal medium composition, culture conditions, characteristics of phase variation and activity of insecticidal toxin by Xenorhabdus nematophilus isolated and identified from Korean entomopathogenic nematode Steinernema carpocapsae were examined. Optimal medium composition of this strain was 50-70 g/L yeast extract, 3 g/L $K_{2}HPO_{4}$, 1g/L $NH_{4}H_{2}PO_{4}$, 2g/L ${MgSO}_4$$\cdot$${7H}_{2}O$, 10g/L NaCl and, these, yeast extract was found as a limiting nutrient for cell growth. When Monod equation was applied, maxmum specific growth rate and Monod constant were estimated as 0.13 $hr^{-1}$ and 20g/L, respectively. The pH of culture medium increased up to 8.5-9.5 regardless of initial pH 6-7 as the cells continued to grow. The specific growth rate in a 7 L fermentor was 0.18 $hr^{-1}$, which was enhancement 1.4 fold compared to a flask culture. In case of phase variation, phase I fraction was maintained above 90% at the stationary phase for both flask and fermentor cultures. According to oral toxicity test of Gallena mellonella by Xenorhabdus nematophilus, the addition of cell pellets into feed inhibited normal growth of insect larvae and killed completely then after 20 days cultivation. When culture supernatant of this strain was injected into hemolymph of insect larva, the toxicity was strongest at 24hr cultivation in the early exponential phase and gradually decreased as the culture time proceeded.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.3
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• pp.254-259
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• 2004

This experiment was conducted to investigate the effects of supplemented diets with Malty Culture(MC) during lactation on sow and litter performance. Eighteen lactating sows were randomly assigned to three dietary treatments(basal diet, basal diet+MC0.5%, basal+MCl.0%). Average daily feed intake of sow was not affected by dietary treatments with treatment means ranging from 4.49 to 4.58kg(p>0.62). All sows lost their backfat thickness during lactation with no difference among the treatments(p>0.25). Fecal moisture was similar for sows fed the control and MC treatments with 70% moisture content. The growth rate of piglets was not significant difference among the treatments ranging from 47 to 48kg. Day to estrus postweaning was not affected by supplementation of MC with treatment means ranging from 5 to 7 days. There was not significant difference in the milk production(i.e, 8.9kg/d for control, 9.18kg/d for MC0.5 and 9.20kg/d for MC1.0). Survivability of piglet was affected by feeding added MC during lactation. There was no significant difference in the digestibility of DM, but the digestibility of N tended to increase in sows fed the MC0.5 and MC1.0 supplemented diets compared to the basal diet(linear effect, p<0.10; quadratic effect. p<0.08). Digestibility of P tended to increase by the treatment of supplemented MC. However, there was no significant difference among the treatments. In conclusion, the results of experiment suggest that lactation diet of supplemented MC could be a beneficial feeding for digestibility in sow and litter performance.

• Clean Technology
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• v.4 no.1
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• pp.45-59
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• 1998

Continuous immobilized-cell culture was carried out for the production of kasugamycin, a secondary metabolite by a filamentous bacteria, Streptomyces kasugaensis, with an intention of reducing waste generation. A sporulation medium was developed for production of bulk amounts of spores, and the spores were entrapped into celite biosupports for immobilization. It was possible to effectively keep the immobilized-cells inside the reactor during the continuous culture by an efficient immobilized cell separator of decantor type on the outlet of the fermentor. Using this continuous immobilized-cell fermentor system, we investigated the effects of feed substrate and phosphate concentrations on kasugamycin production and chemical oxygen demand(COD). Comparing with the conventional suspended-cell batch culture, the kasugamycin productivity was observed to increase by 2.5 times, whereas COD per unit kasugamycin production decreased by 2.3 times in the continuous immobilized-cell culture. Based on these results, the continuous immobilized-cell system was considered to be a cleaner bioprocess than the conventional batch suspended-cell system.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.12
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• pp.1744-1751
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• 2011

This study was conducted to compare the effects of feeding dry or fermented (aerobically or anaerobically with or without lactic acid bacteria) restaurant food residue mixture-containing diets on animal performance and blood profiles. Rats were used as the model animal for the simulation of laboratory rodents, rabbit or horse feeding and fed for 4 wks. The results were compared with feeding a dry diet (control) with the same ingredient composition as diets processed by aerobic and anaerobic methods. Feeding all the fermented diets tended to increase (p>0.05) average daily gain of rats resulting in improved (p<0.01) feed efficiency. Apparent digestibility of NDF was increased (p<0.05) by feeding the fermented diets, although digestibilities of DM, OM, CP, and NFC were not affected (p>0.05). Compared with the aerobically fermented diet, digestibility of ADF was increased (p<0.05) for the anaerobically fermented diet and for the 0.5% LAB culture plus anaerobically fermented diet. The digestibility of crude ash tended to increase (p>0.05) with feeding of the fermented diets. Feeding either of the fermented diets had little effects on serum nutrients, electrolytes, enzymes and blood cell profiles of rats except sodium and uric acid concentrations. These results showed that compared with feeding a dry food residue-containing diet, feeding aerobically or anaerobically fermented diets showed better animal performance as indicated by higher feed efficiency and rat growth rate. These improvements were attributed to the desirable dietary protein conservation during the food residue fermentation process and to higher total tract digestibilities of NDF and crude ash in the fermented food residue diets.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.3
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• pp.233-237
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• 2000

The complete postembryonic development of nauplius stages of Paramphiascella vararensis T. Scotf (Copepoda: Harpacticoida) is described and illustrated based on specimens cultured in laboratory. The nauplii of P. vararensis feed on powder of a green algae, Ulva perusa. This species is metamorphosed to the stages of nauplius. Development from the nauplius stage to the nauplius stage take about 12 days under culture conditions of 33-34 ppt of salinity, 22-23$^{\circ}$C of temperature and feed on the algal powder. In the nauplius stages of P. vararensis, the rudiment of maxillule appeares at the third nauplius stage, and maxilla appeares at the fifth nauplius stage.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.500-506
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• 2017

To investigate the potential applications of bacterial heme, aminolevulinic acid synthase (HemA) was expressed in a Corynebacterium glutamicum HA strain that had been adaptively evolved against oxidative stress. The red pigment from the constructed strain was extracted and it exhibited the typical heme absorbance at 408 nm from the spectrum. To investigate the potential of this strain as an iron additive for swine, a prototype feed additive was manufactured in pilot scale by culturing the strain in a 5 ton fermenter followed by spray-drying the biomass with flour as an excipient (biomass: flour = 1:10 (w/w)). The 10% prototype additive along with regular feed was supplied to a pig, resulting in a 1.1 kg greater increase in weight gain with no diarrhea in 3 weeks as compared with that in a control pig that was fed an additive containing only flour. To verify if C. glutamicum-synthesized heme is a potential electron carrier, lactic acid bacteria were cultured under aerobic conditions with the extracted heme. The biomasses of the aerobically grown Lactococcus lactis, Lactobacillus rhamosus, and Lactobacillus casei were 97%, 15%, and 4% greater, respectively, than those under fermentative growth conditions. As a potential preservative, cultures of the four strains of lactic acid bacteria were stored at $4^{\circ}C$ with the extracted heme and living lactic acid bacterial cells were counted. There were more L. lactis and L. plantarum live cells when stored with heme, whereas L. rhamosus and L. casei showed no significant differences in live-cell numbers. The potential uses of the heme from C. glutamicum are further discussed.

• Microbiology and Biotechnology Letters
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• v.7 no.1
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• pp.9-14
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• 1979

The hemicellulose fraction of ryegrass straw was extracted with NaOH and used for production of glucose isomerase by Streptomyces flavogriseus. Up to 25％ crude hemicellulose (20％ as pentosan) could he obtained by treating straw with 1 to 24％ NaOH. The yield of hemicellulose was increased proportionately with increasing NaOH concentration up to 4％, but the rate of increase was slowed thereafter. The optimum condition for hemicellulose extraction from ryegrass straw was to treat straw with 4％ NaOH for 3hrs at 9$0^{\circ}C$ or 24hrs at 3$0^{\circ}C$. Highest level of glucose isomerase activity (3.04 units/ml culture) was obtained when the organism was grown for 2 days at 3$0^{\circ}C$ on 2％ straw hemicellulose. The organism also produced a good quantity of glucose isomerase on xylan, xylose or H$_2$SO$_4$-hydrolysate of straw. The hemicellulose-extracted straw residue could be used as animal feed, because the residue had 75％ higher digestibility and 20％ better feed efficiency for weanling meadow voles than the untreated straw.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.5
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• pp.683-690
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• 2013

A study was conducted to evaluate the effects of resveratrol and essential oils from medicinal plants on the growth performance, immunity, digestibility, and fecal microbial shedding of weaned piglets. A total of 48 weaned piglets (8 kg initial weight, 28-d-old) were randomly allotted to four dietary treatments with 3 replications of 4 piglets each. The dietary treatments were NC (negative control; basal diet), PC (positive control; basal diet+0.002% apramycin), T1 (basal diet+0.2% resveratrol), and T2 (basal diet+0.0125% essential oil blend). All piglets were orally challenged with 5 ml culture fluid containing $2.3{\times}10^8$ cfu/ml of Escherichia coli KCTC 2571 and $5.9{\times}10^8$ cfu/ml Salmonella enterica serover Typhimurium. The PC group (p<0.05) showed the highest average daily gain (ADG) and average daily feed intake (ADFI) throughout the experimental period, although feed conversion ratio (FCR) was improved in the T1 group (p>0.05). Serum IgG level was increased in the T1 group, whereas TNF-${\alpha}$ levels was reduced in the supplemented groups compared to control (p<0.05). The PC diet improved the dry matter (DM) digestibility, whereas PC and T2 diets improved nitrogen (N) digestibility compared to NC and T1 diets (p<0.05). Fecal Salmonella and E. coli counts were reduced in all treatment groups compared to control (p<0.05). Fecal Lactobacillus spp. count was increased in the T2 group compared to others (p<0.05). Dietary treatments had no significant effect on fecal Bacillus spp. count throughout the entire experimental period. Based on these results, resveratrol showed strong potential as antibiotic alternatives for reversing the adverse effects of weaning stress on growth performance, immunity and microbial environment in E. coli and Salmonella-challenged piglets.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.1
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• pp.8-14
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• 2017

A feeding trial was conducted to evaluate the effect of dietary supplementation with fermented soybean meal by Bacillus subtilis (BFSBM) on growth performance, feed utilization, innate immunity, water quality, and disease resistance of Litopenaeus vannamei. A basal fish meal-based diet was regarded as a control and two other diets were prepared by replacing 30% fish meal with either soybean meal (SBM) or BFSBM. Triplicate groups of shrimp ($0.80{\pm}0.010g$) were fed one of the experimental diets for 6 weeks. No differences were found in final body weight, feed conversion ratio, or survival among all dietary treatments after the feeding trial. Shrimp fed the BFSBM diet had significantly higher phagocytic and phenoloxidase activities than those of shrimp fed the SBM diet. Total ammonia concentrations in culture water during a zero water exchange test tended to decrease in tanks where BFSBM diet was provided. Disease resistance of shrimp to Vibrio harveyi tended to increase in the BFSBM group during 14 days of challenge compared to that in the control (CON) and SBM groups. These results show that dietary supplementation with BFSBM can enhance the innate immunity of Pacific white shrimp and replace at least 30% of dietary fish meal.

• Korean Journal of Organic Agriculture
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• v.20 no.3
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• pp.327-343
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• 2012

In order to develop a high cellulolytic direct-fed microorganism (DFM) for ruminant productivity improvement, this study isolated cellulolytic bacteria from the rumen of Holstein dairy cows, and compared their cellulolytic abilities via DM degradability, gas production and cellulolytic enzyme activities. Twenty six bacteria were isolated from colonies grown in Dehority's artificial (DA) medium with 2% agar and cultured in DA medium containing filter paper at $39^{\circ}C$ for 24h. 16s rDNA gene sequencing of four strains from isolated bacteria showed that H8, H20 and H25 strains identified as Ruminococcus flavefaciens, and H23 strain identified as Fibrobacter succinogenes. H20 strain had higher degradability of filter paper compared with others during the incubation. H8 (R. flavefaciens), H20 (R. flavefaciens), H23 (F. succinogenes), H25 (R. flavefaciens) and RF (R. flavefaciens sijpesteijn, ATCC 19208) were cultured in DA medium with filter paper as a single carbon source for 0, 1, 2, 3, 4 and 6 days without shaking at $39^{\circ}C$, respectively. Dry matter degradability rates of H20, H23 and H25 were relatively higher than those of H8 and RF since 2 d incubation. The cumulative gas production of isolated cellulolytic bacteria increased with incubation time. At every incubation time, the gas production was highest in H20 strain. The activities of carboxymethylcellulase (CMCase) and Avicelase in the culture supernatant were significantly higher in H20 strain compared with others at every incubation time (p<0.05). Therefore, although further researches are required, the present results suggest that H20 strain could be a candidate of DFM in animal feed due to high cellulolytic ability.