• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.3
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• pp.173-178
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• 2001

Food yeast, Saccharomyces cerevisiae, is a safe organism with a long history of use for the production of biomass rich in high quality proteins and vitamins. AmA1, a seed storage albumin from Amaranthus hypochondriacus, has a well-balanced amino acid composition and high levels of essential amino acids and offers the possibility of further improving food animal feed additives. In order to find an effective means of expressing AmA1 in yeast, the gene was cloned into an episomal shuttle vector. Four different promoters were tested: the glyceraldehyde-3-phosphate dehydrogenase promoter, galactose dehydrogenase 10 promoter, alcohol dehydrogenase II promoter, and a hybrid ADH2-GPD promoter. The recombinant AmA1 genes were then introduced into the yeast Saccharomyces cerevisiae 2805. Northern and Western blot analyses of the yeast under appropriate conditions revealed that AmA1 was expressed by all four promoters at varying levels. An enzyme-linked immunosorbent assay demonstrated that the amount of AmA1 protein in the recombinant yeast was 1.3-4.3% of the total soluble proteins. The highest expression level was obtained from the hybrid ADH2-GPD promoter.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.4
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• pp.263-274
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• 2000

Carotenoids are widely distributed natural pigments which are in an increasing demand by the market, due to their applicatins in the human food, animal feed, cosmetics, and pharmaceutical industries. Although more than 600 carotenoids have been identified in nature, only a few are industrially important (${\beta}$-carotene, astaxanthin, lutein or lycopene). To date chemical processes manufacture most of the carotenoid production, but the interest for carotenoids of biological origin is growing since theire is an increased public concern over the safety of artificial food colorants. Although much interest and effort has been devoted to the use of biological sources for industrially important carotenoids, only the production of biological ${\beta}$-carotene and astaxanthin has been reported. Among fungi, several Mucorales strains, particularly Blakeslea trispora, have been used to develop fermentation processes for the production of ${\beta}$-carotene on almost competitive cost-price levels. Similarly, the basidiomycetous yeast Xanthophyllomyces dendrorhous (the perfect state of Phaffia rhodozyma), has been proposed as a promising source of astaxanthin. This paper focuses on recent findings on the fungal pathways for carotenoid production, especially the structure and function of the genes involved in the biosynthesis of carotenoids in the Mucorales. An outlook of the possibilities of an increased industrial production of carotenoids, based on metabolic engineering of fungi for carotenoid content and composition, is also discussed.

• Journal of Animal Science and Technology
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• v.61 no.3
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• pp.122-137
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• 2019

Methane, one of the important greenhouse gas, has a higher global warming potential than that of carbon dioxide. Agriculture, especially livestock, is considered as the biggest sector in producing anthropogenic methane. Among livestock, ruminants are the highest emitters of enteric methane. Methanogenesis, a continuous process in the rumen, carried out by archaea either with a hydrogenotrophic pathway that converts hydrogen and carbon dioxide to methane or with methylotrophic pathway, which the substrate for methanogenesis is methyl groups. For accurate estimation of methane from ruminants, three methods have been successfully used in various experiments under different environmental conditions such as respiration chamber, sulfur hexafluoride tracer technique, and the automated head-chamber or GreenFeed system. Methane production and emission from ruminants are increasing day by day with an increase of ruminants which help to meet up the nutrient demands of the increasing human population throughout the world. Several mitigation strategies have been taken separately for methane abatement from ruminant productions such as animal intervention, diet selection, dietary feed additives, probiotics, defaunation, supplementation of fats, oils, organic acids, plant secondary metabolites, etc. However, sustainable mitigation strategies are not established yet. A cumulative approach of accurate enteric methane measurement and existing mitigation strategies with more focusing on the biological reduction of methane emission by direct-fed microbials could be the sustainable methane mitigation approaches.

• Korean Journal of Poultry Science
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• v.33 no.3
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• pp.233-238
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• 2006

In order to study the effect of feeding rare earth(RE) on growth of broiler chicks, feed conversion ratio, and probable harmfulness of feeding high levels of RE, two feeding trials with broiler chicks were conducted; one using a commercial broiler compound feed and the other using a self mixed feed excluding any growth stimulating feed additives. The the first trial used three hundred sixty of one day old Cobb broiler chicks for six levels of dietary supplementation of RE : 0, 100, 200, 400, 800 and 1,600 mg/kg. There were significant effect of RE stimulating broiler chick growth and improving feed conversion ratio, The dietary supplementation of RE at a level of 100 mg/kg was the best of all and increased body weight gain by 8.9% (p<0.05). Chicks fed RE at a level of 1,600 mg/kg grew as good as chicks fed feeds without RE and did not show my abnormalities. The second feeding trial was conducted in the same manner as the first trial using Ross broiler chicks and self-mixed experimental diets supplemented with RE at levels of 0, 50, 100 and 150 mg/kg. Differently from Results of the first trial, body weight gain and feed conversion ratio of were the best at the level of 50 mg/kg RE supplementation(p<0.05). In this trial all the birds fed RE showed significantly lower ratio of abdominal fat against live weight than those of the control group birds. Overall, it can be said that dietary supplementation of RE will improve broiler growth and feed conversion ratio and the proper dietary level would be $50\sim100mg/kg$. These results suggested that the proper level of RE for broiler chicks would be 50 to 100 mg/kg and its effectiveness is varied depending upon RE mixture. There appears abdominal fat of broiler chicks is decreased by feeding RE but further investigation is in need.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.4
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• pp.411-417
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• 2021

By-products produced from medicinal plants (MP) were evaluated as feed additives on growth performance, blood chemistry, and immune responses of the juvenile red lip mullet Liza haematocheila. A commercial diet was used as the control. Four experimental diets were prepared by combining 0.5% of MPs such as Panax ginseng (PG), Schisandra chinensis (SC), Angelica gigas (AG), and Rehmannia glutinosa (RG), via water absorption, to the control diet. Triplicate groups of fish averaging 61.8 g were fed one of experimental diets to apparent satiation for 8 weeks. Dietary supplementation of MPs did not affect the growth performance, biological indices and whole body composition of fish compared to the control. The fish fed with AG diet had an increased weight gain, and specific growth rate compared to fish in SC group. Decreased level of plasma glucose was observed in fish fed diet containing MPs. Lysozyme activity was significantly increased in the fish fed AG diet compared to that of fish in PG group. These results indicate that dietary supplementation of Angelica gigas may enhance growth performance and immune responses in juvenile red lip mullet.

• Journal of Animal Science and Technology
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• v.65 no.1
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• pp.96-112
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• 2023

Rye (Secale cereale L.) is a valuable annual forage crop in Korea but there is limited information about the impact of chemical and biological additives on fermentation characteristics of the crop. This experiment was conducted to investigate fermentation dynamics of wilted forage rye treated with the following six additives; control (no additive), sodium diacetate applied at 3 g/kg wilted forage weight (SDA3), 6 g/kg wilted forage weight (SDA6), inoculations (10⁶ CFU/g wilted forage) of Lactobacillus plantarum (LP), L. buchneri (LB), or LP+LB. The ensiled rye sampled at 1, 2, 3, 5, 10, 20, 30, and 45 days indicated that the acidification occurred fast within five days of storage than the rest of the storage period. The microbial inoculants decline the pH of ensiled forage, more rapidly than the control or SDA treated, which accompanied by the decrease of water-soluble carbohydrates and increase of lactic acid. Compared with the control silage, all treatments suppressed ammonia-nitrogen formation below to 35 g/kg DM throughout the sampling period. Suppression of total microbial counting occurred in SDA6, LP, and LP + LB. The lactic acid production rates were generally higher in microbial inoculation treatments. Acetic acid concentration was lowest in the LP-treated silage and highest in the SDA- and LB-treated silages. The in vitro dry matter (DM) digestibility and total digestible nutrients were the highest in the silage treated with SDA (6 g/kg) at day 45 of ensiling. Based on lower ammonia-nitrogen concentrations and higher feed value, ensiling forage rye treated with SDA at 6 g/kg is promising through enhanced silage quality.

• Journal of Animal Science and Technology
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• v.65 no.5
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• pp.1105-1109
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• 2023

Pedi coccus acidilactici CACC 537 was isolated from canine feces and reported to have probiotic properties. We aimed to characterize the potential probiotic properties of this strain by functional genomic analysis. Complete genome sequencing of P. acidilactici CACC 537 was performed using a PacBio RSII and Illumina platform, and contained one circular chromosome (2.0 Mb) with a 42% G + C content. The sequences were annotation revealed 1,897 protein-coding sequences, 15 rRNAs, and 56 tRNAs. It was determined that P. acidilactici CACC 537 genome carries genes known to be involved in the immune system, defense mechanisms, restriction-modification (R-M), and the CRISPR system. CACC 537 was shown to be beneficial in preventing pathogen infection during the fermentation process, help host immunity, and maintain intestinal health. These results provide for a comprehensive understanding of P. acidilactici and the development of industrial probiotic feed additives that can help improve host immunity and intestinal health.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.1
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• pp.48-54
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• 2006

Roxarsone (3-nitro-4-hydroxyphenylarsonic acid) has been used as feed additives in poultry industries to improve production and control coccidiosis. The effect of high dietary levels of Roxarsone (ROX) on the performance and function of internal organs and the kinetics of recovery as well as its after-effects were examined in laying hens. The inclusion rates of ROX were 0, 100, 200, 300, and 400 mg per kg feed. Inclusion up to 200 mg did not show any adverse effects (p>0.05), whereas in the 300 and 400 mg groups, significant effects, particularly in the latter, were observed for three weeks after ROX addition (p<0.05). Recovery of the physical appearance occurred soon after ROX addition was withdrawn. Recovery of performance and internal organs, however, appeared to be dependent on the amount of residual ROX in the body; as the amount of ROX decreased, the toxic effect of ROX also decreased. In the third week after the withdrawal of ROX, complete recovery was observed in the lower dosage groups (100 or 200 mg groups) (p>0.05), whereas in the higher dosage groups (300 or 400 mg groups), recovery took at least five weeks; when complete recovery was observed in egg production and in liver weight (p>0.05). On the other hand, ROX might have damaged the liver and other tissues. The recovery of liver weight was probably due to accumulation of fatty particles rather than repair. It appeared, therefore, there were little after-effects of ROX on the hen's physical appearance, but some internal organs were probably damaged.

• 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.

• Korean Journal of Microbiology
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• v.43 no.2
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• pp.124-129
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• 2007

We evaluated the use of citrus fruit fermented by lactic acid bacteria, as a feed supplement for flounder (Paralichthys olivaceus) cultivation. For the fermentation, a lactic acid bacterial strain W-44 showing antibacterial activity was isolated from kimchi. From the phylogenetic analysis based on, 16S rDNA sequence, the strain W-44 was identified as Lactococcus lactis. After the fermentation of citrus fruit with L. lactis W-44, the contents of naringenin and hesperetin, bioactive flavonoid aglycones, were increased about ten-fold and six-fold, respectively. The effects of fermented citrus fruit-based feed additives (CFBFA) were tested on the growth of flounder, Paralichthys olivaceus. There were significant differences in average total length and body weight between the experimental and control group. The growth rate of the experimental group fed with the 0.2% CFBFA-supplemented diet was increased 4.5% and 20.9% more than the control group in total length and body weight, respectively. These results suggest that the fermented citrus fruit could be used as a functional feed additive for flounder cultivation.