• Asian-Australasian Journal of Animal Sciences
• /
• v.2 no.3
• /
• pp.357-358
• /
• 1989

• Korean Journal of Soil Science and Fertilizer
• /
• v.43 no.5
• /
• pp.734-740
• /
• 2010

Overuse of veterinary antibiotics threats public health and surrounding environment due to the occurrence of antibiotic resistant bacteria. The objective of this study was to evaluate the antibiotic's concentrations of tetracycline (TC), chlortetracycline (CTC), and oxytetracycline (OTC) in a tetracycline group (TCs), sulfamethazine (SMT), sulfamethoxazole (SMX), and sulfathiazole (STZ) in a sulfonamide group, lasalocid (LSL), monensin (MNS), and salinomycin (SLM) in a ionophore (IPs), and tylosin (TYL) in a macrolide (MLs) group from soil, water, and sediment samples adjacent to a cattle manure composting facility. For all samples of soil, water, and sediment, the highest concentrations were detected in TCs among the tested antibiotics because of its higher annual consumption in veterinary farms, Korea and its higher cohesiveness with divalent or trivalent cations in soil. Moreover, the concentrations of residual antibiotics in September were generally higher than in June because of heavier rainfall in June. We suggest that continual monitoring and developing guideline of antibiotics are needed to control residual antibiotics in the environment.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.3
• /
• pp.410-416
• /
• 2010

Methane emitted from ruminant livestock is regarded as a loss of feed energy and also a contributor to global warming. Methane is synthesized in the rumen as one of the hydrogen sink products that are unavoidable for efficient succession of anaerobic microbial fermentation. Various attempts have been made to reduce methane emission, mainly through rumen microbial manipulation, by the use of agents including chemicals, antibiotics and natural products such as oils, fatty acids and plant extracts. A newer approach is the development of vaccines against methanogenic bacteria. While ionophore antibiotics have been widely used due to their efficacy and affordable prices, the use of alternative natural materials is becoming more attractive due to health concerns regarding antibiotics. An important feature of a natural material that constitutes a possible alternative methane inhibitor is that the material does not reduce feed intake or digestibility but does enhance propionate that is the major hydrogen sink alternative to methane. Some implications of these approaches, as well as an introduction to antibiotic-alternative natural materials and novel approaches, are provided.

• Journal of the Korean Electrochemical Society
• /
• v.9 no.3
• /
• pp.132-134
• /
• 2006

The main component governing selectivity in ion-selective electrodes and optodes is the ionophore. For this reason, a member of natural products that possess selective ion-binding properties have long been sought after. By applying this principle, the performance of tetracycline used as neutral carriers for cation selective polymeric membrane electrode was investigated. The cation ion-selective electrode based on tetracycline gave a good Nernstian response of 26.6 mV per decade for calcium ion in the activity range $1x10^{-6}M$ to $1x10^{-2}M$ with and without lipophilic additives. The optimized cation ion-selective membrane electrodes displayed very comparable potentiometric responses to various mono and di-valent cations of alkali and alkaline earth metal ions except $Mg^{2+}$.

• Journal of Animal Science and Technology
• /
• v.63 no.1
• /
• pp.16-24
• /
• 2021

The suppressive effect of monensin as an ionophore-feed additive on enteric methane (CH4) emission and renewable methanogenesis were evaluated. To clarify the suppressive effect of monensin a respiratory trial with head cage was performed using Holstein-Friesian steers. Steers were offered high concentrate diets (80% concentrate and 20% hay) ad libitum with or without monensin, galacto-oligosaccharides (GOS) or L-cysteine. Steers that received monensin containing diet had significantly (p < 0.01) lower enteric CH4 emissions as well as those that received GOS containing diet (p < 0.05) compared to steers fed control diets. Thermophilic digesters at 55℃ that received manure from steers fed on monensin diets had a delay in the initial CH4 production. Monensin is a strong inhibitor of enteric methanogenesis, but has a negative impact on biogas energy production at short retention times. Effects of the activity of coprophagous insects on CH4 and nitrous oxide (N2O) emissions from cattle dung pats were assessed in anaerobic in vitro continuous gas quantification system modified to aerobic quantification device. The CH4 emission from dungs with adults of Caccobius jessoensis Harold (dung beetle) and the larvae of the fly Neomyia cornicina (Fabricius) were compared with that from control dung without insect. The cumulative CH4 emission rate from dung with dung insects decreased at 42.2% in dung beetles and 77.8% in fly larvae compared to that from control dung without insects. However, the cumulative N2O emission rate increased 23.4% in dung beetles even though it reduced 88.6% in fly larvae compared to dung without coprophagous insects. It was suggested that the antibacterial efficacy of ionophores supplemented as a growth promoter still continued even in the digested slurry, consequently, possible environmental contamination with the antibiotics might be active to put the negative impact to land ecosystem involved in greenhouse gas mitigation when the digested slurry was applied to the fields as liquid manure.

• Korean Journal of Poultry Science
• /
• v.38 no.2
• /
• pp.155-164
• /
• 2011

The use of antimicrobials will be soon removed due to an increase of occurrence of antibiotic-resistant bacteria or ionophore-resistant Eimeria species in poultry farms and consumers' preference on drug-free chicken meats or eggs. Although dietary antimicrobials contributed to the growth and health of the chickens, we do not fully understand their interrelationship among antimicrobials, gut microbiota, and host immunity in poultry. In this review, we explored the current understanding on the effects of antimicrobials on gut microbiota and immune systems of chickens. Based on the published literatures, it is clear that antibiotics and antibiotic ionophores, when used singly or in combination could influence gut microbiota. However, antimicrobial effect on gut microbiota varied depending on the samples (e.g., gut locations, digesta vs. mucosa) used and among the experiments. It was noted that the digesta vs. the mucosa is the preferred sample with the results of no change, increase, or decrease in gut microbiota community. In future, the mucosa-associated bacteria should be targeted as they are known to closely interact with the host immune system and pathogen control. Although limited, dietary antimicrobials are known to modulate humoral and cell-mediated immunities. Ironically, the evidence is increasing that dietary antimicrobials may play an important role in triggering enteric disease such as gangrenous dermatitis, a devastating disease in poultry industry. Future work should be done to unravel our understanding on the complex interaction of host-pathogen-microbiota-antimicrobials in poultry.

• Korean Journal of Environmental Agriculture
• /
• v.29 no.3
• /
• pp.273-281
• /
• 2010

Concentration of antibiotics including a tetracycline group (TCs) of tetracycline (TC), chlortetracycline (CTC), and oxytetracycline (OTC), a sulfonamide group (SAs) of sulfamethoxazole (SMX), sulfathiazole (STZ), and sulfamethazine (SMT), an ionophore group (IPs) of lasalocid (LSL), monensin (MNS), and salinomycin (SLM), and a macrolide group (MLs) of tylosin (TYL) was determined from samples collected from the agricultural soil, stream water, and sediment. For the agricultural soil samples, the concentration of TCs had the highest value among all tested antibiotic's groups due to its high accumulation rate on the surface soils. The lower concentrations of SAs in the agricultural soils may be resulted from its lower usage and lower distribution coefficient (Kd) compared to TCs. The concentration of TCs in stream water was significantly increased through June to September. It would be likely due to soil loss during an intensive rainfall event and a reduction of water level after the monsoon season. A significant amount of TCs in the sediment was also detected due to its accumulation from runoff, which occurred by complexation of divalent cations, ion exchange, and hydrogen bonding among humic acid molecules. To ensure environmental or human safety, continuous monitoring of antibiotics residues in surrounding ecosystems and systematic approach to the occurrence mechanism of antibiotic resistant bacteria are required.

• Journal of Life Science
• /
• v.11 no.1
• /
• pp.7-10
• /
• 2001

Nonactin is the parent compound of a group of ionophore antibiotics, that known as the macrotetrolides. In previous report, in th course of screening superoxide radical-generating compounds from microbial sources, we first screened Streptomyces viridochromogenes JM-4151 that produces nonactin. It was proved that nonactin is superoxide radical-producing compound. In present study, we examined the optimal culture conditions of nonacin. Th optimal culture conditions for nonactin production were as follows: 1% soluble starch, 1% yeast extract, 0.2% ammonium nitrate, 0.06% magnesium sulfate, 0.2% calcium carbonate, initial pH 7.0 at 28$^{\circ}C$ for 96 h. The highest nonactin production was achieved in the production medium of initial pH7.0 at 28$^{\circ}C$ for 96h. The threshold level of dissolved oxygen was found to be above 33.2% at 28$^{\circ}C$ when 1% soluble starch was used as a carbon source. These results suggest that S. viridochromogenes JM-4151 might be a possible strain for industrial nonactin producer.