• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1444-1452
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• 2007

An in vitro experiment was conducted to evaluate the differences in microbial activity of five faecal inocula from weaned pigs and one faecal inoculum from unweaned pigs in combination with 6 substrates. The substrates tested were negative control diet, corn, soybean meal, oligofructose (OF), ground chicory roots and a mixture (60% chicory pulp and 40% OF). The inocula used were derived from pigs fed either a corn-soy based diet without antibiotics (NCON), the NCON diet supplemented with oligofructose (OF), a mixture of chicory pulp (40%) and OF (60%) (MIX), ground chicory roots (CHR) or the NCON diet supplemented with antibiotics (PCON). The cumulative gas production measured fermentation kinetics and end products, such as total gas production, ammonia and volatile fatty acids, were also determined. Both the substrate and the inoculum significantly affected the fermentation characteristics. The cumulative gas production curve showed that different substrates caused more differences in traits of fermentation kinetics than the different inocula. Inocula of weaned pigs gave a significantly higher VFA production compared to the inoculum from unweaned animals, whilst the rate of fermentation and the total gas produced did not differ. OF showed the highest fermentation kinetics and the lowest $NH_3$, pH and OM loss compared to other substrates. It was concluded that the microbial activity was significantly affected by substrate and inoculum. Inoculum from weaned pigs had more potential for microbial fermentation of the carbohydrate ingredients and oligofructose than that of unweaned pigs. A combination of high and low polymer inulin may be more beneficial to the gut ecosystem than using high- or low-polymer inulin alone.

• Journal of Microbiology and Biotechnology
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• v.13 no.3
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• pp.437-443
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• 2003

Bioremediation technologies were applied to experimental microcosms, simulating an oil spill in a lower intertidal area. Three treatments (oil only, oil plus nutrients, and oil plus nutrients and microbial inocula) were applied, and each microcosm was repeatedly filled and eluted with seawater every 12 h to simulate tidal cycles. To minimize washing-out of the inoculum by the tidal cycles, microbial cells were primarily immobilized on diatomaceous earth before they were applied to the oiled sand. Oil degradation was monitored by gravimetric measurements, thin layer chromatography/flame ionization detector (TLC/FID) analysis, and gas chromatography (GC) analysis, and the loss of oil content was normalized to sand mass or nor-hopane. When the data were normalized to sand mass, no consistent differences were detected between nutrient-amended and nutrient/inoculum-amended microcosms, although both differed from the oil-only microcosm in respect of oil removal rate by a factor of 4 to 14. However, the data relative to nor-hopane showed a significant treatment difference between the nutrient-amended and nutrient/inoculum-treated microcosms, especially in the early phase of the treatment. The accelerating effect of inoculum treatment has hardly been reported in studies of oil bioremediation in the Tower intertidal area. The inoculum immobilized on diatomaceous earth seemed to be a very effective formulation for retaining microbial cells in association with the sand. Results of this study also suggest that interpretation of the effectiveness of bioremediation could be dependent on the selection of monitoring methods, and consequently the application of various analytical methods in combination could be a solution to overcome the limitations of oil bioremediation monitoring.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.12
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• pp.1587-1593
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• 2010

Pastures of the Apennines of Central Italy contribute to feed resources of high altitude (above 1,300 m sea level) grazing systems. The objective of this study was to evaluate the effectiveness of faecal extract from the yak (Bos grunnienes) as an alternative microbial inoculum to rumen fluid for estimation of digestibility of several forage species. Forage samples produced at high altitude were tested in this study: four legumes (Lathyrus sativus L., Lotus corniculatus L., Onobrychis viciaefolia L. and Trifolium pratense L.), three forbs (Achillea millefolium L., Potentilla reptans L. and Teucrium flavum L.) and one grass (Brachipodyum pinnatum L.) were incubated with yak rumen fluid or faecal extract. A large variability in chemical composition was observed among the species collected. Rumen liquor and faecal samples were collected from adult healthy yak. The $Daisy^{II}$ incubator was used to evaluate the nutrient digestibility of forages using rumen liquor as control and faecal extract as alternative microbial inoculum sources. Filter bags containing samples of browse species were added to the four digestion vessels along with their respective inoculum and then incubated for 48 h and dry matter (DM), organic matter (OM), crude protein (CP), neutral and detergent fiber (NDF) digestibility was determined. There was a significant relationship between estimates, indicating that faecal liquor has the potential to be used instead of rumen fluid for estimation of in vitro digestibility of plants. It is concluded that the $Daisy^{II}$ incubator results are appropriate for the determination of in vitro digestibility of nutrients using faecal liquor to define the potential for adaptation of yak to new pastures.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.12
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• pp.635-640
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• 2016

Although microbial fuel cell (MFC) can produce electricity from organics in wastewater, nitrogen removal is required for application of process for wastewater treatment plant. This study developed flat-panel air-cathode MFCs (FA-MFCs) comprised of two large separator electrode assemblies (SEAs) and evaluate total nitrogen removal according to three inoculum sources and pre-nitrification acclimation. The nitrification efficiencies were >99% regardless of inoculum sources under the phase for pre-nitrification acclimation. The total nitrogen removal efficiencies of FA-MFCs without pre-nitrification acclimation were the highest at the low organic conditions (<300 mg-COD/L) under the phase for nitrification and denitrification. The increase of organic concentration influenced the total nitrogen removal efficiency, positively. The organics were removed >95% but were not used for heterotrophic denitrification totally. This study suggests that application of FA-MFC system for wastewater treatment can allow the simultaneous removal of organic and nitrogen compounds, although this affects the low electricity production.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.7
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• pp.990-996
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• 2005

The effect of diets varying in level and source of nitrogen (N) and fermentable organic matter on dynamic characteristics of microbial populations in rumen liquor and their impact on substrate fermentation in vitro was studied. The diets tested were straw alone, straw+concentrate mixture and straw+urea molasses mineral block (UMMB) lick. The same diets were taken as substrates and tested on each inoculum collected from the diets. Diet had no effect on the amino acid (AA) composition of either bacteria or protozoa. Differences among the diets in intake, source of N and OM affected bacterial and protozoal characteristics in the rumen. Upper asymptote of gas production (Y$\alpha$) had a higher correlation with bacterial pool size and production rate than with protozoal pool size and production rate. Among the parameters of the gas production model, Y$\alpha$ and lag time in total gas has showed significant (p<0.01) correlation with bacterial characteristics. Though the rate constant of gas production significantly differed (p<0.01) between diet and type of straw, it was least influenced by the microbial characteristics. The regression coefficient of diet and type of straw for Y$\alpha$ indicated that the effect of diet on Y$\alpha$ was threefold higher than that of the straw. As microbial characteristics showed higher correlation with Y$\alpha$, and diet had more influence on the microbial characteristics, gas production on a straw diet could be used effectively to understand the microbial characteristics.

• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3726-3729
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• 2011

Biofilm formation is inevitable in a bioelectrochemical system in which microorganisms act as a sole biocatalyst. Cathodic biofilm (CBF) works as a double-edged sword in the performance of the air-cathode microbial fuel cells (MFCs). Proton and oxygen crossover through the CBF are limited by the robust structure of extracellular polymeric substances, composition of available constituents and environmental condition from which the biofilm is formed. The MFC performance in terms of power, current and coulombic efficiency is influenced by the nature and origin of CBF. Development of CBF from different ecological environment while keeping the same anode inoculums, contributes additional charge transfer resistance to the total internal resistance, with increase in coulombic efficiency at the expense of power reduction. This study demonstrates that MFC operation conditions need to be optimized on the choice of initial inoculum medium that leads to the biofilm formation on the air cathode.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.552-555
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• 2001

This work reported concerns the removal of mixtures of methyl ethyl ketone (MEKJ, methyl isobutyl ketone (MIBK) and BTXs, which find wide application as industrial solvents, using the biofilter by the microbial consortium, The biofilter was constructed from acryl columns and was 400 mm in length and 55 mm in diameter and the height of fibrous packing material which made of PVC was 160 111111, 8 seconds of the retention time, pH 6.5 - 7.5 and the initial inlet concentration of MEK, MIBK and BTXs were 220 ppm. The removal efficiency of the gaseous mixtures was relatively low during the initial 2 days after inoculum of the microbial consortium, after 3 days, however, the efficiency was increased remarkably. In this study, The removal efficiency of the biofilter for the mixtures show the high degree from one day after inoculum of the microbial consortium, having no relation to the fluctuation of the inlet concentration of MEK, MIBK and BTXs.

• KSBB Journal
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• v.23 no.4
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• pp.285-290
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• 2008

Various methods (OECD 301B, ISO 9439 and ASTM 5864) for biodegradability test of lubricants were reviewed, and a standard procedure was developed. Most lubrication products are released in rivers or sea then is degraded by microbial action in aerobic condition. Most international method are based on $CO_2$ evolution test. Inoculum obtained from a sewage disposal plant and test compound are cultivated in a mineral medium. Organic carbon of the test compound is degraded and oxidized through the enzymatic actions of inoculum, and ultimately mineralized to carbon dioxide. Biodegradability test conditions of lubricant oils were optimized. The highest biodegradability was achieved when the same medium as in ASTM 5864 and inoculum concentration of $10^4{\sim}10^5$ cell/L were used. The optimum standard materials were selected as aniline and sodium acetate. Additionally the effects of inoculum type on microbial growth and biodegradability were examined. Finally the standard operating procedure (SOP) for biodegradability test method was proposed.

• Journal of Applied Biological Chemistry
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• v.58 no.3
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• pp.209-218
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• 2015

Fructooligosaccharides have been mainly produced by microbial fructosyltransferases (FTase) enzymes. The present work focuses on the optimization of medium composition and cultivation parameters affecting FTase produced by Penicillium aurantiogriseum AUMC 5605 in shake flask cultivation. FTase production was optimized in two steps using DeMeo's fractional factorial design. A 1.46-fold increase in FTase production (105.4 U/mL) was achieved using the optimized culture medium consisting of (g/L): sucrose, 600; yeast extract, 10; $K_2HPO_4$, 5; $MgSO_4{\cdot}7H_2O$, 0.5; $(NH_4)_2SO_4$, 1.0 and KCl, 0.5. The obtained results showed that the maximum FTase enzyme activity was produced at initial cultivation pH values ranging from 6.0-6.5, at agitation speed of 200 rpm and using vegetative fungal cells as inoculum. Moreover, results showed that optimization of medium composition and some cultivation parameters resulted in an increase of about 93.7% in the enzyme activity than the nonoptimized cultivation conditions after 96 h of cultivation. Additionally, maximum production and specific production rates recorded 2340 U/L/h and 102 U/L/h/g cells, respectively.

• Journal of Life Science
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• v.11 no.1
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• pp.11-13
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• 2001

Several culture conditions affecting cellulose production by a newly isolated Acetobacter sp. A9 were examined by cultivating cells under shaking cultures. The inoculum size in the range of 1-10% (v/v) did not influence cellulose production. Maximum cellulose production was obtained with 200 rpm of agitation speed. The cells grown in the 75 ml of medium in a 250-ml conical flask produced the highest level of cellulose. The strain was able to produce cellulose at 25-3$0^{\circ}C$ with a maximum at 3$0^{\circ}C$. Cellulose production occurred at pH 4.5-7.5 with a maximum at pH6.5.