• Asian-Australasian Journal of Animal Sciences
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• v.26 no.3
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• pp.358-365
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• 2013

A series of in vitro studies were carried out to determine i) the effects of enzyme and formaldehyde treatment on the degradation characteristics of carbohydrate and protein sources and on the synchronicity of these processes, and ii) the effects of synchronizing carbohydrate and protein supply on rumen fermentation and microbial protein synthesis (MPS) in in vitro experiments. Untreated corn (C) and enzyme-treated corn (EC) were combined with soy bean meal with (ES) and without (S) enzyme treatment or formaldehyde treatment (FS). Six experimental feeds (CS, CES, CFS, ECS, ECES and ECFS) with different synchrony indices were prepared. Highly synchronous diets had the greatest dry matter (DM) digestibility when untreated corn was used. However, the degree of synchronicity did not influence DM digestibility when EC was mixed with various soybean meals. At time points of 12 h and 24 h of incubation, EC-containing diets showed lower ammonia-N concentrations than those of C-containing diets, irrespective of the degree of synchronicity, indicating that more efficient utilization of ammonia-N for MPS was achieved by ruminal microorganisms when EC was offered as a carbohydrate source. Within C-containing treatments, the purine base concentration increased as the diets were more synchronized. This effect was not observed when EC was offered. There were significant effects on VFA concentration of both C and S treatments and their interactions. Similar to purine concentrations, total VFA production and individual VFA concentration in the groups containing EC as an energy source was higher than those of other groups (CS, CES and CFS). The results of the present study suggested that the availability of energy or the protein source are the most limiting factors for rumen fermentation and MPS, rather than the degree of synchronicity.

• Journal of Microbiology and Biotechnology
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• v.22 no.12
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• pp.1636-1643
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• 2012

Enzymatic pre-bleaching by modification of pulp fibers with xylanases is an attractive approach to reduce the consumption of toxic bleaching chemicals in the paper industry. In this study, an alkaliphilic endoxylanase gene was isolated from metagenomic DNA of a structurally stable thermophilic lignocellulose-degrading microbial consortium using amplification with conserved glycosyl hydrolase family 10 primers and subsequent genome walking. The full-length xylanase showed 78% sequence identity to an endo-${\beta}$-1,4-xylanase of Clostridium phytofermentans and was expressed in a mature form with an N-terminal His6 tag fusion in Escherichia coli. The recombinant xylanase Xyn3F was thermotolerant and alkaliphilic, working optimally at $65-70^{\circ}C$ with an optimal pH at 9-10 and retaining >80% activity at pH 9, $60^{\circ}C$ for 1 h. Xyn3F showed a $V_{max}$ of 2,327 IU/mg and $K_m$ of 3.5 mg/ml on birchwood xylan. Pre-bleaching of industrial eucalyptus pulp with no prior pH adjustment (pH 9) using Xyn3F at 50 IU/g dried pulp led to 4.5-5.1% increase in final pulp brightness and 90.4-102.4% increase in whiteness after a single-step hypochlorite bleaching over the untreated pulp, which allowed at least 20% decrease in hypochlorite consumption to achieve the same final bleaching indices. The alkaliphilic xylanase is promising for application in an environmentally friendly bleaching step of kraft and soda pulps with no requirement for pH adjustment, leading to improved economic feasibility of the process.

• Journal of environmental and Sanitary engineering
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• v.5 no.2
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• pp.53-62
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• 1990

There has been considerable organisms the most indicative of the sanitary quality of food products. Of the suggested indices of sanitary quality of foods are coliform organism and SPC. In addition to the usual index organisms on fish products it is also necessary to determining the sanitary quality The authors have tested with 282 fish products (spring : 39, summer : 109, autumn : 112, winter . 22) 1. The range of microbial organism in fish products are as follows Spring : SPC is $13{\times}10^3\; to\; 50{\times}10^8/g$, coliform group is $16{\times}10^2\; to\; 48{\times}10^8/g$ and 2. coli is 50 to $22{\times}10^4/100g$. Summer : SPC is 70 to$64{\times}10^9/g$. coliform group is 25 to $26{\times}10^8/g$ and E. coli is 20 to $22{\times}10^4/100g$. Autumn : SPC is $10{\times}10^3\; to\; 46{\times}10^8/g$, coliform group is 200 to $20{\times}10^5/g$ and E. coli is 20 to $22{\times}10^4/100g$. Winter : SPC is $30{\times}10^3\; to\;30{\times}10^8/g$. coliform group is $21{\times}10^2\;to\;16{\times}10^3/g$ and E. coli is 20 to 790/100g. Salmonella and Staphylococcus species were not in 282 fish products.

• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.360-370
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• 2012

Current ecological knowledge of methanotrophic biofilms is incomplete, although they have been broadly studied in biotechnological processes. Four individual DNA samples were prepared from a methanotrophic biofilm, and a multiplex 16S rDNA pyrosequencing was performed. A complete library (before being de-multiplexed) contained 33,639 sequences (average length, 415 nt). Interestingly, methanotrophs were not dominant, only making up 23% of the community. Methylosinus, Methylomonas, and Methylosarcina were the dominant methanotrophs. Type II methanotrophs were more abundant than type I (56 vs. 44%), but less richer and diverse. Dominant non-methanotrophic genera included Hydrogenophaga, Flavobacterium, and Hyphomicrobium. The library was de-multiplexed into four libraries, with different sequencing efforts (3,915 - 20,133 sequences). Sorrenson abundance similarity results showed that the four libraries were almost identical (indices > 0.97), and phylogenetic comparisons using UniFrac test and P-test revealed the same results. It was demonstrated that the pyrosequencing was highly reproducible. These survey results can provide an insight into the management and/or manipulation of methanotrophic biofilms.

• Environmental Engineering Research
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• v.23 no.4
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• pp.420-429
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• 2018

Soil stabilization is a soil remediation technique that reduces the mobility of heavy metals in soils. Although it is a well-established technique, it is nonetheless essential to perform a follow-up chemical assessment via a leaching test to evaluate the immobilization of heavy metals in the soil matrix. Unfortunately, a standard chemical assessment is not sufficient for evaluation of the biological functional state of stabilized soils slated for agricultural use. Therefore, it is useful to employ a pyrosequencing-based microbial community analysis for the purpose. In this study, a recently stabilized site in the proximity of an exhausted mine was analyzed for bacterial diversity, richness, and relative abundance as well as the effect of environmental factors. Based on the Shannon and Chao1 indices and rarefaction curves, the results showed that the stabilized layer exhibited lower bacterial diversity than control soils. The prevalence of dominant bacterial populations was examined in a hierarchical manner. Relatively high abundances of Proteobacteria and Methylobacter tundripaludum were observed in the stabilized soil. In particular, there was substantial abundance of the Methylobacter genus, which is known for its association with heavy metal contamination. The study demonstrated the efficacy of (micro)biological assessment for aiding in the understanding and post-management of stabilized soils.

• Korean Journal of Veterinary Service
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• v.43 no.4
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• pp.245-250
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• 2020

Infectious bovine keratoconjunctivitis (IBK) is the most common ocular disease in cattle, manifesting as corneal opacity, corneal ulcerations and potentially vision loss. The present report describes a 10-month-old Holstein Friesian heifer with IBK treated by systemic tulathromycin, and subconjunctival injection of penicillin and dexamethasone. We investigated changes in the hematological indices and microorganisms related to IBK after treatment. Neutrophils and monocytes decreased during recovery, so it was assumed that these two types of white cells are associated with IBK. Moraxella bovoculi was cleared in the eye, nasal cavity, and oral cavity after treatment. The distribution of M. bovoculi before treatment indicated that a combined systemic and subconjunctival treatment was necessary. The lesioned eye was found to be overwhelmed by Mycoplasma bovoculi, while pathogen abundance was reduced in the nasal cavity and oral cavities. These results suggest that antibiotic treatment can alter the composition and relative abundance of microorganisms.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.8
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• pp.1381-1384
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• 2004

In order to help the preservation of the cherry tomatoes, antimicrobial paper incorporating grapefruit seed extract and zeolite was applied to packaging fruits. The fruits were packed with a paper bag of 15.5${\times}$24 cm and then stored at 1$0^{\circ}C$. During the storage, weight loss, pH, total acidity, soluble solid content, microbial load and decay were measured as quality indices. Steady weight loss due to the transpiration was observed to slightly increase the solid content during the storage with little difference between the packaging treatments. There were little change in pH and acidity of the stored fruits. The microbial loads of total aerobic bacteria, and yeast/mold counts were significantly suppressed during 10 day storage by the antimicrobial paper packaging, which also contributed to reducing the decayed fruits observed after 15 days.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.2
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• pp.252-261
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• 2008

Two experiments were conducted to compare the effects of feeding organic acids and antibiotic growth promoters in weaned pigs. In Exp. 1, 96 nursery pigs (Large White$\times$Landrace; initial weight $7.80{\pm}0.07kg$) were randomly allotted into one of four dietary treatments. Pigs in treatment 1 were fed a complex starter diet. Treatments 2 to 4 were the same as treatment 1 but supplemented with antibiotics (200 ppm chlortetracycline plus 60 ppm Lincospectin), 0.5% potassium diformate or 0.5% dry organic acid blend ACTIVATE Starter DA (ASD). During the 4-week post-weaning period, pigs fed ASD or antibiotics had better gain (p = 0.03) and feed efficiency (p = 0.04) than pigs fed the control diet. On d 14 post-weaning, pigs fed the control diet had the lowest fecal lactobacilli count among all dietary treatments (p = 0.02), whereas pigs fed ASD or antibiotics had a trend for lower fecal E. coli count compared to the control pigs (p = 0.08). Serum insulin-like growth factor-1 (IGF-1) of pigs fed ASD did not differ from pigs fed the control diet (p>0.05) at d 14 after weaning. In Exp. 2, 24 weaned pigs (Large White$\times$Long White; initial weight $5.94{\pm}0.33kg$) were allotted into four groups and housed individually. Pigs were fed a control diet or diets supplemented with antibiotics (100 ppm colistin sulfate, 50 ppm Kitasamycin plus 60 ppm Olaquindox), 0.5% or 1% ASD. All pigs were orally challenged with E. coli $K88^+$ on d 5. During d 5 to 14 after challenge, pigs fed antibiotics, 0.5% or 1% ASD had better gain (p = 0.01) and feed efficiency (p = 0.03) than pigs fed the control diet. On d 14, compared to the control pigs, pigs fed 0.5% ASD had higher lactobacilli in the duodenum and pigs fed 1% ASD and antibiotics had a trend for higher lactobacilli in the ileum (p = 0.08). Pigs fed antibiotics, 0.5% or 1% ASD diets tended to have decreased ileal E. coli count compared to those fed the control diet (p = 0.08). Serum interleukin-6 and cortisol and digesta pH values were not affected by treatment or time. These results indicate that feeding ASD can improve the growth performance of weaning pigs, mainly via modulating intestinal microflora populations without affecting gastrointestinal pH or immune indices.

• Animal cells and systems
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• v.3 no.2
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• pp.153-159
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• 1999

In an artificial pH-gradient batch culture system, the effects of acidification on the species composition of a heterotrophic bacterial community were analyzed. As a result of this study, it was found that total bacteria numbers were not affected by acidification and that the population of hetero-trophic bacteria decreased as pH became lower. The heterotrophic bacteria isolated from the entire pH gradient were 12 genera and 22 species. Among them, 64% were gram negative and 36% were gram positive bacteria. As pH decreased, the distribution rate of gram negative bacteria increased while that of gram positive bacteria decreased. The diversity of genera decreased from 13 to 5 as pH decreased from 7 to 3. The G+C content of all of the 202 isolated strains varied from 22.8 to 77.0%, and increased in interspecies of same genus as pH decreased. As a result of clustering analysis, the diversity index of species ranged from 1.13 to 2.37, and it had lower indices as pH decreased. In order to evaluate the diversity of numbers of sample of different size, a rarefaction method was used to analyze the expected number of species appearance according to pH. The statistical significance of species diversity was verified by the fact that the number decreased at lower pH.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.461-476
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• 2015

Global warming has accelerated glacial retreat in the high Arctic. The exposed glacier foreland is an ideal place to study chronosequential changes in ecosystems. Although vegetation succession in the glacier forelands has been studied intensively, little is known about the microbial community structure in these environments. Therefore, this study focused on how glacial retreat influences the bacterial community structure and its relationship with soil properties. This study was conducted in the foreland of the Midtre Lovénbreen glacier in Svalbard (78.9°N). Seven soil samples of different ages were collected and analyzed for moisture content, pH, soil organic carbon and total nitrogen contents, and soil organic matter fractionation. In addition, the structure of the bacterial community was determined via pyrosequencing analysis of 16S rRNA genes. The physical and chemical properties of soil varied significantly along the distance from the glacier; with increasing distance, more amounts of clay and soil organic carbon contents were observed. In addition, Cyanobacteria, Firmicutes, and Actinobacteria were dominant in soil samples taken close to the glacier, whereas Acidobacteria were abundant further away from the glacier. Diversity indices indicated that the bacterial community changed from homogeneous to heterogeneous structure along the glacier chronosequence/distance from the glacier. Although the bacterial community structure differed on basis of the presence or absence of plants, the soil properties varied depending on soil age. These findings suggest that bacterial succession occurs over time in glacier forelands but on a timescale that is different from that of soil development.