• Journal of Microbiology and Biotechnology
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• 제31권8호
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• pp.1123-1133
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• 2021

Biodegradation is the key process involved in natural lignocellulose biotransformation and utilization. Microbial consortia represent promising candidates for applications in lignocellulose conversion strategies for biofuel production; however, cooperation among the enzymes and the labor division of microbes in the microbial consortia remains unclear. In this study, metagenomic analysis was performed to reveal the community structure and extremozyme systems of a lignocellulolytic microbial consortium, TMC7. The taxonomic affiliation of TMC7 metagenome included members of the genera Ruminiclostridium (42.85%), Thermoanaerobacterium (18.41%), Geobacillus (10.44%), unclassified_f__Bacillaceae (7.48%), Aeribacillus (2.65%), Symbiobacterium (2.47%), Desulfotomaculum (2.33%), Caldibacillus (1.56%), Clostridium (1.26%), and others (10.55%). The carbohydrate-active enzyme annotation revealed that TMC7 encoded a broad array of enzymes responsible for cellulose and hemicellulose degradation. Ten glycoside hydrolases (GHs) endoglucanase, 4 GHs exoglucanase, and 6 GHs β-glucosidase were identified for cellulose degradation; 6 GHs endo-β-1,4-xylanase, 9 GHs β-xylosidase, and 3 GHs β-mannanase were identified for degradation of the hemicellulose main chain; 6 GHs arabinofuranosidase, 2 GHs α-mannosidase, 11 GHs galactosidase, 3 GHs α-rhamnosidase, and 4 GHs α-fucosidase were identified as xylan debranching enzymes. Furthermore, by introducing a factor named as the contribution coefficient, we found that Ruminiclostridium and Thermoanaerobacterium may be the dominant contributors, whereas Symbiobacterium and Desulfotomaculum may serve as "sugar cheaters" in lignocellulose degradation by TMC7. Our findings provide mechanistic profiles of an array of enzymes that degrade complex lignocellulosic biomass in the microbial consortium TMC7 and provide a promising approach for studying the potential contribution of microbes in microbial consortia.

• Journal of Microbiology and Biotechnology
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• 제14권6호
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• pp.1338-1342
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• 2004

Cyclosophoraoses (Cys), cyclic ${\beta}-(1{\rightarrow}2)-D-glucans$ produced by Rhizobium meliloti 2011, were used as a novel chiral stationary phase for the enantiomeric separation. A novel Cys stationary phase, chemically immobilized onto porous silica via aminopropyltrimethoxysilane as a molecular linker, showed good separation for each racemate of bupivacain (separation factor, $\alpha$=1.3), propranolol ($\alpha$=1.3), and fenoprofen ($\alpha$=2.9), respectively, under the mobile phase of water: methanol (80:20, v/v) at a constant flow rate of 0.9 ml/min at pH7.

• Journal of Microbiology
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• 제44권4호
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• pp.466-471
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• 2006

In this study, we attempted to characterize the biomolecular effects of an atmospheric-pressure cold plasma (APCP) system which utilizes helium/oxygen $(He/O_2)$. APCP using $He/O_2$ generates a low level of UV while generating reactive oxygen radicals which probably serve as the primary factor in sterilization; these reactive oxygen radicals have the advantage of being capable to access the interiors of the structures of microbial cells. The damaging effects of plasma exposure on polypeptides, DNA, and enzyme proteins in the cell were assessed using biochemical methods.

• 한국동물위생학회지
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• 제25권1호
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• pp.31-37
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• 2002

Major hazards existed in slaughterhouse are pathogenic microorganisms originated from intestinal microflora of slaughtered animals. This study was intended for the identification of microbial contamination sources during pork slaughtering in small plants. Total aerobic bacteria, Coliform group, Salmonella spp, Listeria monocytogenes, and Campylobacter jejuni/coli were isolated from the surface sample of pork carcasses. Contamination level among different sampling points of ham, belly and neck did not showed statistical differences. Therefore, the mixed sampling from belly and neck of carcass could be effective for microbiological monitoring. Isolation rates of pathogenic microorganisms showed Salmonella spp 20.9%, Listeria monocytogenes 10.5%, and Campylobacter jejuni/coli 8.1% from 296 sampling points. High prevalence rate of Salmonella spp indicated that the contamination of intestinal microflora occurred due to unsanitary processing control, which required HACCP system in small plants. It was recommended that the prerequisite program should be a key factor for a successful HACCP system implementation especially in small size slaughterhouse.

• Preventive Nutrition and Food Science
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• 제13권4호
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• pp.348-353
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• 2008

Aerobic bacterial growth on Korean pan.fried meat patties as a primary quality deterioration factor was modeled as a function of temperature to estimate microbial spoilage on a real.time basis under dynamic storage conditions. Bacteria counts in the stretch.wrapped foods held at constant temperatures of 0, 5, 10 and $15^{\circ}C$ were measured throughout storage. The bootstrapping method was applied to generate many resampled data sets of mean microbial counts, which were then used to estimate the parameters of the microbial growth model of Baranyi & Roberts in the form of differential equations. The temperature functions of the primary model parameters were set up with confidence limits. Incorporating the temperature dependent parameters into the differential equations of bacterial growth could produce predictions closely representing the experimental data under constant and fluctuating temperature conditions.

• Journal of Microbiology and Biotechnology
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• 제31권6호
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• pp.765-774
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• 2021

Although research on the osteal signaling pathway has progressed, understanding of gut microbial-dependent signaling pathways for metabolic and immune bone homeostasis remains elusive. In recent years, the study of gut microbiota has shed light on our understanding of bone homeostasis. Here, we review microbiota-mediated gut-bone crosstalk via bone morphogenetic protein/SMADs, Wnt and OPG/receptor activator of nuclear factor-kappa B ligand signaling pathways in direct (translocation) and indirect (metabolite) manners. The mechanisms underlying gut microbiota involvement in these signaling pathways are relevant in immune responses, secretion of hormones, fate of osteoblasts and osteoclasts and absorption of calcium. Collectively, we propose a signaling network for maintaining a dynamic homeostasis between the skeletal system and the gut ecosystem. Additionally, the role of gut microbial improvement by dietary intervention in osteal signaling pathways has also been elucidated. This review provides unique resources from the gut microbial perspective for the discovery of new strategies for further improving treatment of bone diseases by increasing the abundance of targeted gut microbiota.

• Asian-Australasian Journal of Animal Sciences
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• 제26권7호
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• pp.952-960
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• 2013

The objective of this study was to investigate the effect of carbohydrate source and cottonseed meal level in the concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in swamp buffaloes. Four, 4-yr old rumen fistulated swamp buffaloes were randomly assigned to receive four dietary treatments according to a $2{\times}2$ factorial arrangement in a $4{\times}4$ Latin square design. Factor A was carbohydrate source; cassava chip (CC) and CC+rice bran at a ratio 3:1 (CR3:1), and factor B was level of cottonseed meal (CM); 109 g CP/kg (LCM) and 328 g CP/kg (HCM) in isonitrogenous diets (490 g CP/kg). Buffaloes received urea-treated rice straw ad libitum and supplemented with 5 g concentrate/kg BW. It was found that carbohydrate source did not affect feed intake, nutrient intake, digested nutrients, nutrient digestibility, ammonia nitrogen concentration, fungi and bacterial populations, or microbial protein synthesis (p>0.05). Ruminal pH at 6 h after feeding and the population of protozoa at 4 h after feeding were higher when buffalo were fed with CC than in the CR3:1 treatment (p<0.05). Buffalo fed with HCM had a lower roughage intake, nutrient intake, population of total viable and cellulolytic bacteria and microbial nitrogen supply than the LCM fed group (p<0.05). However, nutrient digestibility, ruminal pH, ammonia concentration, population of protozoa and fungi, and efficiency of microbial protein synthesis were not affected by cottonseed meal levels (p>0.05). Based on this experiment, concentrate with a low level of cottonseed meal could be fed with cassava chips as an energy source in swamp buffalo receiving rice straw.

• 생명과학회지
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• 제12권5호
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• pp.610-621
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• 2002

미생물 유전체(genome)들 사이의 보존된 유전자 (con-served gene)를 밝히는 것은 생명의 본질을 이해하는데 있어 다양한 의미를 갖는다고 할 수 있을 것이다. 본 연구에서는 보존적 유전자를 찾아내고, distance value를 이용하여 구한 보존성의 정도 C(conservation score)를 이용하여 종간의 유전자 변이의 정도를 단백질 관점에서 분석하였다. 분석에 사용된 자료는 COGs 데이티베이스의 총 43종의 미생물 유전체들이며, 이들은 총 n,009개의 유전자들을 포함하는 3,852 개의 ortholog들로 구성되어있었다. 분석 결과 43종의 미생물 유전체에 대하여 총 $\ulcorner$2개의 유전자들이 보존적인 것으로 나타났으며, 이들 중 72.2%인 52종의 유전자가 단백질 합성에 관련되는 것으로 나타났다. 이들 보존적 유전자들에 대하여 보존성의 정도 C를 계산하여 보존성의 순위를 얻었으며, 가장 잘 보존된 유전자는 CTPase-trans-lation elogation factor (COG0050)로 나타났다. 그리고 72개의 보존적 유전자가 나타내는 CU 모두를 이용한 분석결과 고세균(archaea)과 진정세균(bacteria)이 각각 독자적인 그룹을 형성하는 것을 관찰하였다. 본 연구의 결과에서 도출한 72개의 보존적 유전자는 생명체의 본질적 기능에 중요한 역할을 담당하는 것으로 사료되었고, 생명체의 진화 과정에서 이 유전자들이 보존된 이유와 기능적 연계에 대한 생물학적 연구에 기초 자료를 제공할 것으로 판단되어 진다.

• 한국환경과학회지
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• 제14권2호
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• pp.251-258
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• 2005

Statistical analysis between operating parameters and effluent quality on advanced wastewater treatment plant was performed. Through factor analysis four factors derived varimax rotation were selected each plant. Four components explained $80\%,\;82\%$ of the total variance of the process, respectively. The components on MLE plant were identified in the following order: 1) HRT increase and BOD load decrease by influent decrease, 2) Biomass, 3) SVI increase by internal return increase, 4) Microbial diversity by SRT increase. On $A_2O$ plant, we defined them as follows: factor 1, high MLSS by return rate increase, HRT increase by influent decrease; factor 2, biomass; factor 3, BOD of influent; factor 4 was relate to DO.

• 대한토목학회논문집
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• 제36권5호
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• pp.839-846
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• 2016

유류오염은 우리나라의 대표적인 토양 비점오염원으로 알려져 있으며, 이를 정화하는 토양의 능력은 토양 자원의 기능적 가치 평가에서 매우 유의하다. 특히 절/성토 설계 등의 친환경 건설기술 측면에서 토양의 유류오염정화능력을 평가하는 것은 중요하다. 그러나 마이크로코즘 실험을 포함한 기존의 토양 유류 오염정화능력 평가기법은 경제적, 시간적인 제약이 많아 광범위한 지역에 적용하기 어렵다. 이에 본 연구에서는 유류 오염물질 중 가솔린의 대표적 오염물질인 톨루엔을 선정하여 쉽고 간편하게 측정할 수 있는 토양의 미생물 다양성 지표를 이용, 토양의 유류오염 정화능력을 평가하는 기법을 제시하였다. 연구를 통해 미생물 군집의 다양성 지표 중 Shannon index가 토양의 정화능력 인자인 Specific Degradation Rate ($V_{max}$)와 상관성 관계가 있음을 보였고, 두 인자 간의 상관식을 도출할 수 있었다. 또한 본 상관식을 Michaelis-Menten kinetics에 적용하여 미생물 다양성 인자만으로 토양의 톨루엔 정화능력을 평가할 수 있는 기법을 제시하였다. 본 기법을 통해 간단히 토양의 톨루엔 정화능력을 평가할 수 있으며, 친환경 건설기술분야와 같은 다양한 공학적 분야에 광범위하게 활용될 수 있을 것으로 기대된다.