쌀바구미가 현미의 함수량에 미치는 영향을 조사하여 다음과 같은 결과를 얻었다. A. R.H. 에 있어서의 함수량의 증가 1) 100, 200, 500개체의 쌀바구미에 의하여 산란된 집단에 의하여 4주간에 사수량은 무곤충구에 비하여 의 증가가 있었다. 2) 최대함수량은 500개체구에서 4주후에 , 최소 100개체구에서 였다. 3) 현미함수량의 증가는 현미내의 쌀바구미의 집단이 클수록 많다. B. 에 있어서의 함수량의 층위적 변동 1) 무곤충구에 있어서는 함수량은 계속하여 감소하며 12주후에 있어서는 가 되였다. 2) 실험구에 있어서는 상층을 제외하면 함수량은 12주후에는 최초의 함수량보다 증가하였으며 중층이 , 하층이 였다. 3) 대조구, 실험구 모두 상층에 갈수록 공중에의 수분탈취가 심하여 함수량은 하층보다 적었다. 4) 현미함수량의 증가는 곤충의 활동 급 미생물의 활동에 의한 것이라고 생각된다. 5) 쌀바구미의 집단은 어펄 특정한 층에 집합하는 일은 없으나 하층의 현미의 변질에 따라 상층으로 이동한다. 6) 현미내 온도는 대조구에 있어서는 환경온도와의 차가 적으며 낮은 것이 보통이나 실험구에 있어서는 높은 것이 보통이며 하층은 상층보다 높았다. 7) (6)에서와 갈은 온도의 차의 원인은 곤충의 호흡열 급 미생물의 분해열이 그 원인이라고 생각된다.

This study investigated microbial communities and their diversity in a full-scale mesophilic anaerobic digester treating sewage sludge. Influent sewage sludge and anaerobic digester samples collected from a wastewater treatment plant in Busan were analyzed using high-throughput sequencing. It was found that the microbial community structure and diversity in the anaerobic digester could be affected by inoculation effect with influent sewage sludge. Nevertheless, distinct microbial communities were identified as the dominant microbial communities in the anaerobic digester. Twelve genera were identified as abundant bacterial communities, which included several groups of syntrophic bacteria communities, such as Candidatus Cloacimonas, Cloacimonadaceae W5, Smithella, which are (potential) syntrophic-propionate-oxidizing bacteria and Mesotoga and Thermovigra, which are (potential) syntrophic-acetate-oxidizing bacteria. Lentimicrobium, the most abundant genus in the anaerobic digester, may contribute to the decomposition of carbohydrates and the production of volatile fatty acids during the anaerobic digestion of sewage sludge. Of the methanogens identified, Methanollinea, Candidatus Methanofastidiosum, Methanospirillum, and Methanoculleus were the dominant hydrogenotrophic methanogens, and Methanosaeta was the dominant aceticlastic methanogens. The findings may be used as a reference for developing microbial indicators to evaluate the process stability and process efficiency of the anaerobic digestion of sewage sludge.

This study aimed to investigate the effects of dietary Ptecticus tenebrifer on the fecal microbiomes of bichon frise. A total of 16 bichon frise dogs (average weight, 2 kg) were randomly allotted to 4 dietary treatments (4 dogs/group): general pet food, two types of domestic pet food containing Ptecticus tenebrifer, and one imported pet food containing Ptecticus tenebrifer. In the controls, Firmicutes accounted for the highest proportion (82%) at the phylum level in the fecal microbiomes. The Tax4Fun2's functional prediction program indicated that the control groups showed a relatively high amount of obesity-related microorganisms; the pathways included three types of carbohydrate metabolism. Among the treatments, Firmicutes abundances was the least in the treatments with the two types of domestic pet food containing Ptecticus tenebrifer; this did not affect the functional prediction of Tax4Fun2. In conclusion, the two types of domestic feed with Ptecticus tenebrifer were healthy and suitable for bichon frise; they could be beneficial in terms of obesity.

The present study investigated the effect of ammonia load on microbial communities in mesophilic anaerobic digestion of propionic acid. A laboratory-scale continuous anaerobic digester treating propionic acid as a sole organic substrate was operated under non-inhibitory condition and inhibitory conditions with ammonia (1.5 g and 3.5 g ammonia-N/L, respectively), and bacterial and archaeal communities in the steady states of each ammonia condition were analyzed using high-throughput sequencing. Thirteen bacterial families were detected as abundant bacterial groups in mesophilic anaerobic digestion of propionic acid. Increase in ammonia concentration resulted in significant shifts in microbial community structures. Syntorophobacter, Pelotomaculum, and Thermovigra were determined as the dominant groups of (potential) propionate oxidizing bacteria in the non-inhibitory condition, whereas Cryptanaerobacter and Aminobacterium were the dominant groups of (potential) propionate oxidizing bacteria in the ammonia-inhibitory condition. Methanoculleus and Methanosaeta were the dominant methanogens. Acetate-oxidation coupled with hydrogenotrophic methanogenesis might be enhanced with increases in the relative abundances of Methanoculleus and Tepidanaerobacter acetatoxydans under the ammonia-inhibitory condition. The results of the present study could be a valuable reference for microbial management of anaerobic digestion systems that are exposed to ammonia inhibition and propionic acid accumulation.

To improve the environmental management and resources, in this study, we aimed to investigate the effect of adding oyster shell powder to Hanwoo manure on its characteristics and microbial composition during the storage period. Additives were deposited on top of the manure surface at the rate of 0, 0.5, and 1% of oyster shell powder per 200 g of Hanwoo manure in a plastic container with three replicates; however, untreated manure litter served as the control. Manure characteristics (dry matter, organic matter and crude ash) and microbial composition (lactic acid bacteria, yeast, Bacillus subtilis, Salmonella, and E.coli) were evaluated at day 0, 2, 4, and 8. Manure characteristics exhibited an effect on dry matter, organic matter, and crude ash at day 2 and 8 (p<0.05), and not for day 0 and 4 (p>0.05). With the exception of yeast content at day 4 of storage, lactic acid bacteria, yeast, Bacillus subtilis, Salmonella, and E.coli exhibited no significant differences in all conditions during the storage period. Conclusively, addition of 1% oyster shell powder to Hanwoo manure resulted in slightly better manure characteristics; however, its microbial composition remained unchanged.

한국산업규격(KS)에서 오징어젓은 오징어 배합비율이 75% 이상으로 정하고 있다. 본 연구는 저염 젓갈을 제조하기 위한 기초연구로 유산균 첨가에 따른 영향을 실험한 결과이다. 면역활성이 있는 기능성 유산균을 오징어젓 및 어리굴젓에 각각 첨가한 후, 냉장 또는 실온에서 45일간 보존하면서 미생물학적, 관능적 품질을 평가하였다. 오징어젓은 실온에서 보관한 경우, 보존기간이 경과하면서 유산균 수는 대체로 증가하였다. 어리굴젓의 경우에도 유산균 첨가 시료에서 실온에 2주간 노출한 경우, 생균수가 약 100배 증가하였다. 한편, 일반세균의 경우에는 유산균 첨가 및 비첨가 대조구 모두 현저한 변화가 없이 일정수준으로 유지되는 것으로 나타났다. 미생물 학적 변화를 바탕으로 판단할 경우 본 시험에 공시된 오징어젓 및 어리굴젓은 유산균 첨가에 의한 현저한 미생물의 증식이나 감소는 수반되지 않으며, 소비자가 통상적으로 섭취하는 기간동안 유산균의 빠른 증식은 물론, 일반세균의 증식억제효과는 기대하기 어려울 것으로 판단된다. 그러나 저염화와 더불어 관능적 품질 향상이 뚜렷하게 나타났으며, 기호성이 우수한 제품의 개발이 가능하다고 판단된다.

포스트바이오틱스(postbiotics)는 프로바이오틱스(probiotics)가 발효과정 중 생산하는 유용한 대사산물과 미생물의 구성성분을 포 함하는 개념이다. 포스트바이오틱스는 기존 프로바이오틱스 소재가 갖는 안전성(safety), 기능성(function), 안정성(stability)의 한계를 극복할 수 있는 새로운 대안 소재로 주목받고 있다. 사균화 처리과정으로, 특정 대사물질의 복합물 형태로 제조되고 있기에 기존 생균제보다 가공, 포장, 유통, 섭취가 용이하다. 면역력이 낮은 환자나 건강 취약 계층의 소비자들도 안전하게 섭취할 수 있는 것도 장점이다. 뿐만 아니라, 체내에서 면역 조절, 감염 방지, 지질 및 콜레스테롤 대사, 항산화 기능을 보이고 있어, 앞으로 건강기능 식품 우수 소재로 활용될 가능성은 더 커질 것이다. 다만, 대부분의 연구들이 아직은 세포실험과 동물시험인 단계이기에 실제 인체적용 시험을 마친 소재들은 적은 편이다. 향후 꾸준한 연구성과를 바탕으로 다양한 기능을 가진 포스트바이오틱스 소재와 제품들이 개발된다면 건강기능식품 산업에 새로운 성장동력이 될 것으로 예상 된다.

Soil microorganism activity in an agricultural field is affected by various factors including climate conditions, soil chemical properties, and crop cultivation. In this study, we elucidate the correlation between microorganism activity and agricultural environment factors using the dehydrogenase activity (DHA) value, which is one of the indicators of soil microbial activity. As a result, the various factors noted above were related to the DHA value. Annual rainfall, soil Mg2+, bacterial and fungal diversities, types of crops, developmental stages, seasons, and cultivation status were highly correlated with the DHA value. Furthermore, next-generation sequencing (NGS) analysis was used to identify that the type of crop affected soil microbial compositions of both bacteria and fungi. Soil used for soybean cultivation showed the highest relative abundance for Verrucomicrobia, Planctomycetes, and Acidobacteria but Actinobacteria and Firmicutes had the lowest relative abundance. In the case of soil used for potato cultivation, Actinobacteria had the highest relative abundance but Proteobacteria had the lowest relative abundance. Armatimonadetes showed the highest relative abundance in soil used for cabbage cultivation. Among the fungal communities, Mortierellomycota had the highest relative abundance for soybean cultivation but the lowest relative abundance for cabbage cultivation; further, Rozellomycota, Chytridiomycota, and Cercozoa had the highest relative abundance for cabbage cultivation. Basidiomycota had the highest relative abundance for potato cultivation but the lowest relative abundance for soybean cultivation.

To develop eco-friendly microbial inoculants, siderophore-producing bacteria were isolated and identified, and their production characteristics and plant growth-promoting abilities were investigated. A strain S21 was isolated from rhizosphere of Korean perilla (Perilla frutescens) and identified as Enterobacter amnigenus by phenotypic properties and 16S rRNA gene sequencing. The highest siderophore production was obtained in a medium containing 0.5% fructose, 0.1% urea, 0.5% K2HPO4 and 0.1% succinic acid. By using this improved medium, siderophore production increased by 2.5 times compared to that of basal medium. The strain S21 showed insoluble phosphate solubilizing, ammonification and antifungal activities, and also produced hydrolytic enzymes (protease and lipase), indoleacetic acid and 1-aminocyclopropane-1-carboxylate deaminase. Our data suggest that E. amnigenus S21 is a potential candidate that can be used as eco-friendly biocontrol agent and biofertilizer.

생물체의 활동 특히 미생물의 활동은 직·간접적으로 전 지구적으로 분포하는 퇴적물 및 암석 내부 광물의 형성 및 변형에 영향을 주고, 일부는 특징적인 생물기원구조를 형성한다. 특히, 특징적인 생물기원구조에 분포하는 광물은 기존에 알려진 무기적 과정을 통하여 형성되기 어려운 환경에서 형성되기도 하고, 무기적 과정을 통하여 형성된 광물과는 다른 물성 및 특성을 나타낸다. 이러한 생물체의 영향을 받아 형성된 생물기원구조에 대해 연구·분석하는 것은 새로운 광물 형성 메커니즘을 규명하는데 필수적이라 할 수 있다. 따라서 본 논문은 심해저 망간각 및 해저열수분출공 지역 미생물 매트 시료를 예로 들어, 주사전자현미경 분석을 통한 자연환경에 분포하는 생물기원구조 관찰에 대해 소개하고 분석방법, 장점 및 활용에 대해 설명하고자 한다.

In this study, we investigated culturable bacterial abundance in various crops. Total culturable aerobic bacteria in tomato plants were enumerated on NA and it showed that the amounts of viable bacterial cells were changed among the different parts of the plants (roots, stems, and fruits), ranging between log 1 and 4 per g sample. To investigate the bacterial abundance dynamics in different crops, culturable aerobic bacterial cell numbers were enumerated on NA and compared between the samples (tomato fruit, sesame leaf, and green onion) harvested freshly from one field trial (Yangsan, Korea). In this trial, the number of total culturable aerobic bacteria of the samples were 8 times higher in sesame leaves and green onions compared to the tomato fruits in the field. Interestingly, culturable aerobic bacteria on MRS were only found in sesame leaves, whereas lactic acid bacteria were not detected in tomato fruit and green onion samples in this field. We also found that the field location (Yangsan, Gangneung, or Busan) influenced the number of culturable aerobic bacteria on the surface of the crops. Tomato samples freshly harvested from the different field locations were tested and showed that the amounts of culturable aerobic bacteria on NA and MRS agar were significantly different based on the field locations of the samples. Finally, lactic acid bacteria were isolated from all the tomato and sesame leaf samples used in this study, showing 20 and 28 morphological diversity. With these isolates, we will be able to conduct further biological and functional investigation to develop a new probiotic strain originated from the crops in Korea.

Agricultural practices are known to have a crucial influence not only on soil physico-chemical properties but also on microbial communities. To investigate the effect of farming practices on soil microbial communities, a total of 10 soil samples were collected, including five conventional and five organic farming soils cultivated with peppers in plastic greenhouse. We conducted barcorded-pyrosequencing of V1-V3 regions of 16S rRNA genes to examine soil microbial communities of two different farming practices. Taxonomic classification of the microbial communities at the phylum level indicated that a total of 22 bacterial phyla were present across all samples. Among them, seven abundant phyla (>3%) including Proteobacteria, Actinobacteria, Firmicutes, Acidobacteria, Bacteroidetes, Chloroflexi, and Gemmatimonadetes were found, and Proteobacteria (33.0 ± 5.7%), Actinobacteria (19.9 ± 9.7%), and Firmicutes (13.6 ± 5.0%) comprised more than 66% of the relative abundance of the microbial communities. Organic farming soils showed higher relative abundances of Proteobacteria and Firmicutes, while Actinobacteria and Chloroflexi were more abundant in conventional farming soils. Notably, the genera Bacillus (higher in organic farming soils) and Streptomyces (higher in conventional farming soils) exhibited significant variation in relative abundance between organic and conventional farming soils. Finally, correlation analysis identified significant relationships (p<0.05) between soil chemical properties, in particular, pH and organic matter content and microbial communities. Taken together, this study demonstrated that the changes of soil physico-chemical properties by agricultural farming practices effected significantly (p<0.05) on soil microbial communities.

This study was conducted to investigate the responses of soil properties and microbial communities to different agricultural management and soil types, including organic management in Andisols (Org-A), organic management in Non-andisols (Org-NA), conventional management in Andisols (Con-A) and conventional management in Non-andisols (Con-NA) by using a pyrosequencing approach of 16S rRNA gene amplicon in Radish farms of volcanic ash soil in Jeju island. The results showed that agricultural management systems had a little influence on the soil chemical properties but had significant influence on microbial communities. In addition, soil types had significant influences on both the soil chemical properties and microbial communities. Organic farming increased the microbial density of bacteria and biomass C compared to conventional farming, regardless of soil types. Additionally, Org-NA had the highest dehydrogenase activity among treatments, whereas no difference was found between Org-A, Con-A and Con-NA and had the highest species richness (Chao 1) and diversity (Phyrogenetic diversity). Particularly, Chao 1 and Phyrogenetic diversity were increased in organic plots by 12% and 20%, compared with conventional plots, respectively. Also, regardless of agricultural management and soil types, Proteobacteria was the most abundant bacterial phylum, accounting for 21.9-25.9% of the bacterial 16S rRNAs. The relative abundance of putative copiotroph such as Firmicutes was highest in Org-NA plot by 21.0%, as follows Con-NA (13.1%), Con-A (6.7%) and Org-A (5.1%.), respectively and those of putative oligotrophs such as Acidobacteria and Planctomycetes were higher in Con-A than those in the other plots. Furthermore, LEfSe indicated that organic system enhanced the abundance of Fumicutes, while conventional system increased the abundance of Acidobacteria, especially in Non-andisols. Correlation analysis showed that total organic carbon (TOC) and nutrient levels (e.g. available P and exchangeable K) were significantly correlated to the structure of the microbial community and microbial activity. Overall, our results showed that the continuous organic farming systems without chemical materials, as well as the soil types made by long-term environmental factors might influence on soil properties and increase microbial abundances and diversity.

The purpose of this study was to evaluate the effect of high-salinity wastewater on the microbial activity of Aerobic Granule Sludge (AGS). Laboratory-scale experiments were performed using a sequencing batch reactor, and the Chemical Oxygen Demand (COD), nitrogen removal efficiency, sludge precipitability, and microbial activity were evaluated under various salinity injection. The COD removal efficiency was found to decrease gradually to 3.0% salinity injection, and it tended to recover slightly from 4.0%. The specific nitrification rate was 0.043 0.139 mg NH4 +-N/mg MLVSS·day. The specific denitrification rate was 0.069 0.108 mg NO3 --N/mg MLVSS·day. The sludge volume index (SVI30) ultimately decreased to 46 mL/g. The specific oxygen uptake rate decreased from an initial value 120.3 to a final value 70.7 mg O2/g MLVSS·hr. Therefore, salinity injection affects the activity of AGS, causing degradation of the COD and nitrogen removal efficiency. It can be used as an indicator to objectively determine the effect of salinity on microbial activity.

Ginseng, the root of the Panax ginseng, has been widely used as a traditional herbal medicine in Korea, China, and Japan for thousands of years. Now ginseng has become popular as functional health food and natural medicine and it is one of the bestselling natural products in the world. Gut microbiota has been found to play an important role in the metabolism and pharmacological action of orally administered ginseng. Recent animal and clinical studies have shown that compound K (20-O -beta-D-glucopyranosyl-20(S)-protopanaxadiol, CK) is the major ginsenoside metabolite deriving from gut microbiota-induced biotransformation and is more efficiently absorbed into the systemic circulation than its parent ginsenosides. Since ginsenoside metabolism varies between individuals depending on the population of gut microbiota, much attention paid to the transformation of major ginsenosides into more pharmacologically active ginsenosides using diverse methods including heating, acid hydrolysis, microbial conversion, and enzymatic treatment. Recently, in food and drug industry and academia, the development of fermented ginseng products using probiotic bacteria is being intensively studied due to the potential health benefits of ginsenoside metabolites and probiotics. This review summarizes recent studies on the metabolism of ginsenoside by gut microbiota and biotransformation of ginsenoside using lactic acid bacteria and their enzymes.

금속을 함유하고 있는 산업폐자원과 관련한 재활용 기술을 개발하기 위해 다양한 접근이 시도되고 있으며, 그 중에서 유리는 미생물로 분해되지 않기 때문에 매립은 적합하지 않아 폐유리의 재활용에 대한 관심은 증대되고 있다. 따라서 본 논문에서는 폐유리를 잔골재로 사용하고 폐유리의 중금속 용출을 억제하기 위한 킬레이트 수지를 혼입함으로써, 차폐 채움재의 강도, 건조수축, 알칼리-실리카반응, 중금속 용출 등을 평가하여 폐유리를 경제적이며 환경 친화적인 차폐 채움재로서 활용하기 위한 기초자료를 제시하고자 한다. 시험결과, 폐유리를 잔골재로 사용하였을 경우 강도 발현에 효과적이었으며, 킬레이트 수지를 혼입하였을 경우 강도 발현에 영향이 있는 것으로 나타났다. 또한 킬레이트 수지를 혼입하였을 경우 건조수축의 개선에는 효과적이었으나 알칼리-실리카반응에 영향을 미치는 것으로 나타났다. 중금속 용출 시험결과, 한국 KSLP 시험법에서는 중금속 용출 허용 기준치를 모두 만족하였으나, 납의 경우 미국 ANSI 67-2007a의 허용 기준치를 초과하여 이에 대한 추가적인 연구가 진행되어야 할 것으로 판단되었다.

The aim of this study was to investigate the effect of hazard analysis and critical control point (HACCP) system application on microbial hazard management levels of pork and manufacturing environments. In this study, we compared and analyzed microbial levels in raw meat, finished products, and manufacturing environments (knifes, gloves, and cutting boards) of HACCP and non-HACCP meat markets. In addition, we surveyed the hygiene statuses of HACCP and non-HACCP meat markets. The general bacterial counts in raw meat, finished products, and manufacturing environments were lower in HACCP meat markets than in non-HACCP meat markets. Particularly, non-HACCP meat markets exceeded the Ministry of Food and Drug Safety microbiological recommendation criteria for raw meats (8.7%) and finished products (8.7%). Escherichia coli and coliform counts in raw meat, finished products, and manufacturing environments were also lower in HACCP meat markets than in non-HACCP meat markets. The biological hazard levels of finished products from non-HACCP meat markets were affected by raw meat and manufacturing environment. Moreover, according to questionnaire survey results, personal hygiene, manufacturing environment, and facility standards were lower in non-HACCP meat markets than in HACCP meat markets. Implementation of HACCP at meat markets is expected to minimize food poisoning by reducing the biological hazard levels to provide safe livestock products to consumers.

In this study, basic research was carried out to improve the absorption rate which is a problem in increasing the recycling rate of recycled fine aggregate and to improve the usability as concrete aggregate. It was confirmed that the absorption rate of the recycled aggregate measured after immersing in the microbial culture solution for the purpose of improving the absorption rate of the circulating fine aggregate for concrete was decreased. However, further studies such as improvement of microbial culture are required to satisfy KS standards.

In this study, the crack healing performance of concrete containing microbial - based self - healing agent for the purpose of crack crack healing was evaluated by the permeability test. As a result of the addition of the microbial culture solution to the mixed water at an alternative ratio, the permeability recovery rate increases as the substitution rate increases. It is necessary to develop a microbial concentrate and to study the application of mixed microorganisms for the purpose of increasing the rate of permeability recovery and decreasing the substitution rate of microbial solution.

As a method to improve the water purification performance of porous concrete through existing studies, it has been analyzed how to substitute effective microorganisms at a certain rate for use or immersing porous concrete in a culture solution. In this study, we tried to compare and analyze the viability of microbial cells after mixing spherical microbial cells with useful microbes and natural materials in order to more easily apply high - concentration microbes.