• Title/Summary/Keyword: Microbial Indicator

Search Result 127, Processing Time 0.029 seconds

Chemical and Biological Indicators of Soil Quality in Conventional and Organic Farming Apple Orchards

  • Lee, Yoon-Jung;Chung, Jong-Bae
    • Journal of Applied Biological Chemistry
    • /
    • v.50 no.2
    • /
    • pp.88-96
    • /
    • 2007
  • Organic farming systems based on ecological concepts have the potential to produce sustainable crop yields with no decline in soil and environmental qualities. Recent expansion of sustainable agricultural systems, including organic farming, has brought about need for development of sustainable farming systems based on value judgments for key properties of importance for farming. Chemical and microbiological properties were chosen as indicators of soil quality and measured at soil depth intervals of 5-20 and 20-35 cm in conventional and organic-based apple orchards located in Yeongchun, Gyeongbuk. The orchards were two adjacent fields to ensure the same pedological conditions except management system. Soil pH in organic farming was around 7.5, whereas below 6.0 in conventional farming. Organic farming resulted in significant increases in organic matter and Kjeldahl-N contents compared to those found with conventional management. Microbial populations, biomass C, and enzyme activities (except acid phosphatase) in apple orchard soil of organic farming were higher than those found in conventional farming. Higher microbial quotient ($C_{mic}/C_{org}$ ratio) and lower microbial metabolic quotient for $CO_2(qCO_2)$ in organic farming confirmed that organic farming better conserves soil organic carbon. Biological soil quality indicators showed significant positive correlations with soil organic matter content. These results indicate organic-based farming positively affected soil organic matter content, thus improving soil chemical and biological qualities.

Effects of Continuous Application of Green Manures on Microbial Community in Paddy Soil

  • Kim, Sook-Jin;Kim, Kwang Seop;Choi, Jong-Seo;Kim, Min-Tae;Lee, Yong Bok;Park, Ki-Do;Hur, Seonggi
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.48 no.5
    • /
    • pp.528-534
    • /
    • 2015
  • Green manure crops have been well recognized as the alternative for chemical fertilizer, especially N fertilizer, because of its positive effect on soil and the environment. Hairy vetch and green barley are the most popular crops for cultivation of rice in paddy field. This study was conducted to evaluate effects of hairy vetch and green barley on soil microbial community and chemical properties during short-term application (three years). For this study, treatments were composed of hairy vetch (Hv), green barley (Gb), hairy vetch + green barley (Hv+Gb), and chemical fertilizer without green manure crops (Con.). Hv+Gb treatment showed the highest microbial biomass among treatments. Principal component analysis (PCA) showed that PC1 (73.0 %) was affected by microbial biomass and PC2 (21.5 %) was affected by fungi, cy19:0/18:$1{\omega}7c$ (stress indicator). Combined treatment with hairy vetch and green barley could be more efficient than green manure crop treatment as well as chemical fertilizer treatment for improvement of soil microorganisms.

Characteristics of Microbial Community Enzyme Activity and Substrate Availability of Damaged Soil (훼손 토양의 미생물군집 효소 활성과 기질 이용성 특성)

  • Ji Seul Kim;Gyo-Cheol Jeong;Myoung Hyeon Cho;Eun Young Lee
    • Journal of Soil and Groundwater Environment
    • /
    • v.28 no.5
    • /
    • pp.68-77
    • /
    • 2023
  • The effect of soil damage on the physicochemical characteristics and activity of the soil microbial community is not well known. This study investigates this relationship by analyzing 11 soil samples collected from various points of soil damage across Gyeonggi-do. Soil damage resulted from forest fires, landslides, and development areas, with their impacts most severe on the topsoil layer (0-30 cm). Dehydrogenase and β-glucosidase activities were notably higher at locations damaged by forest fires compared to other sites. While enzyme activities in soils influenced by landslides and development areas were relatively low, sites with a pollution history exhibited elevated dehydrogenase activity, likely due to past microbial response to the pollution. Additionally, an assessment of carbon substrate usability by soil microorganisms indicated higher substrate availability in areas impacted by forest fires, contrasting with lower availability in landslide and development sites. Statistical analysis revealed a positive correlation between organic content of sand and clay and microbial activity. These findings provide valuable insights into soil damage and associated restoration research, as well as management strategies.

Assessment of Compost Maturity on Their Different Stages with Microbial and Biochemical Mass Dynamics (미생물 및 생화학적 질량역적분석에 의한 퇴비화단계별 부숙도 평가)

  • Suresh, Arumuganainar;Choi, Hong Lim;Yao, Hongqing;Zhu, Kun
    • Journal of the Korea Organic Resources Recycling Association
    • /
    • v.17 no.4
    • /
    • pp.36-47
    • /
    • 2009
  • Microbial and related biochemical mass of composts are important for optimization of its process and end-products. This study was carried out to assess the specific microbial and related biochemical mass which could be used as an indicator for compost maturity during composting stages. The samples from five compost plants were collected at three stages (Initial, Thermophilic and Mature) and analyzed for total aerobic bacteria (TAB), Coliforms, Escherichia coli, Actinomycetes and fungi. Significantly, the coliforms and E.coli counts decreased during the thermophilic stage and were completely eliminated during mature stage. However, the other microbial mass were completely eliminated during mature stage. Which disclosed that Coliforms and E.coli communities can be used as compost maturity indicator. Interestingly, the microbial biomass carbon and nitrogen ratio (MBC/MBN) were decreased a little during the thermophilic stage due to the decreasing number of coliforms, Ecoli and fungi, while the ratio increased during the mature stage due to increasing fungal and aerobic bacterial counts. In addition the heavy metals were shown strong negative correlation with Actenomycetes. This study provides insight to the evaluation of compost maturity as well as the quality by the metal-microbial interactions.

  • PDF

Comparison between DNA- and cDNA-based gut microbial community analyses using 16S rRNA gene sequences (16S rRNA 유전자 서열 분석을 이용한 DNA 및 cDNA 기반 장내 미생물 군집 분석의 비교)

  • Jo, Hyejun;Hong, Jiwan;Unno, Tatsuya
    • Korean Journal of Microbiology
    • /
    • v.55 no.3
    • /
    • pp.220-225
    • /
    • 2019
  • Studies based on microbial community analyses have increased in the recent decade since the development of next generation sequencing technology. Associations of gut microbiota with host's health are one of the major outcomes of microbial ecology filed. The major approach for microbial community analysis includes the sequencing of variable regions of 16S rRNA genes, which does not provide the information of bacterial activities. Here, we conducted RNA-based microbial community analysis and compared results obtained from DNA- and its cDNA-based microbial community analyses. Our results indicated that these two approaches differed in the ratio of Firmicutes and Bacteroidetes, known as an obesity indicator, as well as abundance of some key bacteria in gut metabolisms such as butyrate producers and probiotics strains. Therefore, cDNA-based microbial community may provide different insights regarding roles of gut microbiota compared to the previous studies where DNA-based microbial community analyses were performed.

Sanitary Microbial Distribution at the Tomato Farms in Western Gyeongnam (서부 경남지역 토마토 농장에서의 위생 미생물의 분포)

  • Kim Jin-Soo;Shim Won-Bo;Kim Ji-Hun;Kim Se-Ri;Chung Duck-Hwa
    • Journal of Environmental Health Sciences
    • /
    • v.32 no.1 s.88
    • /
    • pp.77-88
    • /
    • 2006
  • This study were conducted to investigate the microbial contamination level in 5 tomato farms in Western Gyeongnam. A total of 130 samples was examined for sanitary indicator bacteria, such as aerobic plate count (APC), coliforms, and Escherchia coli, and pathogenic bacteria such as E. coli O157:H7, Salmonella spp., Staphylococcus aureus, and Listeria monocytogenes. APC and coliform count ranged $0\~6.62\;and\;0\~4.52 log_{10}\;CFU/(ml,\;g,\;100\;cm^2,\;hand)$, respectively, and $32.5\%$ were contaminated with E. coli. Especially, most of the samples from employees are high as above $4.0\;log_{10}\;CFU/(ml,\;g,\;100\;cm^2,\;hand)$ in APC. S. aureus, detected at $10.7\%$, was found in employees' hands, irrigation water, and hydroponic solution. whereas E. coli $O157:H7$, Salmonella spp, and L. monocytogenes were not detected. These results will provide fundamental microbiological information for introduction of good agricultural practice (GAP)system in tomato farms.

Changes of Microbial Populations on Major Leafy Vegetables Cultivated by Different Methods from Production to Washing Stages (재배방법별 주요엽채류의 생산단계에서 세척단계까지 미생물상의 변화)

  • Oh, Soh-Young;Nam, Ki-Woong;Yoon, Deok-Hoon
    • Journal of Food Hygiene and Safety
    • /
    • v.33 no.1
    • /
    • pp.38-43
    • /
    • 2018
  • A few authors have already investigated microbial contamination of leafy vegetables in distribution condition and examined the effect of temperature abuse on microbial safety or product quality. But this study analyzed proliferation of indicator microorganisms and food poisoning bacteria in real situation in Korean agroindustry and investigated washing effect of micobial contamination on leaf surface. Leafy vegetables were found to be contaminated with aerobic bacteria at $0.1{\sim}0.32{\times}10^3CFU/g$. Staphylococcus aureus and Bacillus cereus were detected in leafy vegetables at $0{\sim}0.54{\times}10^3CFU/g$. However, Salmonella spp., Coliforms, Clostridium spp. and Listeria spp. were not detected in any samples. Indicator microorganisms and food poisoning bacteria on leafy vegetables increased at room temperature when simulatively distributed condition. After clean-up, the indicator microorganisms and food poisoning bacteria of kimchi cabbage, lettuce and perilla leaf were decreased to a very low level. This study suggests that it is necessary to improve the level of hygiene management such as use of cold chain system and hygiene management of transport tools during the distribution process for fresh leafy vegetables.

Analysis of Pathogenic Microorganism's Contamination on Organic Leafy Vegetables at Greenhouse in Korea (유기농 시설엽채류의 유해미생물 오염평가)

  • Oh, Soh-Young;Nam, Ki-Woong;Yoon, Deok-Hoon
    • Journal of Food Hygiene and Safety
    • /
    • v.33 no.1
    • /
    • pp.31-37
    • /
    • 2018
  • This study was conducted to evaluate the microbiological safety of leafy vegetables (perilla leaf and lettuce) in relation to cultivation methods. A total of 2,304 samples were collected from plants, harvesting tools and soil mulching film during the production and harvest stages from organic- and conventional- farms. From the samples, sanitary indicator microorganisms (total aerobic bacteria, coliforms, E. coli., Environmental Listeria, and yeast and mold) and pathogenic microorganisms (S. aureus, B. cereus, Salmonella spp., Clostridium spp., and L. monocytogenes) were analyzed. In the production stage of leafy vegetables, the sanitary indicator microorganisms was not detected regardless of cultivation method or it was detected to be less than $3.4\;Log\;CFU/100cm^2$. B. cereus and S. aureus were found to be 0.22~1.55 Log CFU/g in perilla leaf and lettuce produced by organic farms, and S. aureus was not detected and B. cereus was found to be 0.42~2.19 Log CFU/g in conventional farms. There were no significant differences between two cultivation methods. In the harvesting tools and soil mulching film, the contamination levels of sanitary indicator microorganisms and pathogenic microorganisms was low regardless of the cultivation method. However, there was a positive correlation ($R^2=0.4526$) in that the higher the microbial contamination level in the harvesting tool, the higher the microbial contamination on the surface of the plant. In addition, sanitary indicator microorganisms and pathogenic microorganisms were not detected or low in soil mulching during the production of organic leafy vegetables. As a result of this study, microbial hygiene control by soil mulching and harvesting tools was more important than difference of cultivation method in production of leafy vegetables.

Analysis of Microbial Contaminants and Microbial Changes during Dried-laver Pyropia spp. Processing (마른김(Pyropia spp.) 가공 공정 경과에 따른 미생물 오염도 분석)

  • Kwon, Kion;Ryu, Dae-Gyu;Jeong, Min-Chul;Kang, Eun-Hye;Jang, Yumi;Kwon, Ji Young;Kim, Jeong-Mok;Shin, Il-Shik;Kim, Young-Mog
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.51 no.1
    • /
    • pp.8-14
    • /
    • 2018
  • We investigated the levels of microbial contaminants and microbial hazards during dried-laver processing. We analyzed 321 samples obtained from 18 dried-laver Pyropia spp. manufacturing facilities, including water, swab-, and processing samples as well as final products. The levels of microbial contaminants, including viable cell counts (VCC) and coliform bacteria, increased as processing progressed. The sanitary indicator bacterium, Escherichia coli, was not detected in the final products although VCC levels were high, generally exceeding 5 log CFU/g. We also investigated changes in microbial contaminants at each processing step. Both VCC and total coliform dramatically increased after 4 days of continuous processing, indicating that microbial contaminants originated, mainly, from cross contamination during processing.

Investigation of Microbiological and Physiochemical Quality for Irrigation Water used in Napa Cabbage Cultivation (배추 재배에 이용되는 농업용수의 미생물 오염도 조사 및 이화학성분 분석)

  • Yun, Bohyun;Kim, Min Kyung;Ryu, Jin Hee;Kim, Won-Il;Park, Byeong-Yong;Kim, Hyun-Ju;Lee, Seung-Don;Kim, Se-Ri
    • Journal of Food Hygiene and Safety
    • /
    • v.32 no.5
    • /
    • pp.396-403
    • /
    • 2017
  • The purpose of this study was to investigate water quality for irrigation water used in Napa cabbage cultivation. The water samples were analyzed for physiochemical and microbiological quality for a total of 111 samples including surface water (n = 75) and groundwater (n = 36) collected from five different regions where Napa cabbage is massively grown. As a conclusion, the levels of fecal indicators for surface water were higher than those for groundwater. The numbers of coliform from surface water and groundwater were 1.96-4.96 and 0-3.98 log MPN/100 mL, respectively. Enterococci were detected in 95% (72/75) of surface water samples and 22% (8/36) of groundwater samples. Besides, 97% (73/75) of surface water samples were observed being contaminated with Escherichia coli, and 22% (8/36) of groundwater sample was positive for E. coli. In the case of surface water, E. coli and coliform correlate to T-P, and enterococci showed relevance to the suspended solid (SS) and biochemical oxygen demand (BOD). In groundwater, fecal indicator bacteria showed relevance to the SS and chemical oxygen demand (COD). These results could be provided as fundamental date for establishing microbial standard of water used in leafy vegetables cultivation.