• Title/Summary/Keyword: bacterial sp

Search Result 807, Processing Time 0.022 seconds

Production and Structural Analysis of Cellulose by Acetobacter sp. V6 Using Static Culture (정치배양을 이용하여 Acetobacter sp. V6의 셀룰로오스 생산 최적화 및 구조 분석)

  • Kim, Jeong-Do;Jung, Ho-Il;Jeong, Jin-Ha;Park, Ki-Hyun;Jeon, Young-Dong;Hwang, Dae-Youn;Lee, Chung-Yeol;Son, Hong-Joo
    • Korean Journal of Microbiology
    • /
    • v.45 no.3
    • /
    • pp.275-280
    • /
    • 2009
  • The optimal medium compositions for the production of bacterial cellulose (BC) by a Acetobacter sp. V6, which was isolated from the traditionally fermented vinegar in Korea, were investigated in static cultures. The optimum medium compositions for BC production were 3% glucose, 3% soytone, 0.8% $K_2HPO_4$, and 0.4% ethanol, respectively. Adding $NaH_2PO_4$ or $KH_2PO_4$ had not shown the increase in BC production. Under the optimum medium compositions, the highest BC production was 44.67 g/$m^2$ in 8 days and the thickness of BC pellicle was about 1 cm. Structural properties of BC produced in the optimal medium were studied using Fourier-transform infrared spectroscopy and X-ray diffractometer. BC from the optimal medium was found to be of cellulose type I, the same as typical native cellulose. No difference in the compositions between bacterial and plant celluloses, but BC showed unique micro-network structure and high crystallinity (82%).

Optimization of Culture and Sporulation for Two Plant Beneficial Streptomyces Strains (식물 유용 방선균 2종의 배양 및 포자생성 최적화 조건 탐색)

  • Da-Ran Kim;Youn-Sig Kwak
    • Research in Plant Disease
    • /
    • v.29 no.2
    • /
    • pp.174-183
    • /
    • 2023
  • The limited effectiveness of current plant disease management treatments necessitates the development of new methods for controlling diseases using beneficial microbes. Demanding sustainable agriculture is increasingly highlighted as a biocontrol approach, particularly Streptomyces species known to produce a variety of antibiotic compounds and secondary metabolites. The Streptomyces globisporus SP6C4 strain and Streptomyces sp. S8 have been reported as potent antifungal agents and are gaining attention for improving crop growth in sustainable agriculture. In this study, we investigated the use of Streptomyces species formulations to enhance bacterial growth with nitrogen sources. Specifically, the addition of L-glutamic acid and L-cysteine resulted in earlier sporulation and bacterial growth in Streptomyces strains, respectively. This approach could expand the range of fermentation techniques in agriculture and be useful for controlling plant growth-promoting bacteria.

Denaturing Gradient Gel Electrophoresis and Culture-based Analysis of the Bacterial Community in Cheonggukjang, a Korean Traditional Fermented Soybean Food from Gangwon Province (DGGE 방법과 배양법을 이용한 강원지역 전통 발효 청국장에서 미생물의 다양성 분석)

  • Hong, Sung Wook;Lim, In Kyu;Kim, Yong Woo;Shin, Seung-Mee;Chung, Kun Sub
    • Korean Journal of Food Science and Technology
    • /
    • v.45 no.4
    • /
    • pp.515-520
    • /
    • 2013
  • Bacterial communities derived from cheonggukjang and raw rice straw collected from a Mireuksan farm and a Heungup cheonggukjang in Gangwon province were investigated using both culture-based method and denaturing gradient gel electrophoresis (DGGE) analysis. Pure cultures, which were isolated from raw rice straw and cheonggukjang and cultured on tryptic soy agar plates (53-76 colonies per plate), were identified by analysis of 16S rRNA sequences. The traditional culture-based method and analysis of PCR-amplified 16S rRNA by DGGE revealed that for samples collected from the Mireuksan farm, Pantoea agglomerans and Bacillus subtilis were the predominant species in the raw rice-straw and cheonggukjang, respectively. For samples collected from the Heungup cheonggukjang, Bacillus amyloliquefaciens was the predominant species in both raw rice straw and cheonggukjang. Other microorganisms, including members of Pantoea, Bacillus, Enterococcus, Enterobacter, Pseudomonas, Rhodococcus, and Acinetobacter, were also present in the raw rice-straw and cheonggukjang, as were bacteria that could not be cultured.

The First Study on Bacterial Flora and Biological Control Agent of Anoplus roboris (Sufr., Coleoptera)

  • Demirbag, Zihni;Sezen, Kazim;Demir, Ismail
    • Journal of Microbiology
    • /
    • v.40 no.2
    • /
    • pp.104-108
    • /
    • 2002
  • The hazelnut leaf holer (Anoplus roboris Sufr,, Coleoptera: Curculionidae) is a devastating pest of hazelnut and oak trees. It causes approximately 20-30% economic damage to hazelnut production per year in Turkey. In the present study, in order to fond a more effective and safe biological control agent against A. roboris, we investigated the bacterial flora of the hazelnut leave holer, and tested them for insecticidal effects on it. According to morphological, physiological and biochemical tests bacterial flora were identified as Bacillus circulans (Ar1), Bacillus polymyxa (Ar2), Enterobacter sp. (Ar3) and Bacillus sphaelicus (Ar4). Insecticidal effects of bacterial isolates were performed on adult A. roboris. The highest insecticidal effect determined was 67% by B. sphaericus within eight days. The insecticidal effects of the other isolates (Ar1, Ar2 and Ar3) were determined as 33%, 47% and 47% within the same period, respectively.

Isolation of a Phenol-degrading Bacterial Strain and Biological Treatment of Wastewater Containing Phenols (Phenol 분해균주의 분리 및 페놀함유 폐수의 생물학적 처리)

  • Lee, Hyun Don;Lee, Myoung Eun;Kim, Hyung Gab;Suh, Hyun-Hyo
    • Journal of Life Science
    • /
    • v.23 no.10
    • /
    • pp.1273-1279
    • /
    • 2013
  • Aromatic hydrocarbons, such as phenol, have been detected frequently in wastewater, soil, and groundwater because of the extensive use of oil products. Bacterial strains (56 isolates) that degraded phenol were isolated from soil and industrial wastewater contaminated with hydrocarbons. GN13, which showed the best cell growth and phenol degradation, was selected for further analysis. The GN13 isolate was identified as Neisseria sp. based on the results of morphological, physiological, and biochemical taxonomic analyses and designated as Neisseria sp. GN13. The optimum temperature and pH for phenol removal of Neisseria sp. GN13 was $32^{\circ}C$ and 7.0, respectively. The highest cell growth occurred after cultivation for 30 hours in a jar fermentor using optimized medium containing 1,000 mg/l of phenol as the sole carbon source. Phenol was not detected after 27 hours of cultivation. Based on the analysis of catechol dioxygenase, it seemed that catechol was degraded through the meta- and ortho-cleavage pathway. Analysis of the biodegradation of phenol by Neisseria sp. GN13 in artificial wastewater containing phenol showed that the removal rate of phenol was 97% during incubation of 30 hours. The removal rate of total organic carbon (TOC) by Neisseria sp. GN13 and activated sludge was 83% and 78%, respectively. The COD removal rate by Neisseria sp. GN13 from petrochemical wastewater was about 1.3 times higher than that of a control containing only activated sludge.

Isolation, Identification and Biological Control Activity of SKU-78 Strain against Ralstonia solanacearum (풋마름병균, Ralstonia solanacearum의 길항세균 SKU-78 균주의 분리 동정 및 특성)

  • Sung, Pil-Je;Shin, Jeong-Kun;Cho, Hong-Bum;Kim, Shin-Duk
    • Applied Biological Chemistry
    • /
    • v.48 no.1
    • /
    • pp.48-52
    • /
    • 2005
  • Six stains of plant growth promoting rhizobacteria were selected through germinating seed assay and root colonization assay. Among them, SKU-78 strain induced significant suppression of bacterial wilt disease in tomato and pepper plants. Seed treatment followed by soil drench application with this strain resulted in over 60% reduction of bacterial wilt disease compared with the control. It was suggested that SKU-78 strain activated the host defense systems in plants, based on lack of direct antibiosis against pathogen. According to Bergey's Manual of Systemic Bacteriology and 16S rDNA sequence data, SKU-78 stain was identified as Bacillus sp. SKU-78.

Preliminary Study on the Use of Bacillus sp., Vibrio sp. and Egg White to Enhance Growth, Survival Rate and Resistance of Penaeus monodon Fabricius to White Spot Syndrome Virus

  • Yusoff, F.M.;Shariff, M.;Lee, Y.K.;Banerjee, S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.14 no.10
    • /
    • pp.1477-1482
    • /
    • 2001
  • Research in low cost feeds with high nutritional value and immunogenicity is important to reduce production cost and increase yields in the shrimp industry. In this study, immunostimulants of bacterial origin (peptidoglycan and lipopolysaccharides) and egg white were incorporated in shrimp diets as feed additives to determine the growth, survival and tolerance of Penaeus monodon to white spot syndrome virus (WSSV). Although the results obtained were not statistically significant (p>0.05) among the treatments, shrimp fed with bacterial additives and egg white showed higher weight gain, specific growth rate and survival than those fed on commercial shrimp diet. Shrimp fed with artificial diet showed 100% mortality when challenged with WSSV. However, shrimp fed on peptidoglycan supplemented diet had higher survival than their counterpart, whereas shrimp fed on egg white supplemented diet had a higher specific growth rate and better tolerance when challenged with WSSV. Further studies are required to determine the effectiveness and optimization of bacterial strains and egg white as feed additives to increase production and enhance the shrimp immune response to diseases.

Preservation of Takju by Pasteurization (저온살균법에 의한 탁주의 보존성 증진)

  • 배상면;김헌진;고영희;오태광
    • Microbiology and Biotechnology Letters
    • /
    • v.18 no.3
    • /
    • pp.322-325
    • /
    • 1990
  • During transportation and preservation of Takju, alcohol fermentation has continued to produce $C0_2$ from residual sugar and frequently spoiled owing to bacterial contaminants wich produce organic acids. The authors could preserve Takju for more than 50 days at room temperature by pasteurization without any changes of quality. For the optimal condition of pasteurization, fresh Takju was heated at various temperatures and times. D-Value of the Saccharomyces sp. which isolated from Takju collected at seoul area was 19 see at $55^{\circ}C$. Non-spore forming bacterial contaminants, most of which known to cause acid-spoilage, were decreased when heated at $55^{\circ}C$ for 5 min. The optimal pasteurization condition of Takju was at $55^{\circ}C$ for 10 min. Spore forming bacterial contaminants, considered to be EuciiLw sp., were not sterilized after pasteurized at the optimal condition. However, the spore-forming bacteria could not increase any more and also not cause increment of acidity during preservation even at room temperature for 50 days. Reducing sugar was increased during storage of Takju after pasteurization. This suggests that the residual glucoamylase in Takju is still active after pasteurizsation and keep sweet taste.

  • PDF

Development of Microbial Bioassay for Detection of Pesticide Residues (미생물을 이용한 농약잔류 분석법 개발)

  • 백수봉;양창술;오연선
    • Korean Journal Plant Pathology
    • /
    • v.10 no.4
    • /
    • pp.297-304
    • /
    • 1994
  • This study was carried out to develop bioassay for detection of pesticide residues in agricultural products by using the soil microbial isolates sensitive to pesticides. One hundred bacterial isolates and eighty five fungal isolates were obtained from soil and their sensitivity to 10 ppm of several pesticides was examined in vitro. Five bacterial isolates and three fungal isolates were found sensitive to organochloride fungicide and two fungal isolates sensitive to organocopper fungicide. Among these isolates, B46, B93 and F67 were tested to find out the difference in sensitivity according to the methods of fungicide treatment. All of the isolates were found sensitive to 10 ppm of organochloride fungicides mixed directly in PDA. But they were found insensitive to the fungicide mixed in PDA after filtering through membrane filter. In case of organocopper fungicide, the isolates were found sensitive only when it was treated in PDA. And their sensitivity showed difference among various kinds of organochloride fungicides. B46 and B93 were employed to check the possibility as the agent for detection of the pesticidal residues in twenty eight agricultural products including rice. It was found that all samples had not residues because the samples did not inhibit the growth of isolates. When organochloride fungicides were applied to the above products, it was possible to detect the residues in fruits and vegetables at the concentration of 10 ppm, but not in starch-rich grains. B46 and B93 were identified as Bacillus sp. according to their bacterial characteristics in culture.

  • PDF

Isolation and Characterization of Biopolymer Producing Alkali-Tolerant Bacterial Strain (생물고분자 생산 알칼리 내성 균주의 분리 및 특성)

  • Lee, Shin-Young;Lee, Beom-Su;Shin, Weon-Chul;Kwon, Ik-Boo;Yu, Ju-Hyun
    • Korean Journal of Food Science and Technology
    • /
    • v.23 no.2
    • /
    • pp.161-166
    • /
    • 1991
  • For the production of useful products from microorganism, a bacterial strain producing the biopolymer was isolated from soil. The bacteriological characteristics of the strain were examined and some chemical properties of the biopolymer produced were investigated. The bacterial strain was identified as an alkali-tolerant Bacillus sp. The results of chemical composition, various color reactions and I.R. spectrum revealed that the biopolymer contained high protein content, low amino sugar and no uronic acid. However, the biopolymer was precipitated by treating with cetylpiridinium chloride and was found to be acidic.

  • PDF