scholarly journals Improvement of the Culture Medium for the Dichlorvos-Ammonia (DV-AM) Method to Selectively Detect Aflatoxigenic Fungi in Soil

Toxins ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 519 ◽  
Author(s):  
Kimiko Yabe ◽  
Haruna Ozaki ◽  
Takuya Maruyama ◽  
Keisuke Hayashi ◽  
Yuki Matto ◽  
...  
Keyword(s):  
Culture Medium ◽  
Agar Medium ◽  
Carbon Sources ◽  
Tween 80 ◽  
Selective Medium ◽  
Selective Detection ◽  
Aflatoxigenic Fungi ◽  
Aspergillus Nomius ◽  
Rhizopus Sp ◽  
Triton X

The dichlorvos-ammonia (DV-AM) method is a simple but sensitive visual method for detecting aflatoxigenic fungi. Here we sought to develop a selective medium that is appropriate for the growth of aflatoxigenic fungi among soil mycoflora. We examined the effects of different concentrations of carbon sources (sucrose and glucose) and detergents (deoxycholate (DOC), Triton X-100, and Tween 80) on microorganisms in soils, using agar medium supplemented with chloramphenicol. The results demonstrated that 5–10% sucrose concentrations and 0.1–0.15% DOC concentrations were appropriate for the selective detection of aflatoxigenic fungi in soil. We also identified the optimal constituents of the medium on which the normal rapid growth of Rhizopus sp. was completely inhibited. By using the new medium along with the DV-AM method, we succeeded in the isolation of aflatoxigenic fungi from non-agricultural fields in Fukui city, Japan. The fungi were identified as Aspergillus nomius based on their calmodulin gene sequences. These results indicate that the new medium will be useful in practice for the detection of aflatoxigenic fungi in soil samples including those from non-agricultural environments.

Isolation of estrogen-degrading bacteria from an activated sludge bioreactor treating swine waste, including a strain that converts estrone to β-estradiol

2011 ◽  
Vol 57 (7) ◽  
pp. 559-568 ◽  
Author(s):  
Martine Isabelle ◽  
Richard Villemur ◽  
Pierre Juteau ◽  
François Lépine
Keyword(s):  
Carbon Source ◽  
Culture Medium ◽  
Agar Medium ◽  
Carbon Sources ◽  
Bacterial Consortium ◽  
Swine Wastewater ◽  
Low Concentrations ◽  
Degrading Bacteria ◽  
17Β Estradiol ◽  
Reducing Activity

An estrogen-degrading bacterial consortium from a swine wastewater biotreatment was enriched in the presence of low concentrations (1 mg/L) of estrone (E1), 17β-estradiol (βE2), and equol (EQO) as sole carbon sources. The consortium removed 99% ± 1% of these three estrogens in 48 h. Estrogen removal occurred even in the presence of an ammonia monooxygenase inhibitor, suggesting that nitrifiers are not involved. Five strains showing estrogen-metabolizing activity were isolated from the consortium on mineral agar medium with estrogens as sole carbon source. They are related to four genera ( Methylobacterium (strain MI6.1R), Ochrobactrum (strains MI6.1B and MI9.3), Pseudomonas (strain MI14.1), and Mycobacterium (strain MI21.2)) distributed among three classes (Alphaproteobacteria, Gammaproteobacteria, and Actinobacteria). Depending on the culture medium, strains MI6.1B, MI9.3, MI14.1, and MI21.2 partially transform βE2 into E1, whereas Methylobacterium sp. strain MI6.1R reduces E1 into βE2 under aerobic conditions, in contrast with the usually observed conversion of βE2 into E1. Since βE2 is a more potent endocrine disruptor than E1, it means that the presence of Methylobacterium sp. strain MI6.1R (or other bacteria with the same E1-reducing activity) in a treatment could transiently increase the estrogenicity of the effluent. MI6.1R can also reduce the ketone group of 16-ketoestradiol, a hydroxylated analog of E1. All βE2 and E1 transformation activities were constitutive, and many of them are favoured in a rich medium than a medium containing no other carbon source. None of the isolated strains could degrade EQO.

scholarly journals BACTERIAL AND FUNGAL CONTAMINANTS OF TISSUE-CULTURED 'LAKATAN' BANANA

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Carlito M. Hindoy Jr. ◽  
Alminda Magbalot-Fernandez ◽  
Leslie T. Ubaub ◽  
Saikat K. Basu
Keyword(s):  
Culture Medium ◽  
Agar Medium ◽  
Nutrient Agar Medium ◽  
Initiation Stage ◽  
Rhizopus Sp ◽  
Fresh Culture Medium ◽  
Fungal Contaminants ◽  
The University ◽  
Unidentified Fungus ◽  
Fresh Culture

This study aimed to characterize the bacterial and fungal contaminants of tissue-cultured 'Lakatan' banana (Musa acuminata) during initiation stage. This was conducted at the University of Southeastern Philippines, Tagum-Mabini Campus from October 2015 to February 2016. The sterilized banana explant was placed in a bottle of solidified nutrient agar medium. Detectable bacterial and fungal contaminants were isolated and sub-cultured into the fresh medium two to four days after incubation. The bacterial isolates were cultivated by streaking into fresh culture medium and incubated at 0 0 30-32 C for three days and fungi culture disk was transferred to fresh culture medium and incubated at 30-32 C for three to five days. Both bacterial and fungal contaminants were identified and characterized and assessed for extent of contamination. Results showed that the different contaminants occurred during the initiation stage of tissue-cultured 'Lakatan' banana meriplants were composed of Rhizopus sp., unidentified fungus and Gram-negative bacterium. Generally, 35% contamination was observed on this stage.

Influence of Surfactants on Biodegradation of Chlordane by Wood-Rotting Fungus

2013 ◽  
Vol 361-363 ◽  
pp. 908-911
Author(s):  
Peng Fei Xiao ◽  
Tie Xue You ◽  
Yu Zhen Song ◽  
Shan Ying ◽  
Jian Qiao Wang
Keyword(s):  
Liquid Medium ◽  
Degradation Rate ◽  
Solid Medium ◽  
Fungal Growth ◽  
Tween 80 ◽  
Positive Effects ◽  
Lower Effect ◽  
Triton X

Wood-rotting fungus,Phlebia lindtneriGB 1027, was tested in toxicity assays with three surfactants in order to select surfactants for degradation assays of chlordane. Tween 80 and Triton X-100 appeared to have lower effect on the fungal growth on solid medium, while higher effect of fungal growth was observed in solid medium with SDS. Tween 80 had positive effects both on the chlordane degradation and the fungal growth. When fungus was incubated on PDB liquid medium with Tween 80 of 10 CMC after 20 d, 78.6% of chlordane was removed. In the treatments with Triton X-100, this strain showed comparatively greatest degradation rate (70.8%) of chlordane at a concentration of 2 CMC. However, when Triton X-100 concentration was higher than 2 CMC (5 and 10 CMC), the enhancement for the biodegradation of chlordane decreased.

scholarly journals Polyhydroxyalkanoates production by a bacterium isolated from mangrove soil samples collected from Quang Ninh province

2012 ◽  
Vol 3 (2) ◽  
pp. 76-79 ◽  
Author(s):  
Thuoc Van Doan ◽  
Binh Thi Nguyen
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Culture Medium ◽  
Carbon Sources ◽  
Nile Red ◽  
Soil Samples ◽  
Mangrove Soil ◽  
Transmission Electron ◽  
Bacterium Strain ◽  
Quang Ninh

A PHA producing bacterium (strain QN271) was selected from mangrove soil samples collected from Quang Ninh province by using the Nile red dying technique. PHA accumulation in the selected bacterium strain was confirmed by transmission electron microscope. With the exception of maltose or sucrose, the bacterium strain was found to be able to synthesize PHA from various carbon sources (glucose, xylose, fructose, glycerol, and glucose plus propionate). The strain accumulated poly(3-hydroxybutyrate) from glucose, fructose, xylose, and glycerol whereas poly(3-hydroxybutyrate-co-3-hydroxyvalarate) was produced when a combination of glucose and propionate was included in the culture medium. Fructose was found to be most suitable substrate for PHA synthesis by strain QN271. PHA content of 63.3% and CDW of 6 g/L were obtained after 32 hrs of cultivation in fructose medium. Chủng vi khuẩn có khả năng sinh tổng hợp PHA đã được phân lập từ đất rừng ngập mặn tỉnh Quảng Ninh nhờ kỹ thuật nhuộm với Nile red. Ảnh quan sát dưới kính hiển vi điện tử dẫn truyền chứng tỏ rằng chủng vi khuẩn này có khả năng tích lũy lượng lớn PHA trong tế bào. Chủng vi khuẩn tuyển chọn có khả năng sinh tổng hợp PHA từ nhiều nguồn các bon khác nhau như glucose, xylose, fructose, glucerol, glucose và propionate nhưng không có khả năng tổng hợp PHA từ maltose hoặc saccharose. Chủng vi khuẩn tuyển chọn tổng hợp poly (3-hydroxybutyrate) từ các nguồn các-bon như glucose, xylose, fructose, hay glycerol, trong khi đó poly (3-hydroxybutyrate-co-3-hydroxyvalarate) sẽ được tổng hợp khi phối hợp sử dụng hai nguồn các-bon (glucose và propionate). Fructose là nguồn các-bon tốt nhất cho chủng QN271 sinh tổng hợp PHA, khi nuôi cấy trong môi trường có fructose chủng vi khuẩn này có thể tạo ra lượng sinh khối là 6 g/L trong đó có chứa 63.3% PHA sau 32 giờ.

scholarly journals EXPRESSION OF b-XYLOSIDASE ENCODING GENE IN PHIS/ Bacillus megaterium MS SYSTEM

2015 ◽  
Vol 2 (1) ◽  
pp. 25 ◽  
Author(s):  
Sri Sumarsih
Keyword(s):  
Culture Medium ◽  
Culture Supernatant ◽  
Specific Activity ◽  
Agar Medium ◽  
Nitrilotriacetic Acid ◽  
Protoplast Transformation ◽  
E Coli ◽  
Recombinant Cells ◽  
Relative Molecular Weight ◽  
Encoding Gene

b-Xylosidase encoding gene from G. thermoleovorans IT-08 had been expressed in the pHIS1525/ B. megaterium MS941 system. The b-xylosidase gene (xyl) was inserted into plasmid pHIS1525 and propagated in E. coli DH10b. The recombinant plasmid was transformed into B. megaterium MS941 by protoplast transformation. Transformants were selected by growing the recombinant cells on solid LB medium containing tetracycline (10 µg/ ml). The expression of the b-xylosidase gene was assayed by overlaid the recombinant B. megaterium MS941 cell with agar medium containing 0.2% ethylumbelliferyl-b-D-xyloside (MUX). This research showed that the b-xylosidase gene was succesfully sub-cloned in pHIS1525 system and expressed by the recombinant B. megaterium MS941. Theaddition of 0.5% xylose into the culture medium could increase the activity of recombinantactivity of recombinant of recombinantb-xylosidase by 2.74 fold. The recombinant B. megaterium MS941 secreted 75.56% of the expressed b-xylosidase into culture medium. The crude extract b-xylosidase showed the optimum activity at 50° C and pH 6. The recombinant b-xylosidase was purified from culture supernatant by affinity chromatographic method using agarose containing Ni-NTA (Nickel-Nitrilotriacetic acid). The pure b-xylosidase showed a specific activity of 10.06 Unit/mg protein and relative molecular weight ± 58 kDa.

scholarly journals Screening of Amazonian bacillus strains for lipase production using glycerol as substrate

ScientiaTec ◽  
2020 ◽  
Vol 7 (03) ◽  
Author(s):  
Giandra Volpato ◽  
Victória Furtado Migliavacca ◽  
Bruna Coelho de Andrade ◽  
Júlio Xandro Heck ◽  
Marco Antônio Záchia Ayub
Keyword(s):  
Organic Synthesis ◽  
Culture Medium ◽  
Lipolytic Activity ◽  
Gum Arabic ◽  
Lipase Production ◽  
Culture Conditions ◽  
Search And Selection ◽  
Triton X ◽  
Potential Use ◽  
Selection Of

The industrial application of lipolytic enzymes has been studied mainly due to the ability of these enzymes in catalyze reactions of synthesis and their stability in various organic solvents. One possibility is the use of lipase the organic synthesis, taking advantage as the generation of waste and difficult recovery of sub bioproducts. In this work, we carried out a selection of eighty-four isolates of Bacillus amazonian for lipase production, of which 30 strains showed lipolytic activity. The study of the culture conditions was performed through a Plackett-Burman experimental design using the strain that presented the highest lipolytic activity in a culture medium using glycerol as substrate.  The studied conditions were: concentration of soybean oil, olive oil, triton X-100, gum arabic, glycerol, and (NH4)2SO4, pH, temperature and concentration of inoculums. The best result obtained were 27 U/L in 48 h of cultivation by Bacillus circulans BL53. This work shows that the search and selection of microorganism with lipolytic activities can facilitate the discovery of new lipases, with potential use as by-product surplus.

scholarly journals Oil sludge washing with surfactants and co-solvents: oil recovery from different types of oil sludges

2020 ◽  
Author(s):  
Diego Ramirez ◽  
Liz J. Shaw ◽  
Chris D. Collins
Keyword(s):  
Oil Recovery ◽  
Sodium Dodecyl ◽  
Tween 80 ◽  
Selective Extraction ◽  
Oil Sludge ◽  
High Effect ◽  
Recovery Techniques ◽  
Different Types ◽  
Triton X ◽  
Different Sources

Abstract Different physicochemical and biological treatments have been used to treat oil sludges, and oil recovery techniques are preferred such as oil sludge washing (OSW) with surfactants and co-solvents. Toluene is commonly used as co-solvent, but it is non-benign to the environment. This study tested alternative co-solvents (n-pentane, n-hexane, cyclohexane, and isooctane) at 1:1 and 2:1 C/OS (co-solvent to oil sludge ratio). Also, this study evaluated the effect on the oil recovery rate (ORR) of three main parameters in the washing: type, concentration, and application ratio (S/OS) of surfactants to oil sludges. To date, no study has assessed these parameters in the washing of oil sludges from different sources. Four types of oil sludges and five surfactants (Triton X-100 and X-114, Tween 80, sodium dodecyl sulphate (SDS), and rhamnolipid) were used. The results showed that cyclohexane had high ORR and could be used instead of toluene because it is more benign to the environment. The S/OS ratio had a high effect on the ORR and depended on the type of oil sludge. Rhamnolipid, Triton X-100, and Triton X-114 had the highest oil recovery rates (40 – 70%). In addition, it was found that the surfactant concentration had no effect on the ORR. Consequently, the addition of surfactant was not significantly different compared to the washing with no surfactants, except for one sludge. The use of the surfactant in the washing solution can help in the selective extraction of specific oil hydrocarbon fractions in the recovered oil to assess its potential reuse as fuel. Further recommendations were given to improve the OSW process.

scholarly journals A selective medium for the isolation of the acinetobacter genus bacteria

1980 ◽  
Vol 75 (3-4) ◽  
pp. 11-21 ◽  
Author(s):  
Altair A. Zebral
Keyword(s):  
Yeast Extract ◽  
Crystal Violet ◽  
Sodium Citrate ◽  
Agar Medium ◽  
Selective Medium ◽  
Phenol Red ◽  
Gram Positive ◽  
Gram Negative ◽  
Fermentative Activity

A selective and differencial medium was developed for the isolation of Acinetobacter genus bacteria. This Acinobacter Agar Medium (p.H + 7.4) contains in grams per litre: thiotone, 10; yeast extract, 3; naC1, 5; saccharose, 10; mannitol, 10; sodium citrate, 0.5; sodium desoxycholate, 0.1; crystal violet, 0.00025; phenol red, 0.04 and agar-agar 15. This medium has the advantage of inhibiting the growth of cocci and Gram-positive bacilli, by the use of sodium citrate and sodium desoxycholate associated with the crystal violet; and of differentiating the Gram-negative bacilli from the Enterobacteriaceae, through the fermentative activity upon the saccharose and/or mannitol, contrasting with the complete inactivity of the Acinetobacter genus bacteria over those substances.

Selective medium for the isolation and enumeration of Mycobacterium avium-intracellulare and M. scrofulaceum

1986 ◽  
Vol 32 (1) ◽  
pp. 10-14 ◽  
Author(s):  
Karen L. George ◽  
Joseph O. Falkinham III
Keyword(s):  
Carbon Source ◽  
Mycobacterium Avium ◽  
Sole Carbon Source ◽  
Natural Waters ◽  
Tween 80 ◽  
Selective Medium ◽  
Selective Isolation ◽  
Mineral Salts ◽  
Mycobacterium Avium Intracellulare

A medium for the selective isolation and enumeration of Mycobacterium avium-intracellulare and M. scrofulaceum (MAIS) was developed, based upon the ability of these mycobacteria to utilize Tween 80 as sole carbon source and grow optimally at pH 5.5 on a simple mineral salts medium. Representative MAIS strains had higher efficiencies of plating on the Tween 80 medium compared with Middlebrook 7H10. It was shown that nonmycobacterial organisms in natural waters had lower efficiencies of plating on the Tween 80 medium and smaller colonies, thus allowing direct isolation and enumeration of the slowly growing mycobacteria without overgrowth.

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