Comparison of agar-based methods for the isolation and enumeration of heterotrophic bacteria with the new Multidose IDEXX(tm) SimPlate method

2004 ◽  
Vol 50 (1) ◽  
pp. 277-280
Author(s):  
M. Vulindlu ◽  
A. Charlett ◽  
S. Surman ◽  
J.V. Lee
Keyword(s):  
Yeast Extract ◽  
Heterotrophic Bacteria ◽  
Treatment Plant ◽  
Plant Performance ◽  
Extract Agar ◽  
Quality Of Water ◽  
Heterotrophic Microorganisms ◽  
External Sources ◽  
Conventional Methods ◽  
Yeast Extract Agar

Pour and spread plates are the conventional methods of choice for the isolation and enumeration of heterotrophic microorganisms in treated water supplies. The tests are performed at 22°C and 37°C for 72 h and 48 h respectively. Counts at 22°C are associated with pollution of water systems from external sources, while counts at 37°C are used as an indication of treatment plant performance and the deterioration of the general quality of water. Conventional methods using Yeast Extract Agar for a pour plate and R2A agar for a spread plate were compared with the multidose IDEXXTM SimPlate method for the isolation and enumeration of heterotrophic bacteria in water. SimPlate gave a significantly higher count on average than the conventional methods. The R2A method showed the next highest count, being significantly higher than Yeast Extract Agar. In addition, unlike the pour and spread plate methods, SimPlate was easier to use, reduced labour, and the test results were far easier to read.

Nannocystis exedens: A Potential Biocompetitive Agent against Aspergillus flavus and Aspergillus parasiticus

2001 ◽  
Vol 64 (7) ◽  
pp. 1030-1034 ◽  
Author(s):  
WILLIE J. TAYLOR ◽  
FRANCES A. DRAUGHON
Keyword(s):  
Aspergillus Flavus ◽  
Yeast Extract ◽  
Biocontrol Agent ◽  
Aspergillus Parasiticus ◽  
Extract Agar ◽  
Potential Biocontrol Agent ◽  
Aflatoxigenic Fungi ◽  
Close Proximity ◽  
Zones Of Inhibition ◽  
Yeast Extract Agar

This study examined the potential for controlling toxigenic Aspergillus flavus and Aspergillus parasiticus by biological means using a myxobacterium commonly found in soil. The ability of Nannocystis exedens to antagonize A. flavus ATCC 16875, A. flavus ATCC 26946, and A. parasiticus NRRL 3145 was discovered. Cultures of aflatoxigenic fungi were grown on 0.3% Trypticase peptone yeast extract agar for 14 days at 28°C. When N. exedens was grown in close proximity with an aflatoxigenic mold, zones of inhibition (10 to 20 mm) developed between the bacterium and mold colony. A flattening of the mold colony on the sides nearest N. exedens and general stunting of growth of the mold colony were also observed. When N. exedens was added to the center of the cross-streak of a mold colony, lysis of the colony by the bacterium was observed after 24 h. Microscopic observations revealed that N. exedens grew on spores, germinating spores, hyphae, and sclerotia of the molds. These results indicate that N. exedens may be a potential biocontrol agent against A. flavus and A. parasiticus.

scholarly journals Several Metarhizium Species Produce Ergot Alkaloids in a Condition-Specific Manner

2020 ◽  
Vol 86 (14) ◽  
Author(s):  
Caroline E. Leadmon ◽  
Jessi K. Sampson ◽  
Matthew D. Maust ◽  
Angie M. Macias ◽  
Stephen A. Rehner ◽  
...  
Keyword(s):  
Yeast Extract ◽  
Ergot Alkaloid ◽  
Genomic Sequence ◽  
Close Association ◽  
Acid Amide ◽  
Ergot Alkaloids ◽  
Lysergic Acid ◽  
Content Type ◽  
Extract Agar ◽  
Yeast Extract Agar

ABSTRACT Genomic sequence data indicate that certain fungi in the genus Metarhizium have the capacity to produce lysergic acid-derived ergot alkaloids, but accumulation of ergot alkaloids in these fungi has not been demonstrated previously. We assayed several Metarhizium species grown under different conditions for accumulation of ergot alkaloids. Isolates of M. brunneum and M. anisopliae accumulated the lysergic acid amides lysergic acid α-hydroxyethyl amide, ergine, and ergonovine on sucrose-yeast extract agar but not on two other tested media. Isolates of six other Metarhizium species did not accumulate ergot alkaloids on sucrose-yeast extract agar. Conidia of M. brunneum lacked detectable ergot alkaloids, and mycelia of this fungus secreted over 80% of their ergot alkaloid yield into the culture medium. Isolates of M. brunneum, M. flavoviride, M. robertsii, M. acridum, and M. anisopliae produced high concentrations of ergot alkaloids in infected larvae of the model insect Galleria mellonella, but larvae infected with M. pingshaense, M. album, M. majus, and M. guizhouense lacked detectable ergot alkaloids. Alkaloid concentrations were significantly higher when insects were alive (as opposed to killed by freezing or gas) at the time of inoculation with M. brunneum. Roots of corn and beans were inoculated with M. brunneum or M. flavoviride and global metabolomic analyses indicated that the inoculated roots were colonized, though no ergot alkaloids were detected. The data demonstrate that several Metarhizium species produce ergot alkaloids of the lysergic acid amide class and that production of ergot alkaloids is tightly regulated and associated with insect colonization. IMPORTANCE Our discovery of ergot alkaloids in fungi of the genus Metarhizium has agricultural and pharmaceutical implications. Ergot alkaloids produced by other fungi in the family Clavicipitaceae accumulate in forage grasses or grain crops; in this context they are considered toxins, though their presence also may deter or kill insect pests. Our data report ergot alkaloids in Metarhizium species and indicate a close association of ergot alkaloid accumulation with insect colonization. The lack of accumulation of alkaloids in spores of the fungi and in plants colonized by the fungi affirms the safety of using Metarhizium species as biocontrol agents. Ergot alkaloids produced by other fungi have been exploited to produce powerful pharmaceuticals. The class of ergot alkaloids discovered in Metarhizium species (lysergic acid amides) and their secretion into the growth medium make Metarhizium species a potential platform for future studies on ergot alkaloid synthesis and modification.

scholarly journals ISOLASI DAN IDENTIFIKASI KAPANG PADA PINDANG BANDENG (Chanos chanos) PRESTO

2019 ◽  
Vol 2 (1) ◽  
pp. 15
Author(s):  
Resmi Rumenta Siregar
Keyword(s):  
Yeast Extract ◽  
Rose Bengal ◽  
Fusarium Solani ◽  
Penicillium Citrinum ◽  
Malt Extract Agar ◽  
Malt Extract ◽  
Chanos Chanos ◽  
Extract Agar ◽  
Fusarium Sp ◽  
Yeast Extract Agar

Ikan pindang adalah salah satu olahan yang sangat disukai oleh masyarakat Indonesia. Hal ini dapat dilihat dari produksi ikan pindang yang setiap tahunnya mengalami peningkatan. Sebagai contoh di Kabupaten Bogor, produksi ikan pindang pada tahun 2013 sebesar 3.643,56 ton, meningkat menjadi 10.334,44ton pada tahun 2015. Ikan pindang disisi lain, sangat mudah mengalami kemunduran mutu disebabkan masih tingginya kadar air, pengemasan yang tidak memenuhi standar serta proses pengolahan yang pada umumnya kurang menerapkan prinsip sanitasi yang baik. Penelitian ini bertujuan untuk mengisolasi dan mengidentifikasi kapang yang tumbuh pada bandeng presto. Sampel Bandeng presto diambil dari CV. Cindy Group. Kapang diisolasi dengan metode pengenceran bertingkat menggunakan media DRBC (Dichloran Rose Bengal Chloramphenicol Agar), kemudian diidentifikasi secara morfologi menggunakan media Malt Extract Agar dan Czapek’s Yeast Extract Agar. Nilai Aktivitas air (aw) bandeng presto memiliki kisaran rata-rata 0,96 – 0,97. Secara makroskopis terlihat adanya pertubuhan kapang pada permukaan ikan bandeng presto setelah penyimpanan selama 3 hari pada suhu ruang (20-250C). Sebanyak 5 isolat kapang diisolasi dari ikan pindang sampel bandeng presto. Hasil identifikasi secara mikroskopis diketahui bahwa kapang yang tumbuh ada ikan pindang tersebut adalah spesies Penicillium citrinum, Eurotium chevalieri, Fusarium solani, Fusarium sp, dan Cladosporium sp. Kadar aw ikan pindang resto yang masih tinggi (0,96-0,97) menyebabkan ikan pindang mengalami pembusukan yang diakibatkan oleh bakteri.  

Evaluation of Recovery Media for Heated Clostridium sporogenes Spores1

1979 ◽  
Vol 42 (12) ◽  
pp. 946-947 ◽  
Author(s):  
I. J. PFLUG ◽  
M. SCHEYER ◽  
G. M. SMITH ◽  
M. KOPELMAN
Keyword(s):  
Yeast Extract ◽  
Culture Media ◽  
Clostridium Sporogenes ◽  
Extract Agar ◽  
Significant Difference ◽  
Yeast Extract Agar

The efficiency of four culture media for recovery of heat-activated and heated Clostridium sporogenes spores was studied. Yeast extract agar gave the highest spore recovery. The effect of the method of preparing the yeast extract agar on the recovery of heated spores was also evaluated. The results indicate that (a) a significantly lower spore recovery was obtained when the dextrose was omitted completely or when added to the medium before autoclaving, and (b) no significant difference in spore recovery was found between yeast extract agar freshly made or prepared and stored at 4 C up to 11 days before use.

scholarly journals Influence of culture media in viability test of conidia of entomopathogenic fungi

2006 ◽  
Vol 36 (4) ◽  
pp. 1309-1312 ◽  
Author(s):  
Edimara Aparecida Francisco ◽  
Dinalva Alves Mochi ◽  
Antônia do Carmo Barcelos Correia ◽  
Antonio Carlos Monteiro
Keyword(s):  
Yeast Extract ◽  
Culture Medium ◽  
Culture Media ◽  
Complete Medium ◽  
Paecilomyces Fumosoroseus ◽  
Lecanicillium Lecanii ◽  
Extract Agar ◽  
High Germination ◽  
Microscope Slides ◽  
Yeast Extract Agar

This work aimed at investigatimg whether the culture medium used in viability tests affects the conidial germination of Lecanicillium lecanii, Beauveria bassiana and Paecilomyces fumosoroseus isolates. The tests were performed on microscope slides containing one of the culture media: agar-water (AW), minimal medium (MM), potato-dextrose agar (PDA), potato-dextrose-1% yeast extract agar (PDAY), Sabouraud-dextrose-yeast extract agar (SDAY), and complete medium (CM). Three areas per slide were delimited and 0.05ml of a 5.5 x 105 conidia ml-1 suspension was applied to each area. One bioassay was performed for each isolate. Germination was determined after 15 hours of incubation at 26±0.5°C. The culture media influenced the germination of the species studied, verifying within and inter specific variations. CM and PDA provided the highest germination of L. lecanii isolates and the lowest was obtained on SDAY and AW. The germination of B. bassiana isolates was favoured by CM, PDA and PDAY media, a fact not observed in AW and MM. P. fumosoroseus isolates showed the highest germination on CM and PDA media and the lowest on SDAY. However, some isolates presented high germination on nutrient-poor media (AW and MM).

Cultural conditions influencing Basidium formation in the Ceratobasidiaceae

1984 ◽  
Vol 32 (1) ◽  
pp. 101 ◽  
Author(s):  
DIL Murray
Keyword(s):  
Yeast Extract ◽  
External Environment ◽  
Petri Dish ◽  
Physical Characteristics ◽  
Sporulation Medium ◽  
Extract Agar ◽  
Cultural Conditions ◽  
Atmospheric Exchange ◽  
Primary Substrate ◽  
Yeast Extract Agar

Adequate aeration of cultures was shown to be essential for basidium formation in isolates of several species belonging in the Ceratobasidiaceae. Moreover, fruiting was strongly influenced by the physical characteristics of three commercially available brands of petri dish that differed in their capacity to permit atmospheric exchange between the interior of the dish and the external environment. Dextrose-yeast extract agar, on which fungi were grown before transferring to sporulation media, was found to be a suitable primary substrate for eight of 10 species tested but basidium formation in most isolates was critically affected by the composition of the sporulation medium and by the volume of incculum transferred. The significance of these findings is considered in relation to the potential of existing methods to give reproducible leve!s of basidium fcrmation in different laboratories.

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