Nutrient Substratum Research Articles

Мікробіологічна оцінка чорнозему реградованого за різних систем удобрення

Мікроорганізми відіграють дуже важливу роль у формуванні ґрунтів, забезпечуючи їх функціонування як біокосних тіл природи і є індикатором якісних змін ґрунту. Внаслідок антропогенного впливу відбувається зниження чисельності й збіднення видового складу мікробіоти. Досліджено зміни показників мікробіологічної активності чорнозему реградованого під впливом інтенсивної, маловитратної та органічної систем удобрення кукурудзи на зерно. Визначення чисельності різних груп ґрунтових мікроорганізмів проводилось за методикою Д. Г. Звягінцева посівом ґрунтової суспензії на тверді поживні середовища. Встановлено, що найбільш сприятливі показники мікробіоценозу були на варіанті з органічною системою удобрення. Як низький агрохімічний фон, так і варіант інтенсивної системи несприятливо впливали на процеси гуміфікації у чорноземному ґрунті за вмістом педотрофних і гуматрозкладаючих організмів. За інтенсивної технології встановлено посилення оліготрофності, що обумовлює конкуренцію за доступний азот між мікроорганізмами й рослинами. Кількість амоніфікуючих організмів за маловитратної системи була у 2,03 рази більше відносно інтенсивної та у 2,3 – відносно органічної системи, що свідчить про тенденцію до розкладу органічних речовин.

Detection of Glycoprotein Receptors on Blotting Membranes by Binding of Live Bacteria and Amplification by Growth

Conditions have been adapted for detecting bacteria bound to glycoprotein receptors on blotting membranes using a self-enhancing detection method based on bacterial growth. Neutrophil plasma membrane proteins, mediating adherence of mannose-binding type-1-fimbriated Escherichia coli and concanavalin A (Con A) to intact human neutrophils, were separated by SDS-PAGE and transferred onto a polyvinylidene difluoride (PVDF) membrane. The PVDF membrane was immersed in a suspension of mannose-binding type-1-fimbriated E. coli, and after repeated washings, bound bacteria were allowed to multiply into bacterial colonies by placing the membrane on a solid nutrient substratum. About one major and eight minor glycoproteins, some of which also were detected by Con A, selectively induced colony formation in a mannose-inhibitable fashion. Binding of [ 35S]methionine metabolically labeled E. coli to PVDF membranes produced a virtually identical binding pattern, demonstrating further the accuracy of this self-enhancing detection method which is rapid, simple, and sensitive and avoids radioisotopes.

Pleural fluid as nutrient substratum for aspergillus fumigatus and A. flavus submerged growth in pleural fluid and extracellular proteolysis in pleural fluid agar: A preliminary report

Pleural fluid in liquid and agar form from a patient with adenocarcinoma of the lung was used as a nutrient medium for culturing Aspergillus fumigatus and A, flavus. The extracellular proteolytic activity of both strains could be demonstrated after an incubation period of 5 d at 37 degrees C by the agar block method using pleural fluid agar (protein content ca. 0.1-0.5% and initial pH values of 7.0 and 5.0) and protein staining with naphthalene black. In the undiluted pleural fluid, after stationary culture at 37 degrees C for 8 days, compact white granule-like colonies of a size of ca. 0.5-1.0 mm were found near the surface of the liquid and as sediment. Microscopically, these colonies consisted of radially arranged septate hyphae, similar in size and form to those seen in invasive aspergillosis.

Apfel und Apfelsaft als Nährsubstrat für Cryptococcus neoformans

Within our present research dealing with plant material as a nutrient substratum for the pathogen Cryptococcus neoformans , six varieties of apples were included in this study: Jonathan, Red Boscoop, Cox Orange, Delicious, Horneburger and Ingrid Marie. Contrary to the flesh of peaches, the flesh of all tested varieties of apple did not permit a growth of C. neoformans strain W 71. A colonization of C. neoformans could be observed only on the cores of the varieties Jonathan, Red Boscoop and Horneburger. In the freshly produced germ-free filtered juice of all tested varieties of apples, no inhibition of growth like on the flesh was found. In spite of initial p H-values of 3.0–3.9, C. neoformans strain W 71 grew as well as in Sabouraud-glucose-broth (initial p H 6.3) used as control. Also Candida albicans strain CBS 2730 met with good conditions of growth. On apple-juice-agar (Red Boscoop) with an initial p H 5.5, all tested strains showed growth: C. neoformans (5 strains), C. albidus (1 strain) and Candida albicans (1 strain). Four out of five strains of C. neoformans developed a brown pigmentation of the colonies. As control media were used: Sabouraud-glucose-agar and the differential medium for C. neoformans , Guizotia abyssinica-creatinine-agar (formerly called nigerseed-creatinine-agar). The significance of apple and apple-juice as nutrient substratum and possibly questionable habitat for C. neoformans are discussed. 1. Im Gegensatz zum Fruchtfleisch des Pfirsichs ließ das Fruchtfleisch des Apfels (Sorten: Gravensteiner, Jonathan, Roter Boskoop, Cox Orange, Delicius, Horneburger, Ingrid Marie) kein Wachstum von Cryptococcus neoformans W 71 zu. Nur auf dem Kerngehäuse der Sorten Jonathan, Roter Boskoop und Horneburger fand sich Koloniebildung von C. neoformans . 2. Im frisch hergestellten keimfrei filtrierten Saft sämtlicher geprüfter Apfelsorten wurde keine Wachstumshemmung wie auf Fruchtfleisch festgestellt. Trotz der Ausgangs- p H-Werte 3,0–3,9 vermehrte sich C. neoformans W 71 ebenso stark wie im Kontrollmedium Sabouraud-Dextrose-Lösung (Ausgangs- p H-Wert 6,3). Auch der Kontrollstamm Candida albicans CBS 2730 fand in sämtlichen Säften günstige Nährbedingungen. 3. Auf Apfelsaft-Agar (Roter Boskoop) mit Ausgangs- p H-Wert 5,5 wuchsen sämtliche geprüften Pilzstämme: C. neoformans (5 Stämme), C. albidus (1 Stamm) und Candida albicans (1 Stamm). Vier von fünf C. neoformans -Stämmen zeigten eine Braunverfärbung der Kolonien. Als Kontrollmedien dienten Sabouraud-Dextrose-Agar und der Differentialnährboden für C. neoformans Guizotia abyssinica-Kreatinin-Agar (frühere Bezeichnung Negersaat-Kreatinin-Agar). 4. Zum Apfel- und Apfelsaft als Nährsubstrat und Fundort von C. neoformans wurde Stellung genommen.

Mycology Presents Penicillin

A conservative medical official recently told a technical audience that Penicillin is the most potent agent * * * ever encountered, which produces no bad effects upon the patient. He then listed as conspicuous among microbial enemies of man which respond to penicillin, Gonococcus, Meningococcus, Streptococcus hemolyticus and S. viridans, Pneumococcus, Staphylococcus, Clostridium tetanus and C. Welchii, Corynebacterium diplhtheriae and Actinomyces bovis. Such a list justifies the caption miracle drug put upon it by another medical scholar who is rarely swayed by impulse. I am asked to trace the mycological history of the discovery and development of penicillin to its present place among things worth while. Since there are some misunderstandings as to its early history, the data will be presented in as verifiable order as possible. The first ten years. In 1929, Alexander Fleming reported the discovery and naming of penicillin. The essential facts of this discovery consisted (1) in the observation that a particular mold growing as a contaminant in a culture of Staphylococcus aureus inhibited the bacterium, i.e. that the Staphylococcus could not grow in a zone surrounding the mold colony. This observation was already well known as a phenomenon seen frequently when molds and bacteria are found growing together. Most commonly the observation is reversed-a mold fails to develop normally, if at all, in the presence of large numbers of bacteria. (2) Fleming went further and showed that the mold had produced an inhibiting substance in the nutrient substratum which could be separated from the fungus itself and used to inhibit certain bacteria. He tabulated a series of bacteria susceptible and other bacteria resistant to the inhibiting substance. (3) Since the mold was a species of the great genus Penicillium, he called his inhibiting substance penicillin. (4) Not being a mycologist, he undertook to