Recent Changes in Identification and Classification of Some Anaerobes

Holdeman, Lillian V.; Cato, Elizabeth P.; Moore, W. E. C.

doi:10.1007/978-1-4613-3159-9_4

Cited by 22 publications

(28 citation statements)

References 33 publications

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“…The volatile fatty acids produced after 72 h of the fiber degradation were analyzed using gas chromatography [17,18]. The gas liquid chromatography used was Varian 3700 model, equipped with a flame ionization detector with a set temperature of 250 0 C. The Varian recorder was fitted with an automatic integrator, sensitivity set at full scale and a chart speed of 0.5 cm/min, attenuation x 32.…”

Section: Determination Of Volatile Acidic Fermentation Productsmentioning

confidence: 99%

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Degradation of dietary fiber by faecal bacteria and potential physiological effects.

Uzomah¹,

Ofuya²

2009

African Journal of Food, Agriculture, Nutrition and Development

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Dietary fiber was extracted from Nigerian 'gari', Ex Mannihot esculenta; plantain, Musa paradisiaca; Gnetum africana and Telfaria occidentalis and these fiber sources were referred to as GAF, PLF, GF and TF, respectively. Mannihot esculenta and Musa paradisiaca are rich sources of carbohydrate and the fiber extraction was done using termamyl 120L and amyloglucosidase. Gnetum africana and Telfaria occidentalis are vegetables and the acetone dried powder method was employed for fiber extraction. The fiber extracted from each source was subjected to degradation by the gut microbial flora and the extent of degradation after 72 h was determined. Water holding capacity (WHC) of each fiber was measured before and after the degradation. The short chain fatty acids (SCFA) produced during degradation were measured chromatographically. Exposure of the fibers to the gut microflora showed that the non-vegetable fibers (GAF, PLF) were more readily degraded than the vegetable fibers (GF and TF). Consequently, the percentage of the undegraded fiber after 72 h of incubation was highest with the vegetable fibers; GF, 80.0 % and TF, 83.3 %, while that of the non-vegetable fibers (GAF and PLF) was 62.0 % and 72.5 %, respectively. The degradation by the microflora affected the WHC of the fibers (except TF). Water holding capacity (WHC) for GF was 11.1 ± 3.3 g H 2 O / g fiber, before degradation and 6.3 ± 2.5 g H 2 O / g fiber after degradation, indicating a percent decrease of about 43.2%. Similar decrease was observed for GAF (30.4 %) and PLF (13.9 %). Only acetic and butyric acid were detected in the fermenting slurry. The relative composition of acetic acid from each of the fiber source (GAF, 62.0 %; PLF, 70.4%; GF, 62.5%; TF, 52.9%) was found to be greater than that from the slurry (control) (42%). The low pH created by the actions of the microflora in the caecal lumen will decrease the toxicity of luminal contents to the gut mucosa and protect against cancer of the colon

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Section: Determination Of Volatile Acidic Fermentation Productsmentioning

confidence: 99%

“…The ether extract (0.1 µl) was injected into the gas chromatography equipment for the analysis of the volatile fatty acid. The standard solution containing (10 µ mol/ml) acetic acid, propionic acid and n-butyric acid were extracted in the same manner as above [17,18].…”

Section: Determination Of Volatile Acidic Fermentation Productsmentioning

confidence: 99%

Degradation of dietary fiber by faecal bacteria and potential physiological effects.

Uzomah¹,

Ofuya²

2009

African Journal of Food, Agriculture, Nutrition and Development

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“…In vitro cultivation of many species of anaerobic microorganisms must be conducted in an environment that is not merely oxygen-free, but also highly reducing (low redox potential) (5,7,9,10). Because of the vagaries of anaerobic medium preparation, there is a need to use dyes which allow visual assessment of the redox state of culture media.…”

Section: Introductionmentioning

confidence: 99%

“…Resazurin (7-hydroxy-3H-phenoxazin-3-one 10-oxide; Fig. 1) is the most widely used indicator of reducing conditions in these culture media (1,5,7,9). Methods aimed at eliminating dissolved O2 include sparging of culture media with O2-free gas (usually CO2 or N2) for several hours and addition of a chemical reducing agent (2,5,7,15).…”

Section: Introductionmentioning

confidence: 99%

“…1) is the most widely used indicator of reducing conditions in these culture media (1,5,7,9). Methods aimed at eliminating dissolved O2 include sparging of culture media with O2-free gas (usually CO2 or N2) for several hours and addition of a chemical reducing agent (2,5,7,15). However, many anaerobic bacteria do not grow well in media reduced with strong reducing agents like sodium dithionite or sodium sulfide; some reasons for this include the formation of toxic intermediates and precipitation of essential metal ions.…”

Section: Introductionmentioning

confidence: 99%

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Use of photocatalytic reduction to hasten preparation of culture media for saccharolytic Clostridium species

Fukushima¹,

Weimer²,

Kunz³

2003

Braz. J. Microbiol.

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Cysteine is the preferred reducing agent used in the preparation of culture media for the growth of many strictly anaerobic microorganisms; however, redox potential reduction of cysteine is very slow, making it inconvenient if the medium is needed immediately or in large quantity. The time required to reduce culture medium containing resazurin (an indicator of reducing conditions) was dramatically shortened when the medium, after being injected with the reducing agent cysteine, was irradiated with incandescent light from a halogen lamp. Light intensity had an effect upon reduction time: tubes kept in the dark took more than 12 h to achieve the desired degree of anaerobiosis (measured spectrophotometrically by the bleaching of the indicator, resazurin) while tubes subjected to ordinary laboratory illumination were reduced in about 2 h. When exposed to maximum light intensity (equivalent to a regular 100 watt bulb lamp) tubes could be made anaerobic in less than 20 min. Cysteine was essential for the bleaching of resazurin. Evidence that adequate anaerobiosis was achieved by light irradiation was provided by the fact that four Clostridium strains and one Thermoanaerobacter strain displayed similar growth (measured by lag time, growth rate, and extent of growth) in media reduced under high intensity light or under normal laboratory illumination.

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