Yeasts in soils of Egypt

Moawad, Hassan; Salem, S.; El-Din, S. M. S. Badr; Khater, T.; Iskandar, M.

doi:10.1016/s0232-4393(86)80033-6

Cited by 12 publications

(5 citation statements)

References 9 publications

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“…Conversely, it is well known that the optimum growth pH range for yeast is 3.0Á5.0 and that they can also grow well at neutral pH range. Our research results showed the positive correlation between pH and yeasts, although Vreulink et al (2007) found in their study on sandy soil that the correlation between soil pH and culturable soil yeast numbers is negative and Moawad et al (1986) observed no significant effect at all.…”

Section: Soil Phcontrasting

confidence: 70%

The importance of solid cattle manure application on soil microorganisms in organic and conventional cultivation

Edesi

Järvan

Noormets

et al. 2012

Acta Agriculturae Scandinavica, Section B – Soil & Plant Sc

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Microbial communities are integral parts of the soil and their activity is very important to the functioning of the soil but the impact of different factors on soil microbial community composition is not well researched. Many studies have focused only on a few species. The aim of this study was to investigate the impact of treatment and sampling date on soil pH, abundance of total number of bacteria, molds, yeasts, mesophilic spore-forming bacteria, Fusarium spp., actinomycetes, azotobacteria, cellulose decomposers, denitrifying and nitrifying bacteria in organically (ORGGRM Á green manure, and ORGFYM Á green manure, solid cattle manure) and conventionally (CONFYM Á solid cattle manure ' mineral fertilizer and pesticides) cultivated soil.Fertilization with manure had positive direct-and after-effect (pB0.05) on the total number of bacteria, mesophilic sporeforming bacteria, nitrifying bacteria and cellulose decomposers, even in the CONFYM treatment. The abundance of yeasts was higher (pB0.05) in ORGFYM treatment (3.35 )10 3 ) and 34Á48% lower in CONFYM and ORGGRM treatments.The abundance of molds, Fusarium spp., and actinomycetes during the study in different treatments was similar but their abundance was significantly higher (pB0.05) when the weather in the sampling time was warm and humid.The negative impact of pesticides in CONFYM treatment occurred on the total number of bacteria, yeasts, molds, and denitrifying bacteria. The yeasts were most sensitive to pesticides; in study years, when the use of pesticides was very intensive, their abundance in CONFYM treatment decreased 72% compared with the ORGFYM treatment.The 4-year test results showed that although green manuring is considered an important management practice in organic cultivation, to maintain and increase the abundance of microbes in different microbial communities it is important to use other organic fertilizers such as animal manure in addition to green manure.

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Section: Soil Phcontrasting

confidence: 70%

The importance of solid cattle manure application on soil microorganisms in organic and conventional cultivation

Edesi

Järvan

Noormets

et al. 2012

Acta Agriculturae Scandinavica, Section B – Soil & Plant Sc

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“…The choice of sugar beet as a host was intentional in the expectation that a plant high in sugar reserves would be an attractive niche for yeasts in general. Earlier reports have indicated dominance of yeasts on fruits (Wilson and Wisniewski 1989; Filonow 1998) and roots rich in sugars (Babeva and Belyanin 1966; Moawad et al. 1986).…”

Section: Discussionmentioning

confidence: 94%

Suppression of Rhizoctonia solani diseases of sugar beet by antagonistic and plant growth-promoting yeasts

El‐Tarabily

2004

J Appl Microbiol

127

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Aims: Isolates of Candida valida, Rhodotorula glutinis and Trichosporon asahii from the rhizosphere of sugar beet in Egypt were examined for their ability to colonize roots, to promote plant growth and to protect sugar beet from Rhizoctonia solani AG-2-2 diseases, under glasshouse conditions. Methods and Results: Root colonization abilities of the three yeast species were tested using the root colonization plate assay and the sand-tube method. In the root colonization plate assay, C. valida and T. asahii colonized 95% of roots after 6 days, whilst Rhod. glutinis colonized 90% of roots after 8 days. Root-colonization abilities of the three yeast species tested by the sand-tube method showed that roots and soils attached to roots of sugar beet seedlings were colonized to different degrees. Population densities showed that the three yeast species were found at all depths of the rhizosphere soil adhering to taproots up to 10 cm, but population densities were significantly (P < 0AE05) greater in the first 4 cm of the root system compared with other root depths. The three yeast species, applied individually or in combination, significantly (P < 0AE05) promoted plant growth and reduced damping off, crown and root rots of sugar beet in glasshouse trials. The combination of the three yeasts (which were not inhibitory to each other) resulted in significantly (P < 0AE05) better biocontrol of diseases and plant growth promotion than plants exposed to individual species. Conclusions: Isolates of C. valida, Rhod. glutinis and T. asahii were capable of colonizing sugar beet roots, promoting growth of sugar beet and protecting the seedlings and mature plants from R. solani diseases. This is the first successful attempt to use yeasts as biocontrol agents against R. solani which causes root diseases. Significance and Impact of the Study: Yeasts were shown to provide significant protection to sugar beet roots against R. solani, a serious soil-borne root pathogen. Yeasts also have the potential to be used as biological fertilizers.

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“…Some of these genera, such as Aureobasidium and Trichosporon, can also have mycelial phases (Barnett et al 1990). Moawad et al (1986) reported that population densities of yeast in soils correlated significantly with the organic carbon and organic nitrogen content of soils tested. di Menna (1962) concluded, from qualitative and quantitative surveys of the yeast flora of New Zealand soils, that yeast populations varied qualitatively from place to place with soil type and vegetation but not with season, whereas the density of yeast populations was different from place to place and also varied with season.…”

Section: Introductionmentioning

confidence: 98%

“…Bab'eva and Belyanin (1966) found the colony-forming units of yeasts in the rhizosphere of cabbage, corn, sugar beet, and oats to be higher compared to normal bulk soils. Not only were the number of yeasts higher in the rhizosphere, but also the species compositions were more diverse (Bab'eva and Belyanin 1966;Moawad et al 1986). …”

Section: Introductionmentioning

confidence: 99%

Potential of yeasts as biocontrol agents of soil-borne fungal plant pathogens and as plant growth promoters

2006

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Among soil microorganisms, yeasts have received little attention as biocontrol agents of soil-borne fungal plant pathogens in comparison to bacterial, actinomycetes, and filamentous fungal antagonists. The mechanisms of action of potential antagonism by yeasts in relation to soilborne fungal plant pathogens are expected to be similar to those involved with pathogens of aerial parts of the plant, including leaves and fruits. Several taxa of yeasts have been recorded as endophytes in plants, with a small proportion recorded to promote plant growth. The ability of certain taxa of yeasts to multiply rapidly, to produce antibiotics and cell wall-degrading enzymes, to induce resistance of host tissues, and to produce plant growth regulators indicates the potential to exploit them as biocontrol agents and plant growth promoters. More than ten genera of yeasts have been used to control postharvest diseases, especially of fruits. Suppression of classes of fungal pathogens of fruits and foliage that are similar to those associated with soilborne fungal root pathogens, strongly suggests that yeasts also have potential for the biological control of diseases caused by soil-borne fungal plant pathogens, as is evident in reports of certain yeasts in suppressing some soil-borne fungal plant pathogens. This review explores the potential of soil yeasts to suppress a wider range of soil-borne fungal plant pathogens and to promote plant growth.

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Yeasts in soils of Egypt

Cited by 12 publications

References 9 publications

The importance of solid cattle manure application on soil microorganisms in organic and conventional cultivation

The importance of solid cattle manure application on soil microorganisms in organic and conventional cultivation

Suppression of Rhizoctonia solani diseases of sugar beet by antagonistic and plant growth-promoting yeasts

Potential of yeasts as biocontrol agents of soil-borne fungal plant pathogens and as plant growth promoters

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