The Effective Role of Soil Indigenous Fungi on 2.4-D Herbicide Degradation

The normal field soil environment safeguarded, via indigenous microbes in a native manner, with the aim of turning herbicide waste into productive bio-resources, through fungi activities. This study aims to determine the effective role of soil indigenous fungi on 2,4-D herbicide degradation. The research was conducted over a period of six weeks, on Iraqi cereal field. A total of eight fungi species, belonging to six genera, (Aspergillus candidus L. ATCC 1002, A. niger T. ATCC 16888, Curvularia lunata W. B1933, Penicillium sp. L. 1809, Rhizopus stolonifer L. B9770, Stachybotrys atra C. 1837, Trichoderma harzianum R. IOC 3844, and T. lignorum T. Hartz 1872), were isolated from the soil. During the exposure periods, fungal populations were differently affected, upon treatments with herbicide. The applied herbicide treatments showed different effects on growth and development of the isolated fungi. The results showed that, five of the eight fungi species (C. lunata B1933, Penicillium sp. 1809, R. stolonifer B9770, T. harzianum IOC 3844, and T. lignorum Hartz 1872) were greatly enhanced by the treatment process. However, two fungi (S. atra 1837, and A. candidus ATCC 1002) were affected negatively by the herbicide, while one (A. niger ATCC 16888) remained unaffected. Once extracted from the soil of wheat fields in Iraq, the fungus S. atra 1837, was first isolated. The highest inhibitory effect was caused by 2,4-D herbicide, on the toxigenic fungus S. atra, causing its disappearance from the field at the last week of application. The laboratory experiments showed similar herbicide effects on the isolated fungi at low and moderate levels, while those at the high level (800 µg /ml) were toxic. These results showed that the herbicide 2,4-D treatments have substantial effects on microbial population in the field. When applied at recommended field rate, the herbicide causes transient impacts on fungal population growth and biodiversity, with the majority of the organism becoming responsible for 2,4-D mineralization in the soil. Therefore, the use of 2,4-D herbicide does not only control weed population, but it also affects microbial activities, especially indigenous fungi in the soil.

The Common Deathwatch Beetle Xestobium rufovillosum (DeGeer, 1774) as a Pest for Paper in Books

A small repository in a cathedral in Poland, storing severely damaged books, was investigated with regard to insects and fungi. Entomological and microbiological surveys were performed to estimate the extent of the infestation and the microbial deterioration of the books. Most of the books were attacked by insects although to varying degrees. They were damaged by tunnels bored by the larvae and filled with larval faeces. Some living larvae and many dead adult beetles were found in the books or in the frass. The larvae and most of the beetles were identified as the common deathwatch beetle Xestobium rufovillosum (DeGeer, 1774). The development of Xestobium rufovillosum in books is an unusual case and has rarely been mentioned in the literature. Several books in the repository were also covered by microfungi, especially by Chaetomium murorum, Ch. elatum, Myxotrichum chartarum, Stachybotrys atra and Epicoccum nigrum. The temperature in the repository varied, depending on the season of the year (2.6 °C – 26.2 °C), while the relative humidity was high (constantly above 65 %). The concentration of the fungal bioaerosol was very high (4,120 cfu/m3). The article includes a list of recommendations pertaining to the elimination of the microorganisms and insects.

A Study on the Plant Litter Decomposition Using Mycoflora for Sustainable Environment

Most of the agricultural, forest and field crop litters are consisting lignocelluloses, cellulose, hemicellulose and lignin. Among these cellulose is most predominant constituent followed by hemicellulose and lignin. The lignin together with the hemicellulose, encrust the cellulose chains forming a barrier which prevents wetting and access of cellulose-degrading enzymes therefore, the decomposition of litters can be achieved by breaking this association at first. The biodegradation of lignin of field crop litters representing a key step for carbon recycling in land ecosystem, as well as for industrial utilization of plant biomass, humification of dead organic matter by the application of certain bacterial and fungal species. The present study revealed the process of decomposition of plant litters. The fungal species colonized different types of plant litters on the basis of enzymatic activities and resource specificity. The mixtures of microorganisms could degrade lignocellulosic materials of wheat stubbles more efficiently than any individual species; Aspergillus niger, Aspergillus flavus, Aspergillus terreus, Fuserium equiseti, Trichoderma lignorum and Stachybotrys atra. A mixture of fungi and Streptomyces caused 48.0% decomposition while decomposition by an individual species viz. Aspergillus flavus was 36.90% only. It was found that, fungi have better abilities to decompose wheat straw than bacteria and actinomycetes. The mineralisation of plant residues could accelerate the rate of decomposition.

Antagonistic activity “in vitro” of some saprophytic fungi occurring on the phylloplane of rice, wheat and maize

Fue investigada la actividad antagónica in vitro de un total de 51 cepas pertenecientes a 16 géneros fúngicos detectados con mayor frecuencia en el filoplano del centeno, arroz y maíz.El antagonismo fue observado con el método de los cultivos duales en medios con agar, entre estos hongos y los fitopatógenos: Drechslera oryzae, Pyricularia oryzae y Helminthosporium maydis. Los más antagónicos son: Penicillium chrysogenum, P. thomii y Stachybotrys atra; ellos antagonizaron en particular con Botrytis cinerea, Fusarium moniliforme y Alternaria alternata. El antagonismo más exitoso contra los tres patógenos mencionados fue con P. chrysogenum y P. charlesii, quienes fueron notoriamente activos. Las cepas de Chaetomium globosum, Gibberella zeae, Fusarium moniliforme, Trichothecium roseum y B. cinerea presentan una actividad antagónica contra H. maydis; Cladosporium cladosporioides contra P. oryzae y D. oryzae; Aspergillus clavatus frente a D. oryzae. Los resultados son discutidos en relación al control biológico de estos patógenos de cereales

Biocontrol of toxigenic strain of Aspergillus flavus isolated from the root tubers of safed musli (Chlorophytum borivilianum Sant. F) using its rhizospheric mycoflora

Miraculous herb safed musli (Chlorophytum borivilianum Sant. F), family liliaceae, is well recognized for its immense potential as an aphrodisiac. The root tubers of this herbal drug were found to be invested with Aspergillus flavus during field and storage. Therefore, the present study was designed to explore the ability of 26 co-existing rhizospheric mycoflora to inhibit A. flavus invasion and subsequent aflatoxin contamination of safed musli. The interaction of these moulds with highly toxigenic strain (CB55) of A. flavus was evaluated by dual culture method and type of interaction was graded. Most likely antagonistic effects were shown by fifteen (15) moulds, out of which Type ‘C’ interaction was evidenced in the case of six moulds; A. clavatus, A. terreus, Botryotrichum piluliferum, Candida albicans, Cephalosporium acremonium, and Cunninghamella sp. Further, ‘D’ type interaction was displayed by seven moulds which include A. niger, Colletotrichum sp., Drechslera sp., Mucor haemalis, Mycelia sterilia, Rhizopus arrhizus and Stachybotrys atra and ‘E’ type interaction was noted in the case of Trichoderma viride and Trihcothecium roseum. Regarding human health it is critical to use an ecofriendly approach to control the invasion of toxigenic moulds with root tubers of safed musli.

Micro-fungi and mycotoxins in poultry dust

Dust in poultry confinement facilities were investigated for their fungi and mycotoxins contents. Concentrations of microfungiin the air of poultry confinement facilities were determined using air samplers, and fungal isolation from airby plate exposure. Settled dusts were investigated for their fungal load, types of fungi present and mycotoxins present.Microfungal load in settled dust and air of poultry confinements were found to be 3.5-42 x 106 cfu/g and 5-119 x105 cfu/m3 respectively. Fungi isolated from poultry confinements were: Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus,Aspergillus parasiticus, Aspergillus ochraceus Penicillium notatum, Mucor racemosus, Penicillium oxalicum, Trichodermaviride, Stachybotrys atra, Fusarium oxysporum, Candida albicans, Cryptococus neoformans and Saccharomyces cerevisae.Mycotoxins concentrations obtained from the analyses of sieved poultry dust were 21.32 + 2.35 ppb of aflatoxins,11.26 + 1.78 ppb of ochratoxins and 4.10 + 0.13 ppb of fumonisins. Aflatoxin concentrations and fungal loads in settleddust showed positive correlation with duration of dust deposition, but the former produced stronger association than thelatter (r = +0.991, P < 0.001 and r = +0.957, P < 0.02 respectively). Results obtained in this study indicate that poultrydust is rich in mirofungi and mycotoxins which could be of occupational health importance.