Omoanghe S. Isikhuemhen

Identification of fungi associated with municipal compost using DNA-based techniques.

Fungi are important in terrestrial decay processes. However, fungi associated with organic decay during composting are still not well known. In this study culture-independent methods were used to identify fungi associated with composting organic municipal wastes to gain a better understanding of the diversity of fungi associated with this process. Fungal communities from 0, 210, and 410day-old compost samples were assessed with DNA fingerprinting using denaturing gradient gel electrophoresis (DGGE) and by the analysis of DNA sequences from rDNA clone libraries. From 207 rDNA sequences, 82 fungal OTUs were detected. A disproportionate number of yeast sequences were detected in Day 0 clone libraries, including the human pathogens Candida tropicalis and Candida krusei (Saccharomycetales). Basidiomycetes accounted for over half of the clones from the Day 210 sample. Clones of Cercophora and Neurospora species accounted for most of the fungal clones of the Day 410 sample. No Zygomycetes or Aspergillus species were detected in this study. These findings call for a reassessment of long held views about the organisms involved in the composting of organic municipal wastes.

Mating compatibility and phylogeography in Pleurotus tuberregium

Genetic relationships were investigated among several populations of Pleurotus tuberregium from Nigeria, Papua New Guinea and New Caledonia. Intrastock mating compatibility studies using progeny from two collections demonstrated a tetrapolar mating system for P. tuberregium. Interstock matings among the geographically distinct populations were compatible. All isolates were found to be intersterile with tester strains of other Pleurotus species, showing that P. tuberregium represents a unique intersterility group in Pleurotus. Nucleotide sequences of the ITS region of the rDNA gene were determined for 30 isolates and used to infer phylogenetic structure of populations. Phylogenetic analysis shows that African and Australasian-Pacific isolates form at least two distinct evolutionary lineages. Higher genetic divergence was observed among ITS sequences from the Australasian-Pacific region than among African isolates, which suggests a possible origin of P. tuberregium in the Australasian-Pacific region.

Cultivation studies on wild and hybrid strains of Pleurotus tuberregium (Fr.) Sing. on wheat straw substrate

Wild of strains Pleurotus tuberregium from Nigeria and the Australasian-Pacific regions and selected hybrids were studied to determine their growth and sclerotia production capacity on wheat straw substrate. Although the Australasian-Pacific strains showed faster growth rates, the wild strains from Nigeria performed better than the Australasian-Pacific strains in sclerotia yield. Under similar conditions, some hybrids had sclerotial yields that were higher than any wild strain. Our study showed the possibilities of using selected strains and the low cost methods adopted in this experiment, for the cultivation of sclerotia of P. tuberregium.

The Effect of Mushroom and Pokeweed Extract on Salmonella, Egg Production, and Weight Loss in Molting Hens

An experiment was conducted to evaluate the effects of mushroom and pokeweed extract alone or in combination with alfalfa meal on Salmonella spp. population, egg production, and weight loss in laying hens during a 10-d molting period. The trial used 54 active laying hens approximately 77 wk of age that were naturally infected with Salmonella spp. The layers were subjected to 1 of 9 treatment groups, replicated 3 times with 2 hens per replicate cage. The treatment conditions were as follows: 1) full-fed + H(2)0 (FFW), 2) full-fed + mushroom (FFM), 3) full-fed + pokeweed (FFP), 4) nonfed + H(2)0 (NFW), 5) nonfed + mushroom (NFM), 6) nonfed + pokeweed (NFP), 7) full-fed alfalfa meal + H(2)0 (FFAW), 8) full-fed alfalfa meal + mushroom (FFAM), and 9) full-fed alfalfa meal + poke-weed (FFAP). The results showed that the base-10 logarithm values of Salmonella from the ceca significantly increased (P <or= 0.05) in treatment NFW (3.48), NFM (3.22), and FFAW (3.33), whereas the greatest reduction was observed in treatment FFAM (2.72). The number of Salmonella bacteria recovered from the crop was significantly greater in the NFW treatment (3.43) and lowest in treatment FFAM (2.62). Treatment FFAM (30.0%) had the lowest BW loss and differed significantly from treatment NFW (42.3%), NFM (39.7%), and NFP (41.5%) but not from FFAW (38.0%) and FFAP (34.0%). Ovary weights for treatments NFW, NFP, FFAM, and FFAP did not differ significantly from each other but did so for NFM and FFAW (38.0%), which had the lowest weight. Return to egg production at 2 mo lagged behind in treatments FFAM, NFP, and FFM more than in any other treatments. At 3 mo, treatments FFAAM and NFW differed from the other treatments. Findings indicate that a greater decrease in the natural Salmonella population in the ceca and crop can be obtained with the combination of full-fed alfalfa plus mushroom extract in molting hens and induce a comparable molt with feed withdrawal.

Effect of Level and Type of Mushroom on Performance, Blood Parameters and Natural Coccidiosis Infection in Floor-Reared Broilers

An experiment was conducted to evaluate the feeding of four medicinal mushrooms via fungus myceliated grain (FMG) at three levels on production performance, blood parameters and natural coccidiosis oocyst excretion in floor reared broiler chickens. Three hundred day-old female broiler chickens were weighed and randomly assigned to nine different treatment groups. Each group was replicated three times with 10 birds per replicate pen. The four mushrooms utilized were Shiitake (Lentinus edodes), Reishi (Ganoderma lucidum), Oyster (Pleurotus ostreatus) and Cordyceps (Cordycepss inensis). Each mushroom was supplemented at a 5 and 10% inclusion level into a basal meal ration, and compared to a control ration containing no mushrooms. Body weights were assessed on days 28 and 49. Bursa weights, Eimeria oocyst counts, blood differential percentages and mortality rates were measured at 49 days of age. Eimeria oocyst counts, blood differential percentages and both bursa and body weights differed significantly (P ≤ 0.05) between treatment groups. Treatment 8 (Oyster 5%) produced the highest average body weight at 3.21 kg, while treatment 5 (Cordyceps 10%) produced the lowest at 2.33 kg. A higher oocyst count and increased heterophil percentage was observed in treatment 6 (Reishi 5%). There were some basic trends in the patterns of heterophil and lymphocyte percentage elevation in treatment 3 (Shiitake 10%). The results from this experiment demonstrate the ability of certain mushrooms to influence body weight of broiler chickens and show some immune enhancement via the bursa of Fabricius.

Utilizing fungus myceliated grain for molt induction and performance in commercial laying hens.

Molting in poultry is used to rejuvenate hens for a second or third laying cycle. Feed withdrawal was once the most effective method used for molt induction; however, it has being phased out due to food safety and animal welfare concerns. This study evaluated the utilization of fungus myceliated grain as a safe and effective alternative for inducing molt, enhancing immunity, reducing Salmonella growth, and returning to egg production. Laying hens were subjected to 1 of 5 treatments: 1) nonfed (NF), 2) full-fed (FF), 3) fungus myceliated meal (FM), 4) 90% fungus myceliated meal+10% standard layer ration (FM-90), and 5) 90% alfalfa meal+10% fungus myceliated meal (AF-90). Each treatment condition was replicated 9 times during a 9-d molt period. The results revealed that egg production for treatments 1 and 3 ceased completely by d 5, whereas hens in treatments 4 and 5 ceased egg production by d 6. The percentage of BW loss decreased significantly (P<0.05) in treatments 1 (57%), 2 (8%), 3 (35%), 4 (37%), and 5 (44%). Ovary weights of hens fed all molting diets decreased significantly from the full-fed control but did not differ significantly (P<0.05) from each other. Salmonella population in the crop, ovary, and ceca from hens differed significantly (P<0.05) among treatments. Return to egg production differed between treatments with higher production beginning in treatment 3 and ending in treatment 5. Antibody titers did differ (P<0.05) among treatments. From these results, fungus myceliated meal appears to be a viable alternative to conventional feed withdrawal and other methods for the successful induction of molt and retention of postmolt performance.

Medicinal mushrooms: Valuable biological resources of high exploitation potential

Abstract Higher Basidiomycetes and Ascomycetes mushrooms possess various immunological and anticancer properties. They also offer important health benefits and exhibit a broad spectrum of pharmacological activities including antibacterial, antifungal, antiviral, cytotoxic, immunomodulating, anti-inflammatory, antioxidative, antiallergic, antidepressive, antihyperlipidemic, antidiabetic, digestive, hepatoprotective, neuroprotective, nephroprotective, osteoprotective, and hypotensive activities. This minireview summarizes the perspectives, recent advances, and major challenges of medicinal mushrooms with reference to their nutraceutical properties and dietary value, the production of mushroom biomass on various substrates, and the purification, characterization, and pharmaceutical effects of biologically active compounds from medicinal mushrooms.

Lignin degradation, ligninolytic enzymes activities and exopolysaccharide production by Grifola frondosa strains cultivated on oak sawdust

Fourteen strains of Grifola frondosa (Dicks.) S. F. Gray, originating from different regions (Asia, Europe and North America) were tested for lignin degradation, ligninolytic enzyme activities, protein accumulation and exopolysaccharide production during 55 days of cultivation on oak sawdust. Lignin degradation varied from 2.6 to7.1 % of dry weight of the oak sawdust substrate among tested strains. The loss of dry matter in all screened fungi varied between 11.7 and 33.0%, and the amount of crude protein in the dry substrate varied between 0.94 to 2.55%. The strain, MBFBL 596, had the highest laccase activity (703.3 U/l), and the maximum peroxidase activity of 22.6 U/l was shown by the strain MBFBL 684. Several tested strains (MBFBL 21, 638 and 662) appeared to be good producers of exopolysaccharides (3.5, 3.5 and 3.2 mg/ml respectively).

Co-substrating of peanut shells with cornstalks enhances biodegradation by Pleurotus ostreatus.

World consumption of peanuts has increased tremendously, resulting in abundance of peanut shell waste. The high lignin content of peanut shells limits their bioconversion to useful products or recycling. Therefore, the synergy in co-substrating peanut shells (PS) and cornstalks (CS) to enhance biodegradation was evaluated. Various compositions of peanut shells and cornstalks (% dry weight) herein called co-substrate - 90PS:10CS, 75PS:25CS, 50PS:50CS, 25PS:75CS, 10PS:90CS, and two controls Cont1-100PS and Cont2-100CS were studied under solid state fermentation (SSF) with a white rot fungus, Pleurotus ostreatus for 120 days. A two-factorial experiment in a completely randomized design (CRD) was used. Results showed that substrate composition and fermentation time were important variables in substrate degradation. Lignin degradation, losses in organic matter, cellulose and hemicellulose increased with time. Increasing the composition of CS in co-substrates resulted in higher lignin loss. The most lignin (40.6%) was lost in co-substrates with 75-90% CS whereas more organic matter was lost in co-substrate containing 50% CS and above. Highest losses in organic matter (24.09%), cellulose (17.41%), and hemicellulose (52.07%) occurred in co-substrate with 50% CS, which is where the greatest reduction in C:N ratio (33%) also occurred. The macro- and micro-element content of co-substrates and the controls varied and increased significantly after fermentation. Co-substrating PS and CS appears to be a promising, environmentally-friendly approach for bioconversion of both agricultural wastes into bio-products with potential application in animal feed, biofuel, or for cultivation of mushrooms.

Notes on Agaricus section Duploannulati using molecular and morphological data

The position of several endemic and rare species in Agaricus sect. Dulploannulati and the limits of the section were investigated by analysis of sequence data from the ribosomal DNA ITS. The results supported the recognition of two groups, which we treat as subsections Chitonioides and Duploannulati. Most of the species studied proved to belong to subsect. Chitonioides. Species excluded from the section, as well as other potential members of sect. Duploannulati, are considered. Morphological traits deemed important for identification of A. nevoi, A. pequinii, A. gennadii, A. rollanii, and A. padanus are discussed. Taxonomic positions of these species in morphologically-based systems and according to molecular systematics data are compared and analyzed.