MOSP - Macao Scientific Publishers

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Growth and IN VITRO phosphate solubilising ability of SCLERODERMA SINNAMARIENSE: A tropical mycorrhiza fungus isolated from GNETUM AFRICANUM ectomycorrhiza root tips

Eneke Esoeyang Tambe Bechem

Abstract: The growth and ability of SCLERODERMA SINNAMARIENSE isolated from GNETUM AFRICANUM ectomycorrhiza root tips to solubilise calcium tetrahydrogen diorthophosphate, calcium phytate, hydroxyapatite and amorphous iron phosphate was assessed in axenic culture under a range of conditions. S. SINNAMARIENSE grew on all P sources when NH4+ was sole nitrogen source, but failed to grow on amorphous iron phosphate in unbuffered media with peptone as sole nitrogen source. The fungus solubilised calcium tetrahydrogen diorthophosphate and hydroxyapatite in unbuffered media with NH4+ as nitrogen source. The internal phosphorus status of the mycelia had no influence on the ability of the fungus to solubilise the substrates. The data confirmed that mycorrhizal fungi can access P sources which are normally unavailable and may pass on the absorbed P to the plant partner in case of symbiosis.[...] Read More.

Keywords: Phosphorus solubilisation, Scleroderma sinnamariense, mycorrhiza fungus.

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Screening of indigenous yeast isolates obtained from traditional fermented foods of Western Himalayas for probiotic attributes

Aditi Sourabh, Sarbjit Singh Kanwar*, and Om Prakash Sharma

Abstract: Twenty three indigenous isolates of yeast (Saccharomyces cerevisiae) obtained from various traditional fermented foods and traditional inocula of Western Himalayas (Himachal Pradesh) were subjected to in vitro probiotic tests. All the isolates were found to be intrinsically tolerant to upper gastrointestinal transit and this property was isolate dependent. Reduction in viability (in terms of log CFU/ml cells) was more in simulated gastric juice of pH 2 as compared to pH 3. These isolates were also investigated for surface hydrophobicity and autoaggregation abilities. Nine yeast isolates produced exopolysaccharide and four exhibited antioxidative activity using 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay (in methanol and buffered methanol reaction systems). Interestingly, one indigenous yeast isolate (Sc15) was found positive for siderophore production, whereas none of the isolates was positive for bile salt deconjugation activity (towards glycine and taurine conjugated bile salts) and galactosidase enzyme production.[...] Read More.

Keywords: Probiotics, yeast isolates, simulated gastric and intestinal juices, Western Himalayas, antioxidant, exopolysaccharide.

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Biochemical characterisation of two novel laccases from Magnaporthe grisea

Kaminee Ranka and Bharat B. Chattoo*

Abstract: Laccases are widely distributed oxido-reductases that catalyse the biological oxidation-reduction of polyphenols with a concomitant reduction of molecular oxygen to water. Genome analysis of Magnaporthe grisea using bioinformatic approach showed the presence of multiple laccases, which encode proteins with three domains of multicopper oxidase. The transcript levels of all M. grisea laccases were analysed by quantitative RT-PCR, in order to study their expression patterns in normal and nitrogen starved conditions. The highest relative expression was observed for MGG_08127 (MgLac1) in normal conditions. The highest induction was observed for MGG_02876 (MgLac2) in nitrogen starvation. Since total fungal protein extracts would contain multiple laccases, heterologous gene expression, purification and further enzyme characterisation was carried out to analyse the function of these two laccases from M. grisea. Thus, we identified a novel multifunctional laccase, MgLac2, in M. grisea which showed lignin-like dye decolourising activity, 1, 8-dihydroxynapthalene (DHN) polymerisation ability and also ferroxidase activity. Its optimum pH and maximum thermostability were at 4 to 4.5 and 30°C, respectively. MgLac1 also showed dye decolourization activity, its optimum pH and maximum thermostability were at 4 to 5 and 30°C, respectively. We found that the laccases expressed in normal conditions and in conditions which mimic pathogenicity are different biochemically.[...] Read More.

Keywords: Magnaporthe grisea, laccase, dye decolourization, 1, 8-dihydroxynapthalene (DHN) polymerisation, ferroxidase activity, glutathione-S-transferase (GST).

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Effect of carbon, nitrogen and trace elements on growth and sporulation of the Termitomyces striatus (Beeli) Heim

Simerjit Kaur

Abstract: Nutritional studies namely carbon, nitrogen and trace element requirements of Termitomyces striatus have been carried out. Amongst all the carbon compounds used, the most favourable in order of effectiveness are D (+) glucose, D (+) sucrose, maltose and D (+) raffinose. The fungus showed poor growth with lactose. Sodium nitrite served as the best inorganic nitrogen source for the growth of this fungus. Ammonium acetate, ammonium phosphate, ammonium oxalate, potassium nitrate and sodium nitrate supported fairly good growth of the fungus. Among different amino acids tested, maximum average mycelial dry weight was obtained with L-arginine followed by glycine and DL-tryptophan. The fungus showed poor growth with L-α-amino-n-butyric acid, L-cystine, L-cysteine HCl and DL-serine. The selected concentrations of trace elements also affected the mycelial growth of this fungus to a significant level. There is a gradual increase in growth (average mycelial dry weight) from control to optimum concentration of required trace elements beyond which it decreases. None of the trace elements required for growth are found to be completely fungistatic for the growth of this fungi. The fungus formed asexual conidia similar to that formed in the sporodochial stage in the termite garden of termites of the subfamily Macrotermitinae.[...] Read More.

Keywords: Termitomyces, edible mushrooms, cultural studies, C, N nutrition, mycelial growth.

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Effect of some chemicals on growth, melanogenesis, pathogenicity and metabolic activities of Rhizoctonia solani

Amany H. Aboellil* and Neveen M. Mohammed

Abstract: Morphogenesis, cell differentiation, sclerotial formation and melanogenesis of a fungus depend on growth conditions. The present work aims to study the effect of some chemicals on the growth parameters of Rhizoctonia solani, which is the main causal organism of many diseases as damping off disease of many crops such as Phaseolus vulgaris. Different concentrations of hydrogen peroxide H2O2 and Ethylenediaminetetraacetic acid (EDTA) were studied. EDTA showed an inhibitory activity with decreasing sclerotia formation and its pigmentation (melanogenesis), also hyphae became hyaline. This isolate which lacks melanin, was nominated as hyaline Rhizoctonia (HR). Hydrogen peroxide showed highest sclerotia formation and increase in its pigmentation. This isolate, which forms melanin, will be nominated as dark Rhizoctonia (DR). It caused a higher disease index to seeds of P. vulgaris than did HR. Melanin is a virulence factor. The disease index was higher by DR than HR. DR exhibited less protein content, but more diverse proteins than HR. DNA similarity between DR and HR was about 90%. Superoxide dismutase (SOD) was detected in a higher amount in DR than HR. Catalase could not be detected in either DR or HR. EDTA is promising potential drugs for combating pathogenicity.[...] Read More.

Keywords: Rhizoctonia, superoxide dismutase, pathogenicity, melanin, DNA, ethylenediaminetetraacetic acid (EDTA).

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Solid state fermentation of Jatropha curcas kernel cake: Proximate composition and antinutritional components

M. A. Belewu* and R. Sam

Abstract: Five fungi (Aspergillus niger, Penicillium chrysogenum, Rhizopus oligosporus, Rhizopus nigricans and Trichoderma longibrachitum) were used in the fermentation of Jatropha curcas kernel cake for a 7 days period in a completely randomized design model. The results revealed significant increase in the crude protein content of all the fungi treated samples with Aspergillus niger and T. longbrachitum treated cake recorded higher value compared to other treated samples. There was no significant difference in the crude fiber content among all the samples. With the exception of ether extract content of sample treated with Rhizopus nigricans which was similar to that of the control (untreated sample) other samples showed lower significant values than the untreated (control) sample. Contrarily, the ash content was significantly lower in the control sample compared to other fungi treated samples. The content of the trypsin inhibitor was highest (18.6 mg/kg) in the control but reduced significantly in the fungi treated samples (6.50 - 8.23). The lectin, saponins, phytate and phorbolester contents followed similar trend. It could be concluded from this study that solid state fermentation of Jatropha kernel cake detoxified and inactivate almost 100% of the antinutrient contents expect phorbolester to a tolerable level in the A. niger treated sample.[...] Read More.

Keywords: Jatropha curcas kernel cake, proximate composition, trypsin inhibitor, lectin, phytic acid, saponins, phorbolester.

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Interactions between multiple fungi isolated from two bark beetles, Dendroctonus brevicomis and Dendroctonus frontalis (Coleoptera: Curculionidae)

Thomas S. Davis, Richard W. Hofstetter, Kier D. Klepzig, Jeffrey T. Foster and Paul Keim

Abstract: Antagonism between the fungal symbionts of bark beetles may represent a biologically significant interaction when multiple beetle species co-occur in a host tree. Since high density bark beetle populations rapidly and dramatically shift forest characteristics, patterns of competition between the obligate fungal associates of sympatric bark beetle species may have broad ecological effects. Primary and competitive resource acquisition between allopatric and sympatric isolates of mutualist fungi associated with the bark beetles Dendroctonus frontalis and Dendroctonus brevicomis were investigated. Growth assays at multiple temperatures suggest that primary resource acquisition by fungi growing in the absence of competitors varies regionally, and that optimal growth rate is likely to correspond to average summertime maximum temperatures. In competition assays, interactions were asymmetric between fungi isolated from sympatric beetle populations and fungi isolated from allopatric beetle populations: sympatric isolates out-competed allopatric isolates. However, competition between fungi from beetle populations in sympatry was found to be equal. These studies are the first to investigate interactions between the mycangial fungi of multiple Dendroctonus species, and the results suggest that competition is likely to occur when the mycangial fungi of multiple beetle species occur together.[...] Read More.

Keywords: Allopatric, competition, coexistence, mutualism, mutualist, mycangial fungi, sympatric.

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A specific inhibitory protein to a restriction enzyme from Saccharomyces cerevisiae

Mukaram Shikara*

Abstract: A specific protein inhibitor for the restriction enzyme (SacC1) has been purified from Saccharomyces cerevisiae approximately 21,000 fold and its inhibitory properties have been characterized. The isoelectric points (pI) of SacCI and its inhibitor are 9.0 and 5.22, respectively. The molecular weight of SacC1, the inhibitor and SacC1-inhibitor complex were estimated by gel filtration on a Sephadex G-100 column to be 64,000, 32,000 and 85,000, respectively. The inhibitor protein inhibits SacC1 catalytic activities efficiently, but has no effect on other restriction enzymes tested. Inhibition does not occur unless SacC1 enzyme is exposed to the inhibitor protein prior to the reaction of the enzyme with DNA. The inhibitory activity is independent of temperature. The inhibition increased linearly with the addition of inhibitor to various amounts of SacC1, up to 85% inhibition. The slope of inhibition was constant irrespective of the initial amount of SacC1 and Ki value of 3.45 x 10-12 was obtained. The inhibitor interacts strongly with SacC1 and this interaction could increase the stability of the complex, possibly manifesting itself as SacC1 decreases in the dissociation rate due to the electrostatic attraction between the two groups or the stability may increase by potentially stronger electrostatic interaction. The conformational specificity between SacC1 and its inhibitor seems to be essential for their interaction. The extremely strong affinity of the inhibitor to SacC1 is remarkable and stronger than the affinity of several restriction enzymes.[...] Read More.

Keywords: Saccharomyces cerevisiae, inhibitor, protein, restriction enzyme, yeast, purification, Ki.

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Production cellulase by different co-culture of Aspergillus niger and Tricoderma viride from waste paper

Ali A. Juwaied, Suhad Adnan and Ahmed Abdulamier Hussain Hussain Al-Amiery*

Abstract: In Iraq, there is attempts to transfer the various industrial carbon waste to veterinary proteins depend on microorganisms by using of chemical process. Five different co-culture combinations (1:1 ratio, 1 × 106 conidia)of Aspergillus niger and Trichoderma viride, mixing of A. niger and T. viride, in 24 and 48 h old monocultures of Aspergillus similar mixing of A. in 24 and 48 h old monoculture of Trichoderma and the monocultures of both were evaluated for their potential performance of cellulases production. The study indicates that the cellulases obtained from compatible mixed cultures simultaneous mixing of both fungi have more enzyme activity as compared to their pure cultures and other combinations. The fermentation experiments were performed in solid stat fermentation (SSF). Incubation time, carbon sources and initial pH of fermentation medium was optimized with simultaneous mixed culture. It was revealed that the newspaper at pH = 5 and 40°C was the best source of carbon for the enhanced production of cellulase in the compatible mixed culture experiments after 8 days of incubation with 5.70 U/ml. Based on the reported results, it may be concluded that industrial carbon waste can be a potential substrate for production of cellulase, incorporation of co-culturing A. niger and T. viride. The aim of this work is to produce of Cellulase from waste paper and reduce the pollution.[...] Read More.

Keywords: Aspergillus niger, Tricoderma viride, cellulase, culture.

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Evidence of antagonistic interactions between rhizosphere and mycorrhizal fungi associated with Dendrocalamus strictus (Bamboo)

Rohit Sharma,*, Ram .C. Rajak and Akhilesh .K. Pandey

Abstract: The paper deals with interactions of some microfungal strains isolated from rhizosphere soils from three different sites with ectomycorrhizal fungus Cantharellus tropicalis mycelium grown in vitro on agar plates. The rhizospheric fungi were isolated from 3 different sites of bamboo forest and grown against Cantharellus. The cross inoculation method showed that C. tropicalis was highly active against some fungi, thus resulting in different types and strength of interactions. Overgrowth was the most common interaction (45%), followed by inhibition at distance (29%), intermingling (17%) and contact inhibition (13%). The competitive strength of the ectomycorrhizal fungus was high and only affected by some fast growing sterile mycelia, an unidentified fungus and Trichoderma viride.[...] Read More.

Keywords: Cantharellus, ectomycorrhiza, mycorrhizal systems, biological control, soil micro fungi.

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