Ram C. Rajak

Keratinophilic Fungi: Nature's Keratin Degrading Machines! Their Isolation, Identification and Ecological Role

Keratinophilic fungi are an ecologically important group of fungi that cycle one of the most abundant and highly stable animal proteins on earth —keratin. This article briefly explains how to isolate and identify them, the process of keratin degradation, and the ecological role of this important but unnoticed group of minute keratin cycling machines present in soil. We believe that Indian soil contains many more such fungi which have not been isolated and we hope this article will create interest among students to isolate and study these interesting fungi.

Molecular detection of Microsporum persicolor in soil suggesting widespread dispersal in central India.

A survey was conducted from 1999 to 2003 as part of a microbial biodiversity study on geophilic and keratinophilic fungi in central India. Among the keratinophilic fungi recovered were 82 isolates belonging to the dermatophyte genus Microsporum. Species were provisionally identified by morphology and confirmed by PCR-RFLP and sequencing of the ITS regions of rDNA. Microsporum persicolor appeared to be preponderant in central Indian soils, outnumbering the common geophilic species of Microsporum filvum and Microsporum gypseum. Three dinucleotide microsatellite markers were developed and their use revealed immense intraspecific variation among Indian populations of M. persicolor which would indicate that this species was not recently introduced into India. No correlation was established between the genotypes and the geographical location or the habitat of the isolates.

Internal Transcribed Spacer (ITS) of rDNA of appendaged and non-appendaged strains of Microsporum gypseum reveals Microsporum appendiculatum as its synonym.

Recently a new taxon of geophilic dermatophytes was established as Microsporum appendiculatum Bhat and Mariam, based on the presence of appendaged macroconidia. However, such appendages are already known in the related species Microsporum gypseum. We conducted a survey of soil in central India as a part of a microbial biodiversity project and obtained two strains of M. gypseum with appendaged macroconidia. Using phenotypical characterization in combination with sequencing and restriction fragment length polymorphism (RFLP) of the Internal Transcribed Spacer (ITS) region of rDNA, we found that all strains of appendaged species are identical. Therefore M. appendiculatum is regarded as a synonym of M. gypseum.

An improved zymographic method for detection of amylolytic enzymes of fungi on polyacrylamide gels

Zymography is an electrophoretic technique by which enzyme activity can be visualized directly on a polyacrylamide gel as discrete bands. A modified, more rapid technique for amylase zymography is described and compared with previously published methods. Whereas previous methods are based on 0.1 M acetate buffer as substrate buffer, our method utilizes 50mM Tris buffer containing Ca 2+ , Na + , NaN 3 and Triton X-100 which helps rapid hydrolysis of the starch and stabilization of the enzyme. The staining procedure, previously requiring overnight incubation of the gel in iodine solution at 4°C, has been reduced to 5 min at room temperature. Both methods gave rise to comparable levels of enzyme activity on polyacrylamide gels. Our modified method requires 8 h to complete the whole zymographical procedure instead of 18-20 h as in previous methods.

Ectomycorrhizal Interaction Between Cantharellus and Dendrocalamus

Ectomycorrhiza forms an important association with higher plants. The knowledge about interaction of ectomycorrhiza with host plants is scarce and thus deserves much attention, particularly in case of edible ectomycorrhizae.

A Simple New Technique for Ectomycorrhizal Formation between Cantharellus and Dendrocalamus strictus

In vitro ectomycorrhizal formation is important in establishing an ectomycorrhizal relationship between a host tree and mushroom mycelia. Moreover, axenic conditions are considered essential for the synthesis of ectomycorrhiza under laboratory conditions. There have been several attempts in the past to evolve new methods of ectomycorrhizal formation between pine seedlings and fungal mycelia, but there have been few reports with angiosperm trees. In an attempt to design equipment that would require limited space and yet permit the observation of ectomycorrhiza formation, we developed a flask-filter paper technique for in vitro ectomycorrhizal formation between Cantharellus tropicalis and Dendrocalamus strictus. The characteristic feature of this technique is that root and shoot parts extend within a flask forming typical ectomycorrhiza in aseptic synthesis. Hence, this technique enabled Dendrocalamus plants to grow axenically and develop an ectomycorrhizal association with Cantharellus mycelium. This method is simple and will help in the in vitro study of other mycorrhizal fungi which form ectomycorrhiza with other angiosperm trees.

New Indian record of a rare fungus: Asterophora lycoperdoides

Abstract A brief introduction to the fungi is given. A new record of a rare fungus, Asterophora lycoperdoides, growing on Russula sp. from Madhya Pradesh in India is reported, described and illustrated. It is the first generic record from India of a largely understudied group of organisms. A discussion of all three species of Asterophora found worldwide is provided, along with a simple key to the identification of species and their comparison. Harvesting by local tribal people and potential loss of many undescribed species makes it imperative for further surveys and establishment of an ectomycorrhizal database.