Pathogenecity of Aspergillus Niger in Plants

Aspergillus niger is a member of the genus Aspergillus which includes a set of fungi that are generally considered asexual, although perfect forms (forms that reproduce sexually) have been found. Aspergilli are ubiquitous in nature. They are geographically widely distributed and have been observed in a broad range of habitats because they can colonize a wide variety of substrates. Aspergillus niger is commonly found as a saprophyte growing on dead leaves, stored grain, compost piles and other decaying vegetation. Microscopically, its conidiophores are smooth-walled, hyaline or turning dark towards the vesicle. Conidial heads are biseriate with the phialides borne on brown, often septate metulae. Conidia are globose to subglobose (3.5-5.0 um in diameter), dark brown to black and rough-walled. It is known to create increased amount of pathogenecity in various species of plants, which can be treated by antibiotics, chemicals and antibiosis. Biological control however is the best and most effective treatment. INTRODUCTION Aspergillus niger is a fungus and one of the most common species of the genus Aspergillus. It causes a disease called black mold on certain fruits and vegetables such as grapes, onions and peanuts and is a common contaminant of food. It is ubiquitous in soil and is commonly reported from indoor environments. Aspergillus niger is a member of the genus Aspergillus which includes a set of fungi that are generally considered asexual, although perfect forms (forms that reproduce sexually) have been found. Aspergilli are ubiquitous in nature. They are geographically widely distributed and have been observed in a broad range of habitats because they can colonize a wide variety of substrates. Aspergillus niger is commonly found as a saprophyte growing on dead leaves, stored grain, compost piles and other decaying vegetation. The spores are widespread and are often associated with organic materials and soil. Aspergillus niger, a worldwide distributed member of ascomycotina, has been isolated from numerous habitats. Aspergillus niger is one of the fungi that has been labeled with the GRAS (generally recognized as safe) status from the US Food and Drug Administration. This dull or dark black looking fungus has several important products in fermentation industry. But due to cosmopolitan nature, human beings gets frequently exposed to spores and vegetative forms of A. Niger present in air, on foodstuffs and others stored consumables products and suffers with allergic problems. Aspergillus niger may also produce certain mycotoxins which are heptocarcinogenic, nephrogenic immunological in nature. In addition, this fungus is also causative agent for many rot diseases in plants. So, the present review article is an important step to understand the diversity, pathogenicity and toxicology of this important spoilage Aspergillus niger. Aspergillus niger (black mold), a filamentous ascomycete having ability of fast growth and pH tolerance is most important cosmopolitan fungi associated with postharvest decay of different substrates (Pitt and Hocking, 1997; Perfect et al., 2009; Perrone et al., 2007). This organism is a soil saprobe with a wide array of hydrolytic and oxidative enzymes involved in the breakdown of plant lignocelluloses. Because of their ability to produce extracellular organic acids some of them are commonly used in food industry. These features of Aspergillus Niger enable them to cause decay of various organic substances including fruits, vegetables, nuts, beans, cereals, herbs, wood and herbal drugs. Aspergillus niger also plays a significant role in the global carbon cycle (Baker, 2006). Moreover, Cibtech Journal of Microbiology ISSN: 2319–3867 (Online) An Online International Journal Available at http://www.cibtech.org/cjm.htm 2012 Vol. 1 (1) April-June 2012, pp.47-51/Ruchi Sharma