Genus Aspergillus

Significance and Importance of Genus Aspergillus

Significance and Importance of Genus Aspergillus

Introduction

Microorganisms are abundantly seen in nature. They transfer from the earth's surface to the upper atmosphere by air. Microorganisms are present everywhere in nature from mountains to the depths of oceans. They are even present in the fertile soil. Microorganisms occur in large quantities in those areas where they find appropriate moisture and temperature for their growth. The conditions necessary for microbial growth are similar to those under which people usually live. They are frequently seen in the air which we breathe, on the surface of our bodies and orifices and even present in the food we eat. Microorganisms are considered important in maintaining the ecological balance on earth as they are widely distributed throughout the environment. The variety of their activities ranges from disease production to industrial uses of microorganisms in chemical and food industry (Pelczar et.al, 1998, p.15).

Discussion

Genus Aspergillus

Aspergillus is amongst the most widely studied fungal genera which has great value in many applied areas. The genus Aspergillus comes under the kingdom fungi. The first description of this genus was given by, Micheli in 1729 in order to include the fungi having extended stalks and spores which are, branching in the form of long chains from the centre and having a structure similar to aspergillum (a brush like object used for sprinkling holy water in religious ceremonies) (Micheli,1729, p.2). Genus Aspergillus consists of species of diversified nature which are of commercial value and at the same time can cause dangerous diseases and infections. Aspergillus comes under the class deuteromycetes of the kingdom fungi. Class deuteromycetes also include species of penicillium and candida. Aspergillus consists of septate or branches in which the vegetative part is submerged. The conidia arising, from the foot cell are also submerge. These conidia may be septate or nonseptate, at the top most portion these conidia blow up and form a vesicle. Conidia are arranged in the form of chains, and their shapes and size vary depending on the specie. Aspergillus can be distinguished from other species by means of characteristic colours of conidia which may be green, black or brown. Aspergillus can grow in excessive quantities of sugar and saline which signifies that they are capable of removing water from excessively dry substances for their growth (Pelczar et.al, 1998, p.15).

Genus Aspergillus consists of 260 (Samson and Varga 2009, p.1) while some claim that it contains 837 species (Hawksworth, 2011, p.1) these species are further divided into different telemorphic genera (Geiser, 2009, p.1). This proves that this genus is amongst the most diverse groups of fungi. Aspergillus species are considered among the most abundant fungi worldwide as they can grow easily in low humidity and temperature of 6-55°C (Williams and Hallsworth, 2009, p.3292). They feed on a wide variety of substrates which may also include animal waste matter, and are mainly seen on complex plant polymers (Bennett, 2010, p.1).

They are also known as food spoilage fungi as one of the specie Aspergillus Niger ...