Cell-wall fractions were obtained from Aspergillus niger and Chaetomium globosum. Non-structural protein was removed by successive washes in urea, NH,OH and formic acid. Amino acid analyses indicated that structural wall proteins were acidic. Aspartic acid was the free amino terminal residue of the protein in both species. Comparison of the ‘maps’ of peptic peptides indicate that there may be s...

This study investigates the biological activity of two cationic gemini surfactants, hexamethylene-1,6-bis-(N,N-dimethyl-N-dodecylammonium bromide) C6 and pentamethylene-1,5-bis-(N,N-dimethyl-N-dodecyla,.mmonium bromide) C5, and their two neutral analogs, hexamethylene-1,6-bis-(N-methyl-N-dodecylamine) (A6) and pentamethylene-1,5-bis-(N-methyl-N-dodecylamine) (A5). Experiments were performed wit...

The effect of medium pH on conidial aggregation during submerged cultivation of Aspergillus niger is considered to originate from the electrostatic surface properties of the spores. As previously shown, these properties are greatly influenced by the presence of a melanin-containing surface coating covering the outer spore wall layer. The present study was designed to elucidate the impact of suc...

Influences of phenol, α-naphtol and β-naphtol, which are toxic chemicals, on citric acid biosynthesis and biomass in the artificial culture setting of Aspergillus niger using batch fermenter are examined in the most favorable fermentation conditions, and a model is proposed. Addition of certain concentrations of phenol, α-naphtol and β-naphtol to the culture reduces the citric acid production. ...

Penicillium and Aspergillus have been recognized as important aeroallergens for more than 30 years, and are especially significant in indoor environments. There are over 400 species of Penicillium and Aspergillus combined, but there is little information on which species occur most frequently in the environment, or if each exhibits unique allergenic properties. A preliminary study showed no ove...

Bulbine natalensis Baker has been acclaimed to be used as an antimicrobial agent in the folklore medicine of South Africa without scientific evidence to substantiate or refute this claim. In view of this, the in vitro antimicrobial activity of solvent fractions (ethanol, ethyl acetate, n-butanol and water) from Bulbine natalensis Tuber against 4 Gram positive and 12 Gram negative bacteria as we...

BACKGROUND Considering that the costs of cellulases and hemicellulases contribute substantially to the price of bioethanol, new studies aimed at understanding and improving cellulase efficiency and productivity are of paramount importance. Aspergillus niger has been shown to produce a wide spectrum of polysaccharide hydrolytic enzymes. To understand how to improve enzymatic cocktails that can h...

The need of natural antimicrobials is paramount to avoid harmful synthetic chemicals. The study aimed to determine the antifungal activity of natural compound chitosan and its nanoparticles forms against Candida albicans, Fusarium solani and Aspergillus niger. Chitosan nanoparticles were prepared from low (LMW), high molecular weight (HMW) chitosan and its derivative, trimethyl chitosan (TMC). ...

Very little is known about the impact of climate change on fungi and especially on spore production. Fungal spores can be allergenic, thus being important for human health. The aim of this study was to investigate how climate change influences the responsive ability of fungi by simulating differing environmental regimes. Fungal species with high spore allergenic potential and atmospheric abunda...

Micro-organisms are capable of producing extracellular proteases that degrade proteins into amino acids to make their assimilation possible (Zouari et al., 1999). A large number of micro-organisms including bacteria, yeast and fungi produce different groups of enzymes. Selection of a particular strain, however, remains a tedious task, especially when commercially competent enzyme yields are to ...