Extracellular cellulase production by tropical isolates of Aureobasidium pullulans

Abstract

Cellulase production by Aureobasidium pullulans from the temperate regions has remained speculative, with most studies reporting no activity at all. In the current study, tropical isolates from diverse sources were screened for cellulase production. Isolates were grown on a synthetic medium containing cell walls of Msasa tree (Brachystegia sp.) as the sole carbon source, and their cellulolytic activities were measured using carboxymethyl cellulose and alpha-cellulose as substrates. All isolates studied produced carboxymethyl cellulase (endoglucanase) and alpha-cellulase (exoglucanase) activity. Endoglucanase-specific activities of ten selected isolates ranged from 2.375 to 12.884 micromol glucose.(mg protein)-1.h-1, while activities on alpha-cellulose (exoglucanase activity) ranged from 0.293 to 22.442 micromol glucose.(mg protein)-1.day-1. Carboxymethyl cellulose induced the highest cellulase activity in the selected isolates, while the isolates showed variable responses to nitrogen sources. The current study indicates that some isolates of A. pullulans of tropical origin produce significant extracellular cellulolytic activity and that crude cell walls may be good inducers of cellulolytic activity in A. pullulans.

Esterases and putative lipases from tropical isolates of Aureobasidium pullulans

“…pullulans strains used in the current study showed variability in esterase and lipase activities. This could be expected as a result of significant strain variability known about the organism (Deshpande et al 1992, Kudanga andMwenje 2005). While all isolates used in liquid cultures showed esterase activities, the highest activity was produced with Tween 80 as carbon source.…”

Intraspecific diversity of Aureobasidium pullulans strains from different marine environments

“…For example, cellulase, which degrades cellulose to produce glucose, can be applied to detergent, textile, fermentation, food, and pharmaceutical industries (Kudanga and Mwenje, 2005). Proteases have been shown to have many potentials in detergent production, leather processing, silver recovery, medical application, food processing, chemical industry as well as waste treatment.…”

“…After stained for 30 min, the dishes were washed with distilled seawater and then covered by a small amount of 1.0 molL -1 HCl solution. Finally the clear zones on the dishes could be observed (Kudanga and Mwenje, 2005).…”

“…In the last two decades, it has been found that different strains of terrestrial A. pullulans can be used in different fields because of its capacity of producing pullulan and extracellular enzymes including cellulase and xylanase (Kudanga and Mwenje, 2005;Tanaka et al, 2004). At the same time, the gene encoding xylanase has been cloned and characterized from this organism.…”

Enhancing the Nutritional Value of Canola (Brassica napus) Meal Using a Submerged Fungal Incubation Process

“…Figure 6. Reduction of total GLS ± SD following sterilization and submerged fungal incubation in CP canola meal Overall, A. pullulans (NRRL-58522) caused the greatest reduction in GLS levels in both HE and CP canola meals (ranging from 94.5-98.9%), likely due to its robust capability for producing extracellular enzymes (Kudanga & Mwenje, 2005). A. pullulans (NRRL-Y-2311-1) was also very effective in reducing GLS concentrations (ranging from 86.3-93.7%), followed by F. venenatum (81.8-93.5%) and T. reesei (78.7-92.2%).…”