Production of alkaline lipase by Aspergillus terreus AUMC 15762 for laundry application

Abstract

Lipases are extraordinarily critical co-factor-independent enzymes with profound economic consequences. They are utilized extensively in production of fine chemicals, food, textile, pulp and paper, laundry, and biodiesel sectors. In the current study, the lipolytic activity of 141 fungal isolates-representing 21 genera and 38 species-that were isolated from samples of desert soil gathered from the Governorates of Sohag, Qena, and Aswan were examined. Of the 74 isolates showed positive lipase activity, 40 were high lipase producers. In terms of lipase production, Aspergillus terreus AUMC 15762 was the most effective strain. To enhance the synthesis of lipase from Aspergillus terreus AUMC 15762, Plackett-Burman design (PBD) was employed. For the maximal amount of lipase synthesis (103.3 U/mL), ammonium sulphate was required after three days at 25 °C, pH 4.0, and 3.0 g/L. Through the use of Trilite MA 12 anion exchanger and Sephadex G-100 column chromatography, lipase was purified 17.79 times and achieved 64.714 kDa molecular weight on SDS-PAGE. The highest possible specific activity of 3867.85 ± 214.28 U/mg was attained at pH 8.0 and 40 °C. The addition of KCl and ZnSO₄ raised the lipase specific activity by 115.42%. K_m of 19.0 mg/mL and V_max of 1000 μmol/min were determined for the pure lipase. The effects of 20 U/mL pure lipase on corn and olive oily spots were examined in this work at pH 8.0 and 40 °C. The pure lipase completely removed oil contamination from fiber surfaces, as evidenced by the oily spots' separation from the white cotton textiles after 60 min. This work offers a lipase produced from Aspergillus terreus species that showed promise for industrial laundry applications.

Keywords: Aspergillus; Laundry; Lipase; Optimization; Plackett–Burman; Purification; Submerged.

Fig. 1

Maximum likelihood phylogenetic tree obtained from ML/MP analysis of ITS sequences of Aspergillus terreus AUMC 15762 in this study (in blue) compared to the most similar species of Aspergillus terreus group in GenBank. Bootstraps (1000 replications) for ML/MP ≥ 50% are indicated near the respective nodes. The tree is rooted to Aspergillus niger ATCC 16888 (in red)

Fig. 2

Pareto chart of the standardized effects of screened factors on Lipase activity using PBD (A = temperature; B = pH; C = Tween 80; D = peptone; F = sodium nitrate; G = ammonium chloride; H = urea; J = ammonium sulphate)

Fig. 3

3D surface plot representing interaction effect of lipase production, pH and (NH₄)₂SO₄

Fig. 4

A SDS-PAGE illustrating the lipase purification procedures. M: Standard pre-stained marker. Lane 1: Ammonium sulfate-precipitated crude lipase. Lane 2: Purified lipase with Trilite MA-12. Lanes 3 and 4: Pure lipase isolated from Sephadex G 100. B Estimation of the apparent molecular weight of the pure lipase

Fig. 5

Effect of pH A and temperature B on the activity of pure lipase produced by A. terreus AUMC 15762 (Mean values (± SD) with different letters are significantly different (p > 0.05; n = 3)

Fig. 6

Action of the pure lipase produced by A. terreus AUMC 15762 on different kinds of substrates (Mean values (± SD) with different letters are significantly different (p ≤ 0.05; n = 3)

Fig. 7

Removal of oily spots from cotton cloth pieces (10 cm × 10 cm) A and C Stained cotton cloth pieces with corn and olive oil B and D Treated cotton cloth pieces (60 min, 150 rpm at pH 8.0 and 40 °C) with the pure lipase (20 U/mL) produced by A. terreus AUMC 15762