Large-scale analysis of the genome of the rare alkaline-halophilic Stachybotrys microspora reveals 46 cellulase genes.

Fungi are of great importance in biotechnology, for example in the production of enzymes and metabolites. The main goal of this study was to obtain a high-coverage draft of the Stachybotrys microspora genome and to annotate and analyze the genome sequence data. The rare fungus S. microspora N1 strain is distinguished by its ability to grow in an alkaline halophilic environment and to efficiently secrete cellulolytic enzymes. Here we report the draft genome sequence composed of 3715 contigs, a genome size of 35 343 854 bp, with a GC content of 53.31% and a coverage around 20.5×. The identification of cellulolytic genes and of their corresponding functions was carried out through analysis and annotation of the whole genome sequence. Forty-six cellulases were identified using the fungicompanion bioinformatic tool. Interestingly, an S. microspora endoglucanase selected from those with a low isoelectric point was predicted to have a halophilic profile and share significant homology with a well-known bacterial halophilic cellulase. These results confirm previous biochemical studies revealing a halophilic character, which is a very rare feature among fungal cellulases. All these properties suggest that cellulases of S. microspora may have potential for use in the biofuel, textile, and detergent industries.

Artificial Neural Networks and Response Surface Methodology Approach for Optimization of an Eco-Friendly and Detergent-Stable Lipase Production from Actinomadura Keratinilytica Strain Cpt29.

This work mainly focused on the production of an efficient, economical, and eco-friendly lipase (AKL29) from Actinomadura keratinilytica strain Cpt29 isolated from poultry compost in north east of Algeria, for use in detergent industries. AKL29 shows a significant lipase activity (45 U/mL) towards hydrolyzed triacylglycerols, indicating that it is a true lipase. For maximum lipase production the modeling and optimization of potential culture parameters such as incubation temperature, cultivation time, and Tween 80 (v/v) were built using RSM and ANN approaches. The results show that both the two models provided good quality predictions, yet the ANN showed a clear superiority over RSM for both data fitting and estimation capabilities. A 4.1-fold increase in lipase production was recorded under the following optimal condition: incubation temperature (37.9 °C), cultivation time (111 h), and Tween 80 (3.27%, v/v). Furthermore, the partially purified lipase showed good stability, high compatibility, and significant wash performance with various commercial laundry detergents, making this novel lipase a promising potential candidate for detergent industries.

Purification and biochemical characterization of a detergent-stable keratinase from a newly thermophilic actinomycete Actinomadura keratinilytica strain Cpt29 isolated from poultry compost.

An extracellular thermostable keratinase (KERAK-29) was purified and biochemically characterized from a thermophilic actinomycete Actinomadura keratinilytica strain Cpt29 newly isolated from Algerian poultry compost. The isolate exhibited high keratinase production when grown in chicken feather meal media (24,000 U/ml). Based on matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS) analysis, the purified enzyme is a monomer with a molecular mass of 29,233.10-Da. The data revealed that the 25 N-terminal residue sequence displayed by KERAK-29 was TQADPPSWGLNNIDRQTAFTKATSI, which showed high homology with those of Streptomyces proteases. This keratinase was completely inhibited by phenylmethanesulfonyl fluoride (PMSF) and diiodopropyl fluorophosphates (DFP), which suggests that it belongs to the serine protease family. Using keratin azure as a substrate, the optimum pH and temperature values for keratinase activity were pH 10 and 70°C, respectively. KERAK-29 was stable between 20 and 60°C and pH 3 and 10 for 5 and 120 h, respectively, and its thermoactivity and thermostability were enhanced in the presence of 5 mM Mn(2+). Its catalytic efficiency was higher than that of the KERAB keratinase from Streptomyces sp. strain AB1. KERAK-29 was also noted to show high keratinolytic activity and significant stability in the presence of detergents, which made it able to accomplish the entire feather-biodegradation process on its own. The ability of the A. keratinilytica strain Cpt29 to grow and produce substantial levels of keratinase using feather as a substrate could open new promising opportunities for the valorization of keratin-containing wastes and reduction of its impacts on the environment.