Gut bacterial symbionts have an essential role in the nutrition and fitness of xylophagous insects. These bacteria produce several enzymes like cellulase and laccase which are important in industrial applications. In this study, laccase-producing bacteria were isolated and identified from the gut of the wood borer leopard moth. Four novel laccase positive strains were isolated using guaiacol-containing agar plates. Among the strains of dc4f, le2f, lc2, and lb8, the strain le2f displayed high laccase activity of 0.059 U ml^-1 toward syringaldazine as a typical laccase substrate. The isolates were identified based on biochemical tests and 16S rRNA gene sequencing analyses. Nucleotide BLAST analyses of 16S rRNA gene sequence exhibited that the strains of dc4f, lb8, lc2, and le2f, had the most similarity (with more than 98% identity) with Enterobacter sp. strain W-6 16S (ACCN: MK505390), Serratia liquefaciens strain N112 (ACCN: MK629784), Brevibacterium sp. strain 773 (ACCN: MH777897) and Staphylococcus sciuri strain KSI 708 (ACCN: KC113150), respectively. Overall, the current study is the first research on alkaliphilic bacterial strains from the gut of leopard moth with laccase activity.

Aims: Significant amounts of waste, including feathers, bones, blood, etc. are yearly produced by the poultry industry. Feathers are composed of 90% keratin protein, and the rest is composed of lipids and water. Keratinases are one of the most diverse and usable enzymes, which can be produced by bacterial and fungal microorganisms. These enzymes show a wide range of application in various fields.
Materials and Methods: In this study, the keratinolytic activity of the isolated strain from a poultry farm in Mashhad was evaluated and then the medium conditions for keratinase production were optimized. The strains were identified based on the morphological and biochemical methods. 16SrRNA gene of the strain was amplified by PCR and then sequenced. The strain proteolytic activity was examined and compared with its keratinolytic activity. Finally, strain growth ability tested in variety substrate.
Findings: Using 16SrRNA gene sequencing, morphological and biochemical identification, the strain shared 99.9% similarity with Bacillus mojavensis. Optimization of various factors, including temperature, pH, incubation time, carbon and nitrogen sources, aeration and inoculum size showed that the isolated strain has the highest keratinolytic activity at 37°C, 48 hour incubation period, pH=9.5, sucrose 1%, 3% substrate, aeration 75% and 6% (v/v) inoculum amount. None of the nitrogen sources had a positive effect.
Conclusion: The FUM-1 keratinolytic activity was increased approximately 3.38 fold by condition optimization of the medium, indicating the importance of environmental conditions. In the study, the strain with high keratinolytic activity was suggesting its potential use in biotechnological.