Chitinous waste depolymerization and biocontrol potential of Stenotrophomonas maltophilia 3E chitinase against mycophytopathogens and Anopheles gambiae instar 3

In this study, maximum chitinase production was observed around days 3 and 4, utilizing colloidal shrimp waste (5.1 U/mL), NH 4 Cl (5.4 U/mL) 37 °C (5.4 U/mL), pH 5.4 (5.24 U/mL) and 150 rpm (5.18 U/mL). The pH-stable chitinase elicited maximum relative activity at pH 5.4 (100 %), was mesophilic (100 % residual activity at 30 °C and 40 °C) and enhanced with 5 mM Zn 2+ (106.77 % residual activity). The highest bacterial degradation was recorded in shrimp shell (50.7 %). The depolymerization of chitin was evinced by the loss of N H bending and C H stretchings characteristic of chitin in degraded samples, while chitinase-treated demineralized chitin exhibited pores. Moreover, Botrytis sp. was most susceptible to chitinase treatment (10 ± 1.5 mm inhibition), while Anopheles gambiae instar 3 were completely terminated over 48 h of 200 μL chitinase treatment. The characteristics and performance of the studied chitinase demonstrate its relevance in sustainable agriculture and waste management. • Chitinous wastes serve as repositories of robust chitinolytic bacteria. • 3E Chitinase was pH- and thermo-stable. • Phytopathogenic fungi and insect larvae were successfully killed 3E chitinase. • 50 % Chitinous wastes depolymerization was achieved by 3E chitinase. • 3E chitinase holds bright prospects for environmental applications.