Exploring different Pseudomonads strains with efficient cellulolytic, pectinolytic, proteolytic, and lipolytic activity in consortia for bioaugmentation of sustainable urban organic waste composting

The rapid urbanization of megacities has increased the challenge of managing household and municipal waste. Composting is a sustainable alternative to conventional organic waste management, but its efficiency is often limited by the slow decomposition of complex organic materials. This laboratory-based study investigates physiological variants of Pseudomonads exhibiting cellulolytic, pectinolytic, proteolytic, and lipolytic activities, aiming to formulate and assess consortia for bioaugmentation. The objective is to enhance composting efficiency, promote sustainable organic waste management, and improve plant growth-promoting traits in mature compost through the synergistic activity of these microbial communities. Pseudomonas strains were selectively isolated from immature vermicompost and screened for different enzymatic activities. The most efficient strains were combined into a bacterial consortium, which demonstrated enhanced biodegradation potential. Quantitative assays revealed that the mixed consortia released considerably higher reducing sugars from cellulose (0.944 mg/ml) and pectin (0.314 mg/ml) than individual isolates. Proteolytic and lipolytic activities were also enhanced, with increased tyrosine release and free fatty acid production, indicating efficient protein and lipid degradation. Phylogenetic analysis identified the isolates as different strains of Pseudomonas aeruginosa. The consortium exhibited optimal growth at pH 7 and temperatures up to 44°C, suggesting its potential for mesophilic to thermophilic composting. Additionally, the consortium displayed plant growth-promoting properties, including increased indole-3-acetic acid (IAA) production (6.23 µg/ml) and enhanced phosphate solubilizating (2.72 mg/l) activities, further enhancing compost quality. These findings highlight the potential of Pseudomonas-based bioaugmentation for accelerated composting and improved waste management.