Qinzhou Cai,Huifang Zhang,Bingshan Zhao,Lei Ren,Yonghua Wang,Fanghua Wang
Cold-adapted, alkali-stable lipases with surfactant tolerance are highly sought after in the detergent industry. In this study, we recombinantly expressed and characterized a novel lipase from Marinobacter nanhaiticus (MNL). The purified MNL exhibited high stability within a temperature range of 10–30°C and pH values of 8–10, demonstrating optimal activity at 20°C and pH 8. MNL has a preference for substrates with medium chains with the best activity being 3768.6 U/mg using p -nitrophenyl decanoate as a substrate. Remarkably, MNL showed enhanced enzymatic activity in the presence of ionic surfactants and displayed notable resilience when exposed to proteases. Washing performance analysis further revealed MNL's high proficiency in removing oil-based stains from fabrics. Collectively, these results suggest that MNL holds significant promise as a valuable component in laundry detergent formulations.
Soil microbial communities are usually regarded as one of the key players in the global element cycling. Moreover, an important consequence of oil contamination altering the structure of microbial communities is likely to result in an increased carbon emission. However, understanding of the complex interactions between environmental factors and biological communities is clearly lagging behind. Here it showed that the flux of carbon emissions increased in oil-contaminated soils, up to 13.64 g C·(kg soil) −1 ·h −1 . This phenomenon was mainly driven by the enrichment of rare degrading microorganisms (e.g., Methylosinus , Marinobacter , Pseudomona s, Alcanivorax , Yeosuana , Halomonas and Microbulbifer ) in the aerobic layer, rather than the anaerobic layer, which is more conducive to methane formation. In addition, petroleum hydrocarbons and environmental factors are equally important in shaping the structure of microbial communities (the ecological stability) and functional traits (e.g., fatty acid metabolism, lipid metabolism and amino acid metabolism) due to the different ecological sensitivities of microorganisms. Thus, it can be believed that the variability of rare hydrocarbon degrading microorganisms is of greater concern than changes in dominant microorganisms in oil-contaminated soil. Undoubtedly, this study could reveal the unique characterization of bacterial communities that mediate carbon emission and provide evidence for understanding the conversion from carbon stores to carbon gas release in oil-contaminated soils.
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