Carbohydrates and genetic properties of two psychrophile pseudomonas B 5-16 and B 6-15

Abstract

Low temperature environment limits microbial activity results in prolonged composting fermentation time, which urgently required bacteria inoculants to initiate the composting process. Psychrophile bacteria are cold-loving bacteria or archaea, of which focused on enzymatic characteristics and cold tolerance mechanism. B5-16 (Pseudomonas Baetica) and B 6-15 (Pseudomonas Fragi) are two psychrophilic bacteria isolated in the paddy soil at -20 °C, which have been proved to raise the temperature to 53 °C of compost and accelerate degradation of organic macromolecular matters. In this study, the carbon metabolic properties of these two bacteria were determined based on Biolog Ecoplate metabolic analysis at 15 °C. Results showed that two pseudomonas utilized 34 and 26 kinds of monosaccharide or polysaccharide at 15 °C, respectively. We also observed that the activity of B5-16 amylase was 71.4 U/mL, protease was 9.62 U/mL, of which B6-15 cellulase was 27.44 U/mL. Carbohydrate transport and metabolism annotation illustrated that most of genes were related to cellular signaling and metabolism, in which Carbohydrate transport and metabolism, Amino acid transport and Metabolism were involved. We also demonstrated that clpA and cspD of two pseudomonas relative expression up-regulated almost two times at 15 °C. We concluded that both B 5-16 and B 6-15 have characteristics of biodegradable proteins, cellulose and other organic macromolecules at 15 °C. The research shed light on the effect on the raise of composting temperature at low temperature environment.