Metagenomic and proteomic analysis of bacterial retting community and proteome profile in the degumming process of kenaf bast.

ABSTRACT

BACKGROUND: Data on the microbial community and functional proteins associated with degumming in kenaf remains scant. Here, we analyzed the microbial communities associated with kenaf (Hibiscus cannabinus) bast fibers during retting to identify potential candidate degumming bacteria. Retting liquids were collected and analyzed at 0 days, 10 days, and 34 days and then evaluated the yield and quality of kenaf fiber at the different retting times. Besides, the microbial communities were characterized using metagenomic and proteomic analysis by LC-MS/MS technology. RESULTS: The data showed that increase in the retting time significantly improves the softness, dispersion, and fiber whiteness of the kenaf fiber. The relative abundance of Acinetobacter increased from 2.88% at the baseline to 6.64% at the 34th retting. On the other hand, some members of Clostridium were reduced from 3% at the baseline to 2% at the 34th retting. Analysis of carbohydrate active enzymes showed constant changes in the utilization of carbohydrates. Besides, benzoquinone reductase, cellobiose dehydrogenase, glucose 1-oxidase, aryl alcohol oxidase and alcohol oxidase were the top five most abundant enzymes in the retting liquids. This present results demonstrated that the expressions of B7GYR8, Q6RYW5 and Q6FFK2 proteins were suppressed in Acinetobacter with the retting time. On the contrary, P05149 was upregulated with the retting time. In Clostridium, P37698, P52040 and P54937 proteins were upregulated with the retting time. CONCLUSION: In addition, bacteria Acinetobacter and Clostridium might be playing important roles in the kenaf degumming process. Similarly, up-regulation of P37698, P52040 and P54937 proteins is an important manifestation and mediates important roles in the degumming process.