Isolation and characterization of an efficient bacterial cellulose producer strain in agitated culture: Gluconacetobacter hansenii P2A

摘要

In this study, typical niches of acetic acid bacteria were screened for isolation of cellulose producer strains. Hestrin Schramm broth was used as enrichment and production media. Only nine out of 329 isolates formed thick biofilms on liquid surface and were identified as potential cellulose producers. Physiological and biochemical tests proved that all cellulose producers belonged to Gluconacetobacter genus.Most productive and mutation-resistant strain was subjected to 16S rRNA sequence analysis and identified as Gluconacetobacter hansenii P2A due to 99.8 % sequence similarity. X-ray diffraction analysis proved that the biofilm conformed to Cellulose I crystal structure, rich in Iα mass fraction. Static cultivation of G. hansenii P2A in HS medium resulted with 1.89±0.08 g/l of bacterial cellulose production corresponding to 12.0±0.3 % yield in terms of substrate consumption. Shaking and agitation at 120 rpm aided in enhancement of the amount and yield of produced cellulose. Productivity and yield reached up to 3.25± 0.11 g/l and 17.20±0.14 % in agitated culture while a slight decrease from 78.7 % to 77.3 % was observed in the crystallinity index.