Monday, April 30, 2007

Isolation and characterization of a cellulose-producing microorganism

Jin-Nam Kim1, Yong-Jun Kim1, Soo-Yeon Kim2, Young-Jung Wee1, Don-Hee Park1, and Hwa-Won Ryu1. (1) School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757, South Korea, (2) Institute for Radiological Imaging Science, Wonkwang University, Iksan, Jeonbuk 570-749, South Korea

Cellulose is the most abundant organic polymer in nature, where it plays an important role in integrity of plant. Plant cellulose is being intensively used in the paper and textile industries, which leads to a significant demand on wood biomass. Bacterial cellulose (BC) differs from plant cellulose with respect to its size, purity, and crystallinity. Recently, there have been interests in new fields of application of BC such as thickeners for food, materials for protection of burned skin in medical, healthcare, cosmetic, environmental, clothing, and aircraft industries due to its distinguished physicochemical properties. Especially, the use of BC is promising in industrial fields such as selective permeation membranes and sensitive diaphragms for stereo headphones.

In this study, we isolated nine colonies from several ripe persimmon vinegar to screen the efficient BC-producing microorganism. Among these colonies, one colony was screened for BC-producing microorganism on the basis of BC concentrations produced. To confirm whether the product was exactly cellulose or not, the material which was produced on the surface of culture broth was treated with cellulase. Also, the material produced by isolated strain was tested with x-ray diffractometer in order to compare the structure of BC to plant-derived cellulose (CM-cellulose). Morphological and biochemical characterization of this bacterium was also accomplished. Furthermore, 16S rDNA full sequencing analysis was carried out for more accurate identification of this strain and assigned Gluconacetobacter sp. RKY5.