Characterization and optimization of bacterial cellulose produced by Acetobacter spp.

摘要

Aim : The study aimed to search for a potential bacterial strain capable of producing maximal bacterial cellulose under optimized conditions for future scale up.Methodology : Eight cellulose producing bacterial strains were isolated from sugarcane juice using Hestrin and Schramm (HS) medium. These isolates were identified through 16S rDNAbased on molecular phylogenetic approach and the cellulose mat was analyzed for their physico-chemical properties. Morphological, chemical and physical properties of cellulose mat was studied by Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy spectrum, High Performance Liquid Chromotograpy and Differential Scanning Calorimetry. Optimal nutrient composition for maximum cellulose production by the isolate was carried out by response surface methodology.Results : 16S rDNA sequence analysis revealed that the isolates belonged to Acetobacter senegalensis, Acelobacter thailandicus, Acetobacter lambici, Acetobacter lovaniensis and Acinetobacter baumannii. Among them, A. senegalensis MA1 produced the maximum cellulose mat of dry weight 3.6 g per 500 ml of HS medium after 2 weeks of incubation. The morphology of bacterial cellulose produced by A. senegalensis MA1 had a pellicle shaped distinguished network structure and the rod shaped bacterium was attached to the bottom of cellulose mat. HPLC analysis revealed that the peaks obtained from bacterial cellulose were almost similar to carboxymethyl cellulose (CMC) peak. In cellulose mat, the weight of carbon, oxygen were 60.13 and 25.12, respectivety.Analysis of differential scanning calorimetry showed endothermal peak at 139.8 degrees C., indicating the melting point of bacterial cellulose mat. Through response surface methodology analysis, 5 g of glycerol and 1.2 g of yeast extract per 100 ml medium was optimized to get maximum cellulose production (2.04 g) from A. senegalensis MA1.Interpretation : Optimized condition for maximum bacterial cellulose production may be applied at industrial scale for commercial utilization.