Isolation, Screening, and Identification of Local Bacterial Isolates Producing Bio-Cellulose

The current study aims to easily, quickly, and cheaply select the local bacterial isolate that produces bacterial cellulose. Ten samples of spoiled fruits (triplicate for each) were taken in Al-Kut City/ Wasit Province/ Iraq. A modified H-S medium was used to isolate the local bacteria from spoiled fruit samples. One-hundred and twelve bacterial isolates were obtained from all samples, where the lemon sample give the highest number of isolates, as it reached 20 isolates, while the banana sample gives the lowest number of isolates reached to 6 isolates. The two steps of screening were achieved to select the best cellulose-producing local isolate, results from the primary screening indicated that only 18 isolates appeared a clear ability to create clear zones as an indicator to produce bacterial cellulose, and the isolates TELE8, TELE11, TEKI4, and TEAP5 gave the highest clear zones of ​​7.5, 6.1, 6.2, and 6.5 cm, respectively. Also, the second screening step confirmed the results collected from the first step, as the results hydrogel test indicated that only 18 strains showed the ability to produce bacterial cellulose, while the other isolates were unable to do so, as the results showed that the isolate TELE8 was superior in its ability to produce bacterial cellulose than isolates TEK11, TEKI4, and TEAP5. Therefore, the local isolate TELE8 was chosen as the best isolate that produces bacterial cellulose. Thereafter, the phenotype and genotype characteristics were used to identify the TELE8 isolate; its results indicated that the isolate belongs to Komagataeibacter xylinum (previously named first Acetobacter xylinum, and then Gluconacetobacter xylinus). The three methods (static, shaker, and fermenter) were used to produce the bacterial cellulose by using the best local bacterial isolate Acetobacter xylinum TELE8 in HS medium. The results revealed that the highest production of BC (22.8 g/200 ml medium) was obtained when using the fermenter method, while the shaker method did not give the productivity of bacterial cellulose.