Gellan Gum as a Unique Microbial Polysaccharide: Its Characteristics, Synthesis, and Current Application Trends

Gellan gum (GG) is a linear, negatively charged exopolysaccharide that is biodegradable and non-toxic. When metallic ions are present, a hard and transparent gel is produced, which remains stable at a low pH. It exhibits high water solubility, can be easily bio-fabricated, demonstrates excellent film/hydrogel formation, is biodegradable, and shows biocompatibility. These characteristics render GG a suitable option for use in food, biomedical, and cosmetic fields. Thus, this review paper offers a concise summary of microbial polysaccharides. Moreover, an in-depth investigation of trends in different facets of GG, such as biosynthesis, chemical composition, and physical and chemical properties, is emphasized. In addition, this paper highlights the process of extracting and purifying GG. Furthermore, an in-depth discussion of the advantages and disadvantages of GG concerning other polysaccharides is presented. Moreover, the utilization of GG across different industries, such as food, medicine, pharmaceuticals, cosmetics, etc., is thoroughly examined and will greatly benefit individuals involved in this field who are seeking fresh opportunities for innovative projects in the future.

EXTRACTION AND IDENTIFICATION OF ESSENTIAL OIL FROM CINNAMOMUM ZEYLANICUM BARKS AND STUDY THE ANTIBACTERIAL ACTIVITY

This study aimed to identify the essential oil compound from Cinnamomum zeylanicum barks by using GC-MS analysis and evaluate essential oil inhibition effects against Listeria monocytogenes, Escherichia coli, Enterobacter aerogenes, Pseudomonas erogenous and Staphylococcus aureus by using agar diffusion method and studied kill-time for this bacterium. The yield of Cinnamomum zeylanicum essential oil was 5%. Cinnamaldehyde 57.83% was the main compound in the essential oil extract, followed by cyclohexane carboxylic acid 9.29% and 6-octadecenoic acid 8.41%. Gram-positive and Gram-negative bacteria were inhibited growth after addition 6, 12 and 18 μL of essential oil. Zone diameter of inhibition ranged from 17.00-30.30 mm for bacterial test. A concentration of 10, 20 and 30 μL.mL-1 of the essential oil caused a rapid and steady decline in the number of viable cells from 2 to 5 Log. cycles of all strains during 24 hours.